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1

Regulation Of Nf=kb And Mnsod In Low Dose Radiation Induced Adaptive Protection Of Mouse And Human Skin Cells  

SciTech Connect (OSTI)

A sampling of publications resulting from this grant is provided. One is on the subject of NF-κB-Mediated HER2 Overexpression in Radiation-Adaptive Resistance. Another is on NF-κB-mediated adaptive resistance to ionizing radiation.

Jian Li

2012-11-07T23:59:59.000Z

2

A Systems Genetic Approach to Identify Low Dose Radiation-Induced Lymphoma Susceptibility/DOE2013FinalReport  

SciTech Connect (OSTI)

The ultimate goal of this project is to identify the combinations of genetic variants that confer an individual's susceptibility to the effects of low dose (0.1 Gy) gamma-radiation, in particular with regard to tumor development. In contrast to the known effects of high dose radiation in cancer induction, the responses to low dose radiation (defined as 0.1 Gy or less) are much less well understood, and have been proposed to involve a protective anti-tumor effect in some in vivo scientific models. These conflicting results confound attempts to develop predictive models of the risk of exposure to low dose radiation, particularly when combined with the strong effects of inherited genetic variants on both radiation effects and cancer susceptibility. We have used a ??Systems Genetics approach in mice that combines genetic background analysis with responses to low and high dose radiation, in order to develop insights that will allow us to reconcile these disparate observations. Using this comprehensive approach we have analyzed normal tissue gene expression (in this case the skin and thymus), together with the changes that take place in this gene expression architecture a) in response to low or high- dose radiation and b) during tumor development. Additionally, we have demonstrated that using our expression analysis approach in our genetically heterogeneous/defined radiation-induced tumor mouse models can uniquely identify genes and pathways relevant to human T-ALL, and uncover interactions between common genetic variants of genes which may lead to tumor susceptibility.

Balmain, Allan [University of California, San Francisco; Song, Ihn Young [University of California, San Francisco

2013-05-15T23:59:59.000Z

3

Radiation-induced angiosarcoma  

E-Print Network [OSTI]

1a Figure 1b Figure 1. Radiation-induced angiosarcoma in afollowing completion of radiation therapy. Figure 2a Figurecell histiocytosis after radiation for breast carcinoma: can

Anzalone, C Lane; Cohen, Philip R; Diwan, Abdul H; Prieto, Victor G

2013-01-01T23:59:59.000Z

4

Low Dose Radiation-Induced Genome and Epigenome Instability Symposium and Epigenetic Mechanisms, DNA Repair, and Chromatin Symposium at the EMS 2008 Annual Meeting - October 2008  

SciTech Connect (OSTI)

The Low Dose Radiation Symposium thoughtfully addressed ionizing radiation non-mutational but transmissable alterations in surviving cells. Deregulation of epigenetic processes has been strongly implicated in carcinogenesis, and there is increasing realization that a significant fraction of non-targeted and adaptive mechanisms in response to ionizing radiation are likely to be epigenetic in nature. Much remains to be learned about how chromatin and epigenetic regulators affect responses to low doses of radiation, and how low dose radiation impacts other epigenetic processes. The Epigenetic Mechanisms Symposium focused on on epigenetic mechanisms and their interplay with DNA repair and chromatin changes. Addressing the fact that the most well understood mediators of epigenetic regulation are histone modifications and DNA methylation. Low levels of radiation can lead to changes in the methylation status of certain gene promoters and the expression of DNA methyltransferases, However, epigenetic regulation can also involve changes in higher order chromosome structure.

Morgan, William F.; Kovalchuk, Olga; Dolinoy, Dana C.; Dubrova, Yuri E.; Coleman, Matthew A.; Schr, Primo; Pogribny, Igor; Hendzel, Michael

2010-02-19T23:59:59.000Z

5

Radiation Induced Instability Patrick Hagerty  

E-Print Network [OSTI]

Radiation Induced Instability Patrick Hagerty #3; Department of Mathematics University of Michigan of Michigan Ann Arbor, MI 48109 abloch@math.lsa.umich.edu Michael I. Weinstein z Fundamental Mathematics a central rigid body which can radiate energy through exible components such as solar panels and antennae

Bloch, Anthony

6

E-Print Network 3.0 - abnormalities radiation-induced Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

induced cataracts appeared earlier... . In the example given above, about 60% of the low- dose radiation-induced breast cancers comes from a very small... -type animals. 1.3....

7

Time dependent annealing of radiation - induced leakage currents in MOS devices  

SciTech Connect (OSTI)

Results are presented showing the radiation response of several unhardened commercial 1.25-{mu}m bulk CMOS processes using LOCOS isolation technology. In all cases studied radiation-induced failure is caused by effects in the field oxide, and the radiation-induced {delta}V{sub T} in the channel region is usually small at the failure dose. Time dependent leakage current data for the field oxides are presented and discussed.

Terrell, J.M. (Booz Allen and Hamilton, Inc. Bethesda, MD (US)); Olkham, T.R.; Lelis, A.J.; Benedetto, J.M. (Harry Diamond Labs., Adelphi, MD (US))

1989-12-01T23:59:59.000Z

8

A Nonhuman Primate Model of Human Radiation-Induced Venocclusive Liver Disease and Hepatocyte Injury  

SciTech Connect (OSTI)

Background: Human liver has an unusual sensitivity to radiation that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of radiation-induced liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe radiation therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ?40 Gy, animals developed a systemic syndrome resembling human radiation-induced liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher radiation doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after radiation. Even at lower doses in which radiation-induced liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive radiation-induced liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize radiation injury.

Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others

2014-02-01T23:59:59.000Z

9

Parotid Glands DoseEffect Relationships Based on Their Actually Delivered Doses: Implications for Adaptive Replanning in Radiation Therapy of Head-and-Neck Cancer  

SciTech Connect (OSTI)

Purpose: Doses actually delivered to the parotid glands during radiation therapy often exceed planned doses. We hypothesized that the delivered doses correlate better with parotid salivary output than the planned doses, used in all previous studies, and that determining these correlations will help make decisions regarding adaptive radiation therapy (ART) aimed at reducing the delivered doses. Methods and Materials: In this prospective study, oropharyngeal cancer patients treated definitively with chemoirradiation underwent daily cone-beam computed tomography (CBCT) with clinical setup alignment based on the C2 posterior edge. Parotid glands in the CBCTs were aligned by deformable registration to calculate cumulative delivered doses. Stimulated salivary flow rates were measured separately from each parotid gland pretherapy and periodically posttherapy. Results: Thirty-six parotid glands of 18 patients were analyzed. Average mean planned doses was 32 Gy, and differences from planned to delivered mean gland doses were ?4.9 to +8.4 Gy, median difference +2.2 Gy in glands in which delivered doses increased relative to planned. Both planned and delivered mean doses were significantly correlated with posttreatment salivary outputs at almost all posttherapy time points, without statistically significant differences in the correlations. Large dispersions (on average, SD 3.6 Gy) characterized the doseeffect relationships for both. The differences between the cumulative delivered doses and planned doses were evident at first fraction (r=.92, P<.0001) because of complex setup deviations (eg, rotations and neck articulations), uncorrected by the translational clinical alignments. Conclusions: After daily translational setup corrections, differences between planned and delivered doses in most glands were small relative to the SDs of the dosesaliva data, suggesting that ART is not likely to gain measurable salivary output improvement in most cases. These differences were observed at first treatment, indicating potential benefit for more complex setup corrections or adaptive interventions in the minority of patients with large deviations detected early by CBCT.

Hunter, Klaudia U. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Fernandes, Laura L. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Vineberg, Karen A.; McShan, Daniel; Antonuk, Alan E. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cornwall, Craig [Department of Hospital Dentistry, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Mathew J. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Eisbruch, Avraham, E-mail: eisbruch@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

2013-11-15T23:59:59.000Z

10

Radiation-induced chromosomal aberrations at different dose-rates  

E-Print Network [OSTI]

of breakage. These breakages may be due to the physiochemical changes affecting the nucleic acid structure within one or more of the chromatin strands; this is in accordance with the "target theory. " Evans (21) states that after the initial breakage.... The somatic mutation theory purposes that ageing is caused by a gradual accumulation of mutations. Curtis has shown that chroaosomal aberrations of the liver cells increase steadily with age (19). Ionizing radiaticns shorten the lifespan and also increase...

McDaniel, Jackson Dean

2012-06-07T23:59:59.000Z

11

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective  

SciTech Connect (OSTI)

Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR Trade-Mark-Sign ) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR Trade-Mark-Sign . Empirically derived dose reduction limits were established for ASiR Trade-Mark-Sign for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR Trade-Mark-Sign blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR Trade-Mark-Sign implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR Trade-Mark-Sign reconstruction to maintain noise equivalence of the 0% ASiR Trade-Mark-Sign image. Results: The ASiR Trade-Mark-Sign algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR Trade-Mark-Sign reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR Trade-Mark-Sign presented a more smoothed appearance than the pre-ASiR Trade-Mark-Sign 100% FBP image. Finally, relative to non-ASiR Trade-Mark-Sign images with 100% of standard dose across the pediatric phantom age spectrum, similar noise levels were obtained in the images at a dose reduction of 48% with 40% ASIR Trade-Mark-Sign and a dose reduction of 82% with 100% ASIR Trade-Mark-Sign . Conclusions: The authors' work was conducted to identify the dose reduction limits of ASiR Trade-Mark-Sign for a pediatric oncology population using automatic tube current modulation. Improvements in noise levels from ASiR Trade-Mark-Sign reconstruction were adapted to provide lower radiation exposure (i.e., lower mA) instead of improved image quality. We have demonstrated for the image quality standards required at our institution, a maximum dose reduction of 82% can be achieved using 100% ASiR Trade-Mark-Sign ; however, to negate changes in the appearance of reconstructed images using ASiR Trade-Mark-Sign with a medium to low frequency noise preserving reconstruction filter (i.e., standard), 40% ASiR Trade-Mark-Sign was implemented in our clinic for 42%-48% dose reduction at all pediatric ages without a visually perceptible change in image quality or image noise.

Brady, S. L.; Yee, B. S.; Kaufman, R. A. [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States)

2012-09-15T23:59:59.000Z

12

Dosimetric Analysis of Radiation-induced Gastric Bleeding  

SciTech Connect (OSTI)

Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of {>=}grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD{sub 50} (normal) = 56 Gy and TD{sub 50} (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD{sub 50} value for the cirrhosis patients points out their greater sensitivity. Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Normolle, Daniel [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Amarnath, Sudha [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Ensminger, William D. [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Lawrence, Theodore S.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)

2012-09-01T23:59:59.000Z

13

E-Print Network 3.0 - adaptive dose escalation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Summary: )terms of physical dose (< 3-5% change in dose not significant) Guide design of dose escalation studies, compare... Stewart, JH Park, DJ Carlson, Isoeffect...

14

E-Print Network 3.0 - attenuates murine radiation-induced Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

radiation-induced Search Powered by Explorit Topic List Advanced Search Sample search results for: attenuates murine radiation-induced Page: << < 1 2 3 4 5 > >> 1 RADIATION...

15

Radiation induced strand breakage analyzed by tunel technique  

E-Print Network [OSTI]

RADIATION INDUCED STRAND BREAKAGE ANALYZED BY TUNEL TECHNIQUE A Thesis MAtuSSA DAWN REYNOLDS Submitted to the 015ce of Graduate Studies of Texas Ad. M University in partial fu1611ment of the requirements for the dree of MASTER OF SCIENCE May... 2003 Major Subject: Health Physics RADIATION INDUCED STRAND BREAKAGE ANALYZED BY TUNEL TECHNIQUE A Thesis MAtuSSA DAWN REYNOLDS Submitted to Texas %%:M University in partial fulfillmen of the requirements for the degree of MASTER OF SCIENCE...

Reynolds, Marissa Dawn

2003-01-01T23:59:59.000Z

16

Adaptive Liver Stereotactic Body Radiation Therapy: Automated Daily Plan Reoptimization Prevents Dose Delivery Degradation Caused by Anatomy Deformations  

SciTech Connect (OSTI)

Purpose: To investigate how dose distributions for liver stereotactic body radiation therapy (SBRT) can be improved by using automated, daily plan reoptimization to account for anatomy deformations, compared with setup corrections only. Methods and Materials: For 12 tumors, 3 strategies for dose delivery were simulated. In the first strategy, computed tomography scans made before each treatment fraction were used only for patient repositioning before dose delivery for correction of detected tumor setup errors. In adaptive second and third strategies, in addition to the isocenter shift, intensity modulated radiation therapy beam profiles were reoptimized or both intensity profiles and beam orientations were reoptimized, respectively. All optimizations were performed with a recently published algorithm for automated, multicriteria optimization of both beam profiles and beam angles. Results: In 6 of 12 cases, violations of organs at risk (ie, heart, stomach, kidney) constraints of 1 to 6 Gy in single fractions occurred in cases of tumor repositioning only. By using the adaptive strategies, these could be avoided (<1 Gy). For 1 case, this needed adaptation by slightly underdosing the planning target volume. For 2 cases with restricted tumor dose in the planning phase to avoid organ-at-risk constraint violations, fraction doses could be increased by 1 and 2 Gy because of more favorable anatomy. Daily reoptimization of both beam profiles and beam angles (third strategy) performed slightly better than reoptimization of profiles only, but the latter required only a few minutes of computation time, whereas full reoptimization took several hours. Conclusions: This simulation study demonstrated that replanning based on daily acquired computed tomography scans can improve liver stereotactic body radiation therapy dose delivery.

Leinders, Suzanne M. [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Delft University of Technology, Delft (Netherlands); Breedveld, Sebastiaan; Mndez Romero, Alejandra [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Schaart, Dennis [Delft University of Technology, Delft (Netherlands); Seppenwoolde, Yvette, E-mail: y.seppenwoolde@erasmusmc.nl [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Heijmen, Ben J.M. [Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

2013-12-01T23:59:59.000Z

17

Radiation-induced complications in prostate cancer patients treated with radiotherapy  

SciTech Connect (OSTI)

The purpose of the study is to determine the relationship between radiation-induced complications with dosimetric and radiobiological parameters for prostate cancer patients that underwent the conformal radiotherapy treatment. 17 prostate cancer patients that have been treated with conformal radiotherapy were retrospectively analysed. The dosimetric data was retrieved in the form of dose-volume histogram (DVH) from Radiotherapy Treatment Planning System. The DVH was utilised to derived Normal Tissue Complication Probability (NTCP) in radiobiological data. Follow-up data from medical records were used to grade the occurrence of acute gastrointestinal (GI) and genitourinary (GU) complications using Radiation Therapy Oncology Group (RTOG) scoring system. The chi-square test was used to determine the relationship between radiation-induced complication with dosimetric and radiobiological parameters. 8 (47%) and 7 (41%) patients were having acute GI and GU complications respectively. The acute GI complication can be associated with V60{sub rectum}, rectal mean dose and NTCP{sub rectum} with p-value of 0.016, 0.038 and 0.049 respectively. There are no significant relationships of acute GU complication with dosimetric and radiobiological variables. Further study can be done by increase the sample size and follow up duration for deeper understanding of the factors that effecting the GU and GI complication in prostate cancer radiotherapy.

Azuddin, A. Yusof [School of Applied Physics, Faculty of Sciences and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia and Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 53000 Kuala Lumpur (Malaysia); Rahman, I. Abdul; Mohamed, F. [School of Applied Physics, Faculty of Sciences and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Siah, N. J. [Faculty of Health Sciences, Universiti Kebangsaan Malaysia, 53000 Kuala Lumpur (Malaysia); Saadc, M. [Department of Oncology, University Malaya Medical Center, 50603 Kuala Lumpur (Malaysia); Ismail, F. [Department of Oncology and Radiotherapy, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur (Malaysia)

2014-09-03T23:59:59.000Z

18

Modeling radiation-induced mixing at interfaces between low solubility metals  

E-Print Network [OSTI]

This thesis studies radiation-induced mixing at interfaces between low solubility metals using molecular dynamics (MD) computer simulations. It provides original contributions on the fundamental mechanisms of radiation-induced ...

Zhang, Liang, Ph. D. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

19

Roles of Sensory Nerves in the Regulation of Radiation-Induced Structural and Functional Changes in the Heart  

SciTech Connect (OSTI)

Purpose: Radiation-induced heart disease (RIHD) is a chronic severe side effect of radiation therapy of intrathoracic and chest wall tumors. The heart contains a dense network of sensory neurons that not only are involved in monitoring of cardiac events such as ischemia and reperfusion but also play a role in cardiac tissue homeostasis, preconditioning, and repair. The purpose of this study was to examine the role of sensory nerves in RIHD. Methods and Materials: Male Sprague-Dawley rats were administered capsaicin to permanently ablate sensory nerves, 2 weeks before local image-guided heart x-ray irradiation with a single dose of 21 Gy. During the 6 months of follow-up, heart function was assessed with high-resolution echocardiography. At 6 months after irradiation, cardiac structural and molecular changes were examined with histology, immunohistochemistry, and Western blot analysis. Results: Capsaicin pretreatment blunted the effects of radiation on myocardial fibrosis and mast cell infiltration and activity. By contrast, capsaicin pretreatment caused a small but significant reduction in cardiac output 6 months after irradiation. Capsaicin did not alter the effects of radiation on cardiac macrophage number or indicators of autophagy and apoptosis. Conclusions: These results suggest that sensory nerves, although they play a predominantly protective role in radiation-induced cardiac function changes, may eventually enhance radiation-induced myocardial fibrosis and mast cell activity.

Sridharan, Vijayalakshmi; Tripathi, Preeti [Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Sharma, Sunil [Department of Radiation Oncology, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Moros, Eduardo G. [Department of Radiation Oncology, Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); Zheng, Junying [Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Hauer-Jensen, Martin [Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas (United States); Boerma, Marjan, E-mail: mboerma@uams.edu [Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States)

2014-01-01T23:59:59.000Z

20

Radiation-Induced Segregation and Phase Stability in Candidate Alloys for the Advanced Burner Reactor  

SciTech Connect (OSTI)

Major accomplishments of this project were the following: 1) Radiation induced depletion of Cr occurs in alloy D9, in agreement with that observed in austenitic alloys. 2) In F-M alloys, Cr enriches at PAG grain boundaries at low dose (<7 dpa) and at intermediate temperature (400C) and the magnitude of the enrichment decreases with temperature. 3) Cr enrichment decreases with dose, remaining enriched in alloy T91 up to 10 dpa, but changing to depletion above 3 dpa in HT9 and HCM12A. 4) Cr has a higher diffusivity than Fe by a vacancy mechanism and the corresponding atomic flux of Cr is larger than Fe in the opposite direction to the vacancy flux. 5) Cr concentration at grain boundaries decreases as a result of vacancy transport during electron or proton irradiation, consistent with Inverse Kirkendall models. 6) Inclusion of other point defect sinks into the KLMC simulation of vacancy-mediated diffusion only influences the results in the low temperature, recombination dominated regime, but does not change the conclusion that Cr depletes as a result of vacancy transport to the sink. 7) Cr segregation behavior is independent of Frenkel pair versus cascade production, as simulated for electron versus proton irradiation conditions, for the temperatures investigated. 8) The amount of Cr depletion at a simulated planar boundary with vacancy-mediated diffusion reaches an apparent saturation value by about 1 dpa, with the precise saturation concentration dependent on the ratio of Cr to Fe diffusivity. 9) Cr diffuses faster than Fe by an interstitial transport mechanism, and the corresponding atomic flux of Cr is much larger than Fe in the same direction as the interstitial flux. 10) Observed experimental and computational results show that the radiation induced segregation behavior of Cr is consistent with an Inverse Kirkendall mechanism.

Gary S. Was; Brian D. Wirth

2011-05-29T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Neurodegeneration and adaptation in response to low-dose photon irradiation  

SciTech Connect (OSTI)

Neural stem and precursor cells (i.e. multipotent neural cells) are concentrated in the neurogenic regions of the brain (hippocampal dentate gyrus, subventricular zones), and considerable evidence suggests that these cells are important in mediating the stress response of the CNS after damage from ionizing radiation. The capability of these cells to proliferate, migrate and differentiate (i.e. to undergo neurogenesis) suggests they can participate in the repair and maintenance of CNS functions by replacing brain cells damaged or depleted due to irradiation. Importantly, we have shown that multipotent neural cells are markedly sensitive to irradiation and oxidative stress, insults that compromise neurogenesis and hasten the onset and progression of degenerative processes that are likely to have an adverse impact on cognition. Our past and current work has demonstrated that relatively low doses of radiation cause a persistent (weeks-months) oxidative stress in multipotent neural cells that can elicit a range of degenerative sequelae in the CNS. Therefore, our project is focused on determining the extent that endogenous and redox sensitive multipotent neural cells represent important radioresponsive targets for low dose radiation effects. We hypothesize that the activation of redox sensitive signaling can trigger radioadaptive changes in these cells that can be either harmful or beneficial to overall cognitive health.

Limoli, Charles L. [UCI

2014-10-27T23:59:59.000Z

22

Radiative acceleration and transient, radiation-induced electric fields  

E-Print Network [OSTI]

The radiative acceleration of particles and the electrostatic potential fields that arise in low density plasmas hit by radiation produced by a transient, compact source are investigated. We calculate the dynamical evolution and asymptotic energy of the charged particles accelerated by the photons and the radiation-induced electric double layer in the full relativistic, Klein-Nishina regime. For fluxes in excess of $10^{27}$ ${\\rm erg} {\\rm cm}^{-2} {\\rm s}^{-1}$, the radiative force on a diluted plasma ($n\\la 10^{11}$ cm$^{-3}$) is so strong that electrons are accelerated rapidly to relativistic speeds while ions lag behind owing to their larger inertia. The ions are later effectively accelerated by the strong radiation-induced double layer electric field up to Lorentz factors $\\approx 100$, attainable in the case of negligible Compton drag. The asymptotic energies achieved by both ions and electrons are larger by a factor 2--4 with respect to what one could naively expect assuming that the electron-ion assembly is a rigidly coupled system. The regime we investigate may be relevant within the framework of giant flares from soft gamma-repeaters.

L. Zampieri; R. Turolla; L. Foschini; A. Treves

2003-04-14T23:59:59.000Z

23

Nature of Radiation-Induced Defects in Quartz  

E-Print Network [OSTI]

Although quartz ($\\rm \\alpha$-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage have not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics (MD) simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si--O connectivity defects, e.g., small Si--O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on $E^{\\prime}$ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependenc...

Wang, Bu; Pignatelli, Isabella; Sant, Gaurav N; Bauchy, Mathieu

2015-01-01T23:59:59.000Z

24

Radiation-induced solitary waves in hot plasmas of accretion disks  

E-Print Network [OSTI]

It is shown that the existence of radiation-induced solitary waves in hot plasmas of accretion disks depends on the radial temperature profile.

Fedor V. Prigara

2005-07-08T23:59:59.000Z

25

E-Print Network 3.0 - attenuates ionizing radiation-induced Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

silica optical Summary: measurements and the so-called radiation-induced attenuation (RIA) measured in dBm. TSL measurements have been... measurements. Connections between...

26

Radiation-Induced Decomposition of U(VI) Phase to Nanocrystals of UO2  

SciTech Connect (OSTI)

U{sup 6+}-phases are common alteration products, under oxidizing conditions, of uraninite and the UO{sub 2} in spent nuclear fuel. These U{sup 6+}-phases are subjected to a radiation field caused by the {alpha}-decay of U, or in the case of spent nuclear fuel, incorporated actinides, such as {sup 239}Pu and {sup 237}Np. In order to evaluate the effects of {alpha}-decay events on the stability of the U{sup 6+}-phases, we report, for the first time, the results of ion beam irradiations (1.0 MeV Kr{sup 2+}) of U{sup 6+}-phases. The heavy-particle irradiations are used to simulate the ballistic interactions of the recoil-nucleus of an {alpha}-decay event with the surrounding structure. The Kr{sup 2+}-irradiation decomposed the U{sup 6+}-phases to UO{sub 2} nanocrystals at doses as low as 0.006 displacements per atom (dpa). U{sup 6+}-phases accumulate substantial radiation doses ({approx}1.0 displacement per atom) within 100,000 years if the concentration of incorporated {sup 239}Pu is as high as 1 wt%. Similar nanocrystals of UO{sub 2} were observed in samples from the natural fission reactors at Oklo, Gabon. Multiple cycles of radiation-induced decomposition to UO{sub 2} followed by alteration to U{sup 6+}-phases provide a mechanism for the remobilization of incorporated radionuclides.

S. Utsunomiya; R.C. Ewing; L. Wang

2005-06-13T23:59:59.000Z

27

A physical model of the photo- and radiation-induced degradation of ytterbium-doped silica optical fibres  

SciTech Connect (OSTI)

We propose a model to describe the photo- or/and the radiation-induced darkening of ytterbium-doped silica optical fibers. This model accounts for the well-established experimental features of photo-darkening. Degradation behaviors predicted for fibers pumped in harsh environments are also fully confirmed by experimental data reported in the work by Duchez et al. (this proceeding), which gives a detailed characterization of the interplay between the effects of the pump and those of a superimposed ionizing irradiation (actual operation conditions in space-based applications for instance). In particular, dependences of the darkening build-up on the pump power, the total ionizing dose and the dose rate are all correctly reproduced. The presented model is a sufficient one, including the minimal physical ingredients required to reproduce experimental features. Refinements could be proposed to improve, e.g., quantitative kinetics.

Mady, Franck, E-mail: franck.mady@unice.fr; Duchez, Jean-Bernard, E-mail: franck.mady@unice.fr; Mebrouk, Yasmine, E-mail: franck.mady@unice.fr; Benabdesselam, Mourad, E-mail: franck.mady@unice.fr [University of Nice Sophia Antipolis, Laboratoire de Physique de la Matire Condense (LPMC), CNRS UMR 7336, Parc Valrose, 06108 Nice cedex 2 (France)

2014-10-21T23:59:59.000Z

28

Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study  

SciTech Connect (OSTI)

Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

2012-03-03T23:59:59.000Z

29

Poor Baseline Pulmonary Function May Not Increase the Risk of Radiation-Induced Lung Toxicity  

SciTech Connect (OSTI)

Purpose: Poor pulmonary function (PF) is often considered a contraindication to definitive radiation therapy for lung cancer. This study investigated whether baseline PF was associated with radiation-induced lung toxicity (RILT) in patients with non-small cell lung cancer (NSCLC) receiving conformal radiation therapy (CRT). Methods and Materials: NSCLC patients treated with CRT and tested for PF at baseline were eligible. Baseline predicted values of forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and diffusion capacity of lung for carbon monoxide (DLCO) were analyzed. Additional factors included age, gender, smoking status, Karnofsky performance status, coexisting chronic obstructive pulmonary disease (COPD), tumor location, histology, concurrent chemotherapy, radiation dose, and mean lung dose (MLD) were evaluated for RILT. The primary endpoint was symptomatic RILT (SRILT), including grade ?2 radiation pneumonitis and fibrosis. Results: There was a total of 260 patients, and SRILT occurred in 58 (22.3%) of them. Mean FEV1 values for SRILT and non-SRILT patients were 71.7% and 65.9% (P=.077). Under univariate analysis, risk of SRILT increased with MLD (P=.008), the absence of COPD (P=.047), and FEV1 (P=.077). Age (65 split) and MLD were significantly associated with SRILT in multivariate analysis. The addition of FEV1 and age with the MLD-based model slightly improved the predictability of SRILT (area under curve from 0.63-0.70, P=.088). Conclusions: Poor baseline PF does not increase the risk of SRILT, and combining FEV1, age, and MLD may improve the predictive ability.

Wang, Jingbo [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States) [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States); Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China); Cao, Jianzhong [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China)] [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China); Yuan, Shuanghu [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States); Ji, Wei [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China)] [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China); Arenberg, Douglas [Department of Internal Medicine, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States); Dai, Jianrong [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China)] [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China); Stanton, Paul; Tatro, Daniel; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States); Wang, Luhua, E-mail: wlhwq@yahoo.com [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China)] [Department of Radiation Oncology, Cancer Hospital, Chinese Academic Medical Sciences and Peking Union Medical College, Beijing (China); Kong, Feng-Ming, E-mail: fengkong@med.umich.edu [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan/Ann Arbor Veterans Health System, Ann Arbor, Michigan (United States)

2013-03-01T23:59:59.000Z

30

E-Print Network 3.0 - ameliorates radiation-induced lung Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Powered by Explorit Topic List Advanced Search Sample search results for: ameliorates radiation-induced lung Page: << < 1 2 3 4 5 > >> 1 doi:10.1016j.ijrobp.2003.12.010 BIOLOGY...

31

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy  

E-Print Network [OSTI]

Radiation-induced DNA damage is a precursor to mutagenesis and cytotoxicity. During radiotherapy, exposure of healthy tissues can lead to severe side effects. We explored the potential of mitochondrial SOD (MnSOD) gene ...

Niu, Yunyun

32

Evaluation of Reaction Rate Theory and Monte Carlo Methods for Application to Radiation-Induced Microstructural Characterization  

SciTech Connect (OSTI)

The multiscale modeling scheme encompasses models from the atomistic to the continuum scale. Phenomena at the mesoscale are typically simulated using reaction rate theory, Monte Carlo, or phase field models. These mesoscale models are appropriate for application to problems that involve intermediate length scales, and timescales from those characteristic of diffusion to long-term microstructural evolution (~?s to years). Although the rate theory and Monte Carlo models can be used simulate the same phenomena, some of the details are handled quite differently in the two approaches. Models employing the rate theory have been extensively used to describe radiation-induced phenomena such as void swelling and irradiation creep. The primary approximations in such models are time- and spatial averaging of the radiation damage source term, and spatial averaging of the microstructure into an effective medium. Kinetic Monte Carlo models can account for these spatial and temporal correlations; their primary limitation is the computational burden which is related to the size of the simulation cell. A direct comparison of RT and object kinetic MC simulations has been made in the domain of point defect cluster dynamics modeling, which is relevant to the evolution (both nucleation and growth) of radiation-induced defect structures. The primary limitations of the OKMC model are related to computational issues. Even with modern computers, the maximum simulation cell size and the maximum dose (typically much less than 1 dpa) that can be simulated are limited. In contrast, even very detailed RT models can simulate microstructural evolution for doses up 100 dpa or greater in clock times that are relatively short. Within the context of the effective medium, essentially any defect density can be simulated. Overall, the agreement between the two methods is best for irradiation conditions which produce a high density of defects (lower temperature and higher displacement rate), and for materials that have a relatively high density of fixed sinks such as dislocations.

Stoller, Roger E [ORNL; Golubov, Stanislav I [ORNL; Becquart, C. S. [Universite de Lille; Domain, C. [EDF R& D, Clamart, France

2007-08-01T23:59:59.000Z

33

Predictive Models for Regional Hepatic Function Based on 99mTc-IDA SPECT and Local Radiation Dose for Physiologic Adaptive Radiation Therapy  

SciTech Connect (OSTI)

Purpose: High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Methods and Materials: Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF doseresponse functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. Results: The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=?0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001). Conclusions: 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage.

Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Frey, Kirk A. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

2013-08-01T23:59:59.000Z

34

Radiation Dose-Volume Effects in the Heart  

SciTech Connect (OSTI)

The literature is reviewed to identify the main clinical and dose-volume predictors for acute and late radiation-induced heart disease. A clear quantitative dose and/or volume dependence for most cardiac toxicity has not yet been shown, primarily because of the scarcity of the data. Several clinical factors, such as age, comorbidities and doxorubicin use, appear to increase the risk of injury. The existing dose-volume data is presented, as well as suggestions for future investigations to better define radiation-induced cardiac injury.

Gagliardi, Giovanna, E-mail: giovanna.gagliardi@karolinska.s [Department of Medical Physics, Karolinska University Hospital and Karolinska Institute, Stockholm (Sweden); Constine, Louis S. [Department of Radiation Oncology, University of Rochester Cancer Center, Rochester, NY (United States); Moiseenko, Vitali [Vancouver Cancer Centre, British Columbia Cancer Agency, Vancouver, BC (Canada); Correa, Candace; Pierce, Lori J. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Allen, Aaron M. [Department of Radiation Oncology, Dana- Farber Cancer Institute, Boston, MA (United States); Rabin Medical Center Petach Tikvah (Israel); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States)

2010-03-01T23:59:59.000Z

35

RADIATION-INDUCED DECOMPOSITION OF U(VI) ALTERATION PHASES OF UO2  

SciTech Connect (OSTI)

U{sup 6+}-phases are common alteration products of spent nuclear fuel under oxidizing conditions, and they may potentially incorporate actinides, such as long-lived {sup 239}Pu and {sup 237}Np, delaying their transport to the biosphere. In order to evaluate the ballistic effects of {alpha}-decay events on the stability of the U{sup 6+}-phases, we report, for the first time, the results of ion beam irradiations (1.0 MeV Kr{sup 2+}) for six different structures of U{sup 6+}-phases: uranophane, kasolite, boltwoodite, saleeite, carnotite, and liebigite. The target uranyl-minerals were characterized by powder X-ray diffraction and identification confirmed by SAED (selected area electron diffraction) in TEM (transmission electron microscopy). The TEM observation revealed no initial contamination of uraninite in these U{sup 6+} phases. All of the samples were irradiated with in situ TEM observation using 1.0 MeV Kr{sup 2+} in the IVEM (intermediate-voltage electron microscope) at the IVEM-Tandem Facility of Argonne National Laboratory. The ion flux was 6.3 x 10{sup 11} ions/cm{sup 2}/sec. The specimen temperatures during irradiation were 298 and 673 K, respectively. The Kr{sup 2+}-irradiation decomposed the U{sup 6+}-phases to nanocrystals of UO{sub 2} at doses as low as 0.006 dpa. The cumulative doses for the pure U{sup 6+}-phases, e.g., uranophane, at 0.1 and 1 million years (m.y.) are calculated to be 0.009 and 0.09 dpa using SRIM2003. However, with the incorporation of 1 wt.% {sup 239}Pu, the calculated doses reach 0.27 and {approx}1.00 dpa in ten thousand and one hundred thousand years, respectively. Under oxidizing conditions, multiple cycles of radiation-induced decomposition to UO{sub 2} followed by alteration to U{sup 6+}-phases should be further investigated to determine the fate of trace elements that may have been incorporated in the U{sup 6+}-phases.

S. Utsunomiya; R.C. Ewing

2005-09-08T23:59:59.000Z

36

Studies on Pentoxifylline and Tocopherol Combination for Radiation-Induced Heart Disease in Rats  

SciTech Connect (OSTI)

Purpose: To investigate whether the application of pentoxifylline (PTX) and tocopherol l (Vit. E) could modify the development of radiation-induced heart disease and downregulate the expression of transforming growth factor (TGF)-{beta}1mRNA in rats. Methods and Materials: A total of 120 Sprague-Dawley rats were separated into four groups: control group, irradiated group, experimental group 1, and experiment group 2. Supplementation was started 3 days before irradiation; in experimental group 1, injection of PTX (15 mg/kg/d) and Vit. E (5.5 mg/kg/d) continued till the 12th week postirradiation, whereas in experimental group 2 it was continued until the 24th week postirradiation. All rats were administrated a single dose of 20 Gy irradiation to the heart except the control group. Histopathologic evaluation was performed at various time points (Days 1, 2, 4, 8, and 12 and 24th week) up to 24 weeks after irradiation. Changes of levels of TGF-{beta}1 mRNA expression were also investigated at the same time points using competitive polymerase chain reaction. Results: Compared with the irradiated group, levels of TGF-{beta}1 mRNA of the rat hearts were relatively low in the two experimental groups on the 12th week postirradiation. In experimental group 1, there was a rebound expression of TGF-{beta}1 mRNA on the 24th week postirradiation, whereas that of the experimental group 2 remained low (p < 0.05). The proportions of collagen fibers of the two experimental groups were lower than that of irradiated group (p < 0.05). A rebound could be observed in the experimental group 1. Conclusion: PTX and Vit. E downregulated the expression of TGF-{beta}1 mRNA. The irradiated rat hearts showed a marked pathologic response to the drugs. The withdrawal of drugs in the 12th week postirradiation could cause rebound effects of the development of fibrosis.

Liu Hui [State Key Laboratory of Oncology in South China, Guangzhou, Guangdong (China); Department of Radiotherapy, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong (China); Xiong Mai [Department of Cardiac Surgery, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong (China); Xia Yunfei; Cui Nianji; Lu Rubiao [State Key Laboratory of Oncology in South China, Guangzhou, Guangdong (China); Department of Radiotherapy, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong (China); Deng Ling [State Key Laboratory of Oncology in South China, Guangzhou, Guangdong (China); Department of Pathology, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong (China); Lin Yuehao [State Key Laboratory of Oncology in South China, Guangzhou, Guangdong (China); Clinical Laboratory, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong (China); Rong Tiehua [State Key Laboratory of Oncology in South China, Guangzhou, Guangdong (China); Department of Thoracic Surgery, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong (China)], E-mail: esophagus2003@yahoo.com.cn

2009-04-01T23:59:59.000Z

37

Synchrotron-Radiation Induced X-Ray Emission (SRIXE)  

SciTech Connect (OSTI)

Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron radiation-induced x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron radiation, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.

Jones, Keith W.

1999-09-01T23:59:59.000Z

38

Reproductive Status at First Diagnosis Influences Risk of Radiation-Induced Second Primary Contralateral Breast Cancer in the WECARE Study  

SciTech Connect (OSTI)

Purpose: Our study examined whether reproductive and hormonal factors before, at the time of, or after radiation treatment for a first primary breast cancer modify the risk of radiation-induced second primary breast cancer. Methods and Materials: The Women's Environmental, Cancer and Radiation Epidemiology (WECARE) Study is a multicenter, population-based study of 708 women (cases) with asynchronous contralateral breast cancer (CBC) and 1399 women (controls) with unilateral breast cancer. Radiotherapy (RT) records, coupled with anthropomorphic phantom simulations, were used to estimate quadrant-specific radiation dose to the contralateral breast for each patient. Rate ratios (RR) and 95% confidence intervals (CI) were computed to assess the relationship between reproductive factors and risk of CBC. Results: Women who were nulliparous at diagnosis and exposed to {>=}1 Gy to the contralateral breast had a greater risk for CBC than did matched unexposed nulliparous women (RR = 2.2; 95% CI, 1.2-4.0). No increased risk was seen in RT-exposed parous women (RR = 1.1; 95% CI, 0.8-1.4). Women treated with RT who later became pregnant (8 cases and 9 controls) had a greater risk for CBC (RR = 6.0; 95% CI, 1.3-28.4) than unexposed women (4 cases and 7 controls) who also became pregnant. The association of radiation with risk of CBC did not vary by number of pregnancies, history of breastfeeding, or menopausal status at the time of first breast cancer diagnosis. Conclusion: Nulliparous women treated with RT were at an increased risk for CBC. Although based on small numbers, women who become pregnant after first diagnosis also seem to be at an increased risk for radiation-induced CBC.

Brooks, Jennifer D., E-mail: brooksj@mskcc.org [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Boice, John D. [International Epidemiology Institute, Rockville, MD and Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN (United States)] [International Epidemiology Institute, Rockville, MD and Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt-Ingram Cancer Center, Vanderbilt School of Medicine, Nashville, TN (United States); Stovall, Marilyn [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Reiner, Anne S. [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Bernstein, Leslie [Division of Cancer Etiology, Department of Population Sciences, Beckman Research Institute and City of Hope Comprehensive Cancer Center, Duarte, CA (United States)] [Division of Cancer Etiology, Department of Population Sciences, Beckman Research Institute and City of Hope Comprehensive Cancer Center, Duarte, CA (United States); John, Esther M. [Cancer Prevention Institute of California, Fremont, CA, and Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA (United States)] [Cancer Prevention Institute of California, Fremont, CA, and Stanford University School of Medicine and Stanford Cancer Institute, Stanford, CA (United States); Lynch, Charles F. [Department of Epidemiology, University of Iowa, Iowa City, IA (United States)] [Department of Epidemiology, University of Iowa, Iowa City, IA (United States); Mellemkjaer, Lene [Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen (Denmark)] [Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen (Denmark); Knight, Julia A. [Dalla Lana School of Public Health, University of Toronto and Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario (Canada)] [Dalla Lana School of Public Health, University of Toronto and Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario (Canada); Thomas, Duncan C.; Haile, Robert W. [Department of Preventive Medicine, University of Southern California, Los Angeles, CA (United States)] [Department of Preventive Medicine, University of Southern California, Los Angeles, CA (United States); Smith, Susan A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Capanu, Marinela; Bernstein, Jonine L. [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Shore, Roy E. [Department of Environmental Medicine, New York University, New York, NY (United States) [Department of Environmental Medicine, New York University, New York, NY (United States); Radiation Effects Research Foundation, Hiroshima (Japan)

2012-11-15T23:59:59.000Z

39

Normal Tissue Complication Probability Modeling of Radiation-Induced Hypothyroidism After Head-and-Neck Radiation Therapy  

SciTech Connect (OSTI)

Purpose: To determine the dose-response relationship of the thyroid for radiation-induced hypothyroidism in head-and-neck radiation therapy, according to 6 normal tissue complication probability models, and to find the best-fit parameters of the models. Methods and Materials: Sixty-five patients treated with primary or postoperative radiation therapy for various cancers in the head-and-neck region were prospectively evaluated. Patient serum samples (tri-iodothyronine, thyroxine, thyroid-stimulating hormone [TSH], free tri-iodothyronine, and free thyroxine) were measured before and at regular time intervals until 1 year after the completion of radiation therapy. Dose-volume histograms (DVHs) of the patients' thyroid gland were derived from their computed tomography (CT)-based treatment planning data. Hypothyroidism was defined as increased TSH (subclinical hypothyroidism) or increased TSH in combination with decreased free thyroxine and thyroxine (clinical hypothyroidism). Thyroid DVHs were converted to 2 Gy/fraction equivalent doses using the linear-quadratic formula with {alpha}/{beta} = 3 Gy. The evaluated models included the following: Lyman with the DVH reduced to the equivalent uniform dose (EUD), known as LEUD; Logit-EUD; mean dose; relative seriality; individual critical volume; and population critical volume models. The parameters of the models were obtained by fitting the patients' data using a maximum likelihood analysis method. The goodness of fit of the models was determined by the 2-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion. Results: Twenty-nine patients (44.6%) experienced hypothyroidism. None of the models was rejected according to the evaluation of the goodness of fit. The mean dose model was ranked as the best model on the basis of its Akaike's information criterion value. The D{sub 50} estimated from the models was approximately 44 Gy. Conclusions: The implemented normal tissue complication probability models showed a parallel architecture for the thyroid. The mean dose model can be used as the best model to describe the dose-response relationship for hypothyroidism complication.

Bakhshandeh, Mohsen [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Hashemi, Bijan, E-mail: bhashemi@modares.ac.ir [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi Mehdi [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nikoofar, Alireza; Vasheghani, Maryam [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kazemnejad, Anoshirvan [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

2013-02-01T23:59:59.000Z

40

Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons, and  

E-Print Network [OSTI]

Radiation-Induced Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons of Radiation Oncology, The University of Texas Medical Branch, Galveston, Texas, United States of America Abstract Different types of ionizing radiation produce different dependences of cancer risk on radiation

Brenner, David Jonathan

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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41

Pressure-sensitive blackbody point radiation induced by infrared diode laser irradiation  

E-Print Network [OSTI]

Pressure-sensitive blackbody point radiation induced by infrared diode laser irradiation Feng Qin,1 accuracy. © 2011 Optical Society of America OCIS codes: 350.5610, 290.6815, 280.6780, 280.5475. Trivalent, and optical amplifiers in fiber optics. [1,2]. In recent years, there has been an increasing interest

Cao, Wenwu

42

Comparison of radiation-induced transmission degradation of borosilicate crown optical glass from four different manufacturers  

E-Print Network [OSTI]

glass. Our results show that whereas the glasses are optically similar before irradiation, they showComparison of radiation-induced transmission degradation of borosilicate crown optical glass from of Optics and Photonics/CREOL 4000 Central Florida Blvd. Orlando, FL 32816-2700, USA d SCK·CEN Belgian

Glebov, Leon

43

Radiation induced by charged particles in optical fibers Xavier Artru and Cedric Ray  

E-Print Network [OSTI]

Radiation induced by charged particles in optical fibers Xavier Artru and C´edric Ray Universit, 4, 5]. Let us mention two other uses of optical fibers as particle detectors : (i) as dosimeters, through the effect of darkening by irradiation [6]; (ii) in scintillating glass fibers for particle

Paris-Sud XI, Université de

44

Debris and Radiation-Induced Damage Effects on EUV Nanolithography Source Collector Mirror Optics Performance  

E-Print Network [OSTI]

Debris and Radiation-Induced Damage Effects on EUV Nanolithography Source Collector Mirror Optics, Argonne, Illinois ABSTRACT Exposure of collector mirrors facing the hot, dense pinch plasma in plasma region of the lamp are known to induce serious damage to nearby collector mirrors. Candidate collector

Harilal, S. S.

45

Mutation Research 504 (2002) 91100 Bystander effects in radiation-induced genomic instability  

E-Print Network [OSTI]

Mutation Research 504 (2002) 91­100 Bystander effects in radiation-induced genomic instability recombination and other phenotypes associated with genomic instability. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Bystander effects; Genomic instability; Ionizing radiation 1. Introduction Exposure

46

Effects of Adenovirus-Mediated Delivery of the Human Hepatocyte Growth Factor Gene in Experimental Radiation-Induced Heart Disease  

SciTech Connect (OSTI)

Purpose: Irradiation to the heart may lead to late cardiovascular complications. The purpose of this study was to investigate whether adenovirus-mediated delivery of the human hepatocyte growth factor gene could reduce post-irradiation damage of the rat heart and improve heart function. Methods and Materials: Twenty rats received single-dose irradiation of 20 Gy gamma ray locally to the heart and were randomized into two groups. Two weeks after irradiation, these two groups of rats received Ad-HGF or mock adenovirus vector intramyocardial injection, respectively. Another 10 rats served as sham-irradiated controls. At post-irradiation Day 120, myocardial perfusion was tested by myocardial contrast echocardiography with contrast agent injected intravenously. At post-irradiation Day 180, cardiac function was assessed using the Langendorff technique with an isolated working heart model, after which heart samples were collected for histological evaluation. Results: Myocardial blood flow was significantly improved in HGF-treated animals as measured by myocardial contrast echocardiography at post-irradiation Day 120 . At post-irradiation Day 180, cardiac function was significantly improved in the HGF group compared with mock vector group, as measured by left ventricular peak systolic pressure (58.80 +- 9.01 vs. 41.94 +- 6.65 mm Hg, p < 0.05), the maximum dP/dt (5634 +- 1303 vs. 1667 +- 304 mm Hg/s, p < 0.01), and the minimum dP/dt (3477 +- 1084 vs. 1566 +- 499 mm Hg/s, p < 0.05). Picrosirius red staining analysis also revealed a significant reduction of fibrosis in the HGF group. Conclusion: Based on the study findings, hepatocyte growth factor gene transfer can attenuate radiation-induced cardiac injury and can preserve cardiac function.

Hu Shunying; Chen Yundai [Department of Cardiology, Chinese PLA General Hospital, Beijing (China); Li Libing [Department of Cardiovascular Surgery, Chinese PLA General Hospital, Beijing (China); Chen Jinlong; Wu Bin [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing (China); Zhou, Xiao; Zhi Guang [Department of Cardiology, Chinese PLA General Hospital, Beijing (China); Li Qingfang; Wang Rongliang; Duan Haifeng; Guo Zikuan; Yang Yuefeng; Xiao Fengjun [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing (China); Wang Hua, E-mail: wanghua@nic.bmi.ac.c [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing (China); Wang Lisheng [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing (China)

2009-12-01T23:59:59.000Z

47

Sorafenib Enhances Radiation-Induced Apoptosis in Hepatocellular Carcinoma by Inhibiting STAT3  

SciTech Connect (OSTI)

Purpose: Hepatocellular carcinoma (HCC) is one of the most common and lethal human malignancies. Lack of efficient therapy for advanced HCC is a pressing problem worldwide. This study aimed to determine the efficacy and mechanism of combined sorafenib and radiation therapy treatment for HCC. Methods and Materials: HCC cell lines (PLC5, Huh-7, Sk-Hep1, and Hep3B) were treated with sorafenib, radiation, or both, and apoptosis and signal transduction were analyzed. Results: All 4 HCC cell lines showed resistance to radiation-induced apoptosis; however, this resistance could be reversed in the presence of sorafenib. Inhibition of phospho-STAT3 was found in cells treated with sorafenib or sorafenib plus radiation and subsequently reduced the expression levels of STAT3-related proteins, Mcl-1, cyclin D1, and survivin. Silencing STAT3 by RNA interference overcame apoptotic resistance to radiation in HCC cells, and the ectopic expression of STAT3 in HCC cells abolished the radiosensitizing effect of sorafenib. Moreover, sorafenib plus radiation significantly suppressed PLC5 xenograft tumor growth. Conclusions: These results indicate that sorafenib sensitizes resistant HCC cells to radiation-induced apoptosis via downregulating phosphorylation of STAT3 in vitro and in vivo.

Huang, Chao-Yuan [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Radiological Technology, Yuanpei University, Hsinchu, Taiwan (China); Lin, Chen-Si [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China)] [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Tai, Wei-Tien; Hsieh, Chi-Ying [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Shiau, Chung-Wai [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China)] [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China); Cheng, Ann-Lii [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Kuen-Feng, E-mail: kfchen1970@ntu.edu.tw [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China)

2013-07-01T23:59:59.000Z

48

Combining Physical and Biologic Parameters to Predict Radiation-Induced Lung Toxicity in Patients With Non-Small-Cell Lung Cancer Treated With Definitive Radiation Therapy  

SciTech Connect (OSTI)

Purpose: To investigate the plasma dynamics of 5 proinflammatory/fibrogenic cytokines, including interleukin-1beta (IL-1{beta}), IL-6, IL-8, tumor necrosis factor alpha (TNF-{alpha}), and transforming growth factor beta1 (TGF-{beta}1) to ascertain their value in predicting radiation-induced lung toxicity (RILT), both individually and in combination with physical dosimetric parameters. Methods and Materials: Treatments of patients receiving definitive conventionally fractionated radiation therapy (RT) on clinical trial for inoperable stages I-III lung cancer were prospectively evaluated. Circulating cytokine levels were measured prior to and at weeks 2 and 4 during RT. The primary endpoint was symptomatic RILT, defined as grade 2 and higher radiation pneumonitis or symptomatic pulmonary fibrosis. Minimum follow-up was 18 months. Results: Of 58 eligible patients, 10 (17.2%) patients developed RILT. Lower pretreatment IL-8 levels were significantly correlated with development of RILT, while radiation-induced elevations of TGF-ss1 were weakly correlated with RILT. Significant correlations were not found for any of the remaining 3 cytokines or for any clinical or dosimetric parameters. Using receiver operator characteristic curves for predictive risk assessment modeling, we found both individual cytokines and dosimetric parameters were poor independent predictors of RILT. However, combining IL-8, TGF-ss1, and mean lung dose into a single model yielded an improved predictive ability (P<.001) compared to either variable alone. Conclusions: Combining inflammatory cytokines with physical dosimetric factors may provide a more accurate model for RILT prediction. Future study with a larger number of cases and events is needed to validate such findings.

Stenmark, Matthew H. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Cai Xuwei [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States) [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Radiation Oncology, Shanghai Cancer Hospital, Fudan University, Shanghai (China); Shedden, Kerby [Department of Biostatistics, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Biostatistics, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Hayman, James A. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Yuan Shuanghu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States) [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Radiation Oncology, Shangdong Cancer Hospital, Jinan (China); Ritter, Timothy [Veterans Affairs Medical Center, Ann Arbor, Michigan (United States)] [Veterans Affairs Medical Center, Ann Arbor, Michigan (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Kong Fengming, E-mail: fengkong@med.umich.edu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Veterans Affairs Medical Center, Ann Arbor, Michigan (United States)

2012-10-01T23:59:59.000Z

49

Effects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos in vivo  

E-Print Network [OSTI]

that the dose-response of radiation in the low-dose regime deviated from the LNT model. A notable example radiation are linearly proportional to the absorbed dose, evidence accumulated in the past decades showed as a pharmaceutical agent to release a low dose of exogenous carbon monoxide (CO) to attenuate the effect on bystander

Yu, K.N.

50

Gamma radiation-induced refractive index change in Ge- and N-doped silica  

SciTech Connect (OSTI)

We measured the change of the refractive index over a wide wavelength range in Ge- and N-doped high purity (fiber optics grade) silica glasses subjected to gamma irradiation. The radiation-induced change of the refractive index tends to be greater in the infrared part of the spectrum compare to the values measured in the UV-visible part of the spectrum. By means of the Kramers-Kronig relations, we estimate that a weak broadening of the optical vibration band of the silica network adds to this effect. The paper also discusses the difference observed in the spectral behavior of the induced refractive index change for both types of doped glass.

Brichard, Benoit [SCK-CEN-Belgian Nuclear Research Center, Boeretang 200, 2400 Mol (Belgium); Butov, Oleg V.; Golant, Konstantin M. [Fiber Optics Research Center, Russian Academy of Sciences, Vavilov Street 38, 119991 Moscow (Russian Federation); Fernandez Fernandez, Alberto [Masterminds Ltd., rue du Temple 40, CH-2800 Delemont (Switzerland)

2008-03-01T23:59:59.000Z

51

Effect of solvents on the radiation-induced polymerization of ethyl and isopropyl vinyl ethers  

SciTech Connect (OSTI)

The effect of solvents on the radiation-induced cationic polymerization of ethyl and isopropyl vinyl ethers (EVE and IPVE, respectively) was investigated. EVE and IPVE polymerizations were carried out in bulk and in solution under superdry conditions in which polar impurities, especially water, have been reduced to negligible levels. This was accomplished by means of a sodium mirror technique using joint free baked out glass equipment and high vacuum. Plots of the monomer conversions and irradiation times were obtained for EVE and IPVE polymerizations in bulk and in benzene solution at constant monomer concentrations. The monomer concentration dependence of the polymerization rate was studied for EVE polymerization in bulk and in benzene, diethlyl ether, diglyme and methylene chloride, and for IPVE polymerization in bulk and in benzene. Solvent effect on the estimated propagating rate constants was examined for EVE and IPVE polymerization in bulk and in solution. The effect of temperature on the polymerization rate was also investigated for EVE polymerization in bulk ad in benzene, diethyl and diisopropyl ethers, methylene chloride and nitromethane, and for IPVE ploymerization in bulk and in benzene.

Hsieh, W.C.

1981-01-01T23:59:59.000Z

52

Analysis of Vision Loss Caused by Radiation-Induced Optic Neuropathy After Particle Therapy for Head-and-Neck and Skull-Base Tumors Adjacent to Optic Nerves  

SciTech Connect (OSTI)

Purpose: To assess the incident rates of vision loss (VL; based on counting fingers or more severe) caused by radiation-induced optic neuropathy (RION) after particle therapy for tumors adjacent to optic nerves (ONs), and to evaluate factors that may contribute to VL. Methods and Materials: From August 2001 to August 2006, 104 patients with head-and-neck or skull-base tumors adjacent to ONs were treated with carbon ion or proton radiotherapy. Among them, 145 ONs of 75 patients were irradiated and followed for greater than 12 months. The incident rate of VL and the prognostic factors for occurrence of VL were evaluated. The late effects of carbon ion and proton beams were compared on the basis of a biologically effective dose at alpha/beta = 3 gray equivalent (GyE{sub 3}). Results: Eight patients (11%) experienced VL resulting from RION. The onset of VL ranged from 17 to 58 months. The median follow-up was 25 months. No significant difference was observed between the carbon ion and proton beam treatment groups. On univariate analysis, age (>60 years), diabetes mellitus, and maximum dose to the ON (>110 GyE{sub 3}) were significant, whereas on multivariate analysis only diabetes mellitus was found to be significant for VL. Conclusions: The time to the onset of VL was highly variable. There was no statistically significant difference between carbon ion and proton beam treatments over the follow-up period. Based on multivariate analysis, diabetes mellitus correlated with the occurrence of VL. A larger study with longer follow-up is warranted.

Demizu, Yusuke, E-mail: y_demizu@nifty.co [Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan); Murakami, Masao; Miyawaki, Daisuke; Niwa, Yasue [Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan); Akagi, Takashi [Department of Accelerator Managing, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan); Sasaki, Ryohei [Division of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Terashima, Kazuki [Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan); Suga, Daisaku [Department of Radiation Technology, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan); Kamae, Isao [Division of Medical Statistics, Kobe University Graduate School of Medicine, Kobe, Hyogo (Japan); Hishikawa, Yoshio [Department of Radiology, Hyogo Ion Beam Medical Center, Tatsuno, Hyogo (Japan)

2009-12-01T23:59:59.000Z

53

Radiation-induced gain degradation in lateral PNP BJTs with lightly and heavily doped emitters  

SciTech Connect (OSTI)

Ionizing radiation may cause failures in ICs due to gain degradation of individual devices. The base current of irradiated bipolar devices increases with total dose, while the collector current remains relatively constant. This results in a decrease in the current gain. Lateral PNP (LPNP) transistors typically exhibit more degradation than vertical PNP devices at the same total dose, and have been blamed as the cause of early IC failures at low dose rates. It is important to understand the differences in total-dose response between devices with heavily- and lightly-doped emitters in order to compare different technologies and evaluate the applicability of proposed low-dose-rate hardness-assurance methods. This paper addresses these differences by comparing two different LPNP devices from the same process: one with a heavily-doped emitter and one with a lightly-doped emitter. Experimental results demonstrate that the lightly-doped devices are more sensitive to ionizing radiation and simulations illustrate that increased recombination on the emitter side of the junction is responsible for the higher sensitivity.

Wu, A. [Univ. of Arizona, Tucson, AZ (United States); Schrimpf, R.D. [Vanderbilt Univ., Nashville, TN (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L. [VTC Inc., Bloomington, MN (United States)

1997-06-01T23:59:59.000Z

54

Detection and Repair of Ionizing Radiation-Induced DNA Double Strand Breaks: New Developments in Nonhomologous End Joining  

SciTech Connect (OSTI)

DNA damage can occur as a result of endogenous metabolic reactions and replication stress or from exogenous sources such as radiation therapy and chemotherapy. DNA double strand breaks are the most cytotoxic form of DNA damage, and defects in their repair can result in genome instability, a hallmark of cancer. The major pathway for the repair of ionizing radiation-induced DSBs in human cells is nonhomologous end joining. Here we review recent advances on the mechanism of nonhomologous end joining, as well as new findings on its component proteins and regulation.

Wang, Chen [Departments of Biochemistry and Molecular Biology and Oncology, and Southern Alberta Cancer Research Institute, University of Calgary, Calgary (Canada)] [Departments of Biochemistry and Molecular Biology and Oncology, and Southern Alberta Cancer Research Institute, University of Calgary, Calgary (Canada); Lees-Miller, Susan P., E-mail: leesmill@ucalgary.ca [Departments of Biochemistry and Molecular Biology and Oncology, and Southern Alberta Cancer Research Institute, University of Calgary, Calgary (Canada)

2013-07-01T23:59:59.000Z

55

Post Treatment With an FGF Chimeric Growth Factor Enhances Epithelial Cell Proliferation to Improve Recovery From Radiation-Induced Intestinal Damage  

SciTech Connect (OSTI)

Purpose: A fibroblast growth factor (FGF) 1-FGF2 chimera (FGFC) was created previously and showed greater structural stability than FGF1. This chimera was capable of stimulating epithelial cell proliferation much more strongly than FGF1 or FGF2 even without heparin. Therefore FGFC was expected to have greater biologic activity in vivo. This study evaluated and compared the protective activity of FGFC and FGF1 against radiation-induced intestinal injuries. Methods and Materials: We administered FGFC and FGF1 intraperitoneally to BALB/c mice 24 h before or after total-body irradiation (TBI). The numbers of surviving crypts were determined 3.5 days after TBI with gamma rays at doses ranging from 8 to 12 Gy. Results: The effect of FGFC was equal to or slightly superior to FGF1 with heparin. However, FGFC was significantly more effective in promoting crypt survival than FGF1 (p < 0.01) when 10 {mu}g of each FGF was administered without heparin before irradiation. In addition, FGFC was significantly more effective at promoting crypt survival (p < 0.05) than FGF1 even when administered without heparin at 24 h after TBI at 10, 11, or 12 Gy. We found that FGFC post treatment significantly promoted 5-bromo-2'-deoxyuridine incorporation into crypts and increased crypt depth, resulting in more epithelial differentiation. However, the number of apoptotic cells in FGFC-treated mice decreased to almost the same level as that in FGF1-treated mice. Conclusions: These findings suggest that FGFC strongly enhanced radioprotection with the induction of epithelial proliferation without exogenous heparin after irradiation and is useful in clinical applications for both the prevention and post treatment of radiation injuries.

Nakayama, Fumiaki, E-mail: f_naka@nirs.go.j [Department of Radiation Emergency Medicine, National Institute of Radiological Sciences, Chiba (Japan); Hagiwara, Akiko; Umeda, Sachiko [Department of Radiation Emergency Medicine, National Institute of Radiological Sciences, Chiba (Japan); Asada, Masahiro; Goto, Megumi; Oki, Junko; Suzuki, Masashi; Imamura, Toru [Signaling Molecules Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Akashi, Makoto [Department of Radiation Emergency Medicine, National Institute of Radiological Sciences, Chiba (Japan)

2010-11-01T23:59:59.000Z

56

Radiation Leukemogenesis at Low Dose Rates  

SciTech Connect (OSTI)

The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an 'inverse dose rate effect' for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

Weil, Michael; Ullrich, Robert

2013-09-25T23:59:59.000Z

57

Reduction in radiation-induced brain injury by use of pentobarbital or lidocaine protection  

SciTech Connect (OSTI)

To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation exposure. Neural suppression during high-dose cranial irradiation protects brain from acute and early delayed radiation injury. Further development and application of this knowledge may reduce the incidence of radiation toxicity of the central nervous system (CNS) and may permit the safe use of otherwise unsafe doses of radiation in patients with CNS neoplasms.

Oldfield, E.H.; Friedman, R.; Kinsella, T.; Moquin, R.; Olson, J.J.; Orr, K.; DeLuca, A.M. (National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD (USA))

1990-05-01T23:59:59.000Z

58

Radiation-induced risk of resettling Bikini atoll. Final report, November 7, 1981-May 28, 1982  

SciTech Connect (OSTI)

The Department of Energy (DOE) has concluded that the Bikini atoll is unsafe for resettlement. In response to the Bikinians' request for an independent review, we have examined the following DOE findings: (a) radionuclide contamination of Eneu and Bikini Islands, (b) radiation dosage to those who might resettle the islands, and (c) risks to the health of such settlers. We are in practical agreement with the DOE estimates. Resettlement of either island in 1983 would lead to a range of annual or 30-year cumulative doses that exceed the Federal Radiation Council (FRC) guides for the general population, but not those for occupation exposure. By 2013 resettlement of Eneu probably would be permissible. The principal source of radiation dose is local food, especially coconut, owing to contamination of the soil by cesium-137. A precise estimate of dose is impossible. The availability of imported foods would lessen local food consumption, but not sufficiently to meet the FRC guides for the general population. The 30-year cumulative index dose is 61 (25-122) rem for Bikini, and about 8 (3-16) rem for Eneu.

Kohn, H.I.; Dreyer, N.A.

1982-01-01T23:59:59.000Z

59

Radiation hardening and radiation-induced chromium depletion effects on intergranular stress corrosion cracking of austenitic stainless steels  

SciTech Connect (OSTI)

Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength, grain boundary chromium concentration and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in critical fluence (0.2 to 2.5 n/cm[sup 2]) for IGSCC are documented.In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats suggesting a possible role of the radiation-induced hardening (and microstructure) on cracking. However, isolatedheats reveal a wide range of yield strengths from 450 to 800 MPa necessary to promote IGSCC which cannot be understood by strength effects alone. Grain boundary Cr depletion explain differences in IGSCC susceptibility for irradiated stainless steels. Cr contents versus SCC shows that all materials showing IG cracking have some grain boundary depletion ([ge]2%). Grain boundary Cr concentrations for cracking (below [approximately]16 wt %) are in good agreement with similar SCC tests on unirradiated 304 SS with controlled depletion profiles. Heats that prompt variability in the yield strength correlation, are accounted for bydifferences in their interfacial Cr contents. Certain stainless steels are more resistant to cracking even though they have significant radiation-induced Cr depletion. It is proposed that Cr depletion is required for IASCC, but observed susceptibility is modified by other microchemical and microstructural components.

Bruemmer, S.M.; Simonen, E.P.

1993-03-01T23:59:59.000Z

60

Radiation hardening and radiation-induced chromium depletion effects on intergranular stress corrosion cracking of austenitic stainless steels  

SciTech Connect (OSTI)

Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength, grain boundary chromium concentration and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in critical fluence (0.2 to 2.5 n/cm{sup 2}) for IGSCC are documented.In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlated better to yield strength than to fluence for most heats suggesting a possible role of the radiation-induced hardening (and microstructure) on cracking. However, isolatedheats reveal a wide range of yield strengths from 450 to 800 MPa necessary to promote IGSCC which cannot be understood by strength effects alone. Grain boundary Cr depletion explain differences in IGSCC susceptibility for irradiated stainless steels. Cr contents versus SCC shows that all materials showing IG cracking have some grain boundary depletion ({ge}2%). Grain boundary Cr concentrations for cracking (below {approximately}16 wt %) are in good agreement with similar SCC tests on unirradiated 304 SS with controlled depletion profiles. Heats that prompt variability in the yield strength correlation, are accounted for bydifferences in their interfacial Cr contents. Certain stainless steels are more resistant to cracking even though they have significant radiation-induced Cr depletion. It is proposed that Cr depletion is required for IASCC, but observed susceptibility is modified by other microchemical and microstructural components.

Bruemmer, S.M.; Simonen, E.P.

1993-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
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61

Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature  

SciTech Connect (OSTI)

Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

Yuan, Zhi-Min [Harvard School of Public Health

2013-04-28T23:59:59.000Z

62

The susceptibility of silicon-ion implanted gate insulators to x-ray radiation-induced defect generation  

SciTech Connect (OSTI)

This paper examines the x-ray susceptibility of silicon-ion implanted gate insulators of insulated gate-field effect transistors (IGFETs). It is found that silicon-ion implanted gate insulators appear to be much more susceptible to x-ray radiation induced defect generation than unimplanted devices. The residual defect density in silicon-implanted devices, following x-ray radiation, and subsequent postmetal annealing for up to 60 min is found to be greater than that in unimplanted devices. The results with silicon ions indicate that if the insulator is damaged by such a species during processing, as might occur due to knock-on from the gate electrode during source/drain formation, unannealable defects will form which would also tend to make the device structure more susceptible to radiation damage in a hostile environment, or to large hot- electron drift in conventional use.

Reisman, A.; Sune, C.T.; Williams, C.K. (MCNC, Research Triangle Park, NC (US))

1991-03-01T23:59:59.000Z

63

Radiation induced redox reactions and fragmentation of constituent ions in ionic liquids II. Imidazolium cations.  

SciTech Connect (OSTI)

In part 1 of this study, radiolytic degradation of constituent anions in ionic liquids (ILs) was examined. The present study continues the themes addressed in part 1 and examines the radiation chemistry of 1,3-dialkyl substituted imidazolium cations, which currently comprise the most practically important and versatile class of ionic liquid cations. For comparison, we also examined 1,3-dimethoxy- and 2-methyl-substituted imidazolium and 1-butyl-4-methylpyridinium cations. In addition to identification of radicals using electron paramagnetic resonance spectroscopy (EPR) and selective deuterium substitution, we analyzed stable radiolytic products using {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) and tandem electrospray ionization mass spectrometry (ESMS). Our EPR studies reveal rich chemistry initiated through 'ionization of the ions': oxidation and the formation of radical dications in the aliphatic arms of the parent cations (leading to deprotonation and the formation of alkyl radicals in these arms) and reduction of the parent cation, yielding 2-imidazolyl radicals. The subsequent reactions of these radicals depend on the nature of the IL. If the cation is 2-substituted, the resulting 2-imidazolyl radical is relatively stable. If there is no substitution at C(2), the radical then either is protonated or reacts with the parent cation forming a C(2)-C(2) {sigma}{sigma}*-bound dimer radical cation. In addition to these reactions, when methoxy or C{sub {alpha}}-substituted alkyl groups occupy the N(1,3) positions, their elimination is observed. The elimination of methyl groups from N(1,3) was not observed. Product analyses of imidazolium liquids irradiated in the very-high-dose regime (6.7 MGy) reveal several detrimental processes, including volatilization, acidification, and oligomerization. The latter yields a polymer with m/z of 650 {+-} 300 whose radiolytic yield increases with dose (0.23 monomer units per 100 eV for 1-methyl-3-butylimidazolium trifluorosulfonate). Gradual generation of this polymer accounts for the steady increase in the viscosity of the ILs upon irradiation. Previous studies at lower dose have missed this species due to its wide mass distribution (stretching out to m/z 1600) and broad NMR lines, which make it harder to detect at lower concentrations. Among other observed changes is the formation of water immiscible fractions in hydrophilic ILs and water miscible fractions in hydrophobic ILs. The latter is due to anion fragmentation. The import of these observations for use of ILs as extraction solvents in nuclear cycle separations is discussed.

Shkrob, I. A.; Marin, T. W.; Chemerisov, S. D.; Hatcher, J.; Wishart, J. (Chemical Sciences and Engineering Division); (BNL)

2011-04-14T23:59:59.000Z

64

Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging  

SciTech Connect (OSTI)

Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

Gazdzinski, Lisa M.; Cormier, Kyle [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada)] [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Lu, Fred G. [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada)] [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Lerch, Jason P. [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada) [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada) [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Nieman, Brian J., E-mail: bjnieman@phenogenomics.ca [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada)

2012-12-01T23:59:59.000Z

65

Nuclear apoJ: A low dose radiation inducible regulator of cell death. Final report for period September 15, 1998 - September 14, 2001  

SciTech Connect (OSTI)

This project was based on preliminary data that was published by Dr. Boothman (Yang et al. 2000) which indicated a strong induction of apoJ gene expression, increased secretion of the protein, and accumulation of an apparently somewhat different form of the apoJ protein in the nucleus of MCF-7 breast carcinoma cells undergoing response to DNA damage. A clone expressing apoJ protein was isolated that was capable of interacting with Ku80, a component of the double strand break repair complex that is essential for the successful repair of rearranging immunoglobulin and T-cell receptor genes as evidenced by failure to produce mature B and T cells in the absence of Ku70. ApoJ clones isolated and characterized by Dr. Boothman bound strongly to a Ku-70 ''bait'' protein. Over-expression of these same clones in a cell line was capable of killing the cell. ApoJ is very strongly induced in many instances of programmed cell death and has been proposed repeatedly to play some sort of effector role in the process. Our principle hypothesis for this study was that the strong induction of the apoJ gene and the particular expression of a nuclear form of the protein was potentially a causal factor in the decision point made by the cell as it attempts to repair double-strand breakage based DNA damage. The hypothesis was that if sufficiently high damage occurred, it would be deleterious to maintain the cell's viability through continued DNA repair. One method to inhibit DNA repair might be by inhibiting proteins such as Ku-70 that are necessary for double-strand break repair. If apoJ does play a critical role in tipping the decision balance over to cell death, we reasoned that deficiency of apoJ would cause increased accumulation of cells with DNA damage and that this might decrease cell death in response to DNA damage and increase tumor occurrence rates. To test this hypothesis and its potential implications, we exposed wildtype and apoJ deficient animals that we constructed through gene targeting to increasing levels of ionizing radiation from a Cesium source. Data gathered under the support of this grant application initially indicated that apoJ deficient animals were more resistant to radiation, but as we accumulated more and more data points and covered a tighter exposure range, the genotype-based differences became insignificant. However, the possibility existed that because mortality based radiation-resistance could be attributable to mechanism for which nuclear apoJ was not rate determining, we maintained a very large of colony of apoJ knockout and wildtype animals in both the C57/B16 and Cv129 strain backgrounds that were exposed to sub-lethal levels of ionizing radiation to monitor for the occurrence of tumors. These animals were allowed to fully recover and age normally in either germ free or normal animal housing. Our results demonstrated no significant differences between wildtype and apoJ knockout animals over a period that extended up to 30 months for individual animals. We recorded similar weight gain, a relatively low mortality rate, and a similar mixture and rate of sarcoma and adenocarcinomas after surviving the initial ionizing radiation exposures. Thus we conclude that apoJ gene function, which was totally eliminated by our gene targeting, did not influence radiation sensitivity or serve as a tumor suppressor in response to DNA damage.

Aronow, Bruce J.

2002-04-19T23:59:59.000Z

66

Molecular analysis of radiation-induced albino (c)-locus mutations that cause death at preimplantation stages of development  

SciTech Connect (OSTI)

Deletion mutations at the albino (c) locus have been useful for continuing the development of fine-structure physical and functional maps of the Fes-Hbb region of mouse chromosome 7. This report describes the molecular analysis of a number of radiation-induced c deletions that, when homozygous, cause death of the embryo during preimplantation stages. The distal extent of these deletions defines a locus, pid, (preimplantation development) genetically associated with this phenotype. The proximal breakpoints of eight of these deletions were mapped with respect to the Tyr (tyrosinase; albino) gene as well as to anonymous loci within the Fah-Tyr region that are defined by the Pmv-31 viral integration site and by chromosome-microdissection clones. Rearrangements corresponding to the proximal breakpoints of two of these deletions were detected by Southern blot analysis, and a size-altered restriction fragment carrying the breakpoint of one of them was cloned. A probe derived from this deletion fusion fragment defines a locus, D7Rn6, which maps within (or distal to) the pid region, and which discriminates among the distal extents of deletions eliciting the pid phenotype. Extension of physical maps from D7Rn6 should provide access both to the pid region and to loci mapping distal to pid that are defined by N-ethyl-N-nitrosourea-induced lethal mutations. 36 refs., 10 figs.

Rinchik, E.M. (Oak Ridge National Lab., TN (United States)); Toenjes, R.R.; Paul, D. (Fraunhofer-Instituet fuer Toxikologie und Aerosolforschung, Hannover (Germany)); Potter, M.D. (Univ. of Tenn.-Oak Ridge Graduate School of Biomedical Sciences, Oak Ridge, TN (United States))

1993-12-01T23:59:59.000Z

67

Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures  

SciTech Connect (OSTI)

OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase ones risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low-LET radiation). Such phantom risks also may arise from risk assessments conducted for com

Scott, Bobby, R., Ph.D.

2003-06-27T23:59:59.000Z

68

Non-Targeted Effects Induced by Ionizing Radiation: Mechanisms and Potential Impact on Radiation Induced Health Effects  

SciTech Connect (OSTI)

Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing radiation only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher radiation doses (> 1Gy), at low doses (< 100mGy) non-targeted effects associated with radiation exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes.

Morgan, William F.; Sowa, Marianne B.

2015-01-01T23:59:59.000Z

69

Radiation Dose-Volume Effects in the Stomach and Small Bowel  

SciTech Connect (OSTI)

Published data suggest that the risk of moderately severe (>=Grade 3) radiation-induced acute small-bowel toxicity can be predicted with a threshold model whereby for a given dose level, D, if the volume receiving that dose or greater (VD) exceeds a threshold quantity, the risk of toxicity escalates. Estimates of VD depend on the means of structure segmenting (e.g., V15 = 120 cc if individual bowel loops are outlined or V45 = 195 cc if entire peritoneal potential space of bowel is outlined). A similar predictive model of acute toxicity is not available for stomach. Late small-bowel/stomach toxicity is likely related to maximum dose and/or volume threshold parameters qualitatively similar to those related to acute toxicity risk. Concurrent chemotherapy has been associated with a higher risk of acute toxicity, and a history of abdominal surgery has been associated with a higher risk of late toxicity.

Kavanagh, Brian D., E-mail: Brian.Kavanagh@ucdenver.ed [Department of Radiation Oncology, University of Colorado-Denver School of Medicine, Aurora, CO (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada); Das, Shiva K. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Ten Haken, Randall K.; Miften, Moyed [Department of Radiation Oncology, University of Colorado-Denver School of Medicine, Aurora, CO (United States)

2010-03-01T23:59:59.000Z

70

Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity  

SciTech Connect (OSTI)

The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9, influence cataract development and thus radiosensitivity. These observations have direct applicability to various human populations including accidentally exposed individuals, interventional medical workers, astronauts and nuclear plant workers.

Kleiman, Norman Jay [Columbia University] [Columbia University

2013-11-30T23:59:59.000Z

71

Adaptation Plan  

E-Print Network [OSTI]

Environment ? Natural Environment ? People FIVE STRATEGIES Copyright 2011, City of Chicago ADAPTATION ESL-KT-11-11-16 9 CCAP Adaptation Evolution 2007 2008 2009 2010 ? Understood the climate science: Assess climate impacts ? Assessed economic... E xi st in g Tr un k Existing on Rogers Rogers Ave CIP Stormwater management: Chicago?s comprehensive sewer model Climate impacts Example actions to prepare the built environment Copyright 2011, City of Chicago ESL-KT-11-11-16 13 CCAP...

Durnbaugh, A.

2011-01-01T23:59:59.000Z

72

Plasminogen activator activity in lung and alveolar macrophages of rats exposed to graded single doses of. gamma. rays to the right hemithorax  

SciTech Connect (OSTI)

Male rats were sacrificed 2 or 6 months after a single dose of 0-30 Gy of /sup 60/Co ..gamma.. rays to the right hemithorax. At autopsy, macrophages were lavaged from the right lung, counted, and frozen. The right (irradiated) and the left (shielded) lungs were frozen, then assayed for plasminogen activator (PLA) activity by the fibrin plate lysis method. Freeze-thawed macrophages were assayed for both PLA activity (/sup 125/I-fibrin clot lysis method) and fibrinolytic inhibitor activity (inhibition of urokinase-induced fibrin lysis). There was a linear, dose-dependent decrease in right lung PLA activity over the dose range of 10-30 Gy at 2 and 6 months postirradiation, reductions of 3.1 and 2.6% per Gy, respectively. PLA activity at all radiation doses was 10-15% higher at 6 months than at 2 months indicative of a partial recovery of this endothelial function in the irradiated lung. PLA activity per 10/sup 6/ macrophages decreased with increasing radiation dose at both autopsy times, closely paralleling lung PLA activity. This radiation-induced decrease in macrophage PLA activity was not due to increased fibrinolytic inhibitor activity in the irradiated macrophages. These data quantitate the dose response and time course of radiation-induced fibrinolytic defects in rat lung and suggest that information obtained from a minimally invasive procedure such as bronchoalveolar lavage may serve as an index of the degree of pulmonary fibrinolytic dysfunction after irradiation.

Ts'ao, C.; Ward, W.F.

1985-09-01T23:59:59.000Z

73

Bystander effect and adaptive response in C3H 10TK cells S. A. MITCHELL, S. A. MARINO, D. J. BRENNER and E. J. HALL  

E-Print Network [OSTI]

the bystander effect, adaptive response, genomic instabil- ity and low-dose hyper-radiosensitivity. These pheno

74

Radiation-induced instability of MnS precipitates and its possible consequences on irradiation-induced stress corrosion cracking of austenitic stainless steels  

SciTech Connect (OSTI)

Irradiation-assisted stress corrosion cracking (IASCC) is a significant materials issue for the light water reactor (LWR) industry and may also pose a problem for fusion power reactors that will use water as coolant. A new metallurgical process is proposed that involves the radiation-induced release into solution of minor impurity elements not usually thought to participate in IASCC. MnS-type precipitates, which contain most of the sulfur in stainless steels, are thought to be unstable under irradiation. First, Mn transmutes strongly to Fe in thermalized neutron spectra. Second, cascade-induced disordering and the inverse Kirkendall effect operating at the incoherent interfaces of MnS precipitates are thought to act as a pump to export Mn from the precipitate into the alloy matrix. Both of these processes will most likely allow sulfur, which is known to exert a deleterious influence on intergranular cracking, to re-enter the matrix. To test this hypothesis, compositions of MnS-type precipitates contained in several unirradiated and irradiated heats of Type 304, 316, and 348 stainless steels (SSs) were analyzed by Auger electron spectroscopy. Evidence is presented that shows a progressive compositional modification of MnS precipitates as exposure to neutrons increases in boiling water reactors. As the fluence increases, the Mn level in MnS decreases, whereas the Fe level increases. The S level also decreases relative to the combined level of Mn and Fe. MnS precipitates were also found to be a reservoir of other deleterious impurities such as F and O which could be also released due to radiation-induced instability of the precipitates.

Chung, H.M.; Sanecki, J.E. [Argonne National Lab., IL (United States); Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)

1996-12-01T23:59:59.000Z

75

Diffusion Tensor Imaging of Normal-Appearing White Matter as Biomarker for Radiation-Induced Late Delayed Cognitive Decline  

SciTech Connect (OSTI)

Purpose: To determine whether early assessment of cerebral white matter degradation can predict late delayed cognitive decline after radiotherapy (RT). Methods and Materials: Ten patients undergoing conformal fractionated brain RT participated in a prospective diffusion tensor magnetic resonance imaging study. Magnetic resonance imaging studies were acquired before RT, at 3 and 6 weeks during RT, and 10, 30, and 78 weeks after starting RT. The diffusivity variables in the parahippocampal cingulum bundle and temporal lobe white matter were computed. A quality-of-life survey and neurocognitive function tests were administered before and after RT at the magnetic resonance imaging follow-up visits. Results: In both structures, longitudinal diffusivity ({lambda}{sub Double-Vertical-Line }) decreased and perpendicular diffusivity ({lambda}{sub Up-Tack }) increased after RT, with early changes correlating to later changes (p < .05). The radiation dose correlated with an increase in cingulum {lambda}{sub Up-Tack} at 3 weeks, and patients with >50% of cingula volume receiving >12 Gy had a greater increase in {lambda}{sub Up-Tack} at 3 and 6 weeks (p < .05). The post-RT changes in verbal recall scores correlated linearly with the late changes in cingulum {lambda}{sub Double-Vertical-Line} (30 weeks, p < .02). Using receiver operating characteristic curves, early cingulum {lambda}{sub Double-Vertical-Line} changes predicted for post-RT changes in verbal recall scores (3 and 6 weeks, p < .05). The neurocognitive test scores correlated significantly with the quality-of-life survey results. Conclusions: The correlation between early diffusivity changes in the parahippocampal cingulum and the late decline in verbal recall suggests that diffusion tensor imaging might be useful as a biomarker for predicting late delayed cognitive decline.

Chapman, Christopher H., E-mail: chchap@umich.edu [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Nagesh, Vijaya [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Sundgren, Pia C. [Department of Radiology, University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiology, Skane University Hospital, Lund (Sweden); Buchtel, Henry [Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI (United States); Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, MI (United States); Chenevert, Thomas L. [Department of Radiology, University of Michigan Medical School, Ann Arbor, MI (United States); Junck, Larry [Department of Neurology, University of Michigan Medical School, Ann Arbor, MI (United States); Lawrence, Theodore S.; Tsien, Christina I. [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiology, University of Michigan Medical School, Ann Arbor, MI (United States)

2012-04-01T23:59:59.000Z

76

Adaptive sampler  

DOE Patents [OSTI]

An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

Watson, Bobby L. (Idaho Falls, ID); Aeby, Ian (Fremont, CA)

1982-01-01T23:59:59.000Z

77

Adaptive sampler  

DOE Patents [OSTI]

An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

Watson, B.L.; Aeby, I.

1980-08-26T23:59:59.000Z

78

Low Dose Suppression of Neoplastic Transformation in Vitro  

SciTech Connect (OSTI)

This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

John Leslie Redpath

2012-05-01T23:59:59.000Z

79

A Variable-Energy Soft X-Ray Microprobe to Investigate Mechanisms of the Radiation-Induced Bystander Effect.  

SciTech Connect (OSTI)

The Gray Cancer Institute has pioneered the use of X ray focussing techniques to develop systems for micro irradiating individual cells and sub cellular targets in vitro. Cellular micro irradiation is now recognised as a highly versatile technique for understanding how ionising radiation interacts with living cells and tissues. The strength of the technique lies in its ability to deliver precise doses of radiation to selected individual cells (or sub cellular targets). The application of this technique in the field of radiation biology continues to be of great interest for investigating a number of phenomena currently of concern to the radiobiological community. One important phenomenon is the so called bystander effect where it is observed that unirradiated cells can also respond to signals transmitted by irradiated neighbours. Clearly, the ability of a microbeam to irradiate just a single cell or selected cells within a population is well suited to studying this effect. Our prototype tabletop X-ray microprobe was optimised for focusing 278 eV C-K X rays and has been used successfully for a number of years. However, we have sought to develop a new variable energy soft X-ray microprobe capable of delivering focused CK (0.28 keV), Al-K (1.48 keV) and notably, Ti-K (4.5 keV) X rays. Ti-K X rays are capable of penetrating several cell layers and are therefore much better suited to studies involving tissues and multi cellular layers. In our new design, X-rays are generated by the focussed electron bombardment of a material whose characteristic-K radiation is required. The source is mounted on a 1.5 x 1.0 metre optical table. Electrons are generated by a custom built gun, designed to operate up to 15 kV. The electrons are focused using a permanent neodymium iron boron magnet assembly. Focusing is achieved by adjusting the accelerating voltage and by fine tuning the target position via a vacuum position feedthrough. To analyze the electron beam properties, a custom built microscope is used to image the focussed beam on the target, through a vacuum window. The X-rays are focussed by a zone plate optical assembly mounted to the end of a hollow vertical tube that can be precisely positioned above the X ray source. The cell finding and positioning stage comprises an epi-fluorescence microscope and a feedback controlled 3 axis cell positioning stage, also mounted on the optical table. Independent vertical micro positioning of the microscope objective turret allows the focus of the microscope and the X ray focus to coincide in space (i.e. at the point where the cell should be positioned for exposure). The whole microscope stage assembly can be precisely raised or lowered, to cater for large differences in the focal length of the X ray zone plates. The facility is controlled by PC and the software provides full status and control of the source and makes use of a dual-screen for control and display during the automated cell finding and irradiation procedures.

Folkard, Melvyn; Vojnovic, Borivoj; Schettino, Giuseppe; Atkinson, Kirk; Prise, Kevin, M.; Michael, Barry, D.

2007-01-23T23:59:59.000Z

80

Automated size-specific CT dose monitoring program: Assessing variability in CT dose  

SciTech Connect (OSTI)

Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose estimates that were not adjusted by patient size. Additionally, considerable differences were noted in ED{sub adj} distributions between scanners, with scanners employing iterative reconstruction exhibiting significantly lower ED{sub adj} (range: 9%-64%). Finally, a significant difference (up to 59%) in ED{sub adj} distributions was observed between institutions, indicating the potential for dose reduction. Conclusions: The authors developed a robust automated size-specific radiation dose monitoring program for CT. Using this program, significant differences in ED{sub adj} were observed between scanner models and across institutions. This new dose monitoring program offers a unique tool for improving quality assurance and standardization both within and across institutions.

Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

2012-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
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81

Neutron dose equivalent meter  

DOE Patents [OSTI]

A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

1996-01-01T23:59:59.000Z

82

SNP in TXNRD2 Associated With Radiation-Induced Fibrosis: A Study of Genetic Variation in Reactive Oxygen Species Metabolism and Signaling  

SciTech Connect (OSTI)

Purpose: The aim of the study was to identify noninvasive markers of treatment-induced side effects. Reactive oxygen species (ROS) are generated after irradiation, and genetic variation in genes related to ROS metabolism might influence the level of radiation-induced adverse effects (AEs). Methods and Materials: 92 breast cancer (BC) survivors previously treated with hypofractionated radiation therapy were assessed for the AEs subcutaneous atrophy and fibrosis, costal fractures, lung fibrosis, pleural thickening, and telangiectasias (median follow-up time 17.1 years). Single-nucleotide polymorphisms (SNPs) in 203 genes were analyzed for association to AE grade. SNPs associated with subcutaneous fibrosis were validated in an independent BC survivor material (n=283). The influence of the studied genetic variation on messenger ribonucleic acid (mRNA) expression level of 18 genes previously associated with fibrosis was assessed in fibroblast cell lines from BC patients. Results: Subcutaneous fibrosis and atrophy had the highest correlation (r=0.76) of all assessed AEs. The nonsynonymous SNP rs1139793 in TXNRD2 was associated with grade of subcutaneous fibrosis, the reference T-allele being more prevalent in the group experiencing severe levels of fibrosis. This was confirmed in another sample cohort of 283 BC survivors, and rs1139793 was found significantly associated with mRNA expression level of TXNRD2 in blood. Genetic variation in 24 ROS-related genes, including EGFR, CENPE, APEX1, and GSTP1, was associated with mRNA expression of 14 genes previously linked to fibrosis (P?.005). Conclusion: Development of subcutaneous fibrosis can be associated with genetic variation in the mitochondrial enzyme TXNRD2, critically involved in removal of ROS, and maintenance of the intracellular redox balance.

Edvardsen, Hege, E-mail: hege.edvardsen@rr-research.no [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Landmark-Hyvik, Hege [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Reinertsen, Kristin V. [National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway)] [National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway); Zhao, Xi [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Grenaker-Alns, Grethe Irene; Nebdal, Daniel [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway)] [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); Syvnen, Ann-Christine [Department of Medical Sciences, Uppsala University, Uppsala (Sweden)] [Department of Medical Sciences, Uppsala University, Uppsala (Sweden); Rdningen, Olaug [Department of Medical Genetics, OUS Ullevaal, Oslo (Norway)] [Department of Medical Genetics, OUS Ullevaal, Oslo (Norway); Alsner, Jan; Overgaard, Jens [Department of Experimental Clinical Oncology, Ahus University Hospital (Norway)] [Department of Experimental Clinical Oncology, Ahus University Hospital (Norway); Borresen-Dale, Anne-Lise [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Foss, Sophie D. [K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway) [K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); National Resource Centre for Late Effects after Cancer Treatment, OUS Radiumhospitalet, Oslo (Norway); Kristensen, Vessela N. [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway) [Department of Genetics, Institute for Cancer Research, OUS Radiumhospitalet, Oslo (Norway); K. G. Jebsen Breast cancer centre, Institute for Clinical Medicine, University of Oslo, Oslo (Norway); Department of Clinical Molecular Biology (EpiGen), Division of Medicine, Ahus University Hospital (Norway)

2013-07-15T23:59:59.000Z

83

SCIENTIFIC CORRESPONDENCE Radiation doses  

E-Print Network [OSTI]

SCIENTIFIC CORRESPONDENCE Radiation doses and cancert-A T. w- - SIR- In February 1990, the Soviet. Nikipelov et al. published in g Priroda (Nature)' the radiation doses for each year, averaged over environmental impact on the Gulf waters is rapidly ex- ported to the Arabian Sea and then to the Indian Ocean

Shlyakhter, Ilya

84

Radiation Dose Estimates from  

E-Print Network [OSTI]

Summary: Radiation Dose Estimates from Hanford Radioactive Material Releases to the Air and the Columbia River April 21,1994 TheTechnid Steering Panel of the Hanford - Environmental Dose Reconstruction than 40years, the U.S. Government made plutonium for nuclear weapons at the Hanford

85

Radiation-induced lung injury  

SciTech Connect (OSTI)

The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

Rosiello, R.A.; Merrill, W.W. (Yale Univ. Medical Center, New Haven, CT (USA))

1990-03-01T23:59:59.000Z

86

ACDOS2: an improved neutron-induced dose rate code  

SciTech Connect (OSTI)

To calculate the expected dose rate from fusion reactors as a function of geometry, composition, and time after shutdown a computer code, ACDOS2, was written, which utilizes up-to-date libraries of cross-sections and radioisotope decay data. ACDOS2 is in ANSI FORTRAN IV, in order to make it readily adaptable elsewhere.

Lagache, J.C.

1981-06-01T23:59:59.000Z

87

Utirik Atoll Dose Assessment  

SciTech Connect (OSTI)

On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other radionuclides. However, we continually see {sup 137}Cs in the groundwater at all contaminated atolls; the turnover time of the groundwater is about 5 y. The {sup 137}Cs can only get to the groundwater by leaching through the soil column when a portion of the soluble fraction of {sup 137}Cs inventory in the soil is transported to the groundwater when rainfall is heavy enough to cause recharge of the aquifer. This process is causing a loss of {sup 137}Cs out of the root zone of the plants that provides an environmental loss constant ({lambda}{sub env}) in addition to radiological decay {lambda}{sub rad}. Consequently, there is an effective rate of loss, {lambda}{sub eff} = {lambda}{sub rad} + {lambda}{sub env} that is the sum of the radiological and environmental-loss decay constants. We have had, and continue to have, a vigorous program to determine the rate of the environmental loss process. What we do know at this time is that the loss of {sup 137}Cs over time is greater than the estimate based on radiological decay only, and that the actual dose received by the Utirik people over 30-, 50-, or 70-y will be less than those presented in this report.

Robison, W.L.; Conrado, C.L.; Bogen, K.T

1999-10-06T23:59:59.000Z

88

The role of high-dose, single-fraction irradiation in small and large intracranial arteriovenous malformations  

SciTech Connect (OSTI)

Radiosurgery with external beam irradiation is an accepted treatment for small intracranial vascular malformations. It has been proven effective and safe for lesions with volumes of less than 4 cc. However, there is only some limited clinical data for malformations of grade 4 and grade 5, according to Spetzler and Martin. At the Heidelberg radiosurgery facility equipped with a linear accelerator, 212 patients with cerebral arteriovenous malformations have been treated since 1984. Thirty-eight percent of the arteriovenous malformations treated were classified inoperable, 14% grade 5, 19% grade 4, and 29% grades l-3. Radiation doses between 10 and 29 Gy were applied to the 80% isodose contour. Above a threshold dose of 18 Gy, the overall obliteration rate was 72%. After 3 years, the obliteration rates were 83% with volumes of less than 4.2 cc, 75% with volumes of up to 33.5 cc, and 50% with volumes of up to 113 cc. Of the patients presenting with seizures and paresis, 83% and 56%, respectively, showed improvement, which correlated with the degree of obliteration. After a follow-up period of up to 9 years, the rate of radiation-induced severe late complication was 4.3%. In grade 5 lesions, the risk of side effects was 10%. No serious complications occurred if a maximum dose of less than 25 Gy was applied to treatment volumes of less than 33.5 cc. The success of sterotactic high-dose irradiation of arteriovenous malformations depends on the dose applied. The incidence of radiation-induced side effects increased with the applied dose and treatment volumes. From our experience, doses of less than 25 Gy and treatment volumes of up to 33.5 cc are safe and effective. In the future, new techniques of radiosurgery with linear accelerators and dynamically reshaped beams will allow us to apply homogenous dose distributions. Additional use of magnetic resonance angiography for 3D treatment planning will help to identify the nidus more easily. 38 refs., 5 figs., 4 tabs.

Engenhart, R.; Debus, J.; Wannenmacher, M. [Univ. of Heidelberg (Germany)] [and others

1994-10-15T23:59:59.000Z

89

Generalized Adaptive A* Xiaoxun Sun  

E-Print Network [OSTI]

Generalized Adaptive A* Xiaoxun Sun USC Computer Science Los Angeles, California xiaoxuns spaces changes. Adaptive A* [7] is a Cite as: Generalized Adaptive A*, Xiaoxun Sun, Sven Koenig

Yeoh, William

90

Radiation leukaemogenesis at low doses DE-FG02-05 ER 63947 Final Technical Report 15 May 2005 ???????????????¢???????????????????????????????? 14 May 2010  

SciTech Connect (OSTI)

This report provides a complete summary of the work undertaken and results obtained under US Department of Energy grant DF-FG02-05 ER 63947, Radiation leukaemogenesis at low doses. There is ample epidemiological evidence indicating that ionizing radiation is carcinogenic in the higher dose range. This evidence, however, weakens and carries increasing uncertainties at doses below 100-200 mSv. At these low dose levels the form of the dose-response curve for radiation-induced cancer cannot be determined reliably or directly from studies of human populations. Therefore animal, cellular and other experimental systems must be employed to provide supporting evidence on which to base judgements of risk at low doses. Currently in radiological protection a linear non-threshold (LNT) extrapolation of risk estimates derived from human epidemiological studies is used to estimate risks in the dose range of interest for protection purposes. Myeloid leukaemias feature prominently among the cancers associated with human exposures to ionising radiation (eg UNSCEAR 2006; IARC 2000). Good animal models of radiation-induced acute myeloid leukaemia (AML) are available including strains such as CBA, RFM and SJL (eg Major and Mole 1978; Ullrich et al 1976; Resnitzky et al 1985). Early mechanistic studies using cytogenetic methods in these mouse models established that the majority of radiation-induced AMLs carried substantial interstitial deletions in one copy of chromosome (chr) 2 (eg Hayata et al 1983; Trakhtenbrot et al 1988; Breckon et al 1991; Rithidech et al 1993; Bouffler et al 1996). Chr2 aberrations are known to occur in bone marrow cells as early as 24 hours after in vivo irradiation (Bouffler et al 1997). Subsequent molecular mapping studies defined a distinct region of chr2 that is commonly lost in AMLs (Clark et al 1996; Silver et al 1999). Further, more detailed, analysis identified point mutations at a specific region of the Sfpi1/PU.1 haemopoietic transcription factor gene which lies in the commonly deleted region of chr2 (Cook et al 2004; Suraweera et al 2005). These lines of evidence strongly implicate the Sfpi1/PU.1 gene as a tumour suppressor gene, dysregulation of which leads to myeloid leukaemia. The main focus of this project was to utilize the CBA mouse model of radiation leukaemogenesis to explore mechanisms of low dose and low dose-rate leukaemogenesis. A series of mechanistic investigations were undertaken, the central aim of which was to identify the events that convert normal cells into myeloid leukaemia cells and explore the dose-response relationships for these. Much of the work centred on the Sfpi1/PU.1 gene and its role in leukaemogenesis. Specific studies considered the dose-response and time-course relationships for loss of the gene, the functional consequences of Sfpi1/PU.1 loss and mutation on transcriptional programmes and developing an in vivo reporter gene system for radiation-induced alterations to PU.1 expression. Additional work sought further genetic changes associated with radiation-induced AMLs and a better characterization of the cell of origin or 'target cell' for radiation-induced AML. All the information gathered is of potential use in developing biologically realistic mathematical models for low dose cancer risk projection.

Simon Bouffler

2010-07-28T23:59:59.000Z

91

Radiotherapy Adapted to Spatial and Temporal Variability in Tumor Hypoxia  

SciTech Connect (OSTI)

Purpose: To explore the feasibility and clinical potential of adapting radiotherapy to temporal and spatial variations in tumor oxygenation. Methods and Materials: Repeated dynamic contrast enhanced magnetic resonance (DCEMR) images were taken of a canine sarcoma during the course of fractionated radiation therapy. The tumor contrast enhancement was assumed to represent the oxygen distribution. The IMRT plans were retrospectively adapted to the DCEMR images by employing tumor dose redistribution. Optimized nonuniform tumor dose distributions were calculated and compared with a uniform dose distribution delivering the same integral dose to the tumor. Clinical outcome was estimated from tumor control probability (TCP) and normal tissue complication probability (NTCP) modeling. Results: The biologically adapted treatment was found to give a substantial increase in TCP compared with conventional radiotherapy, even when only pretreatment images were used as basis for the treatment planning. The TCP was further increased by repeated replanning during the course of treatment, and replanning twice a week was found to give near optimal TCP. Random errors in patient positioning were found to give a small decrease in TCP, whereas systematic errors were found to reduce TCP substantially. NTCP for the adapted treatment was similar to or lower than for the conventional treatment, both for parallel and serial normal tissue structures. Conclusion: Biologically adapted radiotherapy is estimated to improve treatment outcome of tumors having spatial and temporal variations in radiosensitivity.

Sovik, Aste [Department of Medical Physics, Norwegian Radium Hospital, Oslo (Norway); Department of Physics, University of Oslo, Oslo (Norway); Malinen, Eirik [Department of Medical Physics, Norwegian Radium Hospital, Oslo (Norway) and Department of Physics, University of Oslo, Oslo (Norway)]. E-mail: emalinen@fys.uio.no; Skogmo, Hege K. [Department of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo (Norway); Bentzen, Soren M. [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin (United States); Bruland, Oyvind S. [Department of Oncology, Norwegian Radium Hospital, Oslo (Norway); Department of Clincal Medicine, University of Oslo, Oslo (Norway); Olsen, Dag Rune [Department of Physics, University of Oslo, Oslo (Norway); Department of Radiation Biology, Norwegian Radium Hospital, Oslo (Norway)

2007-08-01T23:59:59.000Z

92

Dose Uncertainties in IMPT for Oropharyngeal Cancer in the Presence of Anatomical, Range, and Setup Errors  

SciTech Connect (OSTI)

Purpose: Setup, range, and anatomical uncertainties influence the dose delivered with intensity modulated proton therapy (IMPT), but clinical quantification of these errors for oropharyngeal cancer is lacking. We quantified these factors and investigated treatment fidelity, that is, robustness, as influenced by adaptive planning and by applying more beam directions. Methods and Materials: We used an in-house treatment planning system with multicriteria optimization of pencil beam energies, directions, and weights to create treatment plans for 3-, 5-, and 7-beam directions for 10 oropharyngeal cancer patients. The dose prescription was a simultaneously integrated boost scheme, prescribing 66 Gy to primary tumor and positive neck levels (clinical target volume-66 Gy; CTV-66 Gy) and 54 Gy to elective neck levels (CTV-54 Gy). Doses were recalculated in 3700 simulations of setup, range, and anatomical uncertainties. Repeat computed tomography (CT) scans were used to evaluate an adaptive planning strategy using nonrigid registration for dose accumulation. Results: For the recalculated 3-beam plans including all treatment uncertainty sources, only 69% (CTV-66 Gy) and 88% (CTV-54 Gy) of the simulations had a dose received by 98% of the target volume (D98%) >95% of the prescription dose. Doses to organs at risk (OARs) showed considerable spread around planned values. Causes for major deviations were mixed. Adaptive planning based on repeat imaging positively affected dose delivery accuracy: in the presence of the other errors, percentages of treatments with D98% >95% increased to 96% (CTV-66 Gy) and 100% (CTV-54 Gy). Plans with more beam directions were not more robust. Conclusions: For oropharyngeal cancer patients, treatment uncertainties can result in significant differences between planned and delivered IMPT doses. Given the mixed causes for major deviations, we advise repeat diagnostic CT scans during treatment, recalculation of the dose, and if required, adaptive planning to improve adequate IMPT dose delivery.

Kraan, Aafke C., E-mail: aafke.kraan@pi.infn.it [Erasmus MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Water, Steven van de; Teguh, David N.; Al-Mamgani, Abrahim [Erasmus MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Madden, Tom; Kooy, Hanne M. [Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Heijmen, Ben J.M.; Hoogeman, Mischa S. [Erasmus MC Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

2013-12-01T23:59:59.000Z

93

Mechanisms of Low Dose Radio-Suppression of Genomic Instability  

SciTech Connect (OSTI)

The major goal of this project is to contribute toward the elucidation of the impact of long term low dose radiation on genomic stability. We have created and characterized novel technologies for delivering long term low dose radiation to animals, and we have studied genomic stability by applying cutting edge molecular analysis technologies. Remarkably, we have found that a dose rate that is 300X higher than background radiation does not lead to any detectable genomic damage, nor is there any significant change in gene expression for genes pertinent to the DNA damage response. These results point to the critical importance of dose rate, rather than just total dose, when evaluating public health risks and when creating regulatory guidelines. In addition to these studies, we have also further developed a mouse model for quantifying cells that have undergone a large scale DNA sequence rearrangement via homologous recombination, and we have applied these mice in studies of both low dose radiation and space radiation. In addition to more traditional approaches for assessing genomic stability, we have also explored radiation and possible beneficial effects (adaptive response), long term effects (persistent effects) and effects on communication among cells (bystander effects), both in vitro and in vivo. In terms of the adaptive response, we have not observed any significant induction of an adaptive response following long term low dose radiation in vivo, delivered at 300X background. In terms of persistent and bystander effects, we have revealed evidence of a bystander effect in vivo and with researchers at and demonstrated for the first time the molecular mechanism by which cells remember radiation exposure. Understanding the underlying molecular mechanisms by which radiation can induce genomic instability is fundamental to our ability to assess the biological impact of low dose radiation. Finally, in a parallel set of studies we have explored the effects of heavy iron particle radiation on large scale sequence rearrangements and we have discovered tissue specific differences in sensitivity to homologous recombination. DOE support has given rise to critical new knowledge about the biological impact of low dose rate radiation and about the underlying mechanisms that govern genomic stability in response to radiation exposure. This work has spurred interest in radiation among MIT scientists, and has fostered ongoing research projects that will continue to contribute toward our understanding of the biological effects of low dose radiation exposure.

Engelward, Bevin P

2009-09-16T23:59:59.000Z

94

Flavin-Induced Oligomerization in Escherichia coli Adaptive Response Protein AidB  

E-Print Network [OSTI]

The process known as adaptive response allows Escherichia coli to respond to small doses of DNA-methylating agents by upregulating the expression of four proteins. While the role of three of these proteins in mitigating ...

Drennan, Catherine L.

95

Is it sensible to 'deform' dose? 3D experimental validation of dose-warping  

SciTech Connect (OSTI)

Purpose: Strategies for dose accumulation in deforming anatomy are of interest in radiotherapy. Algorithms exist for the deformation of dose based on patient image sets, though these are sometimes contentious because not all such image calculations are constrained by physical laws. While tumor and organ motion has been a key area of study for a considerable amount of time, deformation is of increasing interest. In this work, we demonstrate a full 3D experimental validation of results from a range of dose deformation algorithms available in the public domain. Methods: We recently developed the first tissue-equivalent, full 3D deformable dosimetric phantom-'DEFGEL.' To assess the accuracy of dose-warping based on deformable image registration (DIR), we have measured doses in undeformed and deformed states of the DEFGEL dosimeter and compared these to planned doses and warped doses. In this way we have directly evaluated the accuracy of dose-warping calculations for 11 different algorithms. We have done this for a range of stereotactic irradiation schemes and types and magnitudes of deformation. Results: The original Horn and Schunck algorithm is shown to be the best performing of the 11 algorithms trialled. Comparing measured and dose-warped calculations for this method, it is found that for a 10 Multiplication-Sign 10 mm{sup 2} square field, {gamma}{sub 3%/3mm}= 99.9%; for a 20 Multiplication-Sign 20 mm{sup 2} cross-shaped field, {gamma}{sub 3%/3mm}= 99.1%; and for a multiple dynamic arc (0.413 cm{sup 3} PTV) treatment adapted from a patient treatment plan, {gamma}{sub 3%/3mm}= 95%. In each case, the agreement is comparable to-but consistently {approx}1% less than-comparison between measured and calculated (planned) dose distributions in the absence of deformation. The magnitude of the deformation, as measured by the largest displacement experienced by any voxel in the volume, has the greatest influence on the accuracy of the warped dose distribution. Considering the square field case, the smallest deformation ({approx}9 mm) yields agreement of {gamma}{sub 3%/3mm}= 99.9%, while the most significant deformation ({approx}20 mm) yields agreement of {gamma}{sub 3%/3mm}= 96.7%. Conclusions: We have confirmed that, for a range of mass and density conserving deformations representative of those observable in anatomical targets, DIR-based dose-warping can yield accurate predictions of the dose distribution. Substantial differences can be seen between the results of different algorithms indicating that DIR performance should be scrutinized before application todose-warping. We have demonstrated that the DEFGEL deformable dosimeter can be used to evaluate DIR performance and the accuracy of dose-warping results by direct measurement.

Yeo, U. J.; Taylor, M. L.; Supple, J. R.; Smith, R. L.; Dunn, L.; Kron, T.; Franich, R. D. [School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002 (Australia) and Medical Physics, William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, Victoria 3181 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia) and Medical Physics, William Buckland Radiotherapy Centre, Alfred Hospital, Melbourne, Victoria 3181 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia) and Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia)

2012-08-15T23:59:59.000Z

96

Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation  

E-Print Network [OSTI]

R.B. Mikkelsen, Ionizing radiation-induced, mitochondria-W.K. Rorrer, P.B. Chen, Radiation-induced proliferation ofresponse genes to ionizing radiation in human lymphoblastoid

Wyrobek, A. J.

2011-01-01T23:59:59.000Z

97

Adaptive mean filtering for noise reduction in CT polymer gel dosimetry  

SciTech Connect (OSTI)

X-ray computed tomography (CT) as a method of extracting 3D dose information from irradiated polymer gel dosimeters is showing potential as a practical means to implement gel dosimetry in a radiation therapy clinic. However, the response of CT contrast to dose is weak and noise reduction is critical in order to achieve adequate dose resolutions with this method. Phantom design and CT imaging technique have both been shown to decrease image noise. In addition, image postprocessing using noise reduction filtering techniques have been proposed. This work evaluates in detail the use of the adaptive mean filter for reducing noise in CT gel dosimetry. Filter performance is systematically tested using both synthetic patterns mimicking a range of clinical dose distribution features as well as actual clinical dose distributions. Both low and high signal-to-noise ratio (SNR) situations are examined. For all cases, the effects of filter kernel size and the number of iterations are investigated. Results indicate that adaptive mean filtering is a highly effective tool for noise reduction CT gel dosimetry. The optimum filtering strategy depends on characteristics of the dose distributions and image noise level. For low noise images (SNR {approx}20), the filtered results are excellent and use of adaptive mean filtering is recommended as a standard processing tool. For high noise images (SNR {approx}5) adaptive mean filtering can also produce excellent results, but filtering must be approached with more caution as spatial and dose distortions of the original dose distribution can occur.

Hilts, Michelle; Jirasek, Andrew [Medical Physics, BC Cancer Agency-Vancouver Island Centre, Victoria, British Columbia, V8R6V5 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8W2Y2 (Canada)

2008-01-15T23:59:59.000Z

98

The Impact of Heart Irradiation on Dose-Volume Effects in the Rat Lung  

SciTech Connect (OSTI)

Purpose: To test the hypothesis that heart irradiation increases the risk of a symptomatic radiation-induced loss of lung function (SRILF) and that this can be well-described as a modulation of the functional reserve of the lung. Methods and Materials: Rats were irradiated with 150-MeV protons. Dose-response curves were obtained for a significant increase in breathing frequency after irradiation of 100%, 75%, 50%, or 25% of the total lung volume, either including or excluding the heart from the irradiation field. A significant increase in the mean respiratory rate after 6-12 weeks compared with 0-4 weeks was defined as SRILF, based on biweekly measurements of the respiratory rate. The critical volume (CV) model was used to describe the risk of SRILF. Fits were done using a maximum likelihood method. Consistency between model and data was tested using a previously developed goodness-of-fit test. Results: The CV model could be fitted consistently to the data for lung irradiation only. However, this fitted model failed to predict the data that also included heart irradiation. Even refitting the model to all data resulted in a significant difference between model and data. These results imply that, although the CV model describes the risk of SRILF when the heart is spared, the model needs to be modified to account for the impact of dose to the heart on the risk of SRILF. Finally, a modified CV model is described that is consistent to all data. Conclusions: The detrimental effect of dose to the heart on the incidence of SRILF can be described by a dose dependent decrease in functional reserve of the lung.

Luijk, Peter van [Department of Radiation Oncology, University Medical Center, Groningen (Netherlands)], E-mail: p.van.luijk@rt.umcg.nl; Faber, Hette [Department of Radiation Oncology, University Medical Center, Groningen (Netherlands); Department of Cell Biology, Section Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Meertens, Harm [Department of Radiation Oncology, University Medical Center, Groningen (Netherlands); Schippers, Jacobus M. [Accelerator Department, Paul Scherrer Institut, Villigen, Switerland (Switzerland); Langendijk, Johannes A. [Department of Radiation Oncology, University Medical Center, Groningen (Netherlands); Brandenburg, Sytze [Kernfysisch Versneller Instituut, University of Groningen, Groningen (Netherlands); Kampinga, Harm H. [Department of Cell Biology, Section Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Coppes, Robert P. Ph.D. [Department of Radiation Oncology, University Medical Center, Groningen (Netherlands); Department of Cell Biology, Section Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)

2007-10-01T23:59:59.000Z

99

Standardized radiological dose evaluations  

SciTech Connect (OSTI)

Following the end of the Cold War, the mission of Rocky Flats Environmental Technology Site changed from production of nuclear weapons to cleanup. Authorization baseis documents for the facilities, primarily the Final Safety Analysis Reports, are being replaced with new ones in which accident scenarios are sorted into coarse bins of consequence and frequency, similar to the approach of DOE-STD-3011-94. Because this binning does not require high precision, a standardized approach for radiological dose evaluations is taken for all the facilities at the site. This is done through a standard calculation ``template`` for use by all safety analysts preparing the new documents. This report describes this template and its use.

Peterson, V.L.; Stahlnecker, E.

1996-05-01T23:59:59.000Z

100

Prediction of radiation-induced liver disease by Lyman normal-tissue complication probability model in three-dimensional conformal radiation therapy for primary liver carcinoma  

SciTech Connect (OSTI)

Purpose: To describe the probability of RILD by application of the Lyman-Kutcher-Burman normal-tissue complication (NTCP) model for primary liver carcinoma (PLC) treated with hypofractionated three-dimensional conformal radiotherapy (3D-CRT). Methods and Materials: A total of 109 PLC patients treated by 3D-CRT were followed for RILD. Of these patients, 93 were in liver cirrhosis of Child-Pugh Grade A, and 16 were in Child-Pugh Grade B. The Michigan NTCP model was used to predict the probability of RILD, and then the modified Lyman NTCP model was generated for Child-Pugh A and Child-Pugh B patients by maximum-likelihood analysis. Results: Of all patients, 17 developed RILD in which 8 were of Child-Pugh Grade A, and 9 were of Child-Pugh Grade B. The prediction of RILD by the Michigan model was underestimated for PLC patients. The modified n, m, TD{sub 5} (1) were 1.1, 0.28, and 40.5 Gy and 0.7, 0.43, and 23 Gy for patients with Child-Pugh A and B, respectively, which yielded better estimations of RILD probability. The hepatic tolerable doses (TD{sub 5}) would be MDTNL of 21 Gy and 6 Gy, respectively, for Child-Pugh A and B patients. Conclusions: The Michigan model was probably not fit to predict RILD in PLC patients. A modified Lyman NTCP model for RILD was recommended.

Xu ZhiYong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China); Liang Shixiong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Zhu Ji [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China); Zhu Xiaodong [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Zhao Jiandong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China); Lu Haijie [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Yang Yunli [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Chen Long [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Wang Anyu [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Fu Xiaolong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China); Jiang Guoliang [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China) and Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China)]. E-mail: jianggl@21cn.com

2006-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

Finch, S.M.; McMakin, A.H. (comps.)

1992-06-01T23:59:59.000Z

102

ORISE: Dose modeling and assessments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

or state regulatory compliance requirements are being met during the decontamination and decommissioning of nuclear facilities. Dose modeling is an important step in the...

103

Online Adaptive Replanning Method for Prostate Radiotherapy  

SciTech Connect (OSTI)

Purpose: To report the application of an adaptive replanning technique for prostate cancer radiotherapy (RT), consisting of two steps: (1) segment aperture morphing (SAM), and (2) segment weight optimization (SWO), to account for interfraction variations. Methods and Materials: The new 'SAM+SWO' scheme was retroactively applied to the daily CT images acquired for 10 prostate cancer patients on a linear accelerator and CT-on-Rails combination during the course of RT. Doses generated by the SAM+SWO scheme based on the daily CT images were compared with doses generated after patient repositioning using the current planning target volume (PTV) margin (5 mm, 3 mm toward rectum) and a reduced margin (2 mm), along with full reoptimization scans based on the daily CT images to evaluate dosimetry benefits. Results: For all cases studied, the online replanning method provided significantly better target coverage when compared with repositioning with reduced PTV (13% increase in minimum prostate dose) and improved organ sparing when compared with repositioning with regular PTV (13% decrease in the generalized equivalent uniform dose of rectum). The time required to complete the online replanning process was 6 {+-} 2 minutes. Conclusion: The proposed online replanning method can be used to account for interfraction variations for prostate RT with a practically acceptable time frame (5-10 min) and with significant dosimetric benefits. On the basis of this study, the developed online replanning scheme is being implemented in the clinic for prostate RT.

Ahunbay, Ergun E., E-mail: eahunbay@mcw.ed [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Peng Cheng; Holmes, Shannon; Godley, Andrew; Lawton, Colleen; Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

2010-08-01T23:59:59.000Z

104

BIODIVERSITY Incorporating sociocultural adaptive  

E-Print Network [OSTI]

BIODIVERSITY VIEWPOINT Incorporating sociocultural adaptive capacity in conservation hotspot of biodiversity threats. Conservation biogeography (Whittaker et al., 2005) has emerged as a critical area biodiversity (Mawdsley et al., 2009). Adjusting conservation strategies to maintain diversity in recognition

105

Dynamic Adaptation using Xen  

SciTech Connect (OSTI)

The topic of virtualization has received renewed attention. Xen is a popular open source type-I hypervisor. The Xen hypervisor currently has limited capabilities for runtime modification to the core hypervisor, which impairs research into dynamic adaptation for system-level virtualization. This paper discusses recent investigations into the feasibility of extending Xen to support runtime adaptation for core hypervisor service, e.g., scheduler.

Naughton, III, Thomas J [ORNL; Vallee, Geoffroy R [ORNL; Scott, Stephen L [ORNL

2007-01-01T23:59:59.000Z

106

Molecular dissection of the roles of the SOD genes in mammalian response to low dose irradiation  

SciTech Connect (OSTI)

It has been long recognized that a significant fraction of the radiation-induced genetic damage to cells are caused by secondary oxidative species. Internal cellular defense systems against oxidative stress play significant roles in countering genetic damage induced by ionizing radiation. The role of the detoxifying enzymes may be even more prominent in the case of low-dose, low-LET irradiation, as the majority of genetic damage may be caused by secondary oxidative species. In this study we have attempted to decipher the roles of the superoxide dismutase (SOD) genes, which are responsible for detoxifying the superoxide anions. We used adenovirus vectors to deliver RNA interference (RNAi or siRNA) technology to down-regulate the expression levels of the SOD genes. We have also over-expressed the SOD genes by use of recombinant adenovirus vectors. Cells infected with the vectors were then subjected to low dose ?-irradiation. Total RNA were extracted from the exposed cells and the expression of 9000 genes were profiled by use of cDNA microarrays. The result showed that low dose radiation had clear effects on gene expression in HCT116 cells. Both over-expression and down-regulation of the SOD1 gene can change the expression profiles of sub-groups of genes. Close to 200 of the 9000 genes examined showed over two-fold difference in expression under various conditions. Genes with changed expression pattern belong to many categories that include: early growth response, DNA-repair, ion transport, apoptosis, and cytokine response.

Eric Y. Chuang

2006-08-31T23:59:59.000Z

107

Discriminative Adaptive Training and Bayesian Inference for  

E-Print Network [OSTI]

adaptation is a standard part of many speech recognition systems. This process requires some adaptation data

de Gispert, Adrià

108

ADAPTIVE RADIATION ROSEMARY G. GILLESPIE  

E-Print Network [OSTI]

1 A ADAPTIVE RADIATION ROSEMARY G. GILLESPIE University of California, Berkeley Adaptive radiation- tions and convergence of species groups on different land masses. Since then, adaptive radiation has diversity within a rapidly multiplying lineage." There are radiations that are not adaptive

Gillespie, Rosemary

109

Non-Invasive Early Detection and Molecular Analysis of Low X-ray Dose Effects in the Lens  

SciTech Connect (OSTI)

This is the Final Progress Report for DOE-funded research project DE-PS02-08ER08-01 titled Non-Invasive Early Detection and Molecular Analysis of Low X-ray Dose Effects in the Lens. The project focuses on the effects of low-linear energy transfer (LET) radiation on the ocular lens. The lens is an exquisitely radiosensitive tissue with a highly-ordered molecular structure that is amenable to non-invasive optical study from the periphery. These merits point to the lens as an ideal target for laser-based molecular biodosimetry (MBD). Following exposure to different types of ionizing radiations, the lens demonstrates molecular changes (e.g., oxidation, racemization, crosslinkage, truncation, aggregation, etc.) that impact the structure and function of the long-lived proteins in the cytosol of lens fiber cells. The vast majority of proteins in the lens comprise the highly-ordered crystallins. These highly conserved lens proteins are amongst the most concentrated and stable in the body. Once synthesized, the crystallins are retained in the fiber cell cytoplasm for life. Taken together, these properties point to the lens as an ideal system for quantitative in vivo MBD assessment using quasi-elastic light scattering (QLS) analysis. In this project, we deploy a purpose-designed non-invasive infrared laser QLS instrument as a quantitative tool for longitudinal assessment of pre-cataractous molecular changes in the lenses of living mice exposed to low-dose low-LET radiation compared to non-irradiated sham controls. We hypothesize that radiation exposure will induce dose-dependent changes in the molecular structure of matrix proteins in the lens. Mechanistic assays to ascertain radiation-induced molecular changes in the lens focus on protein aggregation and gene/protein expression patterns. We anticipate that this study will contribute to our understanding of early molecular changes associated with radiation-induced tissue pathology. This study also affords potential for translational development of molecular biodosimetry instrumentation to assess human exposure to mixed radiation fields.

Goldstein, Lee [Boston University] [Boston University

2014-07-02T23:59:59.000Z

110

Direct aperture optimization for online adaptive radiation therapy  

SciTech Connect (OSTI)

This paper is the first investigation of using direct aperture optimization (DAO) for online adaptive radiation therapy (ART). A geometrical model representing the anatomy of a typical prostate case was created. To simulate interfractional deformations, four different anatomical deformations were created by systematically deforming the original anatomy by various amounts (0.25, 0.50, 0.75, and 1.00 cm). We describe a series of techniques where the original treatment plan was adapted in order to correct for the deterioration of dose distribution quality caused by the anatomical deformations. We found that the average time needed to adapt the original plan to arrive at a clinically acceptable plan is roughly half of the time needed for a complete plan regeneration, for all four anatomical deformations. Furthermore, through modification of the DAO algorithm the optimization search space was reduced and the plan adaptation was significantly accelerated. For the first anatomical deformation (0.25 cm), the plan adaptation was six times more efficient than the complete plan regeneration. For the 0.50 and 0.75 cm deformations, the optimization efficiency was increased by a factor of roughly 3 compared to the complete plan regeneration. However, for the anatomical deformation of 1.00 cm, the reduction of the optimization search space during plan adaptation did not result in any efficiency improvement over the original (nonmodified) plan adaptation. The anatomical deformation of 1.00 cm demonstrates the limit of this approach. We propose an innovative approach to online ART in which the plan adaptation and radiation delivery are merged together and performed concurrently--adaptive radiation delivery (ARD). A fundamental advantage of ARD is the fact that radiation delivery can start almost immediately after image acquisition and evaluation. Most of the original plan adaptation is done during the radiation delivery, so the time spent adapting the original plan does not increase the overall time the patient has to spend on the treatment couch. As a consequence, the effective time allotted for plan adaptation is drastically reduced. For the 0.25, 0.5, and 0.75 cm anatomical deformations, the treatment time was increased by only 2, 4, and 6 s, respectively, as compared to no plan adaptation. For the anatomical deformation of 1.0 cm the time increase was substantially larger. The anatomical deformation of 1.0 cm represents an extreme case, which is rarely observed for the prostate, and again demonstrates the limit of this approach. ARD shows great potential for an online adaptive method with minimal extension of treatment time.

Mestrovic, Ante; Milette, Marie-Pierre; Nichol, Alan; Clark, Brenda G.; Otto, Karl [Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada and Medical Physics, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada); Physics and Astronomy, University of British Columbia, Vancouver, British Columbia (Canada) and Medical Physics, BC Cancer Agency-Centre for the Southern Interior, Kelowna, British Columbia (Canada); Department of Radiation Oncology, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada); Medical Physics, Ottawa Hospital Regional Cancer Centre, Ottawa, Ontario (Canada); Medical Physics, BC Cancer Agency-Vancouver Centre, Vancouver, British Columbia (Canada)

2007-05-15T23:59:59.000Z

111

Technical basis for dose reconstruction  

SciTech Connect (OSTI)

The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied.

Anspaugh, L.R.

1996-01-31T23:59:59.000Z

112

Weldon Spring historical dose estimate  

SciTech Connect (OSTI)

This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.

Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

1986-07-01T23:59:59.000Z

113

a 50% reduction in Prlr gene dose, provides strong evidence for PRL being the mediator  

E-Print Network [OSTI]

a 50% reduction in Prlr gene dose, provides strong evidence for PRL being the mediator of pregnancy adaptation initiated early in pregnancy and mediated by PRL. Pregnancy is associated with several other transient alterations in mater- nal physiological functions, many of which can be affected by PRL and

Kenig, Fabien

114

Experimental determination of the radial dose distribution in high gradient regions around {sup 192}Ir wires: Comparison of electron paramagnetic resonance imaging, films, and Monte Carlo simulations  

SciTech Connect (OSTI)

Purpose: The experimental determination of doses at proximal distances from radioactive sources is difficult because of the steepness of the dose gradient. The goal of this study was to determine the relative radial dose distribution for a low dose rate {sup 192}Ir wire source using electron paramagnetic resonance imaging (EPRI) and to compare the results to those obtained using Gafchromic EBT film dosimetry and Monte Carlo (MC) simulations. Methods: Lithium formate and ammonium formate were chosen as the EPR dosimetric materials and were used to form cylindrical phantoms. The dose distribution of the stable radiation-induced free radicals in the lithium formate and ammonium formate phantoms was assessed by EPRI. EBT films were also inserted inside in ammonium formate phantoms for comparison. MC simulation was performed using the MCNP4C2 software code. Results: The radical signal in irradiated ammonium formate is contained in a single narrow EPR line, with an EPR peak-to-peak linewidth narrower than that of lithium formate ({approx}0.64 and 1.4 mT, respectively). The spatial resolution of EPR images was enhanced by a factor of 2.3 using ammonium formate compared to lithium formate because its linewidth is about 0.75 mT narrower than that of lithium formate. The EPRI results were consistent to within 1% with those of Gafchromic EBT films and MC simulations at distances from 1.0 to 2.9 mm. The radial dose values obtained by EPRI were about 4% lower at distances from 2.9 to 4.0 mm than those determined by MC simulation and EBT film dosimetry. Conclusions: Ammonium formate is a suitable material under certain conditions for use in brachytherapy dosimetry using EPRI. In this study, the authors demonstrated that the EPRI technique allows the estimation of the relative radial dose distribution at short distances for a {sup 192}Ir wire source.

Kolbun, N.; Leveque, Ph.; Abboud, F.; Bol, A.; Vynckier, S.; Gallez, B. [Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Institute of Experimental and Clinical Research, Universite catholique de Louvain, Avenue Hippocrate 55, B-1200 Brussels (Belgium); Biomedical Magnetic Resonance Unit, Louvain Drug Research Institute, Universite catholique de Louvain, Avenue Mounier 73.40, B-1200 Brussels (Belgium)

2010-10-15T23:59:59.000Z

115

Adaptive Medical Information Delivery Combining User, Task and Situation Models  

E-Print Network [OSTI]

., in their model for adaptive hypermedia AHAM [2], distinguish contentadaptation from link adaptation

116

Biological doses with template distribution patterns  

SciTech Connect (OSTI)

Consideration of radiation dose rate effects emphasizes advantages of the template method for lateral distribution of multiple sources in treatment of laterally infiltrating gynecologic cancer, when compared to a conventional technique with colpostats. Biological doses in time dose fractionation (TDF), ret and reu units are calculated for the two treatment methods. With the template method the lateral dose (point B) is raised without significantly increasing the doses to the rectum and bladder, that is, relatively, the calculated biological doses at point A and B are more nearly equivalent and the doses to the rectum and bladder are significantly lower than the dose to point B.

Harrop, R. (Simon Fraer Univ., Burnaby, British Columbia); Haymond, H.R.; Nisar, A.; Syed, A.N.M.; Feder, B.H.; Neblett, D.L.

1981-02-01T23:59:59.000Z

117

Adaptation and adaptability : expectant design for resilience in coastal urbanity  

E-Print Network [OSTI]

What is the nature of and possibility for urban resiliency through adaptation? Adaptation implies responsiveness to phenomena that are disruptive to a system's functioning; it is a willful evolution in response to changed ...

Ruskeep, Laura A. Delaney (Laura Ashley Delaney)

2011-01-01T23:59:59.000Z

118

Adaptive sequential controller  

DOE Patents [OSTI]

An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

El-Sharkawi, Mohamed A. (Renton, WA); Xing, Jian (Seattle, WA); Butler, Nicholas G. (Newberg, OR); Rodriguez, Alonso (Pasadena, CA)

1994-01-01T23:59:59.000Z

119

A Phase I Clinical and Pharmacology Study Using Amifostine as a Radioprotector in Dose-escalated Whole Liver Radiation Therapy  

SciTech Connect (OSTI)

Purpose: Diffuse intrahepatic tumors are difficult to control. Whole-liver radiotherapy has been limited by toxicity, most notably radiation-induced liver disease. Amifostine is a prodrug free-radical scavenger that selectively protects normal tissues and, in a preclinical model of intrahepatic cancer, systemic amifostine reduced normal liver radiation damage without compromising tumor effect. We hypothesized that amifostine would permit escalation of whole-liver radiation dose to potentially control microscopic disease. We also aimed to characterize the pharmacokinetics of amifostine and its active metabolite WR-1065 to optimize timing of radiotherapy. Methods and Materials: We conducted a radiation dose-escalation trial for patients with diffuse, intrahepatic cancer treated with whole-liver radiation and intravenous amifostine. Radiation dose was assigned using the time-to-event continual reassessment method. A companion pharmacokinetic study was performed. Results: Twenty-three patients were treated, with a maximum dose of 40 Gy. Using a logistical regression model, compared with our previously treated patients, amifostine increased liver tolerance by 3.3 {+-} 1.1 Gy (p = 0.007) (approximately 10%) with similar response rates. Peak concentrations of WR-1065 were 25 {mu}M with an elimination half-life of 1.5 h; these levels are consistent with radioprotective effects of amifostine in patients. Conclusion: These findings demonstrate for the first time that amifostine is a normal liver radioprotector. They further suggest that it may be useful to combine amifostine with fractionated or stereotactic body radiation therapy for patients with focal intrahepatic cancer.

Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Smith, David E. [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States); Normolle, Daniel P. [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Knol, James A. [Department of Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie C.; Ben-Josef, Edgar [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lu Zheng; Feng, Meihua R.; Chen Jun [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States); Ensminger, William [Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lawrence, Theodore S. [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)

2012-08-01T23:59:59.000Z

120

AGING FACILITY WORKER DOSE ASSESSMENT  

SciTech Connect (OSTI)

The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering.

R.L. Thacker

2005-03-24T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS  

E-Print Network [OSTI]

ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS MOODY T. CHU \\Lambda Abstract. The wavefront aberrations induced by atmospheric turbulence can severely degrade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions

122

ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS  

E-Print Network [OSTI]

ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS MOODY T. CHU Abstract. The wavefront aberrations induced by atmospheric turbulence can severely degrade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions

123

Spectral-element adaptive refinement  

E-Print Network [OSTI]

Spectral-element adaptive refinement magnetohydrodynamic simulations of the island coalescence;Abstract A recently developed spectral-element adaptive refinement incompressible magnetohydrodynamic (MHD statically refined and dynamically refined grids. The island coalescence instability is a fundamental MHD

Ng, Chung-Sang

124

Adaptation of Microvasculature to Pulsatility  

E-Print Network [OSTI]

adaptation has not yet been fully characterized. In fact, standard mathematical models using the common assumption that vessels solely adapt to steady flow do not reproduce normal vascular structure. Therefore, we developed a simple, mathematical model of a...

Bimal, Tia

2013-09-24T23:59:59.000Z

125

Climate Change, Adaptation, and Development  

E-Print Network [OSTI]

Climate Change, Adaptation, and Development Daniel H. Cole*THE COSTS OF CLIMATE CHANGE . ADAPTATIONCONVENTION ON CLIMATE CHANGE . IV. A.

Cole, Daniel H.

2008-01-01T23:59:59.000Z

126

Radiation Induced Nanocrystal Formation in Metallic Glasses  

E-Print Network [OSTI]

The irradiation of metallic glasses to induce nanocrystallization was studied in two metallic glass compositions, Cu50Zr45Ti5 and Zr55Cu30Al10Ni5. Atomic mobility was described using a model based on localized excess free volume due to displace...

Carter, Jesse

2010-01-14T23:59:59.000Z

127

Mitigation of radiation induced surface contamination  

DOE Patents [OSTI]

A process for mitigating or eliminating contamination and/or degradation of surfaces having common, adventitious atmospheric contaminants adsorbed thereon and exposed to radiation. A gas or a mixture of gases is introduced into the environment of a surface(s) to be protected. The choice of the gaseous species to be introduced (typically a hydrocarbon gas, water vapor, or oxygen or mixtures thereof) is dependent upon the contaminant as well as the ability of the gaseous species to bind to the surface to be protected. When the surface and associated bound species are exposed to radiation reactive species are formed that react with surface contaminants such as carbon or oxide films to form volatile products (e.g., CO, CO.sub.2) which desorb from the surface.

Klebanoff, Leonard E. (Dublin, CA); Stulen, Richard H. (Livermore, CA)

2003-01-01T23:59:59.000Z

128

Adaptive control for accelerators  

DOE Patents [OSTI]

An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

Eaton, Lawrie E. (Los Alamos, NM); Jachim, Stephen P. (Los Alamos, NM); Natter, Eckard F. (Santa Fe, NM)

1991-01-01T23:59:59.000Z

129

Static jaw collimation settings to minimize radiation dose to normal brain tissue during stereotactic radiosurgery  

SciTech Connect (OSTI)

At University of Arkansas for Medical Sciences (UAMS) intracranial stereotactic radiosurgery (SRS) is performed by using a linear accelerator with an add-on micromultileaf collimator (mMLC). In our clinical setting, static jaws are automatically adapted to the furthest edge of the mMLC-defined segments with 2-mm (X jaw) and 5-mm (Y jaw) margin and the same jaw values are applied for all beam angles in the treatment planning system. This additional field gap between the static jaws and the mMLC allows additional radiation dose to normal brain tissue. Because a radiosurgery procedure consists of a single high dose to the planning target volume (PTV), reduction of unnecessary dose to normal brain tissue near the PTV is important, particularly for pediatric patients whose brains are still developing or when a critical organ, such as the optic chiasm, is near the PTV. The purpose of this study was to minimize dose to normal brain tissue by allowing minimal static jaw margin around the mMLC-defined fields and different static jaw values for each beam angle or arc. Dose output factors were measured with various static jaw margins and the results were compared with calculated doses in the treatment planning system. Ten patient plans were randomly selected and recalculated with zero static jaw margins without changing other parameters. Changes of PTV coverage, mean dose to predefined normal brain tissue volume adjacent to PTV, and monitor units were compared. It was found that the dose output percentage difference varied from 4.9-1.3% for the maximum static jaw opening vs. static jaw with zero margins. The mean dose to normal brain tissue at risk adjacent to the PTV was reduced by an average of 1.9%, with negligible PTV coverage loss. This dose reduction strategy may be meaningful in terms of late effects of radiation, particularly in pediatric patients. This study generated clinical knowledge and tools to consistently minimize dose to normal brain tissue.

Han, Eun Young, E-mail: eyhan@uams.edu [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Zhang Xin; Yan Yulong; Sharma, Sunil; Penagaricano, Jose [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Moros, Eduardo [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Corry, Peter [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States)

2012-01-01T23:59:59.000Z

130

Uncertainty and Sensitivity Analyses Plan. Draft for Peer Review: Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

Hanford Environmental Dose Reconstruction (HEDR) Project staff are developing mathematical models to be used to estimate the radiation dose that individuals may have received as a result of emissions since 1944 from the US Department of Energy`s (DOE) Hanford Site near Richland, Washington. An uncertainty and sensitivity analyses plan is essential to understand and interpret the predictions from these mathematical models. This is especially true in the case of the HEDR models where the values of many parameters are unknown. This plan gives a thorough documentation of the uncertainty and hierarchical sensitivity analysis methods recommended for use on all HEDR mathematical models. The documentation includes both technical definitions and examples. In addition, an extensive demonstration of the uncertainty and sensitivity analysis process is provided using actual results from the Hanford Environmental Dose Reconstruction Integrated Codes (HEDRIC). This demonstration shows how the approaches used in the recommended plan can be adapted for all dose predictions in the HEDR Project.

Simpson, J.C.; Ramsdell, J.V. Jr.

1993-04-01T23:59:59.000Z

131

Transforming Growth Factor ?-1 (TGF-?1) Is a Serum Biomarker of Radiation Induced Fibrosis in Patients Treated With Intracavitary Accelerated Partial Breast Irradiation: Preliminary Results of a Prospective Study  

SciTech Connect (OSTI)

Purpose: To examine a relationship between serum transforming growth factor ? -1 (TGF-?1) values and radiation-induced fibrosis (RIF). Methods and Materials: We conducted a prospective analysis of the development of RIF in 39 women with American Joint Committee on Cancer stage 0-I breast cancer treated with lumpectomy and accelerated partial breast irradiation via intracavitary brachytherapy (IBAPBI). An enzyme-linked immunoassay (Quantikine, R and D, Minneapolis, MN) was used to measure serum TGF-?1 before surgery, before IBAPBI, and during IBAPBI. Blood samples for TGF-?1 were also collected from 15 healthy, nontreated women (controls). The previously validated tissue compliance meter (TCM) was used to objectively assess RIF. Results: The median time to follow-up for 39 patients was 44 months (range, 5-59 months). RIF was graded by the TCM scale as 0, 1, 2, and 3 in 5 of 20 patients (25%), 6 of 20 patients (30%), 5 of 20 patients (25%), and 4 of 20 patients (20%), respectively. The mean serum TGF-?1 values were significantly higher in patients before surgery than in disease-free controls, as follows: all cancer patients (30,201 5889 pg/mL, P=.02); patients with any type of RIF (32,273 5016 pg/mL, P<.0001); and women with moderate to severe RIF (34,462 4713 pg/mL, P<0.0001). Patients with moderate to severe RIF had significantly elevated TGF-?1 levels when compared with those with none to mild RIF before surgery (P=.0014) during IBAPBI (P?0001), and the elevation persisted at 6 months (P?.001), 12 months (P?.001), 18 months (P?.001), and 24 months (P=.12). A receiver operating characteristic (ROC) curve of TGF-?1 values predicting moderate to severe RIF was generated with an area under the curve (AUC){sub ROC} of 0.867 (95% confidence interval 0.700-1.000). The TGF-?1 threshold cutoff was determined to be 31,000 pg/mL, with associated sensitivity and specificity of 77.8% and 90.0%, respectively. Conclusions: TGF-?1 levels correlate with the development of moderate to severe RIF. The pre-IBAPBI mean TGF-?1 levels can serve as an early biomarker for the development of moderate to severe RIF after IBAPBI.

Boothe, Dustin L. [Weill Cornell Medical College of Cornell University, New York, New York (United States); Coplowitz, Shana [Department of Radiation Oncology, Stich Radiation Center, Weill Cornell Medical College of Cornell University, New York, New York (United States); Greenwood, Eleni [Weill Cornell Medical College of Cornell University, New York, New York (United States); Barney, Christian L. [Department of Radiation Oncology, Ohio State University, Columbus, Ohio (United States); Christos, Paul J. [Division of Biostatistics and Epidemiology, Department of Public Health, Weill Cornell Medical College of Cornell University, New York, New York (United States); Parashar, Bhupesh; Nori, Dattatreyudu; Chao, K. S. Clifford [Department of Radiation Oncology, Stich Radiation Center, Weill Cornell Medical College of Cornell University, New York, New York (United States); Wernicke, A. Gabriella, E-mail: gaw9008@med.cornell.edu [Department of Radiation Oncology, Stich Radiation Center, Weill Cornell Medical College of Cornell University, New York, New York (United States)

2013-12-01T23:59:59.000Z

132

Adapting to Survive  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building TechnologiesS1!4T op Document: NAActivitiesAdapting to

133

Radiation dose from cigarette tobacco  

SciTech Connect (OSTI)

The radioactivity in tobacco leaves collected from 15 different regions of Greece before cigarette production was studied in order to estimate the effective dose from cigarette tobacco due to the naturally occurring primordial radionuclides, such as {sup 226}Ra and {sup 210}Pb of the uranium series and {sup 228}Ra of the thorium series and/or man-made produced radionuclides, such as {sup 137}Cs of Chernobyl origin. Gamma-ray spectrometry was applied using Ge planar and coaxial type detectors of high resolution and high efficiency. It was concluded that the annual effective dose due to inhalation for adults (smokers) for {sup 226}Ra varied from 42.5 to 178.6 {mu}Sv y{sup -1} (average 79.7 {mu}Sv y{sup -1}), while for {sup 228}Ra from 19.3 to 116.0 {mu}Sv y{sup -1} (average 67.1 {mu}Sv y{sup -1}) and for {sup 210}Pb from 47.0 to 134.9 {mu}Sv y{sup -1} (average 104.7 {mu}Sv y{sup -1}), that is the same order of magnitude for each radionuclide. The sum of the effective dose of the three natural radionuclides varied from 151.9 to 401.3 {mu}Sv y{sup -1} (average 251.5 {mu}Sv y{sup -1}). The annual effective dose from {sup 137}Cs of Chernobyl origin was three orders of magnitude lower as it varied from 70.4 to 410.4 nSv y{sup -1} (average 199.3 nSv y{sup -1})

Papastefanou, C. [Aristotle University of Thessaloniki, Atomic and Nuclear Physics Laboratory, Thessaloniki 54124 (Greece)

2008-08-07T23:59:59.000Z

134

Tolerance doses for treatment planning  

SciTech Connect (OSTI)

Data for the tolerance of normal tissues or organs to (low-LET) radiation has been compiled from a number of sources which are referenced at the end of this document. This tolerance dose data are ostensibly for uniform irradiation of all or part of an organ, and are for either 5% (TD/sub 5/) or 50% (TD/sub 50/) complication probability. The ''size'' of the irradiated organ is variously stated in terms of the absolute volume or the fraction of the organ volume irradiated, or the area or the length of the treatment field. The accuracy of these data is questionable. Much of the data represents doses that one or several experienced therapists have estimated could be safely given rather than quantitative analyses of clinical observations. Because these data have been obtained from multiple sources with possible different criteria for the definition of a complication, there are sometimes different values for what is apparently the same endpoint. The data from some sources shows a tendancy to be quantized in 5 Gy increments. This reflects the size of possible round off errors. It is believed that all these data have been accumulated without the benefit of 3-D dose distributions and therefore the estimates of the size of the volume and/or the uniformity of the irradiation may be less accurate than is now possible. 19 refs., 4 figs.

Lyman, J.T.

1985-10-01T23:59:59.000Z

135

RADIATION SENSITIVITY & PROCESSING OF DNA DAMAGE FOLLOWING LOW DOSES OF GAMMA-RAY ALPHA PARTICLES & HZE IRRADIATION OF NORMAL DSB REPAIR DEFICIENT CELLS  

SciTech Connect (OSTI)

Non-homologous end joining (NHEJ) predominates in the repair of DNA double strand breaks (DSB) over homologous recombination (HR). NHEJ occurs throughout the cell cycle whereas HR occurs in late S/G2 due to the requirement of a sister chromatid (Rothkamm et al, Mol Cell Biol 23 5706-15 [2003]). To date evidence obtained with DSB repair deficient cells using pulsed-field gel electrophoresis has revealed the major pathway throughout all phases of the cell cycle for processing high dose induced DSBs is NHEJ (Wang et al, Oncogene 20 2212-24 (2001); Pluth et al, Cancer Res. 61 2649-55 [2001]). These findings however were obtained at high doses when on average >> 20-30 DSBs are formed per cell. The contribution of the repair pathways (NHEJ and HR) induced in response to DNA damage during the various phases of the cell cycle may depend upon the dose (the level of initial DSBs) especially since low levels of DSBs are induced at low dose. To date, low dose studies using NHEJ and HR deficient mutants have not been carried out to address this important question with radiations of different quality. The work presented here leads us to suggest that HR plays a relatively minor role in the repair of radiation-induced prompt DSBs. SSBs lead to the induction of DSBs which are associated specifically with S-phase cells consistent with the idea that they are formed at stalled replication forks in which HR plays a major role in repair. That DNA-PKcs is in some way involved in the repair of the precursors to replication-induced DSB remains an open question. Persistent non-DSB oxidative damage also leads to an increase in RAD51 positive DSBs. Both simple and complex non-DSB DNA damage may therefore contribute to indirect DSBs induced by ionising radiation at replication forks.

O'Neil, Peter

2009-05-15T23:59:59.000Z

136

Dosimetric and Radiobiological Consequences of Computed TomographyGuided Adaptive Strategies for Intensity Modulated Radiation Therapy of the Prostate  

SciTech Connect (OSTI)

Purpose: To examine a range of scenarios for image-guided adaptive radiation therapy of prostate cancer, including different schedules for megavoltage CT imaging, patient repositioning, and dose replanning. Methods and Materials: We simulated multifraction dose distributions with deformable registration using 35 sets of megavoltage CT scans of 13 patients. We computed cumulative dosevolume histograms, from which tumor control probabilities and normal tissue complication probabilities (NTCPs) for rectum were calculated. Five-field intensity modulated radiation therapy (IMRT) with 18-MV x-rays was planned to achieve an isocentric dose of 76 Gy to the clinical target volume (CTV). The differences between D{sub 95}, tumor control probability, V{sub 70Gy}, and NTCP for rectum, for accumulated versus planned dose distributions, were compared for different target volume sizes, margins, and adaptive strategies. Results: The CTV D{sub 95} for IMRT treatment plans, averaged over 13 patients, was 75.2 Gy. Using the largest CTV margins (10/7 mm), the D{sub 95} values accumulated over 35 fractions were within 2% of the planned value, regardless of the adaptive strategy used. For tighter margins (5 mm), the average D{sub 95} values dropped to approximately 73.0 Gy even with frequent repositioning, and daily replanning was necessary to correct this deficit. When personalized margins were applied to an adaptive CTV derived from the first 6 treatment fractions using the STAPLE (Simultaneous Truth and Performance Level Estimation) algorithm, target coverage could be maintained using a single replan 1 week into therapy. For all approaches, normal tissue parameters (rectum V{sub 70Gy} and NTCP) remained within acceptable limits. Conclusions: The frequency of adaptive interventions depends on the size of the CTV combined with target margins used during IMRT optimization. The application of adaptive target margins (<5 mm) to an adaptive CTV determined 1 week into therapy minimizes the need for subsequent dose replanning.

Battista, Jerry J., E-mail: j2b@uwo.ca [Department of Medical Biophysics, Western University, London, ON (Canada); Department of Oncology, Western University, London, ON (Canada); London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada); Johnson, Carol; Turnbull, David; Kempe, Jeff [London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada); Bzdusek, Karl [Philips Healthcare (Radiation Oncology Systems), Fitchburg, Wisconsin (United States); Van Dyk, Jacob; Bauman, Glenn [Department of Medical Biophysics, Western University, London, ON (Canada); Department of Oncology, Western University, London, ON (Canada); London Regional Cancer Program, London Health Sciences Centre, London, ON (Canada)

2013-12-01T23:59:59.000Z

137

Hanford Environmental Dose Reconstruction Project. Monthly report  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

Cannon, S.D.; Finch, S.M. [comps.

1992-10-01T23:59:59.000Z

138

Multiple anatomy optimization of accumulated dose  

SciTech Connect (OSTI)

Purpose: To investigate the potential advantages of multiple anatomy optimization (MAO) for lung cancer radiation therapy compared to the internal target volume (ITV) approach. Methods: MAO aims to optimize a single fluence to be delivered under free-breathing conditions such that the accumulated dose meets the plan objectives, where accumulated dose is defined as the sum of deformably mapped doses computed on each phase of a single four dimensional computed tomography (4DCT) dataset. Phantom and patient simulation studies were carried out to investigate potential advantages of MAO compared to ITV planning. Through simulated delivery of the ITV- and MAO-plans, target dose variations were also investigated. Results: By optimizing the accumulated dose, MAO shows the potential to ensure dose to the moving target meets plan objectives while simultaneously reducing dose to organs at risk (OARs) compared with ITV planning. While consistently superior to the ITV approach, MAO resulted in equivalent OAR dosimetry at planning objective dose levels to within 2% volume in 14/30 plans and to within 3% volume in 19/30 plans for each lung V20, esophagus V25, and heart V30. Despite large variations in per-fraction respiratory phase weights in simulated deliveries at high dose rates (e.g., treating 4/10 phases during single fraction beams) the cumulative clinical target volume (CTV) dose after 30 fractions and per-fraction dose were constant independent of planning technique. In one case considered, however, per-phase CTV dose varied from 74% to 117% of prescription implying the level of ITV-dose heterogeneity may not be appropriate with conventional, free-breathing delivery. Conclusions: MAO incorporates 4DCT information in an optimized dose distribution and can achieve a superior plan in terms of accumulated dose to the moving target and OAR sparing compared to ITV-plans. An appropriate level of dose heterogeneity in MAO plans must be further investigated.

Watkins, W. Tyler, E-mail: watkinswt@virginia.edu; Siebers, Jeffrey V. [Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Moore, Joseph A. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Gordon, James [Henry Ford Health System, Detroit, Michigan 48202 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Hugo, Geoffrey D. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

2014-11-01T23:59:59.000Z

139

Maintainable and Reusable Scientific Software Adaptation Democratizing Scientific Software Adaptation  

E-Print Network [OSTI]

Adaptation Pilsung Kang, Eli Tilevich, Srinidhi Varadarajan, and Naren Ramakrishnan Center for High, and available resources to en- sure its efficiency and reliability. Although adaptation pat- terns can be found, Maintenance, and Enhancement; D.2.13 [Reusable Soft- ware]: [Reusable libraries]; D.3.3 [Language Constructs

Ryder, Barbara G.

140

BRIDGING NAVIGATION, SEARCH AND ADAPTATION. Adaptive Hypermedia Models Evolution  

E-Print Network [OSTI]

Corpus, Dexter Model, AHAM, GAF. Abstract: Adaptive Hypermedia Systems (AHS) have long been concentrating The most referenced (but certainly not only) Adaptive Hypermedia (AH) model dates back to 1999. Since AHAM/Hypermedia modelling from Dexter Model through AHAM to the proposed GAF model, out- line advantages of each framework

De Bra, Paul

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141

ORISE: Dose modeling and assessments  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory |CHEMPACK Mapping Application ORISECenterMakingDOEOakDose modeling

142

JOURNAL DE PHYSIQUE Colloque C6, supplement au no 7, Tome 4 1, Juillet 1980, page C6-344 Radiation induced color center and colloid formation in synthetic NaCl  

E-Print Network [OSTI]

crystals with apparatus for making optical absorption measurements during irradiation. Fcenter and colloid- tiques de NaCl avec un appareil permettant la mesure de I'absorption optique pendant I'irradiation. La d'irradiation et dc la dose totale, ainsi que des contraintes appliquees avant irradiation. Beaucoup

Paris-Sud XI, Université de

143

Organizational Adaptation Kathleen M. Carley  

E-Print Network [OSTI]

-humans. For example, they suggest that organizational learning resides not just in the minds of the personnel withinOrganizational Adaptation Kathleen M. Carley Dept. of Social and Decision Sciences Carnegie Mellon: Kathleen M. Carley, 1998, "Organizational Adaptation." Annals of Operations Research. 75: 25-47. #12

Sadeh, Norman M.

144

Adaptation, Learning, and Optimization over  

E-Print Network [OSTI]

Adaptation, Learning, and Optimization over Networks Ali H. Sayed University of California at Los 2014 A. H. Sayed DOI: 10.1561/2200000051 Adaptation, Learning, and Optimization over Networks Ali H . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.6 Notation and Symbols . . . . . . . . . . . . . . . . . . . . 8 2 Optimization by Single Agents

California at Los Angeles, University of

145

Adaptive Optics in Star Formation  

E-Print Network [OSTI]

Over the past ten years, the concept of adaptive optics has evolved from early experimental stages to a standard observing tool now available at almost all major optical and near-infrared telescope facilities. Adaptive optics will also be essential in exploiting the full potential of the large optical/infrared interferometers currently under construction. Both observations with high-angular resolution and at high contrast, and with a high point source sensitivity are facilitated by adaptive optics. Among the areas which benefit most from the use of adaptive optics are studies of the circumstellar environment (envelopes, disks, outflows), substellar companions and multiple systems, and dense young stellar populations. This contribution highlights some of the recent advances in star formation studies facilitated by adaptive optics, and gives a brief tutorial on optimized observing and data reduction strategies.

Wolfgang Brandner

2003-09-29T23:59:59.000Z

146

Irradiation of the prostate and pelvic lymph nodes with an adaptive algorithm  

SciTech Connect (OSTI)

Purpose: The simultaneous treatment of pelvic lymph nodes and the prostate in radiotherapy for prostate cancer is complicated by the independent motion of these two target volumes. In this work, the authors study a method to adapt intensity modulated radiation therapy (IMRT) treatment plans so as to compensate for this motion by adaptively morphing the multileaf collimator apertures and adjusting the segment weights. Methods: The study used CT images, tumor volumes, and normal tissue contours from patients treated in our institution. An IMRT treatment plan was then created using direct aperture optimization to deliver 45 Gy to the pelvic lymph nodes and 50 Gy to the prostate and seminal vesicles. The prostate target volume was then shifted in either the anterior-posterior direction or in the superior-inferior direction. The treatment plan was adapted by adjusting the aperture shapes with or without re-optimizing the segment weighting. The dose to the target volumes was then determined for the adapted plan. Results: Without compensation for prostate motion, 1 cm shifts of the prostate resulted in an average decrease of 14% in D-95%. If the isocenter is simply shifted to match the prostate motion, the prostate receives the correct dose but the pelvic lymph nodes are underdosed by 14% {+-} 6%. The use of adaptive morphing (with or without segment weight optimization) reduces the average change in D-95% to less than 5% for both the pelvic lymph nodes and the prostate. Conclusions: Adaptive morphing with and without segment weight optimization can be used to compensate for the independent motion of the prostate and lymph nodes when combined with daily imaging or other methods to track the prostate motion. This method allows the delivery of the correct dose to both the prostate and lymph nodes with only small changes to the dose delivered to the target volumes.

Hwang, A. B.; Chen, J.; Nguyen, T. B.; Gottschalk, A. G.; Roach, M. R. III; Pouliot, J. [Department of Radiation Oncology, University of California San Francisco, 1600 Divisadero Street, San Francisco, California 94143 (United States); Prowess Inc., Concord, California 94520 (United States); Department of Radiation Oncology, University of California San Francisco, 1600 Divisadero Street, San Francisco, California 94143 (United States)

2012-02-15T23:59:59.000Z

147

anthropometrically derived dosing: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 102 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

148

additional dose assessment: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 139 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

149

absorbed gamma dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

150

atoll dose assessment: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 89 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

151

absorbed dose profiles: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

152

astronaut absorbed dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

153

absorbed dose kerma: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

154

assess lung dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Morgan 68 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

155

avaliacao da dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 31 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

156

absorbed dose estimates: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NTS tests 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

157

absorbed doses: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

158

absorbed doses received: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

159

absorbed radiation dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

10 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

160

average absorbed doses: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

assessing organ doses: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 140 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

162

absorbed dose optimization: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

163

afterloading high dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

71 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

164

absorbed dose estimation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

NTS tests 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

165

absorbed glandular dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

166

absorbed dose metrology: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

167

affecting dose distributions: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 141 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

168

absorbed doses profiles: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

169

absorbed dose appears: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

170

absorbed dose computations: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

171

acenocoumarol dose based: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Jonathan 48 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

172

absorbed dose evaluation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Index 1 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

173

Adaptive excitation control in power systems  

E-Print Network [OSTI]

This thesis presents an adaptive excitation controller of power systems. The control law is derived by using model reference adaptive control (MRAC) or adaptive pole placement control (APPC) and an equilibrium tracking mechanism is implemented...

Chiu, Pei-Chen

2006-08-16T23:59:59.000Z

174

Multicriteria optimization of the spatial dose distribution  

SciTech Connect (OSTI)

Purpose: Treatment planning for radiation therapy involves trade-offs with respect to different clinical goals. Typically, the dose distribution is evaluated based on few statistics and dosevolume histograms. Particularly for stereotactic treatments, the spatial dose distribution represents further criteria, e.g., when considering the gradient between subregions of volumes of interest. The authors have studied how to consider the spatial dose distribution using a multicriteria optimization approach.Methods: The authors have extended a stepwise multicriteria optimization approach to include criteria with respect to the local dose distribution. Based on a three-dimensional visualization of the dose the authors use a software tool allowing interaction with the dose distribution to map objectives with respect to its shape to a constrained optimization problem. Similarly, conflicting criteria are highlighted and the planner decides if and where to relax the shape of the dose distribution.Results: To demonstrate the potential of spatial multicriteria optimization, the tool was applied to a prostate and meningioma case. For the prostate case, local sparing of the rectal wall and shaping of a boost volume are achieved through local relaxations and while maintaining the remaining dose distribution. For the meningioma, target coverage is improved by compromising low dose conformality toward noncritical structures. A comparison of dosevolume histograms illustrates the importance of spatial information for achieving the trade-offs.Conclusions: The results show that it is possible to consider the location of conflicting criteria during treatment planning. Particularly, it is possible to conserve already achieved goals with respect to the dose distribution, to visualize potential trade-offs, and to relax constraints locally. Hence, the proposed approach facilitates a systematic exploration of the optimal shape of the dose distribution.

Schlaefer, Alexander [Medical Robotics Group, Universitt zu Lbeck, Lbeck 23562, Germany and Institute of Medical Technology, Hamburg University of Technology, Hamburg 21073 (Germany)] [Medical Robotics Group, Universitt zu Lbeck, Lbeck 23562, Germany and Institute of Medical Technology, Hamburg University of Technology, Hamburg 21073 (Germany); Viulet, Tiberiu [Medical Robotics Group, Universitt zu Lbeck, Lbeck 23562 (Germany)] [Medical Robotics Group, Universitt zu Lbeck, Lbeck 23562 (Germany); Muacevic, Alexander; Frweger, Christoph [European CyberKnife Center Munich, Munich 81377 (Germany)] [European CyberKnife Center Munich, Munich 81377 (Germany)

2013-12-15T23:59:59.000Z

175

Dynamically accumulated dose and 4D accumulated dose for moving tumors  

SciTech Connect (OSTI)

Purpose: The purpose of this work was to investigate the relationship between dynamically accumulated dose (dynamic dose) and 4D accumulated dose (4D dose) for irradiation of moving tumors, and to quantify the dose uncertainty induced by tumor motion. Methods: The authors established that regardless of treatment modality and delivery properties, the dynamic dose will converge to the 4D dose, instead of the 3D static dose, after multiple deliveries. The bounds of dynamic dose, or the maximum estimation error using 4D or static dose, were established for the 4D and static doses, respectively. Numerical simulations were performed (1) to prove the principle that for each phase, after multiple deliveries, the average number of deliveries for any given time converges to the total number of fractions (K) over the number of phases (N); (2) to investigate the dose difference between the 4D and dynamic doses as a function of the number of deliveries for deliveries of a 'pulsed beam'; and (3) to investigate the dose difference between 4D dose and dynamic doses as a function of delivery time for deliveries of a 'continuous beam.' A Poisson model was developed to estimate the mean dose error as a function of number of deliveries or delivered time for both pulsed beam and continuous beam. Results: The numerical simulations confirmed that the number of deliveries for each phase converges to K/N, assuming a random starting phase. Simulations for the pulsed beam and continuous beam also suggested that the dose error is a strong function of the number of deliveries and/or total deliver time and could be a function of the breathing cycle, depending on the mode of delivery. The Poisson model agrees well with the simulation. Conclusions: Dynamically accumulated dose will converge to the 4D accumulated dose after multiple deliveries, regardless of treatment modality. Bounds of the dynamic dose could be determined using quantities derived from 4D doses, and the mean dose difference between the dynamic dose and 4D dose as a function of number of deliveries and/or total deliver time was also established.

Li Heng; Li Yupeng; Zhang Xiaodong; Li Xiaoqiang; Liu Wei; Gillin, Michael T.; Zhu, X. Ronald [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2012-12-15T23:59:59.000Z

176

Autonomous adaptive acoustic relay positioning  

E-Print Network [OSTI]

We consider the problem of maximizing underwater acoustic data transmission by adaptively positioning an autonomous mobile relay so as to learn and exploit spatial variations in channel performance. The acoustic channel ...

Cheung, Mei Yi, S.M. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

177

COMMENTARY:Limits to adaptation  

SciTech Connect (OSTI)

An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

Preston, Benjamin L [ORNL

2013-01-01T23:59:59.000Z

178

Adaptive multiconfigurational wave functions  

SciTech Connect (OSTI)

A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

Evangelista, Francesco A., E-mail: francesco.evangelista@emory.edu [Department of Chemistry and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States)

2014-03-28T23:59:59.000Z

179

Hanford Environmental Dose Reconstruction Project Monthly Report  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demographics; agriculture; food habits; and environmental pathways and dose estimates. 3 figs.

Finch, S.M. (comp.)

1990-01-01T23:59:59.000Z

180

X-band EPR imaging as a tool for gradient dose reconstruction in irradiated bones  

SciTech Connect (OSTI)

Purpose: Various tools are currently available for dose reconstruction in individuals after accidental exposure to ionizing radiation. Among the available biological analyses, Monte Carlo simulations, and biophysical methods, such as electron paramagnetic resonance (EPR), the latter has proved its usefulness for retrospective dosimetry. Although EPR spectroscopy is probably the most sensitive technique, it does not provide spatial dosimetric data. This information is, however, highly desirable when steep dose gradient irradiations are involved. The purpose of this work was to explore the possibilities of EPR imaging (EPRI) for spatial dose reconstruction in irradiated biological material. Methods: X-band EPRI was used to reconstruct ex vivo the relative dose distribution in human bone samples and hydroxyapatite phantoms after irradiation with brachytherapy seeds or x rays. Three situations were investigated: Homogeneous, stepwise gradient, and continuous gradient irradiation. Results: EPRI gave a faithful relative spin density distribution in bone samples and in hydroxyapatite phantoms. Measured dose ratios were in close agreement with the actual delivered dose ratios. EPRI was able to distinguish the dose gradients induced by two different sources ({sup 125}I and {sup 192}Ir). However, the measured spatial resolution of the system was 1.9 mm and this appeared to be a limiting factor. The method could be improved by using new signal postprocessing strategies. Conclusions: This study demonstrates that EPRI can be used to assess the regional relative dose distribution in irradiated bone samples. The method is currently applicable to ex vivo measurements of small size samples with low variation in tissue density but is likely to be adapted for in vivo application using L-band EPRI.

Leveque, Philippe; Godechal, Quentin; Bol, Anne; Trompier, Francois; Gallez, Bernard [Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Institut de Surete Nucleaire et de Radioprotection, F-92262 Fontenay-aux-Roses (France); Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium)

2009-09-15T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Determination of radionuclides and pathways contributing to cumulative dose. Hanford Environmental Dose Reconstruction Project: Dose code recovery activities, Calculation 004  

SciTech Connect (OSTI)

A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows` milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

Napier, B.A.

1992-12-01T23:59:59.000Z

182

Matrix adaptation in discriminative vector quantization  

E-Print Network [OSTI]

. Gabriel Zachmann (Computer Graphics) #12;Matrix adaptation in discriminative vector quantization Petra

Zachmann, Gabriel

183

Regional Water Management: Adapting to Uncertain Water  

E-Print Network [OSTI]

Regional Water Management: Adapting to Uncertain Water Supply and Demand Jim Schneider, Ph · How Nebraska manages water · Dealing with uncertain water supplies: adaptive management #12;Regional-wide, systematic approach · Flexible--Adaptive Management Adaptive Manageme nt #12;Integrated Water Management

Nebraska-Lincoln, University of

184

An updated dose assessment for Rongelap Island  

SciTech Connect (OSTI)

We have updated the radiological dose assessment for Rongelap Island at Rongelap Atoll using data generated from field trips to the atoll during 1986 through 1993. The data base used for this dose assessment is ten fold greater than that available for the 1982 assessment. Details of each data base are presented along with details about the methods used to calculate the dose from each exposure pathway. The doses are calculated for a resettlement date of January 1, 1995. The maximum annual effective dose is 0.26 mSv y{sup {minus}1} (26 mrem y{sup {minus}1}). The estimated 30-, 50-, and 70-y integral effective doses are 0.0059 Sv (0.59 rem), 0.0082 Sv (0.82 rem), and 0.0097 Sv (0.97 rem), respectively. More than 95% of these estimated doses are due to 137-Cesium ({sup 137}Cs). About 1.5% of the estimated dose is contributed by 90-Strontium ({sup 90}Sr), and about the same amount each by 239+240-Plutonium ({sup 239+240}PU), and 241-Americium ({sup 241}Am).

Robison, W.L.; Conrado, C.L.; Bogen, K.T.

1994-07-01T23:59:59.000Z

185

Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny  

E-Print Network [OSTI]

Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny in the human Abstract To calculate the absorbed dose in the human lung due to inhaled radon progeny, ICRP focussed and secretory cells). The absorbed energy for alpha particles emitted by radon progeny in the human respiratory

Yu, K.N.

186

Dose reduction at nuclear power plants  

SciTech Connect (OSTI)

The collective dose equivalent at nuclear power plants increased from 1250 rem in 1969 to nearly 54,000 rem in 1980. This rise is attributable primarily to an increase in nuclear generated power from 1289 MW-y to 29,155 MW-y; and secondly, to increased average plant age. However, considerable variation in exposure occurs from plant to plant depending on plant type, refueling, maintenance, etc. In order to understand the factors influencing these differences, an investigation was initiated to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at light water plants. Objectives are to: identify high-dose maintenance tasks and related dose-reduction techniques; investigate utilization of high-reliability, low-maintenance equipment; recommend improved radioactive waste handling equipment and procedures; examine incentives for dose reduction; and compile an ALARA handbook.

Baum, J.W.; Dionne, B.J.

1983-01-01T23:59:59.000Z

187

Hanford Environmental Dose Reconstruction Project Monthly Report  

SciTech Connect (OSTI)

This monthly report summarizes the technical progress and project status for the Hanford Environmental Dose Reconstruction (HEDR) Project being conducted at Pacific Northwest Laboratory (PNL) under the direction of a Technical Steering Panel (TSP). The TSP is composed of experts in numerous technical fields related to this project and represents the interests of the public. The US Department of Energy (DOE) funds the project. The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks address each of the primary steps in the path from radioactive releases to dose estimates source terms, environmental transport, environmental monitoring data, demographics, agriculture, and food habits, and environmental pathways and dose estimates.

Finch, S.M. (comp.)

1990-05-01T23:59:59.000Z

188

Adaptive Liquid Crystal Windows  

SciTech Connect (OSTI)

Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft 1ft prototype panels for the worlds first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicrons patented e-Tint technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of power consumption by ALCWs allows for on-board power electronics for automatic matching of transmission through windows to varying climate conditions without drawing the power from the power grid. ALCWs are capable of transmitting more sunlight in winters to assist in heating and less sunlight in summers to minimize overheating. As such, they can change the window from being a source of energy loss to a source of energy gain. In addition, the scalable AMIs roll-to-roll process, proved by making 1ft 1ftALCW prototype panels, allows for cost-effective production of large-scale window panels along with capability to change easily their color and shape. In addition to architectural glazing in houses and commercial buildings, ALCWs can be used in other applications where control of sunlight is needed, such as green houses, used by commercial produce growers and botanical gardens, cars, aircrafts, etc.

Taheri, Bahman; Bodnar, Volodymyr

2011-12-31T23:59:59.000Z

189

Adaptive Sampling in Hierarchical Simulation  

SciTech Connect (OSTI)

We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

2007-07-09T23:59:59.000Z

190

Adaptive Optics for Large Telescopes  

SciTech Connect (OSTI)

The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

Olivier, S

2008-06-27T23:59:59.000Z

191

Training Adaptive Decision-Making.  

SciTech Connect (OSTI)

Adaptive Thinking has been defined here as the capacity to recognize when a course of action that may have previously been effective is no longer effective and there is need to adjust strategy. Research was undertaken with human test subjects to identify the factors that contribute to adaptive thinking. It was discovered that those most effective in settings that call for adaptive thinking tend to possess a superior capacity to quickly and effectively generate possible courses of action, as measured using the Category Generation test. Software developed for this research has been applied to develop capabilities enabling analysts to identify crucial factors that are predictive of outcomes in fore-on-force simulation exercises.

Abbott, Robert G.; Forsythe, James C.

2014-10-01T23:59:59.000Z

192

Adaptive constructive processes 1 Running head: Adaptive constructive processes  

E-Print Network [OSTI]

to a current environmental demand when automatic, learned responses are not elicited. Bartlett argued further of Psychology Harvard University Cambridge, Massachusetts 02138 phone: (617) 495-3856 fax: (617) 496-3122 e to be operating in any well-adapted organic response (1932, p. 201)". He further emphasized the importance of "the

Schacter, Daniel

193

Maintainable and Reusable Scientific Software Adaptation Democratizing Scientific Software Adaptation  

E-Print Network [OSTI]

.kang@samsung.com Eli Tilevich, Srinidhi Varadarajan, and Naren Ramakrishnan Center for High-End Computing Systems Dept resources to ensure its efficiency and reliability. Although adaptation patterns can be found in a sizable-oriented Pro- gramming; D.2.7 [Software Engineering]: Distribution, Maintenance, and Enhancement; D.2

Ramakrishnan, Naren

194

Hanford Environmental Dose Reconstruction Project monthly report  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction MDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in envirorunental pathways. epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering. radiation dosimetry. and cultural anthropology. Included are appointed members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data Demography, Food Consumption, and Agriculture; and Environmental Pathways and Dose Estimates.

McMakin, A.H., Cannon, S.D.; Finch, S.M. (comps.) [comps.

1992-09-01T23:59:59.000Z

195

Adaptive wiener image restoration kernel  

DOE Patents [OSTI]

A method and device for restoration of electro-optical image data using an adaptive Wiener filter begins with constructing imaging system Optical Transfer Function, and the Fourier Transformations of the noise and the image. A spatial representation of the imaged object is restored by spatial convolution of the image using a Wiener restoration kernel.

Yuan, Ding (Henderson, NV)

2007-06-05T23:59:59.000Z

196

BC Agriculture Climate Change Adaptation  

E-Print Network [OSTI]

BC Agriculture Climate Change Adaptation Risk + Opportunity Assessment Provincial Report #12;published March 2012 by the British Columbia Agriculture & Food Climate Action Initiative www.BCAgClimateAction.ca project funding provided by Agriculture and Agri-food Canada BC Ministry of Agriculture BC Ministry

Pedersen, Tom

197

BC Agriculture Climate Change Adaptation  

E-Print Network [OSTI]

BC Agriculture Climate Change Adaptation Risk + Opportunity Assessment Provincial Report executive summary #12;published March 2012 by the British Columbia Agriculture & Food Climate Action Initiative www.BCAgClimateAction.ca project funding provided by Agriculture and Agri-food Canada BC Ministry of Agriculture BC Ministry

Pedersen, Tom

198

Adaptive protection algorithm and system  

DOE Patents [OSTI]

An adaptive protection algorithm and system for protecting electrical distribution systems traces the flow of power through a distribution system, assigns a value (or rank) to each circuit breaker in the system and then determines the appropriate trip set points based on the assigned rank.

Hedrick, Paul (Pittsburgh, PA) [Pittsburgh, PA; Toms, Helen L. (Irwin, PA) [Irwin, PA; Miller, Roger M. (Mars, PA) [Mars, PA

2009-04-28T23:59:59.000Z

199

7, 72357275, 2007 Adaptive radiative  

E-Print Network [OSTI]

Discussions Two adaptive radiative transfer schemes for numerical weather prediction models V. Venema 1 , A numerical weather prediction (NWP) and climate models. The atmosphere and the land surface are complex-stream approximation. In most weather prediction models these parameterisation schemes are therefore called infre

Boyer, Edmond

200

Adaptive Radiotherapy for Locally Advanced Non-Small-Cell Lung Cancer Does Not Underdose the Microscopic Disease and has the Potential to Increase Tumor Control  

SciTech Connect (OSTI)

Purpose: To evaluate doses to the microscopic disease (MD) in adaptive radiotherapy (ART) for locally advanced non-small-cell lung cancer (NSCLC) and to model tumor control probability (TCP). Methods and Materials: In a retrospective planning study, three-dimensional conformal treatment plans for 13 patients with locally advanced NSCLC were adapted to shape and volume changes of the gross tumor volume (GTV) once or twice during conventionally fractionated radiotherapy with total doses of 66 Gy; doses in the ART plans were escalated using an iso-mean lung dose (MLD) approach compared to non-adapted treatment. Dose distributions to the volumes of suspect MD were simulated for a scenario with synchronous shrinkage of the MD and GTV and for a scenario of a stationary MD despite GTV shrinkage; simulations were performed using deformable image registration. TCP calculations considering doses to the GTV and MD were performed using three different models. Results: Coverage of the MD at 50 Gy was not compromised by ART. Coverage at 60 Gy in the scenario of a stationary MD was significantly reduced from 92% {+-} 10% to 73% {+-} 19% using ART; however, the coverage was restored by iso-MLD dose escalation. Dose distributions in the MD were sufficient to achieve a TCP >80% on average in all simulation experiments, with the clonogenic cell density the major factor influencing TCP. The combined TCP for the GTV and MD was 19.9% averaged over all patients and TCP models in non-adaptive treatment with 66 Gy. Iso-MLD dose escalation achieved by ART increased the overall TCP by absolute 6% (adapting plan once) and by 8.7% (adapting plan twice) on average. Absolute TCP values were significantly different between the TCP models; however, all TCP models suggested very similar TCP increase by using ART. Conclusions: Adaptation of radiotherapy to the shrinking GTV did not compromise dose coverage of volumes of suspect microscopic disease and has the potential to increase TCP by >40% compared with radiotherapy planning without ART.

Guckenberger, Matthias, E-mail: guckenberger_m@klinik.uni-wuerzburg.de [Department of Radiation Oncology, University Hospital Wuerzburg, Wuerzburg (Germany); Academic Unit of Radiotherapy and Oncology, Institute of Cancer Research, Sutton, Surrey (United Kingdom); Lung Unit, The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Richter, Anne; Wilbert, Juergen; Flentje, Michael [Department of Radiation Oncology, University Hospital Wuerzburg, Wuerzburg (Germany); Partridge, Mike [Joint Department of Physics, Institute of Cancer Research, Sutton, Surrey (United Kingdom)

2011-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

adaptive control algorithm: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

24 25 Next Page Last Page Topic Index 1 ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS Mathematics Websites Summary: ON AN ADAPTIVE CONTROL ALGORITHM FOR...

202

absorbed dose calculation: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 4 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

203

absorbed dose measurements: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2013-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

204

air dose absorbed: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2009-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

205

absorbed dose distribution: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

206

absorbed dose measurement: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2013-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

207

absorbed dose determination: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2012-06-07 5 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

208

absorbed dose effective: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 2 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

209

absorbed dose standard: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 4 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

210

absorbed doses distribution: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

211

absorbed dose distributions: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

212

absorbed dose rate: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 3 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

213

absorbed dose determinations: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2012-06-07 5 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

214

absorbed dose calculations: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2010-01-01 4 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

215

CLIMATE VULNERABILITY AND ADAPTATION STUDY FOR  

E-Print Network [OSTI]

CLIMATE VULNERABILITY AND ADAPTATION STUDY FOR CALIFORNIA Legal Analysis of Barriers's California Climate Change Center JULY 2012 CEC5002012019 Prepared for: California Energy Commission to that framework that would facilitate adaptation to climate change. Since such changes may be difficult

216

Climate Change Adaptation Planning | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Change Adaptation Planning Climate Change Adaptation Planning October 7, 2014 6:00AM CDT to October 9, 2014 3:00PM CDT Norman, Oklahoma This course provides an introduction to...

217

IIR algorithms for adaptive line enhancement  

SciTech Connect (OSTI)

We introduce a simple IIR structure for the adaptive line enhancer. Two algorithms based on gradient-search techniques are presented for adapting the structure. Results from experiments which utilized real data as well as computer simulations are provided.

David, R.A.; Stearns, S.D.; Elliott, G.R.; Etter, D.M.

1983-01-01T23:59:59.000Z

218

Mechanics and Applications of Pressure Adaptive Honeycomb  

E-Print Network [OSTI]

A pressure-adaptive wing structure is presented that relies on the pressure-altitude relation to adapt the wing shape to the various flight conditions (e.g. landing and cruise). This structure employs conventional, certified ...

Vos, Roelof

2009-07-31T23:59:59.000Z

219

Adaptive security systems -- Combining expert systems with adaptive technologies  

SciTech Connect (OSTI)

The Adaptive Multisensor Integrated Security System (AMISS) uses a variety of computational intelligence techniques to reason from raw sensor data through an array of processing layers to arrive at an assessment for alarm/alert conditions based on human behavior within a secure facility. In this paper, the authors give an overview of the system and briefly describe some of the major components of the system. This system is currently under development and testing in a realistic facility setting.

Argo, P.; Loveland, R.; Anderson, K. [and others

1997-09-01T23:59:59.000Z

220

Adaptation in constant utility nonstationary environments  

E-Print Network [OSTI]

Adaptation in constant utility nonstationary environments Michael L. Littman & David H. Ackley Abstract Environments that vary over time present a fundamental problem to adaptive systems. Although adaptive opportunities. We consider a broad class of nonstationary environments, those which combine

Littman, Michael L.

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Anisotropic Grid Adaptation for Multiple Aerodynamic Outputs  

E-Print Network [OSTI]

Anisotropic Grid Adaptation for Multiple Aerodynamic Outputs David A. Venditti and David L Anisotropic gridadaptive strategies are presented for viscous flow simulations in which the accurate estimation and Hessian-based anisotropic grid adaptation. Airfoil test cases are presented to demonstrate

Peraire, Jaime

222

Article original Adaptation digestive du lapin  

E-Print Network [OSTI]

Article original Adaptation digestive du lapin la teneur en constituants paritaux du rgime ne diffre pas d'un rgime l'autre, du fait d'une rgulation de l'nergie digestible ingre. L le rgime B. lapin / digestion / fibre / adaptation / transit Summary Digestive adaptation

Boyer, Edmond

223

E-Print Network 3.0 - adaptive systems Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

adaptive systems Page: << < 1 2 3 4 5 > >> 1 From Adaptive Hypermedia to the Adaptive Web Systems Summary: 1 From Adaptive Hypermedia to the Adaptive Web Systems Peter...

224

Approach for calculating population doses using the CIDER computer code  

SciTech Connect (OSTI)

This report describes an approach for calculating radiation doses for the Hanford Environmental Dose Reconstruction Project. The approach utilizes the CIDER computer code.

Shipler, D.B.

1993-04-29T23:59:59.000Z

225

Calculation of extremity neutron fluence-to-dose equivalent conversion factors  

E-Print Network [OSTI]

) Figure 4. Comparison of NCRP 38 and Siebert and Schuhmacher quality factors. Table 2. PNNL dose equivalent averaged quality factors (Q). * Phantom Finger Wrist 30 cm ICRU sphere Composition PMMA PMMA Tissue-and-bone Tissue-and-bone PMMA PMMA... Tissue-and-bone Tissue-and-bone PM MA PMMA (???) 'Adapted from reference 53. Source Bare Cf Moderated Cf Bare Cf Moderated Cf Bare Cf Moderated Cf Bare Cf Moderated Cf Bare Cf Moderated Cf 9. 2 9. 7 9. 2 9. 7 9. 4 9. 7 9. 4 9. 7 10...

Wood-Zika, Annmarie Ruth

1997-01-01T23:59:59.000Z

226

Agriculture-related radiation dose calculations  

SciTech Connect (OSTI)

Estimates of radiation dose to the public must be made at each stage in the identification and qualification process leading to siting a high-level nuclear waste repository. Specifically considering the ingestion pathway, this paper examines questions of reliability and adequacy of dose calculations in relation to five stages of data availability (geologic province, region, area, location, and mass balance) and three methods of calculation (population, population/food production, and food production driven). Calculations were done using the model PABLM with data for the Permian and Palo Duro Basins and the Deaf Smith County area. Extra effort expended in gathering agricultural data at succeeding environmental characterization levels does not appear justified, since dose estimates do not differ greatly; that effort would be better spent determining usage of food types that contribute most to the total dose; and that consumption rate and the air dispersion factor are critical to assessment of radiation dose via the ingestion pathway. 17 refs., 9 figs., 32 tabs.

Furr, J.M.; Mayberry, J.J.; Waite, D.A.

1987-10-01T23:59:59.000Z

227

DRY TRANSFER FACILITY WORKER DOSE ASSESSMENT  

SciTech Connect (OSTI)

The purpose of this calculation is to estimate radiation doses received by personnel working in the Dry Transfer Facility No.1 (DTF-1) performing operations to receive transportation casks, transfer wastes, prepare waste packages, and ship out loaded waste packages and empty casks. Doses received by workers due to maintenance operations are also included in this revision. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation, excluding the remediation area of the building. The results of this calculation will be used to support the design of the DTF-1 and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in the Environmental and Nuclear Engineering.

J.S. Tang

2004-09-23T23:59:59.000Z

228

adapter protein tsad: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ecosystem Adaptive Management Environmental Sciences and Ecology Websites Summary: ;2 Baltic Ecosystem Adaptive Management, BEAM, r ett tvrvetenskapligt...

229

adaptive antitumor immunity: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ecosystem Adaptive Management Environmental Sciences and Ecology Websites Summary: ;2 Baltic Ecosystem Adaptive Management, BEAM, r ett tvrvetenskapligt...

230

adaptation azole drug: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ecosystem Adaptive Management Environmental Sciences and Ecology Websites Summary: ;2 Baltic Ecosystem Adaptive Management, BEAM, r ett tvrvetenskapligt...

231

Extended range radiation dose-rate monitor  

DOE Patents [OSTI]

An extended range dose-rate monitor is provided which utilizes the pulse pileup phenomenon that occurs in conventional counting systems to alter the dynamic response of the system to extend the dose-rate counting range. The current pulses from a solid-state detector generated by radiation events are amplified and shaped prior to applying the pulses to the input of a comparator. The comparator generates one logic pulse for each input pulse which exceeds the comparator reference threshold. These pulses are integrated and applied to a meter calibrated to indicate the measured dose-rate in response to the integrator output. A portion of the output signal from the integrator is fed back to vary the comparator reference threshold in proportion to the output count rate to extend the sensitive dynamic detection range by delaying the asymptotic approach of the integrator output toward full scale as measured by the meter.

Valentine, Kenneth H. (Knoxville, TN)

1988-01-01T23:59:59.000Z

232

Historical river flow rates for dose calculations  

SciTech Connect (OSTI)

Annual average river flow rates are required input to the LADTAP Computer Code for calculating offsite doses from liquid releases of radioactive materials to the Savannah River. The source of information on annual river flow rates used in dose calculations varies, depending on whether calculations are for retrospective releases or prospective releases. Examples of these types of releases are: Retrospective - releases from routine operations (annual environmental reports) and short term release incidents that have occurred. Prospective - releases that might be expected in the future from routine or abnormal operation of existing or new facilities (EIS`s, EID`S, SAR`S, etc.). This memorandum provides historical flow rates at the downstream gauging station at Highway 301 for use in retrospective dose calculations and derives flow rate data for the Beaufort-Jasper and Port Wentworth water treatment plants.

Carlton, W.H.

1991-06-10T23:59:59.000Z

233

Center for Adaptive Optics* Santa Cruz,CA  

E-Print Network [OSTI]

Center for Adaptive Optics* Santa Cruz,CA The Center for Adaptive Optics (CfAO) will concentrate on astronomical and vision science applications of adaptive optics and will reach out to other adaptive optics communities to share technologies. It will develop new instruments optimized for adaptive optics. Adaptive

Grether, Gregory

234

FINAL REPORT DOSES TO THE PUBLIC  

E-Print Network [OSTI]

Oak Ridge, Inc. 102 Donner Drive Oak Ridge, Tennessee 37830 Authors: A. Iulian Apostoaei / SENES Oak Ridge, Inc. Brian A. Thomas / SENES Oak Ridge, Inc. David C. Kocher / SENES Oak Ridge, Inc. F. Owen Hoffman / SENES Oak Ridge, Inc. July 2005 #12;Doses to the Public from Atmospheric

235

NON-MONOTONIC DOSE DEPENDENCE OF THERMOLUMINESCENCE  

E-Print Network [OSTI]

Scientific Inc., Pacifica, CA, USA The thermoluminescence (TL) intensity in different materials is usually material used for archaeological and geological TL dating. Ichikawa(6) found that in gammaNON-MONOTONIC DOSE DEPENDENCE OF THERMOLUMINESCENCE R. Chen1,? , D. Lo2 and J. L. Lawless3 1 School

Chen, Reuven

236

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear EnergyTransfer Ionizing Radiation Exposure  

E-Print Network [OSTI]

Human In vivo Dose-Response to Controlled, Low-Dose Low Linear EnergyTransfer Ionizing Radiation Purpose: The effect of low doses of low ^ linear energy transfer (photon) ionizing radiation (LDIR, and pathway. Conclusions: These results show for the first time that low doses of radiation have an identifi

Rocke, David M.

237

Issues in adaptive mesh refinement  

SciTech Connect (OSTI)

In this paper, we present an approach for a patch-based adaptive mesh refinement (AMR) for multi-physics simulations. The approach consists of clustering, symmetry preserving, mesh continuity, flux correction, communications, and management of patches. Among the special features of this patch-based AMR are symmetry preserving, efficiency of refinement, special implementation offlux correction, and patch management in parallel computing environments. Here, higher efficiency of refinement means less unnecessarily refined cells for a given set of cells to be refined. To demonstrate the capability of the AMR framework, hydrodynamics simulations with many levels of refinement are shown in both two- and three-dimensions.

Dai, William Wenlong [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

238

Total dose and dose rate models for bipolar transistors in circuit simulation.  

SciTech Connect (OSTI)

The objective of this work is to develop a model for total dose effects in bipolar junction transistors for use in circuit simulation. The components of the model are an electrical model of device performance that includes the effects of trapped charge on device behavior, and a model that calculates the trapped charge densities in a specific device structure as a function of radiation dose and dose rate. Simulations based on this model are found to agree well with measurements on a number of devices for which data are available.

Campbell, Phillip Montgomery; Wix, Steven D.

2013-05-01T23:59:59.000Z

239

Adapting Dry Cask Storage for Aging at a Geologic Repository  

SciTech Connect (OSTI)

A Spent Nuclear Fuel (SNF) Aging System is a crucial part of operations at the proposed Yucca Mountain repository in the United States. Incoming commercial SNF that does not meet thermal limits for emplacement will be aged on outdoor pads. U.S. Department of Energy SNF will also be managed using the Aging System. Proposed site-specific designs for the Aging System are closely based upon designs for existing dry cask storage (DCS) systems. This paper evaluates the applicability of existing DCS systems for use in the SNF Aging System at Yucca Mountain. The most important difference between existing DCS facilities and the Yucca Mountain facility is the required capacity. Existing DCS facilities typically have less than 50 casks. The current design for the aging pad at Yucca Mountain calls for a capacity of over 2,000 casks (20,000 MTHM) [1]. This unprecedented number of casks poses some unique problems. The response of DCS systems to off-normal and accident conditions needs to be re-evaluated for multiple storage casks. Dose calculations become more complicated, since doses from multiple or very long arrays of casks can dramatically increase the total boundary dose. For occupational doses, the geometry of the cask arrays and the order of loading casks must be carefully considered in order to meet ALARA goals during cask retrieval. Due to the large area of the aging pad, skyshine must also be included when calculating public and worker doses. The expected length of aging will also necessitate some design adjustments. Under 10 CFR 72.236, DCS systems are initially certified for a period of 20 years [2]. Although the Yucca Mountain facility is not intended to be a storage facility under 10 CFR 72, the operational life of the SNF Aging System is 50 years [1]. Any cask system selected for use in aging will have to be qualified to this design lifetime. These considerations are examined, and a summary is provided of the adaptations that must be made in order to use DCS technologies successfully at a geologic repository.

C. Sanders; D. Kimball

2005-08-02T23:59:59.000Z

240

Machine Learning for Adaptive Computer Game Opponents .  

E-Print Network [OSTI]

??This thesis investigates the use of machine learning techniques in computer games to create a computer player that adapts to its opponent's game-play. This includes (more)

Miles, Jonathan David

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

AN ADAPTIVE FINITE ELEMENT METHOD FOR THE ...  

E-Print Network [OSTI]

adaptive strategy is established for the diffraction grating problem, such that ...... applications in optical filters and guided mode resonance devices. the...

2014-05-20T23:59:59.000Z

242

Adaptive Barrier Strategies for Nonlinear Interior Methods  

E-Print Network [OSTI]

Feb 25, 2005 ... that adaptive choices, such as Mehrotra's probing procedure, outperform ... focus on the effects of merit functions or filters, and on regularization...

2005-02-25T23:59:59.000Z

243

Training for Climate Adaptation in Conservation  

Broader source: Energy.gov [DOE]

The Wildlife Conservation Society and the Northern Institute of Applied Climate Science are hosting this two-day training for climate adaptation.

244

Assessing Climate Change Impacts, Vulnerability and Adaptation...  

Open Energy Info (EERE)

The Case of Pantabangan-Carranglan Watershed Jump to: navigation, search Name Assessing Climate Change Impacts, Vulnerability and Adaptation: The Case of Pantabangan-Carranglan...

245

Mainstreaming Climate Change Adaptation into Development Planning...  

Open Energy Info (EERE)

Practitioners Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Mainstreaming Climate Change Adaptation into Development Planning: A Guide for Practitioners Agency...

246

Adapting California's water management to climate change  

E-Print Network [OSTI]

storage, water transfers, conservation, recycling, and desalination to meet changing demands. These same settlers had fewer intellectual, organizational, and economic resources to adapt than present

Pasternack, Gregory B.

247

Crosscutting Subsurface Initiative: Adaptive Control of Subsurface...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

in the ability to access, characterize, predict, and adaptively manipulate fracture and flow processes over scales from nanometers to kilometers. This town hall...

248

Dose reduction for snubber inspection and testing  

SciTech Connect (OSTI)

This paper reports that Health physics staff members at Grand Gulf Nuclear Station have implemented several dose reduction methods for snubber inspection, testing and changeout. These methods include construction maps to permit easy location of snubbers in the drywell, painting azimuth numbers on the inside drywell wall and biological shield wall to coincide with the maps, requiring pre-job briefings for quality inspectors and craft support personnel, using job history files for work planning, using experienced inspectors and craft personnel whenever possible, designating certain craft personnel solely for snubber work, and cutting out stuck snubber pins rather than attempting intact removal. The total dose for snubber-related tasks has been significantly reduced using these methods.

Morrison, G.M.; Cotton, S.R. (Entergy Operations, Inc. (US))

1991-10-01T23:59:59.000Z

249

Technical Note: Contrast solution density and cross section errors in inhomogeneity-corrected dose calculation for breast balloon brachytherapy  

SciTech Connect (OSTI)

Purpose: Recent recommendations by the American Association of Physicists in Medicine Task Group 186 emphasize the importance of understanding material properties and their effect on inhomogeneity-corrected dose calculation for brachytherapy. Radiographic contrast is normally injected into breast brachytherapy balloons. In this study, the authors independently estimate properties of contrast solution that were expected to be incorrectly specified in a commercial brachytherapy dose calculation algorithm. Methods: The mass density and atomic weight fractions of a clinical formulation of radiographic contrast solution were determined using manufacturers' data. The mass density was verified through measurement and compared with the density obtained by the treatment planning system's CT calibration. The atomic weight fractions were used to determine the photon interaction cross section of the contrast solution for a commercial high-dose-rate (HDR) brachytherapy source and compared with that of muscle. Results: The density of contrast solution was 10% less than that obtained from the CT calibration. The cross section of the contrast solution for the HDR source was 1.2% greater than that of muscle. Both errors could be addressed by overriding the density of the contrast solution in the treatment planning system. Conclusions: The authors estimate the error in mass density and cross section parameters used by a commercial brachytherapy dose calculation algorithm for radiographic contrast used in a clinical breast brachytherapy practice. This approach is adaptable to other clinics seeking to evaluate dose calculation errors and determine appropriate density override values if desired.

Kim, Leonard H.; Zhang Miao; Howell, Roger W.; Yue, Ning J.; Khan, Atif J. [Department of Radiation Oncology, University of Medicine and Dentistry of New Jersey: Robert Wood Johnson Medical School and Cancer Institute of New Jersey, New Brunswick, New Jersey 08903 (United States); Department of Radiology, University of Medicine and Dentistry of New Jersey: New Jersey Medical School, Newark, New Jersey 07103 (United States); Department of Radiation Oncology, University of Medicine and Dentistry of New Jersey: Robert Wood Johnson Medical School and Cancer Institute of New Jersey, New Brunswick, New Jersey 08903 (United States)

2013-01-15T23:59:59.000Z

250

Nominal Performance Biosphere Dose Conversion Factor Analysis  

SciTech Connect (OSTI)

The purpose of this report was to document the process leading to development of the Biosphere Dose Conversion Factors (BDCFs) for the postclosure nominal performance of the potential repository at Yucca Mountain. BDCF calculations concerned twenty-four radionuclides. This selection included sixteen radionuclides that may be significant nominal performance dose contributors during the compliance period of up to 10,000 years, five additional radionuclides of importance for up to 1 million years postclosure, and three relatively short-lived radionuclides important for the human intrusion scenario. Consideration of radionuclide buildup in soil caused by previous irrigation with contaminated groundwater was taken into account in the BDCF development. The effect of climate evolution, from the current arid conditions to a wetter and cooler climate, on the BDCF values was evaluated. The analysis included consideration of different exposure pathway's contribution to the BDCFs. Calculations of nominal performance BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. BDCFs for the nominal performance, when combined with the concentrations of radionuclides in groundwater allow calculation of potential radiation doses to the receptor of interest. Calculated estimates of radionuclide concentration in groundwater result from the saturated zone modeling. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA) to calculate doses to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain.

Wasiolek, Maryla A.

2000-12-21T23:59:59.000Z

251

Downhole tool adapted for telemetry  

DOE Patents [OSTI]

A cycleable downhole tool such as a Jar, a hydraulic hammer, and a shock absorber adapted for telemetry. This invention applies to other tools where the active components of the tool are displaced when the tool is rotationally or translationally cycled. The invention consists of inductive or contact transmission rings that are connected by an extensible conductor. The extensible conductor permits the transmission of the signal before, after, and during the cycling of the tool. The signal may be continuous or intermittent during cycling. The invention also applies to downhole tools that do not cycle, but in operation are under such stress that an extensible conductor is beneficial. The extensible conductor may also consist of an extensible portion and a fixed portion. The extensible conductor also features clamps that maintain the conductor under stresses greater than that seen by the tool, and seals that are capable of protecting against downhole pressure and contamination.

Hall, David R. (Provo, UT); Fox, Joe (Provo, UT)

2010-12-14T23:59:59.000Z

252

A fuzzy-tuned adaptive Kalman filter  

E-Print Network [OSTI]

In this paper, fuzzy processing is applied to the adaptive Kalman filter. The filter gain coefficients are adapted over a 50 dB range of unknown signal/noise dynamics, using fuzzy membership functions. Specific simulation results are shown for a...

Painter, John H.; Young Hwan Lho

1993-12-01T23:59:59.000Z

253

Outreach and Adaptive Strategies for Climate Change  

E-Print Network [OSTI]

Outreach and Adaptive Strategies for Climate Change: The Role of NOAA Sea Grant Extension years and generations about how to adapt to a changing climate. Effective preparation for possible effects of climate change includes engagement of resource managers, planners, public works officials

254

Adaptive Composite Map Projections Bernhard Jenny  

E-Print Network [OSTI]

Adaptive Composite Map Projections Bernhard Jenny Abstract--All major web mapping services use.The proposed composite map projection combines several projections that are recommended in cartographic.The composite projection adapts the maps geometry to scale, to the maps height-to-width ratio

Jenny, Bernhard

255

Enabling Informed Adaptation of Reformed Instructional Materials  

E-Print Network [OSTI]

Enabling Informed Adaptation of Reformed Instructional Materials Rachel E. Scherr and Andrew Elby 20742 USA Abstract. Instructors inevitably need to adapt even the best reform materials to suit instructors, and video clips of students working on the materials. Our materials thus facilitate their own

Elby, Andy

256

Adaptive Filtering of Multilingual Document Streams  

E-Print Network [OSTI]

the volume of new documents that must be examined by the user to manageable levels. This paper presents three techniques for extending adaptive monolingual text ltering techniques to manage multilingual document streamsAdaptive Filtering of Multilingual Document Streams Douglas W. Oard College of Library

Oard, Doug

257

WORKLOAD ADAPTATION IN AUTONOMIC DATABASE MANAGEMENT SYSTEMS  

E-Print Network [OSTI]

in Autonomic DBMSs", Proceedings of the 2nd International Workshop on Self-Managing Database Systems (SMDB 2007 to meet its Service Level Objectives (SLOs). It is a challenge to adapt multiple workloads with complex scheduler that performs workload adaptation in a DBMS, as the test bed to prove the effectiveness

258

Proceedings of the International Workshop on Adaptation,  

E-Print Network [OSTI]

Proceedings of the 1st International Workshop on Adaptation, Personalization and REcommendation. Carrero3 1 Universidad Autónoma de Madrid, Spain {ivan.cantador, david.vallet}@uam.es 2 Yahoo! Research.carrero}@uem.es #12;#12;Preface The 1st International Workshop on Adaptation, Personalization and REcommendation

Cantador, Iván

259

Adaptive Web Sites: Automatically Synthesizing Web Pages  

E-Print Network [OSTI]

Adaptive Web Sites: Automatically Synthesizing Web Pages Mike Perkowitz Oren Etzioni Department interfaces Abstract The creation of a complex web site is a thorny problem in user interface design. In IJCAI '97, we challenged the AI community to address this problem by creating adaptive web sites: sites

Etzioni, Oren

260

ORIGINAL ARTICLE Mitigation needs adaptation: Tropical forestry  

E-Print Network [OSTI]

ORIGINAL ARTICLE Mitigation needs adaptation: Tropical forestry and climate change Manuel R adapt to this change. This paper discusses how tropical forestry practices can contribute to maintaining Forestry Research, P.O. Box 6596 JKPWB, Jakarta 10065, Indonesia e-mail: m.guariguata@cgiar.org J. P

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

General Adaptive Replacement Policies Yannis Smaragdakis  

E-Print Network [OSTI]

General Adaptive Replacement Policies Yannis Smaragdakis College of Computing Georgia Institute of Technology yannis@cc.gatech.edu ABSTRACT We propose a general scheme for creating adaptive replace- ment any two existing replacement policies so that the resulting policy provably can never perform worse

Smaragdakis, Yannis

262

Adaptive Port Reduction in Static Condensation  

E-Print Network [OSTI]

Adaptive Port Reduction in Static Condensation JL Eftang DBP Huynh DJ Knezevic EM Rønquist a framework for adaptive reduction of the degrees of freedom associated with ports in static condensation (SC reduction for the interior of a component with model order reduction on the ports in order to rapidly

Rønquist, Einar M.

263

CT effective dose per dose length product using ICRP 103 weighting factors  

SciTech Connect (OSTI)

Purpose: To generate effective dose per unit dose length product (E/DLP) conversion factors incorporating ICRP Publication 103 tissue weighting factors. Methods: Effective doses for CT examinations were obtained using the IMPACT Dosimetry Calculator using all 23 dose data sets that are offered by this spreadsheet. CT examinations were simulated for scans performed along the patient long axis for each dosimetry data set using a 4 cm beam width ranging from the upper thighs to top of the head. Five basic body regions (head, neck, chest, abdomen, and pelvis), as well as combinations of the regions (head/neck, chest/abdomen, abdomen/pelvis, and chest/abdomen/pelvis) and whole body CT scans were investigated. Correction factors were generated that can be applied to convert E/DLP conversion factors based on ICRP 60 data to conversion factors that are valid for ICRP 103 data (i.e., E{sub 103}/E{sub 60}). Results: Use of ICRP 103 weighting factors increase effective doses for head scans by {approx}11%, for chest scans by {approx}20%, and decrease effective doses for pelvis scans by {approx}25%. Current E/DLP conversion factors are estimated to be 2.4 {mu}Sv/mGy cm for head CT examinations and range between 14 and 20 {mu}Sv/mGy cm for body CT examinations. Conclusions: Factors that enable patient CT doses to be adjusted to account for ICRP 103 tissue weighting factors are provided, which result in E/DLP factors that were increased in head and chest CT, reduced in pelvis CT, and showed no marked change in neck and abdomen CT.

Huda, Walter; Magill, Dennise; He Wenjun [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, South Carolina 29425 (United States); Department of Bioengineering, Clemson-MUSC Bioengineering Program, Clemson University, Charleston, South Carolina 29425 (United States)

2011-03-15T23:59:59.000Z

264

Disruptive Event Biosphere Dose Conversion Factor Analysis  

SciTech Connect (OSTI)

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed descriptions of the model input parameters, their development and the relationship between the parameters and specific features, events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2004 [DIRS 169671]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis''. The objective of this analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). For the volcanic ash exposure scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process model for this scenario uses the surface deposition of contaminated ash as the source of radionuclides in the biosphere. The initial atmospheric transport and dispersion of the ash as well as its subsequent redistribution by fluvial and aeolian processes are not addressed within the biosphere model. These processes influence the value of the source term that is calculated elsewhere and then combined with the BDCFs in the TSPA model to calculate expected dose to the receptor. Another objective of this analysis was to re-qualify the output of the previous revision (BSC 2003 [DIRS 163958]).

M. Wasiolek

2004-09-08T23:59:59.000Z

265

E-Print Network 3.0 - adaptive information processing Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

user (adaptable... .1 Adaptation and Adaptivity Even if ... Source: Oppermann, Reinhard - Fraunhofer-Institute for Applied Information Technology & Fachbereich Informatik,...

266

Ensuring the Availability and Reliability of Urea Dosing For...  

Broader source: Energy.gov (indexed) [DOE]

Ensuring the Availability and Reliability of Urea Dosing For On-Road and Non-Road Ensuring the Availability and Reliability of Urea Dosing For On-Road and Non-Road 2003 DEER...

267

arteries dose reduction: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

artery Price, Paul A. 8 a 50% reduction in Prlr gene dose, provides strong evidence for PRL being the mediator Geosciences Websites Summary: a 50% reduction in Prlr gene dose,...

268

Bounding the total-dose response of modern bipolar transistors  

SciTech Connect (OSTI)

The base current in modern bipolar transistors saturates at large total doses once a critical oxide charge is reached. The saturated value of base current is dose-rate independent. Testing implications are discussed.

Kosier, S.L.; Wei, A.; Schrimpf, R.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Combs, W.E. [Naval Surface Warfare Center-Crane, Crane, IN (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); DeLaus, M. [Analog Devices, Inc., Wilmington, MA (United States); Pease, R.L. [RLP Research, Albuquerque, NM (United States)

1994-03-01T23:59:59.000Z

269

Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations  

SciTech Connect (OSTI)

Purpose: In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. Methods: Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR{sup 60}Co and {sup 192}Ir sources and a hypothetical {sup 169}Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. Results: For a 5 cm 5 cm{sup 192}Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about ?3%. When the source was positioned at the skin surface, dose differences were smaller than ?1% for {sup 60}Co and {sup 192}Ir, yet ?3% for {sup 169}Yb. For the interstitial implant, dose differences at the skin surface were ?7% for {sup 60}Co, ?0.6% for {sup 192}Ir, and ?2.5% for {sup 169}Yb. Conclusions: This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either {sup 60}Co and {sup 192}Ir. For lower energy radionuclides like {sup 169}Yb, bolus may be needed; and (iii) for the interstitial case, at least a 0.1 cm bolus is advised for {sup 60}Co to avoid underdosing superficial target layers. For {sup 192}Ir and {sup 169}Yb, no bolus is needed. For those cases where no bolus is needed, its use might be detrimental as the lack of radiation scatter may be beneficial to the patient, although the 2% tolerance for dose calculation accuracy recommended in the AAPM TG-56 report is not fulfilled.

Granero, Domingo, E-mail: dgranero@eresa.com [Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia (Spain)] [Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia (Spain); Perez-Calatayud, Jose [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain)] [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, Javier [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980 (Spain)] [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980 (Spain); Ballester, Facundo [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain)] [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)] [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

2014-02-15T23:59:59.000Z

270

E-Print Network 3.0 - adaptive systems theory Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

systems theory Page: << < 1 2 3 4 5 > >> 1 From Adaptive Hypermedia to the Adaptive Web Systems Summary: 1 From Adaptive Hypermedia to the Adaptive Web Systems Peter...

271

Hanford Environmental Dose Reconstruction Project monthly report, February 1993  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project Is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demography, Food Consumption, and Agriculture; and Environmental Pathways and Dose Estimates.

Cannon, S.D.; Finch, S.M. (comps.)

1993-01-01T23:59:59.000Z

272

Hanford Environmental Dose Reconstruction Project monthly report, February 1993  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project Is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demography, Food Consumption, and Agriculture; and Environmental Pathways and Dose Estimates.

Cannon, S.D.; Finch, S.M. [comps.

1993-03-01T23:59:59.000Z

273

RIS-M-2254 ON A RADIOCHROMIC DYE DOSE METER  

E-Print Network [OSTI]

RIS?-M-2254 ON A RADIOCHROMIC DYE DOSE METER Arne Miller and William L. McLaughlin Abstract. Radiochromic dye dose meters made of polyvinyl butyral (PVB) with hexa(hydroxyethyl)pararosaniline cyanide (HPR results and outlines plans for further research on this dose meter. Currently the response is found

274

Real-time Molecular Study of Bystander Effects of Low dose Low LET radiation Using Living Cell Imaging and Nanoparticale Optics  

SciTech Connect (OSTI)

In this study two novel approaches are proposed to investigate precisely the low dose low LET radiation damage and its effect on bystander cells in real time. First, a flow shear model system, which would provide us a near in vivo situation where endothelial cells in the presence of extra cellular matrix experiencing continuous flow shear stress, will be used. Endothelial cells on matri-gel (simulated extra cellular matrix) will be subjected to physiological flow shear (that occurs in normal blood vessels). Second, a unique tool (Single nano particle/single live cell/single molecule microscopy and spectroscopy; Figure A) will be used to track the molecular trafficking by single live cell imaging. Single molecule chemical microscopy allows one to single out and study rare events that otherwise might be lost in assembled average measurement, and monitor many target single molecules simultaneously in real-time. Multi color single novel metal nanoparticle probes allow one to prepare multicolor probes (Figure B) to monitor many single components (events) simultaneously and perform multi-complex analysis in real-time. These nano-particles resist to photo bleaching and hence serve as probes for unlimited timeframe of analysis. Single live cell microscopy allows one to image many single cells simultaneously in real-time. With the combination of these unique tools, we will be able to study under near-physiological conditions the cellular and sub-cellular responses (even subtle changes at one molecule level) to low and very low doses of low LET radiation in real time (milli-second or nano-second) at sub-10 nanometer spatial resolution. This would allow us to precisely identify, at least in part, the molecular mediators that are responsible of radiation damage in the irradiated cells and the mediators that are responsible for initiating the signaling in the neighboring cells. Endothelial cells subjected to flow shear (2 dynes/cm2 or 16 dynes/cm2) and exposed to 0.1, 1 and 10 cGy on coverslips will be examined for (a) low LET radiation-induced alterations of cellular function and its physiological relevance in real time; and (b) radiation damage triggered bystander effect on the neighboring unirradiated cells. First, to determine the low LET radiation induced alteration of cellular function we will examine: (i) the real time transformation of single membrane transporters in single living cells; (ii) the pump efficiency of membrane efflux pump of live cells in real time at the molecular level; (iii) the kinetics of single-ligand receptor interaction on single live cell surface (Figure C); and (iv) alteration in chromosome replication in living cell. Second, to study the radiation triggered bystander responses, we will examine one of the key signaling pathway i.e. TNF- alpha/NF-kappa B mediated signaling. TNF-alpha specific nano particle sensors (green) will be developed to detect the releasing dynamics, transport mechanisms and ligand-receptor binding on live cell surface in real time. A second sensor (blue) will be developed to simultaneously monitor the track of NF-kB inside the cell. The proposed nano-particle optics approach would complement our DOE funded study on biochemical mechanisms of TNF-alpha- NF-kappa B-mediated bystander effect.

Natarajan, Mohan [UT Health Science Center at San Antonio; Xu, Nancy R [Old Dominion University; Mohan, Sumathy [UT Health Science Center at San Antonio

2013-06-03T23:59:59.000Z

275

Probing young massive clusters with laser guide star adaptive optics  

E-Print Network [OSTI]

laser guide star adaptive optics Nate McCrady Received: 10laser guide star adaptive optics (LGS/AO) on the 10 m Keckof 4 Mpc. Our adaptive optics work is motivated by three

McCrady, Nate

2009-01-01T23:59:59.000Z

276

Pacific Adaptation Strategy Assistance Program Dynamical Seasonal Forecasting  

E-Print Network [OSTI]

Pacific Adaptation Strategy Assistance Program Dynamical Seasonal Forecasting Seasonal Prediction · POAMA · Issues for future Outline #12;Pacific Adaptation Strategy Assistance Program Major source Adaptation Strategy Assistance Program El Nino Mean State · Easterlies westward surface current upwelling

Lim, Eun-pa

277

Nominal Performance Biosphere Dose Conversion Factor Analysis  

SciTech Connect (OSTI)

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standard. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. The objectives of this analysis are to develop BDCFs for the groundwater exposure scenario for the three climate states considered in the TSPA-LA as well as conversion factors for evaluating compliance with the groundwater protection standard. The BDCFs will be used in performance assessment for calculating all-pathway annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle activity in groundwater and the annual dose from drinking water for beta- and photon-emitting radionuclides. Another objective of this analysis was to re-qualify the output of the previous revision (BSC 2003 [DIRS 164403]).

M. Wasiolek

2004-09-08T23:59:59.000Z

278

Nominal Performance Biosphere Dose Conversion Factor Analysis  

SciTech Connect (OSTI)

This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the Total System Performance Assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the groundwater exposure scenario, and the development of conversion factors for assessing compliance with the groundwater protection standards. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop BDCFs, which are input parameters for the TSPA-LA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the ''Biosphere Model Report'' in Figure 1-1, contain detailed description of the model input parameters, their development, and the relationship between the parameters and specific features events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the groundwater exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and the five analyses that develop parameter values for the biosphere model (BSC 2005 [DIRS 172827]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis'' (Figure 1-1). The objectives of this analysis are to develop BDCFs for the groundwater exposure scenario for the three climate states (present day, monsoon, and glacial transition) considered in the TSPA-LA, as well as conversion factors for compliance evaluation with the groundwater protection standards. The BDCFs will be used in performance assessment for calculating all-pathway annual doses for a given concentration of radionuclides in groundwater. The conversion factors will be used for calculating gross alpha particle activity in groundwater and the annual dose from drinking water for beta- and photon-emitting radionuclides.

M.A. Wasiolek

2005-04-28T23:59:59.000Z

279

National Adaptation Forum Webinar Series: Out of Town, Not Out...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Adaptation Forum Webinar Series: Out of Town, Not Out of Trouble: Small Agriculture and Indigenous Communities National Adaptation Forum Webinar Series: Out of Town, Not Out of...

280

Farming in a Changing Climate: Agricultural Adaptation in Canada  

E-Print Network [OSTI]

Agricultural Adaptation in Canada Ellen Wall, Barry Smit,Agricultural Adaptation in Canada. Vancouver, BC: Universitythe agri-food sector in Canada, the insights provided are so

Jain, Varinder

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

adaptive signal processing: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING Int. J. Adapt. Control Signal Process. (in press) Engineering Websites Summary: predictive control 1....

282

adaptive predictive control: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

applied to analyze the transient Antsaklis, Panos 44 ADAPTIVE ROBUST TRACKING CONTROL OF PRESSURE Engineering Websites Summary: 1---- 1 ADAPTIVE ROBUST TRACKING CONTROL OF...

283

India-Vulnerability Assessment and Enhancing Adaptive Capacities...  

Open Energy Info (EERE)

Adaptive Capacities to Climate Change Jump to: navigation, search Name India-Vulnerability Assessment and Enhancing Adaptive Capacities to Climate Change AgencyCompany...

284

Software Adaptation Patterns for Service-Oriented Architectures .  

E-Print Network [OSTI]

??This thesis describes the concept of software adaptation patterns and how they can be used in software adaptation of service-oriented architectures. The patterns are described (more)

Hashimoto, Koji

2010-01-01T23:59:59.000Z

285

adaptive interactive technologies: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Shock-induced combustion Fluid-structure interaction Implementation Parallel Adaptive Cartesian Upwind Mathematics Websites Summary: Finite volume methods Adaptive mesh refinement...

286

Development of an adaptive fuzzy logic controller for HVAC system.  

E-Print Network [OSTI]

??An adaptive approach to control a cooling coil chilled water valve operation, called adaptive fuzzy logic control (AFLC), is developed and validated in this study. (more)

Navale, Rahul Laxman

2006-01-01T23:59:59.000Z

287

adaptive particle swarm: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Last Page Topic Index 1 An Adaptive Learning Particle Swarm Optimizer for Function Optimization Computer Technologies and Information Sciences Websites Summary: An Adaptive...

288

adaptive intrusion detection: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Last Page Topic Index 1 Adaptive Model Generation for Intrusion Detection Systems Computer Technologies and Information Sciences Websites Summary: Adaptive Model Generation for...

289

Improved dose estimates for nuclear criticality accidents  

SciTech Connect (OSTI)

Slide rules are improved for estimating doses and dose rates resulting from nuclear criticality accidents. The original slide rules were created for highly enriched uranium solutions and metals using hand calculations along with the decades old Way-Wigner radioactive decay relationship and the inverse square law. This work uses state-of-the-art methods and better data to improve the original slide rules and also to extend the slide rule concept to three additional systems; i.e., highly enriched (93.2 wt%) uranium damp (H/{sup 235}U = 10) powder (U{sub 3}O{sub 8}) and low-enriched (5 wt%) uranium mixtures (UO{sub 2}F{sub 2}) with a H/{sup 235}U ratio of 200 and 500. Although the improved slide rules differ only slightly from the original slide rules, the improved slide rules and also the new slide rules can be used with greater confidence since they are based on more rigorous methods and better nuclear data.

Wilkinson, A.D.; Basoglu, B.; Bentley, C.L.; Dunn, M.E.; Plaster, M.J.; Dodds, H.L. [Univ. of Tennessee, Knoxville, TN (United States). Nuclear Engineering Dept.; Haught, C.F. [Martin Marietta Utility Systems, Piketon, OH (United States); Yamamoto, T. [Japan Atomic Energy Research Inst., Tokai (Japan). Tokai Research Establishment; Hopper, C.M. [Oak Ridge National Lab., TN (United States)

1995-08-01T23:59:59.000Z

290

Misonidazole with dexamethasone rescue: an escalating dose toxicity study  

SciTech Connect (OSTI)

Neurotoxicity induced by misonidazole (MISO) and desmethylmisonidazole (DMM) has become the dose limiting factor in clinical work. In 1981, the authors reported a preliminary study suggestive that Dexamethasone (DEXA) does have a protective effect against peripheral neuropathies (PN) resulting from toxicity of misonidazole. The authors are presently investigating the use of DEXA, with escalating doses of MISO in an attempt to modify its neurotoxicity. To date, 16 patients have been registered to receive total doses of MISO given in 9 equally divided doses over 3 weeks. DEXA is given 3 days prior to the first dose and continues for the duration of therapy. All patients receive palliative radiation. No toxicity was seen at the total dose of 13.5 gm/M/sub 2/. One grade I PN occurred in the first four patients receiving 15.5 gm/M/sub 2/. Six additional patients were entered at this dose level and no further incidence of PN was observed.

Tanasichuk, H.; Urtasun, R.C.; Fulton, D.S.; Raleigh, J.

1984-09-01T23:59:59.000Z

291

accidental radiation-induced hematopoietic: Topics by E-print...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

solar and atmospheric neutrino oscillation, some of them can also induce neutrinoless double beta decay and mu- -- e+ conversion in nuclei large enough to be potentially...

292

acute radiation-induced proctosigmoiditis: Topics by E-print...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

solar and atmospheric neutrino oscillation, some of them can also induce neutrinoless double beta decay and mu- -- e+ conversion in nuclei large enough to be potentially...

293

Radiation induces turbulence in particle-laden fluids  

SciTech Connect (OSTI)

When a transparent fluid laden with solid particles is subject to radiative heating, non-uniformities in particle distribution result in local fluid temperature fluctuations. Under the influence of gravity, buoyancy induces vortical fluid motion which can lead to strong preferential concentration, enhancing the local heating and more non-uniformities in particle distribution. By employing direct numerical simulations this study shows that the described feedback loop can create and sustain turbulence. The velocity and length scale of the resulting turbulence is not known a priori, and is set by balance between viscous forces and buoyancy effects. When the particle response time is comparable to a viscous time scale, introduced in our analysis, the system exhibits intense fluctuations of turbulent kinetic energy and strong preferential concentration of particles.

Zamansky, Rmi [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Coletti, Filippo [Mechanical Engineering, Stanford University, California 94305-3035 (United States); Massot, Marc [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Ecole Centrale Paris, Laboratoire EM2C - UPR CNRS 288 et Fdration de Mathmatiques - FR CNRS 3487, Grande Voie des Vignes, 92295 Chatenay-Malabry Cedex (France); Mani, Ali [Centre for Turbulence Research, Stanford University, Stanford, California 94305-3035 (United States); Mechanical Engineering, Stanford University, California 94305-3035 (United States)

2014-07-15T23:59:59.000Z

294

Radiation-Induced Radicals in Polyurea-Crosslinked Silica Aerogel.  

E-Print Network [OSTI]

?? Free radicals are atoms or molecules with an odd number of electrons in an outer shell. Since electrons typically occur in pairs, this leaves (more)

Walters, Benjamin Michael

2014-01-01T23:59:59.000Z

295

Radiation induced by relativistic beams passing over a diffraction grating  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromising Science for1 20115,Performance QualityRadiation August

296

a-bisabolol induces dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

42 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

297

We can do better than effective dose for estimating or comparing low-dose radiation risks  

E-Print Network [OSTI]

of the radiation risks they are trying to control. ? 2012 ICRP. Published by Elsevier Ltd. All rights reserved Effective dose (ICRP, 1977) represents an attempt to provide a quantity which is proportional of the International Commission on Radiological Protection. 124 #12;and hereditary effects. Specifically, it is the sum

Brenner, David Jonathan

298

Oak Ridge Dose Reconstruction Project Summary Report; Reports of the Oak Ridge Dose Reconstruction, Vol. 7  

SciTech Connect (OSTI)

In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel of individuals appointed by Tennessee's Commissioner of Health. The panel requested that the principal investigator for the project prepare the following report, ''Oak Ridge Dose Reconstruction Project Summary Report,'' to serve the following purposes: (1) summarize in a single, less technical report, the methods and results of the various investigations that comprised the Phase II of the dose reconstruction; (2) describe the systematic searching of classified and unclassified historical records that was a vital component of the project; and (3) summarize the less detailed, screening-level assessments that were performed to evaluate the potential health significance of a number of materials, such a uranium, whose priority did not require a complete dose reconstruction effort. This report describes each major step of the dose reconstruction study: (1) the review of thousands of historical records to obtain information relating to past operations at each facility; (2) estimation of the quantity and timing of releases of radioiodines from X-10, of mercury from Y-12, of PCB's from all facilities, and of cesium-137 and other radionuclides from White Oak Creek; (3) evaluation of the routes taken by these contaminants through the environment to nearby populations; and (4) estimation of doses and health risks to exposed groups. Calculations found the highest excess cancer risks for a female born in 1952 who drank goat milk; the highest non-cancer health risk was for children in a farm family exposed to PCBs in and near East Fork Poplar Creek. More detailed dose and risk estimates, and associated uncertainties, are presented in several technical reports. One way to easily locate them in OSTI's Information Bridge is by searching the ''report number field'' for the number DOE/OR/21981*. The asterisk placed after the base number will enable the search to list all of the related reports in this series.

Thomas E. Widner; et. al.

1999-07-01T23:59:59.000Z

299

Adaptive Mesh Refinement and Relativistic MHD  

E-Print Network [OSTI]

We solve the general relativistic magnetohydrodynamics equations using distributed parallel adaptive mesh refinement. We discuss strong scaling tests of the code, and present evolutions of Michel accretion and a TOV star.

David Neilsen; Eric W. Hirschmann; Matthew Anderson; Steven L. Liebling

2007-02-06T23:59:59.000Z

300

Adaptive control of a generic hypersonic vehicle  

E-Print Network [OSTI]

This thesis presents a an adaptive augmented, gain-scheduled baseline LQR-PI controller applied to the Road Runner six-degree-of-freedom generic hypersonic vehicle model. Uncertainty in control effectiveness, longitudinal ...

Wiese, Daniel Philip

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Adaptive Reliability Analysis of Excavation Problems  

E-Print Network [OSTI]

. This analysis couples the adaptive design capabilities of the observational method with updated reliability indices, to be used in risk-based design decisions. A probabilistic framework is developed to predict three-dimensional deformation profiles due...

Park, Jun Kyung

2012-10-19T23:59:59.000Z

302

Scalable Adaptive Multilevel Solvers for Multiphysics Problems  

SciTech Connect (OSTI)

In this project, we investigated adaptive, parallel, and multilevel methods for numerical modeling of various real-world applications, including Magnetohydrodynamics (MHD), complex fluids, Electromagnetism, Navier-Stokes equations, and reservoir simulation. First, we have designed improved mathematical models and numerical discretizaitons for viscoelastic fluids and MHD. Second, we have derived new a posteriori error estimators and extended the applicability of adaptivity to various problems. Third, we have developed multilevel solvers for solving scalar partial differential equations (PDEs) as well as coupled systems of PDEs, especially on unstructured grids. Moreover, we have integrated the study between adaptive method and multilevel methods, and made significant efforts and advances in adaptive multilevel methods of the multi-physics problems.

Xu, Jinchao

2014-12-01T23:59:59.000Z

303

Optimization Online - Multistage Adaptive Robust Optimization for ...  

E-Print Network [OSTI]

Sep 5, 2014 ... ... with the increasing penetration of wind and solar power generation has ... Keywords: Electric energy systems, multistage robust optimization, ... Multistage Adaptive Robust Optimization for the Unit Commitment Problem.

Alvaro Lorca

2014-09-05T23:59:59.000Z

304

Anisotropic Grid Adaptation for Multiple Aerodynamic Outputs  

E-Print Network [OSTI]

Anisotropic gridadaptive strategies are presented for viscous flow simulations in which the accurate prediction of multiple aerodynamic outputs (such as the lift, drag, and moment coefficients) is required from a single ...

Venditti, David A.

305

Marginalized Monitoring: Adaptively Managing Urban Stormwater  

E-Print Network [OSTI]

environmental assessment, 28 Superfund decisionmaking, 29 Endangered Species Act decisionmaking, 30 and water management.Environmental Impacts Under Florida Water Law: From Water Wars Towards Adaptive Management ,water infrastructure problems. And yet, the environmental management

Scanlan, Melissa K; Tai, Stephanie

2013-01-01T23:59:59.000Z

306

Fast Adaptive Silhouette Area based Template Matching  

E-Print Network [OSTI]

Fast Adaptive Silhouette Area based Template Matching Daniel Mohr and Gabriel Zachmann If (Technical Informatics and Computer Systems) Prof. Dr. Gabriel Zachmann (Computer Graphics) Prof. Dr Template Matching Daniel Mohr and Gabriel Zachmann Clausthal University of Technology, Department

Zachmann, Gabriel

307

A Logical Characterization of Adaptive Educational Hypermedia  

E-Print Network [OSTI]

reference models for adaptive hypermedia, e.g. the AHAM Reference Model [4], or the Munich Reference Model [20]. Both, the AHAM and Munich Reference Model, extend the Dexter Hypertext Model [16], and pro- vide

Henze, Nicola

308

Adaptive Importance Sampling via Stochastic Convex Programming  

E-Print Network [OSTI]

Adaptive Importance Sampling via Stochastic Convex Programming Ernest K. Ryu1 and Stephen P. Boyd1 Abstract We show that the variance of the Monte Carlo estimator that is importance sam- pled from

309

Developmental Plasticity Links Local Adaptation and Evolutionary  

E-Print Network [OSTI]

Developmental Plasticity Links Local Adaptation and Evolutionary Diversification in Foraging, University of Arizona, Tucson, Arizona Developmental plasticity is thought to reconcile the constraining role morphology into adulthood, providing an opportunity to directly examine the links between plasticity of bone

Badyaev, Alex

310

Adaptive control for optimizing microalgae production  

E-Print Network [OSTI]

Adaptive control for optimizing microalgae production Francis Mairet Rafael Mu for light-limited microalgae culture. This controller regulates the light absorption factor, defined productivity under day-night cycles. Keywords: Nonlinear controller, Microalgae, Optimization, Biomass

Paris-Sud XI, Universit de

311

Exponential convergence with adaptive Monte Carlo  

SciTech Connect (OSTI)

For over a decade, it has been known that exponential convergence on discrete transport problems was possible using adaptive Monte Carlo techniques. Now, exponential convergence has been empirically demonstrated on a spatially continuous problem.

Booth, T.E.

1997-11-01T23:59:59.000Z

312

Challenges of Adapting to a Changing Climate  

E-Print Network [OSTI]

of Global Climate Change on Agriculture: An Interpretiveon U.S. Agriculture, in THE IMPACT OF CLIMATE CHANGE ON THEclimate change and the potential roles for adaptation are more severe for ecosystems than they are for managed systems like agriculture.

Hurd, Brian H.

2008-01-01T23:59:59.000Z

313

Robust adaptive control of switched systems  

E-Print Network [OSTI]

In this thesis, robust adaptive controllers are developed for classes of switched nonlinear systems. Switched systems are those governed by differential equations, which undergo vector field switching due to sudden changes ...

El-Rifai, Khalid, 1979-

2007-01-01T23:59:59.000Z

314

Convert! : the adaptive reuse of churches  

E-Print Network [OSTI]

This thesis examines the phenomenon of vacated churches and analyzes the major issues underlying their adaptive reuse in order to help promulgate an awareness of the range of successful strategies and solutions that are ...

Kiley, Christopher John, 1972-

2004-01-01T23:59:59.000Z

315

Climate Change: High Water Impacts and Adaptation  

E-Print Network [OSTI]

Climate Change: High Water Impacts and Adaptation David S. Liebl and Kenneth W. Potter Co of global climate change­ WICCI Stormwater Working Group #12;Projected Climate Change 200-2100 What Global

Sheridan, Jennifer

316

Skeletal adaptation to reduced mechanical loading  

E-Print Network [OSTI]

Bone adapts its mass and architecture in response to its mechanical environment. Yet control of this process by mechanical cues is poorly understood, particularly for unloading. Defining the fundamental mechanoregulation ...

Eliman, Rachel

2014-01-01T23:59:59.000Z

317

Adaptive sampling in autonomous marine sensor networks  

E-Print Network [OSTI]

In this thesis, an innovative architecture for real-time adaptive and cooperative control of autonomous sensor platforms in a marine sensor network is described in the context of the autonomous oceanographic network scenario. ...

Eickstedt, Donald Patrick

2006-01-01T23:59:59.000Z

318

Adaptive gain improves reactor control  

SciTech Connect (OSTI)

An interesting application of the modern control theory technique called adaptive control is presently in use on a process located at a plant in the Standard Oil Co. (Ind.) system. The results of this application are: first, the transformation of an uncontrollable process to a controllable one; and, second, a significant economic savings to the corporation. It also shows that a detailed analysis of the mechanical, chemical and control systems can provide both the basis for revising an existing control system and some of the reasons why that system is inadequate. The contrast between classical and modern control theories is seen in four major areas. In classical systems, the controller manipulates the error to calculate its output. The error is subjected to a limited number of analog computing functions such as multiplication by a constant and integration. Each controller has one specific strategy--to hold the measured variable at the setpoint. And each controller controls only one variable, independent of all others. In a modern system, the controller can manipulate many different variables in addition to the error to compute its output. Its computing power is unlimited in a practical sense. It can do all classical computations plus many others, including a table look-up. The controller can independently change its strategy as a function of time or the condition of the process. It can also control many variables at one time to accomplish a complex objective. The implementation of a modern control theory project requires a good understanding of the dynamic, as well as the steady-state character of the process. As you can see we are limited only by our understanding of the process, our imagination, and the economics of the situation.

Whatley, M.J.; Pott, D.C.

1984-05-01T23:59:59.000Z

319

Factors for converting dose measured in polystyrene phantoms to dose reported in water phantoms for incident proton beams  

SciTech Connect (OSTI)

Purpose: Previous dosimetry protocols allowed calibrations of proton beamline dose monitors to be performed in plastic phantoms. Nevertheless, dose determinations were referenced to absorbed dose-to-muscle or absorbed dose-to-water. The IAEA Code of Practice TRS 398 recommended that dose calibrations be performed with ionization chambers only in water phantoms because plastic-to-water dose conversion factors were not available with sufficient accuracy at the time of its writing. These factors are necessary, however, to evaluate the difference in doses delivered to patients if switching from calibration in plastic to a protocol that only allows calibration in water. Methods: This work measured polystyrene-to-water dose conversion factors for this purpose. Uncertainties in the results due to temperature, geometry, and chamber effects were minimized by using special experimental set-up procedures. The measurements were validated by Monte Carlo simulations. Results: At the peak of non-range-modulated beams, measured polystyrene-to-water factors ranged from 1.015 to 1.024 for beams with ranges from 36 to 315 mm. For beams with the same ranges and medium sized modulations, the factors ranged from 1.005 to 1.019. The measured results were used to generate tables of polystyrene-to-water dose conversion factors. Conclusions: The dose conversion factors can be used at clinical proton facilities to support beamline and patient specific dose per monitor unit calibrations performed in polystyrene phantoms.

Moyers, M. F.; Vatnitsky, A. S.; Vatnitsky, S. M. [Loma Linda University Medical Center, Loma Linda, California 92354 (United States); Guthrie Clinic/Robert Packard Hospital, Sayre, Pennsylvania 18840 (United States); EBG MedAustron, Wiener Neustadt, Austria A2700 (Austria)

2011-10-15T23:59:59.000Z

320

Fully Adaptive AMG Scott MacLachlan  

E-Print Network [OSTI]

" Ah "-1 ik ff Energy measure: Let G (i) j = (Ah )-1 ij , Sij = G(i) - G (i) j e(j) Ah G(i) Ah Fully, Sij? Apply (localized) relaxation to Ah G(i) = e(i) Fully Adaptive AMG ­ p.11 #12;Approximating Sij to Ah G(i) = e(i) Weighted Jacobi, 1 step: Fully Adaptive AMG ­ p.11 #12;Approximating Sij Can

MacLachlan, Scott

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

The Durham ELT adaptive optics simulation platform  

E-Print Network [OSTI]

Adaptive optics systems are essential on all large telescopes where image quality is important. These are complex systems with many design parameters requiring optimisation before good performance can be achieved. The simulation of adaptive optics systems is therefore necessary to categorise the expected performance. This paper describes an adaptive optics simulation platform, developed at Durham University, which can be used to simulate adaptive optics systems on the largest proposed future extremely large telescopes (ELTs) as well as current systems. This platform is modular, object oriented and has the benefit of hardware application acceleration which can be used to improve the simulation performance, essential for ensuring that the run time of a given simulation is acceptable. The simulation platform described here can be highly parallelised using parallelisation techniques suited for adaptive optics simulation, whilst still offering the user complete control while the simulation is running. Results from the simulation of a ground layer adaptive optics system are provided as an example to demonstrate the flexibility of this simulation platform.

Alastair Basden; Timothy Butterley; Richard Myers; Richard Wilson

2006-11-09T23:59:59.000Z

322

PhotoPhoto--and Radiation Induced Processesand Radiation Induced Processes ** Research Focus in PhotochemistryResearch Focus in Photochemistry  

E-Print Network [OSTI]

--term storage of solar energy as fuels or valuable chemicalsterm storage of solar energy as fuels or valuable

323

Occupational dose estimates for a monitored retrievable storage facility  

SciTech Connect (OSTI)

Occupational doses were estimated for radiation workers at the monitored retrievable storage (MRS) facility. This study provides an estimate of the occupational dose based on the current MRS facility design, examines the extent that various design parameters and assumptions affect the dose estimates, and identifies the areas and activities where exposures can be reduced most effectively. Occupational doses were estimated for both the primary storage concept and the alternate storage concept. The dose estimates indicate the annual dose to all radiation workers will be below the 5 rem/yr federal dose equivalent limit. However, the estimated dose to most of the receiving and storage crew (the workers responsible for the receipt, storage, and surveillance of the spent fuel and its subsequent retrieval), to the crane maintenance technicians, and to the cold and remote maintenance technicians is above the design objective of 1 rem/yr. The highest annual dose is received by the riggers (4.7 rem) in the receiving and storage crew. An indication of the extent to which various design parameters and assumptions affect the dose estimates was obtained by changing various design-based assumptions such as work procedures, background dose rates in radiation zones, and the amount of fuel received and stored annually. The study indicated that a combination of remote operations, increased shielding, and additional personnel (for specific jobs) or changes in operating procedures will be necessary to reduce worker doses below 1.0 rem/yr. Operations that could be made at least partially remote include the removal and replacement of the tiedowns, impact limiters, and personnel barriers from the shipping casks and the removal or installation of the inner closure bolts. Reductions of the background dose rates in the receiving/shipping and the transfer/discharge areas may be accomplished with additional shielding.

Harty, R.; Stoetzel, G.A.

1986-06-01T23:59:59.000Z

324

DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR  

E-Print Network [OSTI]

DCS1800/WCDMA ADAPTIVE VOLTAGE-CONTROLLED OSCILLATOR Aleksandar Tasi, Wouter A. Serdijn and John R, an adaptive 2G/3G voltage-controlled oscillator (VCO) is described in this paper. For the DCS1800 operation with this reasoning, an adaptive 2G/3G voltage- controlled oscillator, meant for a dual-standard adaptive front

Serdijn, Wouter A.

325

IEEE INFOCOM 2001 1 Pricing Network Resources for Adaptive  

E-Print Network [OSTI]

, and provides a natural and equitable incentive for applications to adapt their service contract according

Wang, Xin

326

Radiation dose rates from UF{sub 6} cylinders  

SciTech Connect (OSTI)

This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

Friend, P.J. [Urenco, Capenhurst (United Kingdom)

1991-12-31T23:59:59.000Z

327

Further evaluation of dose estimation using the FBX dosimeter  

E-Print Network [OSTI]

offset and general discrep- ancy between the expected dose and the one measured by the FBX dosimeter. To determine the origin of these anomalies, the dosimeter was used in intimate mixtures with tritiated water, HTO, iodine crystals, and various dilute... iodine solutions. When mixed with HTO, the doses measured by the FBX solution were in better agree- ment with the doses predicted by MIRD techniques than the measurements with I. In 131 subsequent mixtures with stable iodine crystals, the dosimeter...

Helfinstine, Suzanne Yvette

1988-01-01T23:59:59.000Z

328

Guidance on Dose Rate Measurements for Use in Dose-to-Curie Conversions  

SciTech Connect (OSTI)

The dose-to-curie (DTC) methodology used at SRS was developed in early 1994 by Health Physics Technology (HPT) for inclusion in the Site Waste Information Tracking System (WITS). DTC is used to estimate the nuclide activity in a waste container based on the measured dose rate from the container. The DTC method is a simple and easy to apply method that can provide a reasonable estimate of the container activity by nuclide when properly applied. In order to make the method practical, numerous assumptions had to be made and limitations placed on its use. Many of these assumptions and limitations can only be procedurally controlled and must be well understood by these individuals in order to assure proper application numerous the method. These limitations are addressed in this report.

Howell, R.S.

2000-09-05T23:59:59.000Z

329

E-Print Network 3.0 - anticipated radiological dose Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

- thropomorphic models. II. Organ doses from computed tomographic examinations in pediatric radiology. Neuherberg... dose at CT in pediatric patients. Radiology...

330

Adaptive Plasticity and Plasticity as an Adaptation: A Selective Review of Plasticity in Animal Morphology and Life History  

E-Print Network [OSTI]

Adaptive Plasticity and Plasticity as an Adaptation: A Selective Review of Plasticity in Animal wide-ranging. All key REVIEW references should be cited. A summary is required. Adaptive plasticity and plasticity as an adaptation: a selective review of plasticity in animal morphology and life history Karl

Gotthard, Karl

331

Adaptive method with intercessory feedback control for an intelligent agent  

DOE Patents [OSTI]

An adaptive architecture method with feedback control for an intelligent agent provides for adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. An adaptive architecture method with feedback control for multiple intelligent agents provides for coordinating and adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. Re-programming of the adaptive architecture is through a nexus which coordinates reflexive and deliberator components.

Goldsmith, Steven Y.

2004-06-22T23:59:59.000Z

332

Developing Quality Assurance Processes for Image-Guided Adaptive Radiation Therapy  

SciTech Connect (OSTI)

Quality assurance has long been implemented in radiation treatment as systematic actions necessary to provide adequate confidence that the radiation oncology service will satisfy the given requirements for quality care. The existing reports from the American Association of Physicists in Medicine Task Groups 40 and 53 have provided highly detailed QA guidelines for conventional radiotherapy and treatment planning. However, advanced treatment processes recently developed with emerging high technology have introduced new QA requirements that have not been addressed previously in the conventional QA program. Therefore, it is necessary to expand the existing QA guidelines to also include new considerations. Image-guided adaptive radiation therapy (IGART) is a closed-loop treatment process that is designed to include the individual treatment information, such as patient-specific anatomic variation and delivered dose assessed during the therapy course in treatment evaluation and planning optimization. Clinical implementation of IGART requires high levels of automation in image acquisition, registration, segmentation, treatment dose construction, and adaptive planning optimization, which brings new challenges to the conventional QA program. In this article, clinical QA procedures for IGART are outlined. The discussion focuses on the dynamic or four-dimensional aspects of the IGART process, avoiding overlap with conventional QA guidelines.

Yan Di [Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (United States)], E-mail: dyan@beaumont.edu

2008-05-01T23:59:59.000Z

333

Hanford Environmental Dose Reconstruction Project. Monthly report, June 1992  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

Finch, S.M.; McMakin, A.H. [comps.

1992-06-01T23:59:59.000Z

334

how many doses can you miss before resistance emerges?  

E-Print Network [OSTI]

Title: Adherence to antiretroviral HIV drugs: how many doses can you miss before resistance emerges? Abstract. The emergence of drug resistance is one of the...

335

ascending dose study: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Masahiko; Saito, Kimiaki 2015-01-01 72 Environmental Radioactivity 56 (2001) 327340 Radon progeny dose conversion coefficients for Biology and Medicine Websites Summary: Journal of...

336

EcoAdapt Working Paper Series N1 Adaptation to climate change for local development  

E-Print Network [OSTI]

1 EcoAdapt Working Paper Series N°1 Adaptation to climate change for local development Análisis in terms of employment, water situation and land use, at a quantitative and qualitative level, in three and summer pastures, due to the geographic and climatic conditions. hal-01059368,version1-30Aug2014 #12

Boyer, Edmond

337

Radiation Therapy Photon Beams Dose Conformation According to Dose Distribution Around Intracavitary-Applied Brachytherapy Sources  

SciTech Connect (OSTI)

Intracavitary application of brachytherapy sources followed by external beam radiation is essential for the local treatment of carcinoma of the cervix. Due to very high doses to the central portion of the target volume delivered by brachytherapy sources, this part of the target volume must be shielded while being irradiated by photon beams. Several shielding techniques are available, from rectangular block and standard cervix wedge to more precise, customized step wedge filters. Because the calculation of a step wedge filter's shape was usually based on effective attenuation coefficient, an approach that accounts, in a more precise way, for the scattered radiation, is suggested. The method was verified under simulated clinical conditions using film dosimetry. Measured data for various compensators were compared to the numerically determined sum of the dose distribution around brachytherapy sources and one of compensated beam. Improvements in total dose distribution are demonstrated, using our method. Agreement between calculation and measurements were within 3%. Sensitivity of the method on sources displacement during treatment has also been investigated.

Jurkovic, Slaven [Department of Radiotherapy and Oncology, University Hospital, Rijeka (Croatia)], E-mail: slaven.jurkovic@ri.htnet.hr; Zauhar, Gordana [Department of Physics, School of Medicine, Rijeka (Croatia); Faj, Dario [Department of Radiotherapy and Oncology, University Hospital, Osijek (Croatia); Radojcic, Deni Smilovic; Svabic, Manda [Department of Radiotherapy and Oncology, University Hospital, Rijeka (Croatia)

2010-04-01T23:59:59.000Z

338

Ground-water contribution to dose from past Hanford Operations. Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

The Hanford Environmental Dose Reconstruction (HEDR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides migrating in ground water on the Hanford Site could have reached the public have been identified: (1) through contaminated ground water migrating to the Columbia River; (2) through wells on or adjacent to the Hanford Site; (3) through wells next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ``ground-water pathway,`` which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated.

Freshley, M.D.; Thorne, P.D.

1992-08-01T23:59:59.000Z

339

Load attenuating passively adaptive wind turbine blade  

DOE Patents [OSTI]

A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

Veers, Paul S. (Albuquerque, NM); Lobitz, Donald W. (Albuquerque, NM)

2003-01-01T23:59:59.000Z

340

Load attenuating passively adaptive wind turbine blade  

DOE Patents [OSTI]

A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

Veers, Paul S.; Lobitz, Donald W.

2003-01-07T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Determination of radionuclides and pathways contributing to dose in 1945. Hanford Environmental Dose Reconstruction Project: Dose code recovery activities, Calculation 003  

SciTech Connect (OSTI)

A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 003) examined the contributions of numerous radionuclides to dose via environmental exposures and accumulation in foods. This study builds on the work initiated in the first scoping study of iodine in cow`s milk (calculation 001). Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows` milk from Feeding Regime 1, as described in Calculation 001.

Napier, B.A.

1992-12-01T23:59:59.000Z

342

Three-dimensional anisotropic adaptive filtering of projection data for noise reduction in cone beam CT  

SciTech Connect (OSTI)

Purpose: The combination of quickly rotating C-arm gantry with digital flat panel has enabled the acquisition of three-dimensional data (3D) in the interventional suite. However, image quality is still somewhat limited since the hardware has not been optimized for CT imaging. Adaptive anisotropic filtering has the ability to improve image quality by reducing the noise level and therewith the radiation dose without introducing noticeable blurring. By applying the filtering prior to 3D reconstruction, noise-induced streak artifacts are reduced as compared to processing in the image domain. Methods: 3D anisotropic adaptive filtering was used to process an ensemble of 2D x-ray views acquired along a circular trajectory around an object. After arranging the input data into a 3D space (2D projections + angle), the orientation of structures was estimated using a set of differently oriented filters. The resulting tensor representation of local orientation was utilized to control the anisotropic filtering. Low-pass filtering is applied only along structures to maintain high spatial frequency components perpendicular to these. The evaluation of the proposed algorithm includes numerical simulations, phantom experiments, and in-vivo data which were acquired using an AXIOM Artis dTA C-arm system (Siemens AG, Healthcare Sector, Forchheim, Germany). Spatial resolution and noise levels were compared with and without adaptive filtering. A human observer study was carried out to evaluate low-contrast detectability. Results: The adaptive anisotropic filtering algorithm was found to significantly improve low-contrast detectability by reducing the noise level by half (reduction of the standard deviation in certain areas from 74 to 30 HU). Virtually no degradation of high contrast spatial resolution was observed in the modulation transfer function (MTF) analysis. Although the algorithm is computationally intensive, hardware acceleration using Nvidia's CUDA Interface provided an 8.9-fold speed-up of the processing (from 1336 to 150 s). Conclusions: Adaptive anisotropic filtering has the potential to substantially improve image quality and/or reduce the radiation dose required for obtaining 3D image data using cone beam CT.

Maier, Andreas; Wigstroem, Lars; Hofmann, Hannes G.; Hornegger, Joachim; Zhu Lei; Strobel, Norbert; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States) and Center for Medical Image Science and Visualization, Linkoeping University, Linkoeping (Sweden); Pattern Recognition Laboratory, Department of Computer Science, Friedrich-Alexander University of Erlangen-Nuremberg, 91054, Erlangen (Germany); Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Siemens AG Healthcare, Forchheim 91301 (Germany); Department of Radiology, Stanford University, Stanford, California 94305 (United States)

2011-11-15T23:59:59.000Z

343

Technical Note: DIRART- A software suite for deformable image registration and adaptive radiotherapy research  

SciTech Connect (OSTI)

Purpose: Recent years have witnessed tremendous progress in image guide radiotherapy technology and a growing interest in the possibilities for adapting treatment planning and delivery over the course of treatment. One obstacle faced by the research community has been the lack of a comprehensive open-source software toolkit dedicated for adaptive radiotherapy (ART). To address this need, the authors have developed a software suite called the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART). Methods: DIRART is an open-source toolkit developed in MATLAB. It is designed in an object-oriented style with focus on user-friendliness, features, and flexibility. It contains four classes of DIR algorithms, including the newer inverse consistency algorithms to provide consistent displacement vector field in both directions. It also contains common ART functions, an integrated graphical user interface, a variety of visualization and image-processing features, dose metric analysis functions, and interface routines. These interface routines make DIRART a powerful complement to the Computational Environment for Radiotherapy Research (CERR) and popular image-processing toolkits such as ITK. Results: DIRART provides a set of image processing/registration algorithms and postprocessing functions to facilitate the development and testing of DIR algorithms. It also offers a good amount of options for DIR results visualization, evaluation, and validation. Conclusions: By exchanging data with treatment planning systems via DICOM-RT files and CERR, and by bringing image registration algorithms closer to radiotherapy applications, DIRART is potentially a convenient and flexible platform that may facilitate ART and DIR research.

Yang Deshan; Brame, Scott; El Naqa, Issam; Aditya, Apte; Wu Yu; Murty Goddu, S.; Mutic, Sasa; Deasy, Joseph O.; Low, Daniel A. [Department of Radiation Oncology, School of Medicine, Washington University in Saint Louis, Missouri 63110 (United States)

2011-01-15T23:59:59.000Z

344

Improved dose estimates for nuclear criticality accidents: Preliminary results  

SciTech Connect (OSTI)

A method for the determination of radiation doses resulting from a hypothetical crticality accident is presented. The method is an improvement over the slide-rule method cuurently used. The improved method calculates doses for low eneriched uranium as well as highly enriched solutions.

Wilkinson, A.; Basoglu, B.; Bentley, C.; Dunn, M.; Plaster, M.; Yamamoto, T.; Dodds, H. [Univ. of Tennessee, Knoxville, TN (United States); Hopper, C. [Oak Ridge National Lab., TN (United States)

1994-12-31T23:59:59.000Z

345

Measurements of Cavitation Dose, Echogenicity, and Temperature during Ultrasound Ablation  

E-Print Network [OSTI]

Measurements of Cavitation Dose, Echogenicity, and Temperature during Ultrasound Ablation T traces from the array, time-domain signals received by a 1 MHz, unfocused passive cavitation detector signals received by the array. Cavitation dose was quantified from the spectra of signals measured

Mast, T. Douglas

346

Radiological Dose Assessment 8 2007 Site environmental report8-  

E-Print Network [OSTI]

) and 64 ± 10 mrem (640 ± 100 Sv) at off-site locations. Both on-and off-site dose measurements include doses measured using thermoluminescent dosimeters (TLDs) at 49 on-site and 15 off-site locations showed penetrating radiation expo- sures both on and off site. The direct measure- ments taken at the off-site

347

Radiological Dose Assessment 8 2008 Site environmental report8-  

E-Print Network [OSTI]

from ambient sources was 69 ± 13 mrem (690 ± 130 Sv) and 63 ± 11 mrem (630 ± 110 Sv) at off-site locations. Both on- and off-site dose measurements include the contribution from natural terrestrial thermoluminescent dosimeters (TLDs) at 49 on-site and 15 off-site locations showed that there was no external dose

348

Hanford Site Annual Report Radiological Dose Calculation Upgrade Evaluation  

SciTech Connect (OSTI)

Operations at the Hanford Site, Richland, Washington, result in the release of radioactive materials to offsite residents. Site authorities are required to estimate the dose to the maximally exposed offsite resident. Due to the very low levels of exposure at the residence, computer models, rather than environmental samples, are used to estimate exposure, intake, and dose. A DOS-based model has been used in the past (GENII version 1.485). GENII v1.485 has been updated to a Windows-based software (GENII version 2.08). Use of the updated software will facilitate future dose evaluations, but must be demonstrated to provide results comparable to those of GENII v1.485. This report describes the GENII v1.485 and GENII v2.08 dose exposure, intake, and dose estimates for the maximally exposed offsite resident reported for calendar year 2008. The GENII v2.08 results reflect updates to implemented algorithms. No two environmental models produce the same results, as was again demonstrated in this report. The aggregated dose results from 2008 Hanford Site airborne and surface water exposure scenarios provide comparable dose results. Therefore, the GENII v2.08 software is recommended for future offsite resident dose evaluations.

Snyder, Sandra F.

2010-02-28T23:59:59.000Z

349

Determination of radionuclides and pathways contributing to cumulative dose  

SciTech Connect (OSTI)

A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows' milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

Napier, B.A.

1992-12-01T23:59:59.000Z

350

Phase 1 of the Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

The work described in this report was prompted by the public's concern about potential effect from the radioactive materials released from the Hanford Site. The Hanford Environmental Dose Reconstruction (HEDR) Project was established to estimate radiation dose the public might have received from the Hanford Site since 1944, when facilities began operating. Phase 1 of the HEDR Project is a pilot'' or demonstration'' phase. The objectives of this initial phase were to determine whether enough historical information could be found or reconstructed to be used for dose estimation and develop and test conceptual and computational models for calculating credible dose estimates. Preliminary estimates of radiation doses were produced in Phase 1 because they are needed to achieve these objectives. The reader is cautioned that the dose estimates provided in this and other Phase 1 HEDR reports are preliminary. As the HEDR Project continues, the dose estimates will change for at least three reasons: more complete input information for models will be developed; the models themselves will be refined; and the size and shape of the geographic study area will change. This is one of three draft reports that summarize the first phase of the four-phased HEDR Project. This, the Summary Report, is directed to readers who want a general understanding of the Phase 1 work and preliminary dose estimates. The two other reports -- the Air Pathway Report and the Columbia River Pathway Report -- are for readers who understand the radiation dose assessment process and want to see more technical detail. Detailed descriptions of the dose reconstruction process are available in more than 20 supporting reports listed in Appendix A. 32 refs., 46 figs.

Not Available

1991-08-01T23:59:59.000Z

351

The Northern Marshall Islands radiological survey: Data and dose assessments  

SciTech Connect (OSTI)

Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu and {sup 241}Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from {sup 137}Cs accounts for about 10% to 30% of the dose. {sup 239+240}Pu and {sup 241}Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y{sup -1}. The background dose in the Marshall Islands is estimated to be 2.4 mSv y{sup -1} to 4.5 mSv y{sup -1}. The 50-y integral dose ranges from 0.5 to 65 mSv. 35 refs., 2 figs., 9 tabs.

Robison, W.L.; Noshkin, V.E.; Conrado, C.L. [Lawrence Livermore National Lab., CA (United States)] [and others

1997-07-01T23:59:59.000Z

352

The Building Adaptive Re-Use  

E-Print Network [OSTI]

81 The Building 7.0 #12;82 Adaptive Re-Use 7.1 7.1.1 Retaining the Ruskin Building's Facades building fabric. The need for a fully accessible and environmentally sustainable building led the team to a solution that requires the full reconstruction of the Ruskin Building, save its primary facades

Flynn, E. Victor

353

Relativistic MHD with Adaptive Mesh Refinement  

E-Print Network [OSTI]

This paper presents a new computer code to solve the general relativistic magnetohydrodynamics (GRMHD) equations using distributed parallel adaptive mesh refinement (AMR). The fluid equations are solved using a finite difference Convex ENO method (CENO) in 3+1 dimensions, and the AMR is Berger-Oliger. Hyperbolic divergence cleaning is used to control the $\

Matthew Anderson; Eric Hirschmann; Steven L. Liebling; David Neilsen

2006-10-11T23:59:59.000Z

354

Adaptive Scheduling Algorithms for Planet Searches  

E-Print Network [OSTI]

High-precision radial velocity planet searches have surveyed over ~2000 nearby stars and detected over ~200 planets. While these same stars likely harbor many additional planets, they will become increasingly challenging to detect, as they tend to have relatively small masses and/or relatively long orbital periods. Therefore, observers are increasing the precision of their observations, continuing to monitor stars over decade timescales, and also preparing to survey thousands more stars. Given the considerable amounts of telescope time required for such observing programs, it is important use the available resources as efficiently as possible. Previous studies have found that a wide range of predetermined scheduling algorithms result in planet searches with similar sensitivities. We have developed adaptive scheduling algorithms which have a solid basis in Bayesian inference and information theory and also are computationally feasible for modern planet searches. We have performed Monte Carlo simulations of plausible planet searches to test the power of adaptive scheduling algorithms. Our simulations demonstrate that planet searches performed with adaptive scheduling algorithms can simultaneously detect more planets, detect less massive planets, and measure orbital parameters more accurately than comparable surveys using a non-adaptive scheduling algorithm. We expect that these techniques will be particularly valuable for the N2K radial velocity planet search for short-period planets as well as future astrometric planet searches with the Space Interferometry Mission which aim to detect terrestrial mass planets.

Eric B. Ford

2007-12-17T23:59:59.000Z

355

Reservation Price Estimation by Adaptive Conjoint Analysis  

E-Print Network [OSTI]

Reservation Price Estimation by Adaptive Conjoint Analysis Christoph Breidert1 , Michael Hahsler1 applied the eco- nomic definition of reservation price in combination with a conjoint study on product pricing. In this paper we present a novel approach to estimate the economic reser- vation price using

Schmidt-Thieme, Lars

356

CLIMATE CHANGE ADAPTATIONS FOR LOCAL WATER MANAGEMENT  

E-Print Network [OSTI]

CLIMATE CHANGE ADAPTATIONS FOR LOCAL WATER MANAGEMENT IN THE SAN FRANCISCO BAY AREA A White Paper from the California Energy Commission's California Climate Change Center JULY 2012 CEC Climate change will affect both sea level and the temporal and spatial distribution of runoff

357

Adaptive Personalisation for Researcher-Independent  

E-Print Network [OSTI]

Adaptive Personalisation for Researcher-Independent Brain-Body Interface Usage Abstract In this case study, we report what we believe to be the first prolonged in-situ use of a brain-body interface for rehabilitation of individuals with severe neurological impairment due to traumatic brain injury

Boetticher, Gary D.

358

Adaptive, full-spectrum solar energy system  

DOE Patents [OSTI]

An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

Muhs, Jeffrey D.; Earl, Dennis D.

2003-08-05T23:59:59.000Z

359

Adaptive Training for Large Vocabulary Continuous  

E-Print Network [OSTI]

Adaptive Training for Large Vocabulary Continuous Speech Recognition Kai Yu Hughes Hall College for the degree of Doctor of Philosophy #12;ii Summary In recent years, there has been a trend towards training is to train hidden Markov models (HMMs) on the whole data set as if all data comes from a single acoustic

Hain, Thomas

360

Semantic Web Technologies for the Adaptive Web  

E-Print Network [OSTI]

23 Semantic Web Technologies for the Adaptive Web Peter Dolog1 and Wolfgang Nejdl2 1 Department.de Abstract. Ontologies and reasoning are the key terms brought into focus by the semantic web community. Formal representation of ontologies in a common data model on the web can be taken as a foundation

Nejdl, Wolfgang

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

An Infrastructure for Adaptive Dynamic Optimization  

E-Print Network [OSTI]

An Infrastructure for Adaptive Dynamic Optimization Derek Bruening, Timothy Garnett, and Saman,timothyg,saman}@lcs.mit.edu Abstract Dynamic optimization is emerging as a promising ap- proach to overcome many of the obstacles static optimizations, there are very few for developing dynamic optimizations. We present a framework

Amarasinghe, Saman

362

Grid adaptation for multiscale plasma simulations  

E-Print Network [OSTI]

Grid adaptation for multiscale plasma simulations Gian Luca Delzanno Los Alamos National Laboratory In collaboration with L. Chacon and J.M. Finn #12;delzanno@lanl.gov Outline Introduction and motivation Grid tests New directions Conclusions #12;delzanno@lanl.gov Outline Introduction and motivation Grid

Ito, Atsushi

363

ADAPTIVE ROBUST TRACKING CONTROL OF PRESSURE  

E-Print Network [OSTI]

accuracy of pressure trajectory in the chamber when the pneumatic cylinder is moving. Off-line fitting, it is necessary to utilize the adaptive model compensation for improving the tracking accuracy of pressure and attenuation in pneumatic lines, valve dynamics, flow nonlinearities through the valve orifice, piston friction

Yao, Bin

364

Provably Efficient Two-Level Adaptive Scheduling  

E-Print Network [OSTI]

processor reallocation, our schedulers provide control over the scheduling overhead and ensure effectiveProvably Efficient Two-Level Adaptive Scheduling Yuxiong He1 , Wen-Jing Hsu1 , and Charles E. Multiprocessor scheduling in a shared multiprogramming en- vironment can be structured in two levels, where

Feitelson, Dror

365

Climate Change Basics: Science, Adaptation, & Mitigation  

E-Print Network [OSTI]

Science Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased from ice cores spanning many thousands of years. The global increases in carbon dioxide concentrationClimate Change Basics: Science, Adaptation, & Mitigation with a Family Forest Perspective Baylor

Fox-Kemper, Baylor

366

Comp Plan: A computer program to generate dose and radiobiological metrics from dose-volume histogram files  

SciTech Connect (OSTI)

Treatment planning studies often require the calculation of a large number of dose and radiobiological metrics. To streamline these calculations, a computer program called Comp Plan was developed using MATLAB. Comp Plan calculates common metrics, including equivalent uniform dose, tumor control probability, and normal tissue complication probability from dose-volume histogram data. The dose and radiobiological metrics can be calculated for the original data or for an adjusted fraction size using the linear quadratic model. A homogeneous boost dose can be added to a given structure if desired. The final output is written to an Excel file in a format convenient for further statistical analysis. Comp Plan was verified by independent calculations. A lung treatment planning study comparing 45 plans for 7 structures using up to 6 metrics for each structure was successfully analyzed within approximately 5 minutes with Comp Plan. The code is freely available from the authors on request.

Holloway, Lois Charlotte, E-mail: lois.holloway@sswahs.nsw.gov.au [Liverpool and Macarthur Cancer Therapy Centres, Sydney (Australia); Center for Medical Radiation Physics, University of Wollongong (Australia); Institute of Medical Physics, University of Sydney (Australia); Miller, Julie-Anne [Liverpool and Macarthur Cancer Therapy Centres, Sydney (Australia); Institute of Medical Physics, University of Sydney (Australia); Kumar, Shivani [Liverpool and Macarthur Cancer Therapy Centres, Sydney (Australia); Whelan, Brendan M. [Institute of Medical Physics, University of Sydney (Australia); Vinod, Shalini K. [Liverpool and Macarthur Cancer Therapy Centres, Sydney (Australia); University of New South Wales (Australia)

2012-10-01T23:59:59.000Z

367

An Enabling Study of Diesel Low-Temperautre Combustion via Adaptive...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

An Enabling Study of Diesel Low-Temperautre Combustion via Adaptive Control An Enabling Study of Diesel Low-Temperautre Combustion via Adaptive Control Adaptive control strategies...

368

E-Print Network 3.0 - adaptive management department Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for: adaptive management department Page: << < 1 2 3 4 5 > >> 1 Regional Water Management: Adapting to Uncertain Water Summary: Regional Water Management: Adapting to...

369

E-Print Network 3.0 - adaptive methods final Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

mechanisms. Finally the actors in the process of adaptation will be discussed like the user (adaptable... adaptation methods and tools that are under the control of the user...

370

E-Print Network 3.0 - adaptive specialization conditional Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

conditional Page: << < 1 2 3 4 5 > >> 1 From Adaptive Hypermedia to the Adaptive Web Systems Summary: Adaptive presentation techniques Conditional text filtering - ITEM...

371

E-Print Network 3.0 - adaptive direct search Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

direct search Page: << < 1 2 3 4 5 > >> 1 From Adaptive Hypermedia to the Adaptive Web Systems Summary: Evaluation of Adaptive Link Sorting HYPERFLEX: IR System -...

372

E-Print Network 3.0 - adaptive fe-be coupling Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Modeling and Simulation of the CORBA Portable Object Adapter Summary: the Coupled Model ports: X<adapter, activate, findpoa()>. "adapter", "activate" are parameter ports while......

373

E-Print Network 3.0 - adaptive seamless design Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

(VTP) to adapt video... need to be resolved: 1) seamless mobility across het- erogeneous networks, 2) application adaptation... incorporate both seamless handoff and adaptive ......

374

Adaptation, Speciation, and Convergence: A Hierarchical Analysis of Adaptive Radiation in Caribbean Anolis Lizards  

E-Print Network [OSTI]

Caribbean Anolis lizards are a classic case of adaptive radiation, repeated four times across islands of the Greater Antilles. On each island, very similar patterns of evolutionary divergence have occurred, resulting in the evolution of the same set...

Losos, Jonathan B.; Glor, Richard E.; Kolbe, Jason J.; Nicholson, Kirsten

2006-05-01T23:59:59.000Z

375

Geometric Structure of the Adaptive Controller of the Human Arm  

E-Print Network [OSTI]

The objects with which the hand interacts with may significantly change the dynamics of the arm. How does the brain adapt control of arm movements to this new dynamic? We show that adaptation is via composition of a ...

Shadmehr, Reza

1993-07-01T23:59:59.000Z

376

Adaptive Treatment Strategies Getting SMART About Developing Individualized  

E-Print Network [OSTI]

Other names are dynamic treatment regimes, treatment algorithms, stepped care models, expert systems: prevent relapse to alcohol abuse · Critical treatment decisions: which treatment to provide first?; which1 Adaptive Treatment Strategies Getting SMART About Developing Individualized Sequences of Adaptive

Murphy, Susan A.

377

Artificial gravity : neurovestibular adaptation to incremental exposure to centrifugation  

E-Print Network [OSTI]

(cont.) not build up adaptation, all subjects in the experimental group who completed the protocol showed signs of adaptation to the stimulus. Only one subject did not complete the five sessions, setting the drop-out rate ...

Bruni, Sylvain, 1981-

2004-01-01T23:59:59.000Z

378

Adaptive Power Control for Single and Multiuser Opportunistic Systems  

E-Print Network [OSTI]

In this dissertation, adaptive power control for single and multiuser opportunistic systems is investigated. First, a new adaptive power-controlled diversity combining scheme for single user systems is proposed, upon which is extended...

Nam, Sung Sik

2010-07-14T23:59:59.000Z

379

Funding for adaptation to climate change : the case of Surat  

E-Print Network [OSTI]

The need for cities to adapt to climate change is widely acknowledged, yet the question of adaptation finance remains uncertain. Unable to access global climate funds, cities must seek out alternative sources to support ...

Patel, Toral

2014-01-01T23:59:59.000Z

380

Climate Change Adaptation: A Collective Action Perspective on Federalism Considerations  

E-Print Network [OSTI]

adaptation to minimize the adverse effects of climate change. Climate change adaptation is designed to increase the resilience of natural and human ecosystems to the threats posed by a changing environment. Although an extensive literature concerning...

Glicksman, Robert L.; Levy, Richard E.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Urban climate resilience : a global assessment of city adaptation plans  

E-Print Network [OSTI]

As policy makers accept climate change as an irrefutable threat, adaptation planning has emerged as a necessary action for countries, states, and municipalities. This thesis explores adaptive responses to climate change ...

Katich, Kristina Noel

2009-01-01T23:59:59.000Z

382

Accelerated Adaptive Markov Chain for Partition Function Computation  

E-Print Network [OSTI]

Accelerated Adaptive Markov Chain for Partition Function Computation Stefano Ermon, Carla P. Gomes Ithaca NY 14853, U.S.A. Abstract We propose a novel Adaptive Markov Chain Monte Carlo algorithm

Keinan, Alon

383

The Binding of Learning to Action in Motor Adaptation  

E-Print Network [OSTI]

In motor tasks, errors between planned and actual movements generally result in adaptive changes which reduce the occurrence of similar errors in the future. It has commonly been assumed that the motor adaptation arising ...

Gonzalez Castro, Luis Nicolas

384

Learning from Monitoring & Evaluation a blueprint for an adaptive organisation  

E-Print Network [OSTI]

Learning from Monitoring & Evaluation a blueprint for an adaptive organisation Learning from Monitoring & Evaluation a blueprint for an adaptive organisation Jake Morris and Anna Lawrence Social & Economic Research Group, Forest Research Aim and structure Learning is an essential characteristic

385

Evaluation and Adaptation of 5-Cycle Fuel Economy Testing and...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Adaptation of 5-Cycle Fuel Economy Testing and Calculations for HEVs and PHEVs Evaluation and Adaptation of 5-Cycle Fuel Economy Testing and Calculations for HEVs and PHEVs 2012...

386

Overview of the Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that specific and representative individuals and populations may have received as a result of releases of radioactive materials from historical operations at the Hanford Site. These dose estimates would account for the uncertainties of information regarding facilities operations, environmental monitoring, demography, food consumption and lifestyles, and the variability of natural phenomena. Other objectives of the HEDR Project include: supporting the Hanford Thyroid Disease Study (HTDS), declassifying Hanford-generated information and making it available to the public, performing high-quality, credible science, and conducting the project in an open, public forum. The project is briefly described.

Shipler, D.B.; Napier, B.A.; Ikenberry, T.A.

1992-04-01T23:59:59.000Z

387

BIA Request for Proposals for Climate Adaptation Grants for Tribes  

Broader source: Energy.gov [DOE]

Download the Bureau of Indian Affairs Request for Proposals for Climate Adaptation Grants for Tribes, due November 29.

388

Communication adapter for use with a drilling component  

DOE Patents [OSTI]

A communication adapter is disclosed that provides for removable attachment to a drilling component when the drilling component is not actively drilling and for communication with an integrated transmission system in the drilling component. The communication adapter comprises a data transmission coupler that facilitates communication between the drilling component and the adapter, a mechanical coupler that facilitates removable attachment of the adapter to the drilling component, and a data interface.

Hall, David R. (Provo, UT); Pixton, David S. (Lehi, UT); Hall; Jr.; H. Tracy (Provo, UT); Bradford, Kline (Orem, UT); Rawle, Michael (Springville, UT)

2007-04-03T23:59:59.000Z

389

Genomic islands predict functional adaptation in marine actinobacteria  

E-Print Network [OSTI]

Ecological adaptations among bacterial populations have been linked to genomic islands, strain-specific regions of DNA that house

Penn, Kevin

2010-01-01T23:59:59.000Z

390

Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits  

SciTech Connect (OSTI)

The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes included increasing the time horizon beyond 1,050 years (yr), and using the radionuclide concentrations provided by the DOE-PPPO as inputs into the codes. The deterministic peak doses were evaluated within time horizons of 70 yr (for the Landfill Worker and Trespasser), 1,050 yr, 10,000 yr and 100,000 yr (for the Resident Farmer [onsite], Resident Gardener, Recreational User, Outdoor Worker and Offsite Resident Farmer) at the request of the DOE-PPPO. The time horizons of 10,000 yr and 100,000 yr were used at the request of the DOE-PPPO for informational purposes only. The probabilistic peak of the mean dose assessment was performed for the Offsite Resident Farmer using Technetium-99 (Tc-99) and a time horizon of 1,050 yr. The results of the deterministic analyses indicate that among all receptors and time horizons evaluated, the highest projected dose, 2,700 mrem/yr, occurred for the Resident Farmer (onsite) at 12,773 yr. The exposure pathways contributing to the peak dose are ingestion of plants, external gamma, and ingestion of milk, meat and soil. However, this receptor is considered an implausible receptor. The only receptors considered plausible are the Landfill Worker, Recreational User, Outdoor Worker and the Offsite Resident Farmer. The maximum projected dose among the plausible receptors is 220 mrem/yr for the Outdoor Worker and it occurs at 19,045 yr. The exposure pathways contributing to the dose for this receptor are external gamma and soil ingestion. The results of the probabilistic peak of the mean dose analysis for the Offsite Resident Farmer indicate that the average (arithmetic mean) of the peak of the mean doses for this receptor is 0.98 mrem/yr and it occurs at 1,050 yr. This dose corresponds to Tc-99 within the time horizon of 1,050 yr.

Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

2012-06-01T23:59:59.000Z

391

A Fully Automated Method for CT-on-Rails-Guided Online Adaptive Planning for Prostate Cancer Intensity Modulated Radiation Therapy  

SciTech Connect (OSTI)

Purpose: This study was designed to validate a fully automated adaptive planning (AAP) method which integrates automated recontouring and automated replanning to account for interfractional anatomical changes in prostate cancer patients receiving adaptive intensity modulated radiation therapy (IMRT) based on daily repeated computed tomography (CT)-on-rails images. Methods and Materials: Nine prostate cancer patients treated at our institution were randomly selected. For the AAP method, contours on each repeat CT image were automatically generated by mapping the contours from the simulation CT image using deformable image registration. An in-house automated planning tool incorporated into the Pinnacle treatment planning system was used to generate the original and the adapted IMRT plans. The cumulative dosevolume histograms (DVHs) of the target and critical structures were calculated based on the manual contours for all plans and compared with those of plans generated by the conventional method, that is, shifting the isocenters by aligning the images based on the center of the volume (COV) of prostate (prostate COV-aligned). Results: The target coverage from our AAP method for every patient was acceptable, while 1 of the 9 patients showed target underdosing from prostate COV-aligned plans. The normalized volume receiving at least 70 Gy (V{sub 70}), and the mean dose of the rectum and bladder were reduced by 8.9%, 6.4 Gy and 4.3%, 5.3 Gy, respectively, for the AAP method compared with the values obtained from prostate COV-aligned plans. Conclusions: The AAP method, which is fully automated, is effective for online replanning to compensate for target dose deficits and critical organ overdosing caused by interfractional anatomical changes in prostate cancer.

Li, Xiaoqiang; Quan, Enzhuo M.; Li, Yupeng [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Pan, Xiaoning [Department of Radiation Oncology, University of Texas Health Science Center at Tyler, Tyler, Texas (United States); Zhou, Yin [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Xiaochun [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Du, Weiliang [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kudchadker, Rajat J.; Johnson, Jennifer L. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kuban, Deborah A.; Lee, Andrew K. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang, Xiaodong, E-mail: xizhang@mdanderson.org [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2013-08-01T23:59:59.000Z

392

Genetic Factors Affecting Susceptibility to Low Dose & Low Dose-Rate Radiation  

SciTech Connect (OSTI)

Our laboratory has, among other things, developed and used the gamma H2AX focus assay and other chromosomal and cell killing assays to show that differences in this DNA double strand break (dsb) related response can be clearly and distinctly demonstrated for cells which are mildly hyper-radiosensitive such as those associated with A-T heterozygosity. We have found this level of mild hypersensitivity for cells from some 20 to 30 % of apparently normal individuals and from apparently normal parents of Retinoblastoma patients. We found significant differences in gene expression in somatic cells from unaffected parents of Rb patients as compared with normal controls, suggesting that these parents may harbor some as yet unidentified genetic abnormality. In other experiments we sought to determine the extent of differences in normal human cellular reaponses to radiation depending on their irradiation in 2D monolayer vs 3D organized acinar growth conditions. We exmined cell reproductive death, chromosomal aberration induction, and the levels of ?-H2AX foci in cells after single acute gamma-ray doses and immediately after 20 hours of irradiation at a dose rate of 0.0017 Gy/min. We found no significant differences in the dose-responses of these cells under the 2D or 3D growth conditions. While this does not mean such differences cannot occur in other situations, it does mean that they do not generally or necessarily occur. In another series of studies in collaboration with Dr Chuan Li, with supprt from this current grant. We reported a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. In yet another collaboration with Dr, B. Chen with funds from this grant, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase activity) were examined after exposure of synchronized G1 cells to 137Cs c rays. DNA-PKcs mutant cells defective in phosphorylation at multiple sites withinthe T2609 cluster or within the PI3K domain displayed extreme radiosensitivity. Cells defective at the S2056 cluster or T2609 single site alone were only mildly radiosensitive, but cells defective at even one site in both the S2056 and T2609 clusters were maximally radiosensitive. Thus a synergism between the capacity for phosphorylation at the S2056 and T2609 clusterswas found to be critical for induction of radiosensitivity.

Bedford, Joel

2014-04-18T23:59:59.000Z

393

CY 1995 radiation dose reconciliation report and resulting CY 1996 dose estimate for the 324 nuclear facility  

SciTech Connect (OSTI)

In this report, the dose estimate for CY 1995 is reconciled by month wih actual doses received. Results of the reconciliation were used to revise estimates of worker dose for CY 1996. Resulting dose estimate for the facility is also included. Support for two major programs (B-Cell Cleanout and Surveillance and Maintenance) accounts for most of the exposure received by workers in the faility. Most of the expousre received by workers comes from work in the Radiochemical Engineering Complex airlock. In spite of schedule and work scope changes during CY 1995, dose estimates were close to actual exposures received. A number of ALARA measures were taken throughout the year; exposure reduction due to those was 20.6 Man-Rem, a 28% reduction from the CY 1995 estimate. Baseline estimates for various tasks in the facility were used to compile the CY 1996 dose estimate of 45.4 Man-Rem; facility goal for CY 1996 is to reduce worker dose by 20%, to 36.3 Man-Rem.

Landsman, S.D.; Thornhill, R.E.; Peterson, C.A.

1996-04-01T23:59:59.000Z

394

Some Computational Problems Arising in Adaptive Optics Imaging Systems  

E-Print Network [OSTI]

Some Computational Problems Arising in Adaptive Optics Imaging Systems Robert J. Plemmons \\Lambda numerical linear algebra tech­ niques in adaptive optics imaging control computations. Real­time adaptive optics is a means for enhancing the resolution of ground based, optical telescopes beyond the limits

Plemmons, Robert J.

395

Adaptive beam profile control using a simulated annealing algorithm  

E-Print Network [OSTI]

adaptive optics system," Opt. Commun. 176, 339-345 (2000). 3. R. B. Shake and B. C. Platt, "Production. Murnane, H. C. Kapteyn, S. Backus, G. Vdovin "Adaptive pulse compensation for transform-limited 15-fs high-energy transverse mode control and optimisation of an all-solid-state laser using an intracavity adaptive

396

Extending Mobile Computer Battery Life through Energy-Aware Adaptation  

E-Print Network [OSTI]

Extending Mobile Computer Battery Life through Energy-Aware Adaptation Jason Flinn CMU-CS-01 entity. #12;Keywords: Energy-aware adaptation, application-aware adaptation, power manage- ment, mobile and applications, must also contribute to energy conservation. This dissertation puts forth the claim that energy-aware

397

Extending Mobile Computer Battery Life through EnergyAware Adaptation  

E-Print Network [OSTI]

Extending Mobile Computer Battery Life through EnergyAware Adaptation Jason Flinn CMUCS01 entity. #12; Keywords: Energyaware adaptation, applicationaware adaptation, power manage ment, mobile and applications, must also contribute to energy conservation. This dissertation puts forth the claim that energyaware

Flinn, Jason

398

Automated Web Page Synthesis in Adaptive Web Systems  

E-Print Network [OSTI]

Automated Web Page Synthesis in Adaptive Web Systems Hossein Sadat and Ali Ghorbani Intelligent, Canada {t15h7,ghorbani}@unb.ca Abstract. An adaptive Web system adapts the Web pages to its users, based of the system. In this paper, we formalize dynamic generation of Web pages and refer to it as Web page synthesis

Ghorbani, Ali

399

Phenotypic plasticity facilitates recurrent rapid adaptation to introduced predators  

E-Print Network [OSTI]

Phenotypic plasticity facilitates recurrent rapid adaptation to introduced predators Alison G) A central role for phenotypic plasticity in adaptive evolution is often posited yet lacks empirical support of preexisting developmental pathways, producing rapid adaptive change. We examined the role of plasticity

Pfrender, Michael

400

Grid adaptation for multiscale plasma simulations Gian Luca Delzanno  

E-Print Network [OSTI]

Grid adaptation for multiscale plasma simulations Gian Luca Delzanno Los Alamos National Laboratory tools need to be developed to bridge the gap between these disparate scales. Grid adaptation is one of such tools, useful to address multiple length scales, and we present a new powerful grid adaptation method

Ito, Atsushi

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

MEDIA RESOURCES ADAPTATION FOR LIMITED DEVICES TAYEB LEMLOUMA1  

E-Print Network [OSTI]

MEDIA RESOURCES ADAPTATION FOR LIMITED DEVICES TAYEB LEMLOUMA1 ; NABIL LAYADA1 1 WAM Project, INRIA.Lemlouma@inrialpes.fr; Nabil.Layaida@inrialpes.fr In this paper, we define a framework for media resources manipulation in an adaptive content delivery system. We discuss the media resources manipulation in an adaptation

Paris-Sud XI, Universit de

402

What Should Adaptivity Mean to Interactive Software Programmers?  

E-Print Network [OSTI]

and adaptation are combined in a simple and innovative manner. Author Keywords Adaptive software, plasticity.2.11.Software engineering: Software Architectures INTRODUCTION Software adaptivity is a long time- stood as the self-modification of a system under context vari- ations, arose as a significant issue

Paris-Sud XI, Université de

403

Creating an adaptable workforce: important implications for CIOs  

E-Print Network [OSTI]

talent Planning for leadership succession Fostering workforce adaptability Unquestionably, to winMarch 2008 Creating an adaptable workforce: important implications for CIOs #12;Creating an adaptable workforce: important implications for CIOs Page 2 Contents 2 Introduction 3 The IBM Global Human

404

Market-based mechanisms for climate change adaptation  

E-Print Network [OSTI]

of Climate Change and Energy Efficiency) and the National Climate Change Adaptation Research FacilityMarket-based mechanisms for climate change adaptation Final Report John McAneney, Ryan Crompton FOR CLIMATE CHANGE ADAPTATION Assessing the potential for and limits to insurance and market-based mechanisms

Colorado at Boulder, University of

405

Adaptation Control in Adaptive Hypermedia Systems Hongjing Wu, Paul De Bra, Ad Aerts, GeertJan Houben  

E-Print Network [OSTI]

model for the architecture of adaptive hypermedia applications: AHAM (for Adaptive Hypermedia Application Model) [DHW99], which is an extension of the Dexter hypermedia reference model [HS90, HS94]. AHAM

De Bra, Paul

406

Adaptation Control in Adaptive Hypermedia Systems Hongjing Wu, Paul De Bra, Ad Aerts, Geert-Jan Houben  

E-Print Network [OSTI]

model for the architecture of adaptive hypermedia applications: AHAM (for Adaptive Hypermedia Application Model) [DHW99], which is an extension of the Dexter hypermedia reference model [HS90, HS94]. AHAM

Houben, Geert-Jan

407

Radiation Dose From Medical Imaging: A Primer for Emergency Physicians  

E-Print Network [OSTI]

taking charge of radiation dose. J Am Coll Radiol. 2010;7:Diederich S, Lenzen H. Radiation exposure associated withand computed ionizing radiation. Health Phys. 2008;95:612

Jones, Jesse G.A.; Mills, Christopher N.; Mogensen, Monique A.; Lee, Christoph I.

2012-01-01T23:59:59.000Z

408

Dental dose and image quality surveys using optically stimulated luminescence  

E-Print Network [OSTI]

The correlation of x-ray beam quality at typical energies used for dental radiography with dosimeter response was studied. Landauer Luxel ? Optically Stimulated Luminescence (OSL) dosimeters were analyzed for the dose response with respect...

Handley, Stephen Michael

2006-04-12T23:59:59.000Z

409

TECHNICAL ADVANCE Therapeutic Dose from a Pyroelectric Electron Accelerator  

E-Print Network [OSTI]

interactions with the Faraday cup. Based on these measurements, the dose that this source could deliver cylindrical lithium tantalate crystals, with the cylinder's axis parallel to the axis of polarization. At any

Danon, Yaron

410

Dose Rate Calculations for Rotary Mode Core Sampling Exhauster  

E-Print Network [OSTI]

This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

Foust, D J

2000-01-01T23:59:59.000Z

411

Determination of radionuclides and pathways contributing to dose in 1945  

SciTech Connect (OSTI)

A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 003) examined the contributions of numerous radionuclides to dose via environmental exposures and accumulation in foods. This study builds on the work initiated in the first scoping study of iodine in cow's milk (calculation 001). Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows' milk from Feeding Regime 1, as described in Calculation 001.

Napier, B.A.

1992-12-01T23:59:59.000Z

412

Ectodysplasin signaling in cutaneous appendage development: Dose, duration and diversity  

E-Print Network [OSTI]

The development of several skin appendages is guided by prenatal Ectodysplasin signalling. Cui et al. (this issue, 2009) report on the dose and duration of Ectodysplasin signalling required for the maintenance and morphogenesis ...

Headon, Denis J.

2009-01-01T23:59:59.000Z

413

annual dose mass: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

414

additional thyroid dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

415

assessing total doses: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

416

antigen dose dependent: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

417

average glandular dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

418

accumulated dose measurement: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of sup 2...

419

adults measuring dose: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

This work describes a pilot study to calculate lung dose from the deposition of radon progeny, via estimates of cumulative exposure derived from in vivo measurements of sup 2...

420

GROUND-WATER CONTRIBUTION TO DOSE FROM PAST HANFORD OPERATIONS  

SciTech Connect (OSTI)

The Hanford Environmental Dose Reconstruction (HEOR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides originating in ground water on the Hanford Site could have reached the public have been identified: 1) through contaminated ground water migrating to the Columbia River; 2) through wells on or adjacent to the Hanford Site; 3) through wells that draw some or all of their water from the Columbia River (riparian wells); and 4) through atmospheric deposition resulting in the contamination of a small watershed that, in turn, results in contamination of a shallow well or spring. These four pathways make up the "ground-water pathway ," which is the subject of this study. The objective of the study was to assess the extent to which the groundwater pathway contributed to radiation doses that populations or individuals may have received from past operations at Hanford. The assessment presented in this report was performed by 1) reviewing the extensive ?literature on ground water and ground-water monitoring at Hanford and 2) performing simple calculations to estimate radionuclide concentrations in ground water and the Columbia River resulting from ground-water discharge. Radiation doses that would result from exposure to this ground water and surface water were calculated. The study conclusion is that the ground-water pathways did not contribute significantly to dose. Compared with background radiation in the TriCities {300 mrem/yr), estimated doses are small: 0.02 mrem/yr effective dose equivalent from discharge of contaminated ground water to the Columbia River; 1 mrem/yr effective dose equivalent from Hanford Site wells; 11 mrem/yr effective dose equivalent from riparian wells; and 1 mrem/yr effective dose equivalent from the watershed. Because the estimated doses are so small, the recommendation is that further work on the ground-water pathway be limited to tracking ongoing ground-water studies at the Hanford Site.

Freshley, M. D.; Thorne, P. D.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off  

SciTech Connect (OSTI)

Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters {<=}20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R{sub 50}-R{sub 100} (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV{sub 50}) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R{sub 50}-R{sub 100} and NTV{sub 50} initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group (maximum diameters {<=}20 mm) had the most HI dependence for dose fall off. For treated plans, CI averaged 2.55{+-}0.79 with HI 1.23{+-}0.06; the average R{sub 50}-R{sub 100} was 0.41{+-}0.08, 0.55{+-}0.10, and 0.65{+-}0.09 cm, respectively, for tumors {<=}20 mm, between 20 and 30 mm, and >30 mm. Conclusions: Tumor dose inhomogeneity can be used as an important and convenient parameter to evaluate mMLC LINAC-based SRS plans. Sharp dose fall off in the normal tissue is achieved with sufficiently high tumor dose inhomogeneity. By adjusting beam margins, a homogeneity index of approximately 1.3 would provide best conformity for the authors' SRS system.

Hong, Linda X.; Garg, Madhur; Lasala, Patrick; Kim, Mimi; Mah, Dennis; Chen, Chin-Cheng; Yaparpalvi, Ravindra; Mynampati, Dinesh; Kuo, Hsiang-Chi; Guha, Chandan; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Neurosurgery, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Epidemiology and Population Health, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2011-03-15T23:59:59.000Z

422

Monte Carlo simulations of dose near a nonradioactive gold seed  

SciTech Connect (OSTI)

The relative doses and hot/cold spot positions around a non-radioactive gold seed, irradiated by a 6 or 18 MV photon beam in water, were calculated using Monte Carlo simulation. Phase space files of 6 and 18 MV photon beams with a field size of 1x1 cm{sup 2} were generated by a Varian 21 EX linear accelerator using the EGSnrc and BEAMnrc code. The seed (1.2x1.2x3.2 mm{sup 3}) was positioned at the isocenter in a water phantom (20x20x20 cm{sup 2}) with source-to-axis distance=100 cm. For the single beam geometry, the relative doses (normalized to the dose at 5 mm distance above the isocenter) at the upstream seed surface were calculated to be 1.64 and 1.56 for the 6 and 18 MV beams respectively when the central beam axis (CAX) is parallel to the width of the seed. These doses were slightly higher than those (1.58 and 1.52 for 6 and 18 MV beams respectively) calculated when the CAX is perpendicular to the width of the seed. Compared to the relative dose profiles with the same beam geometry without the seed in the water phantom, the presence of the seed affects the dose distribution at about 3 mm distance beyond both the upstream and downstream seed surface. For a pair of opposing beams with equal and unequal beam weight, the hot and cold spots of both opposing beams were mixed. For a 360 degree photon arc around the longitudinal axis of the seed, the relative dose profile along the width of the seed was similar to that of the opposing beam pair, except the former geometry has a larger dose gradient near the seed surface. In this study, selected results from our simulation were compared to previous measurements using film dosimetry.

Chow, James C. L.; Grigorov, Grigor N. [Department of Radiation Oncology, University of Toronto and Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, ON N2G 1G3 (Canada) and Department of Physics, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1 (Canada); Medical Physics Department, Grand River Regional Cancer Center, Grand River Hospital, 835 King Street West, Kitchener, ON N2G 1G3 (Canada)

2006-12-15T23:59:59.000Z

423

An internal dose monitoring program at an academic research institution  

E-Print Network [OSTI]

echniques . Page Intake Calculation. Analysis of Results Dose Calculation. . 31 Recording and Reporting Results PROPOSED INTERNAL DOSE MONITORING PROGRAM FOR TFXAS A&M UNIVERSll Y Selection of Partictpants'Participant Eltgibtiity 38 Measurement... that the monitonng system will detect releases to the environment which could lead to an intake by workers (NCRP 1987) ~ Levels ol airborne radioactivity air sampling Results from air sampling measurements may indicate that the potential exists for personnel...

Carsten, Keith Eric

1997-01-01T23:59:59.000Z

424

Adaptive phase measurements for narrowband squeezed beams  

E-Print Network [OSTI]

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and hence can be significantly squeezed only over a limited frequency range. In this paper we analyze adaptive phase measurements of this type for a realistic model of a squeezed beam. We show that, provided it is possible to suitably choose the parameters of the beam, a mean-square phase uncertainty scaling as (N/kappa)^{-5/8} is possible, where kappa is the linewidth of the beam resulting from the fluctuating phase. This is an improvement over the (N/kappa)^{-1/2} scaling found previously for coherent beams. In the experimentally realistic case where there is a limit on the maximum squeezing possible, the variance will be reduced below that for coherent beams, though the scaling is unchanged.

Dominic W. Berry; Howard M. Wiseman

2006-03-22T23:59:59.000Z

425

Robust adaptive control of HVDC systems  

SciTech Connect (OSTI)

The transient performance of an HVDC power system is highly dependent on the parameters of the current/voltage regulators of the converter controls. In order to better accommodate changes in system structure or dc operating conditions, this paper introduces a new adaptive control strategy. The advantages of automatic tuning for continuous fine tuning are combined with predetermined gain scheduling in order to achieve robustness for large disturbances. Examples are provided for a digitally simulated back-to-back dc system.

Reeve, J.; Sultan, M. (Univ. of Waterloo, Ontario (Canada))

1994-07-01T23:59:59.000Z

426

RUMINAL ADAPTATION TO INCREASING LEVELS OF CONCENTRATES  

E-Print Network [OSTI]

.0 % citrus pulp, 1.0 % lard, 7.0 % sugarbeet pulp, 3.3 % oat husk meal, 2.0 % coconut expeller and 2-chromatography. The rate of lactate fermentation was measured by incubation of 10 ml rumen fluid (taken at 14.00 h) with 1. If adaptation occurs one should expect an increase of lactate and a higher rate of L- lactate fermentation

Paris-Sud XI, Universit de

427

Tissue Heterogeneity in IMRT Dose Calculation for Lung Cancer  

SciTech Connect (OSTI)

The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiation therapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the {gamma} function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the lung and in the tumor area. These differences are not always in DVH of the lung, although the Wilcoxon test indicated significant differences in 2 of 4 patients. Disagreement in the lung region was also found when the {Gamma} analysis was performed. The effect on TCP is less important than for NTCP because of the slope of the curve at the level of the dose of interest. The effect of dose calculation inaccuracy is patient-dependent and strongly related to beam geometry and to the localization of the tumor. When multiple intensity-modulated beams are used, the effect of the presence of the heterogeneity on dose distribution may not always be easily predictable.

Pasciuti, Katia, E-mail: ka.pasciuti@libero.i [Laboratory of Medical Physics, Istituto Regina Elena, Roma (Italy); Iaccarino, Giuseppe; Strigari, Lidia [Laboratory of Medical Physics, Istituto Regina Elena, Roma (Italy); Malatesta, Tiziana [Medical Physics Department, S. Giovanni Calibita, Fatebenefratelli Hospital, Roma (Italy); Benassi, Marcello; Di Nallo, Anna Maria [Laboratory of Medical Physics, Istituto Regina Elena, Roma (Italy); Mirri, Alessandra; Pinzi, Valentina [Division of Radiotherapy, Istituto Regina Elena, Roma (Italy); Landoni, Valeria [Laboratory of Medical Physics, Istituto Regina Elena, Roma (Italy)

2011-07-01T23:59:59.000Z

428

E-Print Network 3.0 - accurate dose calibrator Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

for the same dosed levels for a standard calibration thimble ion- isation and dose meter system... applied doses are used for analysis but ... Source: Yu, Peter K.N. -...

429

E-Print Network 3.0 - adaptive simulated annealing Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Report Summary: mimicking each specific behavior. 12; Keywords: simulated annealing, organizational learning, adaptation... on structure and adaptability, under the...

430

Adaptive powertrain control for plugin hybrid electric vehicles  

DOE Patents [OSTI]

A powertrain control system for a plugin hybrid electric vehicle. The system comprises an adaptive charge sustaining controller; at least one internal data source connected to the adaptive charge sustaining controller; and a memory connected to the adaptive charge sustaining controller for storing data generated by the at least one internal data source. The adaptive charge sustaining controller is operable to select an operating mode of the vehicle's powertrain along a given route based on programming generated from data stored in the memory associated with that route. Further described is a method of adaptively controlling operation of a plugin hybrid electric vehicle powertrain comprising identifying a route being traveled, activating stored adaptive charge sustaining mode programming for the identified route and controlling operation of the powertrain along the identified route by selecting from a plurality of operational modes based on the stored adaptive charge sustaining mode programming.

Kedar-Dongarkar, Gurunath; Weslati, Feisel

2013-10-15T23:59:59.000Z

431

E-Print Network 3.0 - accumulated radiation dose Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

. At the end, this seminar concentrates on the dose contributions of naturally occurring ionizing radiation... particles. - The equivalent dose, HT, which takes into account...

432

E-Print Network 3.0 - administer therapeutic dose Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of MRT (Tolerable- dose) with Broad Beams Tumor scar, neuronal depletion... Conventional Radiation Therapy Dose fractionation: commonly 30 daily fractions ... Source: Brookhaven...

433

E-Print Network 3.0 - antagonist multiple dose Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diagnostic x-rays (mean breast dose, 108 m... not necessarily hold in the relevant dose range if multiple radiation-damaged cells influenced each other, either... synergis-...

434

PRECEDENTS FOR AUTHORIZATION OF CONTENTS USING DOSE RATE MEASUREMENTS  

SciTech Connect (OSTI)

For the transportation of Radioactive Material (RAM) packages, the requirements for the maximum allowed dose rate at the package surface and in its vicinity are given in Title 10 of the Code of Federal Regulations, Section 71.47. The regulations are based on the acceptable dose rates to which the public, workers, and the environment may be exposed. As such, the regulations specify dose rates, rather than quantity of radioactive isotopes and require monitoring to confirm the requirements are met. 10CFR71.47 requires that each package of radioactive materials offered for transportation must be designed and prepared for shipment so that under conditions normally incident to transportation the radiation level does not exceed 2 mSv/h (200 mrem/h) at any point on the external Surface of the package, and the transport index does not exceed 10. Before shipment, the dose rate of the package is determined by measurement, ensuring that it conforms to the regulatory limits, regardless of any analyses. This is the requirement for all certified packagings. This paper discusses the requirements for establishing the dose rates when shipping RAM packages and the precedents for meeting these requirements by measurement.

Abramczyk, G.; Bellamy, S.; Nathan, S.; Loftin, B.

2012-06-05T23:59:59.000Z

435

AdaptiveARC | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectric Coop,SaveWhiskeyEnergyAd-Venta Jump to:Colorado:01.AdamsvilleAdaptiveARC

436

WeADAPT | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of InspectorConcentrating SolarElectric Coop,Save EnergyGlouster,Winside,Warren CountyUtility JumpWeADAPT Jump

437

Adaptive schemes for incomplete quantum process tomography  

SciTech Connect (OSTI)

We propose an iterative algorithm for incomplete quantum process tomography with the help of quantum state estimation. The algorithm, which is based on the combined principles of maximum likelihood and maximum entropy, yields a unique estimator for an unknown quantum process when one has less than a complete set of linearly independent measurement data to specify the quantum process uniquely. We apply this iterative algorithm adaptively in various situations and so optimize the amount of resources required to estimate a quantum process with incomplete data.

Teo, Yong Siah [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, Singapore 117597 (Singapore); Englert, Berthold-Georg [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Rehacek, Jaroslav; Hradil, Zdenek [Department of Optics, Palacky University, 17. listopadu 12, CZ-77146 Olomouc (Czech Republic)

2011-12-15T23:59:59.000Z

438

Radiation Dose-Volume Effects and the Penile Bulb  

SciTech Connect (OSTI)

The dose, volume, and clinical outcome data for penile bulb are reviewed for patients treated with external-beam radiotherapy. Most, but not all, studies find an association between impotence and dosimetric parameters (e.g., threshold doses) and clinical factors (e.g., age, comorbid diseases). According to the data available, it is prudent to keep the mean dose to 95% of the penile bulb volume to <50 Gy. It may also be prudent to limit the D70 and D90 to 70 Gy and 50 Gy, respectively, but coverage of the planning target volume should not be compromised. It is acknowledged that the penile bulb may not be the critical component of the erectile apparatus, but it seems to be a surrogate for yet to be determined structure(s) critical for erectile function for at least some techniques.

Roach, Mack, E-mail: mroach@radonc.ucsf.ed [Department of Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Nam, Jiho [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Gagliardi, Giovanna [Department of Medical Physics, Karolinska University Hospital and Karolinska Institutet, Stockholm (Sweden); El Naqa, Issam; Deasy, Joseph O. [Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, St. Louis, MO (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)

2010-03-01T23:59:59.000Z

439

HDRMC, an accelerated Monte Carlo dose calculator for high dose rate brachytherapy with CT-compatible applicators  

SciTech Connect (OSTI)

Purpose: To present a new accelerated Monte Carlo code for CT-based dose calculations in high dose rate (HDR) brachytherapy. The new code (HDRMC) accounts for both tissue and nontissue heterogeneities (applicator and contrast medium). Methods: HDRMC uses a fast ray-tracing technique and detailed physics algorithms to transport photons through a 3D mesh of voxels representing the patient anatomy with applicator and contrast medium included. A precalculated phase space file for the{sup 192}Ir source is used as source term. HDRM is calibrated to calculated absolute dose for real plans. A postprocessing technique is used to include the exact density and composition of nontissue heterogeneities in the 3D phantom. Dwell positions and angular orientations of the source are reconstructed using data from the treatment planning system (TPS). Structure contours are also imported from the TPS to recalculate dose-volume histograms. Results: HDRMC was first benchmarked against the MCNP5 code for a single source in homogenous water and for a loaded gynecologic applicator in water. The accuracy of the voxel-based applicator model used in HDRMC was also verified by comparing 3D dose distributions and dose-volume parameters obtained using 1-mm{sup 3} versus 2-mm{sup 3} phantom resolutions. HDRMC can calculate the 3D dose distribution for a typical HDR cervix case with 2-mm resolution in 5 min on a single CPU. Examples of heterogeneity effects for two clinical cases (cervix and esophagus) were demonstrated using HDRMC. The neglect of tissue heterogeneity for the esophageal case leads to the overestimate of CTV D90, CTV D100, and spinal cord maximum dose by 3.2%, 3.9%, and 3.6%, respectively. Conclusions: A fast Monte Carlo code for CT-based dose calculations which does not require a prebuilt applicator model is developed for those HDR brachytherapy treatments that use CT-compatible applicators. Tissue and nontissue heterogeneities should be taken into account in modern HDR brachytherapy planning.

Chibani, Omar, E-mail: omar.chibani@fccc.edu; C-M Ma, Charlie [Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States)] [Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States)

2014-05-15T23:59:59.000Z

440

Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma  

SciTech Connect (OSTI)

Purpose: To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT). Patients and Methods: A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains. Results: With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged {<=}7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions. Conclusions: DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

Yang, Joanna C.; Dharmarajan, Kavita V. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wexler, Leonard H. [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); La Quaglia, Michael P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Happersett, Laura [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

2012-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Phase 1 of the Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

For more than 40 years, the US government made plutonium for nuclear weapons at the Hanford Site in southeastern Washington State. Radioactive materials were released to both the air and water from Hanford. People could have been exposed to these materials, called radionuclides. The Hanford Environmental Dose Reconstruction (HEDR) Project is a multi-year scientific study to estimate the radiation doses the public may have received as a results of these releases. The study began in 1988. During the first phase, scientists began to develop and test methods for reconstructing the radiation doses. To do this, scientists found or reconstructed information about the amount and type of radionuclides that were released from Hadford facilities, where they traveled in environment, and how they reached people. Information about the people who could have been exposed was also found or reconstructed. Scientists then developed a computer model that can estimate doses from radiation exposure received many years ago. All the information that had been gathered was fed into the computer model. Then scientists did a test run'' to see whether the model was working properly. As part of its test run,'' scientists asked the computer model to generate two types of preliminary results: amounts of radionuclides in the environment (air, soil, pasture grass, food, and milk) and preliminary doses people could have received from all the routes of radiation exposure, called exposure pathways. Preliminary dose estimates were made for categories of people who shared certain characteristics and for the Phase 1 population as a whole. 26 refs., 48 figs.

Not Available

1990-07-20T23:59:59.000Z

442

Supporting User Adaptation in Adaptive Hypermedia Applications Hongjing Wu, GeertJan Houben, Paul De Bra  

E-Print Network [OSTI]

applications, named AHAM (for Adaptive Hypermedia Application Model) [DHW99]. In AHAM knowledge is represented through hierarchies of large composite abstract concepts as well as small atomic ones. AHAM also divides. In this paper, we concentrate on the user modeling aspects of AHAM, but also describe how they relate

De Bra, Paul

443

Supporting User Adaptation in Adaptive Hypermedia Applications Hongjing Wu, Geert-Jan Houben, Paul De Bra  

E-Print Network [OSTI]

applications, named AHAM (for Adaptive Hypermedia Application Model) [DHW99]. In AHAM knowledge is represented through hierarchies of large composite abstract concepts as well as small atomic ones. AHAM also divides. In this paper, we concentrate on the user modeling aspects of AHAM, but also describe how they relate

Houben, Geert-Jan

444

Restricted Complexity Framework for Nonlinear Adaptive Control in Complex Systems  

SciTech Connect (OSTI)

Control law adaptation that includes implicit or explicit adaptive state estimation, can be a fundamental underpinning for the success of intelligent control in complex systems, particularly during subsystem failures, where vital system states and parameters can be impractical or impossible to measure directly. A practical algorithm is proposed for adaptive state filtering and control in nonlinear dynamic systems when the state equations are unknown or are too complex to model analytically. The state equations and inverse plant model are approximated by using neural networks. A framework for a neural network based nonlinear dynamic inversion control law is proposed, as an extrapolation of prior developed restricted complexity methodology used to formulate the adaptive state filter. Examples of adaptive filter performance are presented for an SSME simulation with high pressure turbine failure to support extrapolations to adaptive control problems.

Williams, Rube B. [Los Alamos National Laboratory, P.O. Box 1663, MS K575, Los Alamos, NM 87545 (United States)

2004-02-04T23:59:59.000Z

445

Decision management for the Hanford Environmental Dose Reconstruction Project  

SciTech Connect (OSTI)

The Hanford Environmental Dose Reconstruction (HEDR) Project is in the process of developing estimates for the radiation doses that individuals and population groups may have received as a result of past activities at the Hanford Reservation in Eastern Washington. A formal decision-aiding methodology has been developed to assist the HEDR Project in making significant and defensible decisions regarding how this study will be conducted. These decisions relate primarily to policy (e.g., the appropriate level of public participation in the study) and specific technical aspects (e.g., the appropriate domain and depth of the study), and may have significant consequences with respect to technical results, costs, and public acceptability.

Roberds, W.J.; Haerer, H.A. (Golder Associates, Inc., Redmond, WA (United States)); Winterfeldt, D.V. (Decision Insights, Laguna Beach, CA (United States))

1992-04-01T23:59:59.000Z

446

Dose estimates in a loss of lead shielding truck accident.  

SciTech Connect (OSTI)

The radiological transportation risk & consequence program, RADTRAN, has recently added an updated loss of lead shielding (LOS) model to it most recent version, RADTRAN 6.0. The LOS model was used to determine dose estimates to first-responders during a spent nuclear fuel transportation accident. Results varied according to the following: type of accident scenario, percent of lead slump, distance to shipment, and time spent in the area. This document presents a method of creating dose estimates for first-responders using RADTRAN with potential accident scenarios. This may be of particular interest in the event of high speed accidents or fires involving cask punctures.

Dennis, Matthew L.; Osborn, Douglas M.; Weiner, Ruth F.; Heames, Terence John (Alion Science & Technology Albuquerque, NM)

2009-08-01T23:59:59.000Z

447

Analysis Approach and Data Package for Mayak Public Doses  

SciTech Connect (OSTI)

Historical activities at facilities producing nuclear materials for weapons released radioactivity into the air and water. Past studies in the United States have evaluated the release, atmospheric transport and environmental accumulation of 131I from the nuclear facilities at Hanford in Washington State and the resulting dose to members of the public (Farris et al. 1994). A multi-year dose reconstruction effort (Mokrov et al. 2004) is also being conducted to produce representative dose estimates for members of the public living near Mayak, Russia, from atmospheric releases of 131I at the facilities of the Mayak Production Association. The approach to calculating individual doses to members of the public from historical releases of airborne 131I has the following general steps: Construct estimates of releases 131I to the air from production facilities. Model the transport of 131I in the air and subsequent deposition on the ground and vegetation. Model the accumulation of 131I in soil, water and food products (environmental media). Calculate the dose for an individual by matching the appropriate lifestyle and consumption data for the individual to the concentrations of 131I in environmental media at their residence location. A number of computer codes were developed to facilitate the study of airborne 131I emissions at Hanford. Of particular interest is DESCARTES code that modeled accumulation of 131I in environmental media (Miley et al. 1994). In addition, the CIDER computer code estimated annual doses to individuals (Eslinger et al. 1994) using the equations and parameters specific to Hanford (Snyder et al. 1994). Several of the computer codes developed to model 131I releases from Hanford are general enough to be used for other facilities. Additional codes have been developed, including the new individual dose code CiderF (Eslinger and Napier 2013), and applied to historical releases of 131I from Mayak. This document provides a data package that identifies computer code runs and associated input and output files prepared for the purpose of calculating doses to members of the public from atmospheric releases of 131I at the Mayak Production Association for the time period 1948 through 1972.

Eslinger, Paul W.; Napier, Bruce A.

2013-09-18T23:59:59.000Z

448

Adaptive Non-Boltzmann Monte Carlo  

SciTech Connect (OSTI)

This manuscript generalizes the use of transition probabilities (TPs) between states, which are efficient relative to histogram procedures in deriving system properties. The empirical TPs of the simulation depend on the importance weights and are temperature-specific, so they are not conducive to accumulating statistics as weights change or to extrapolating in temperature. To address these issues, the authors provide a method for inferring Boltzmann-weighted TPs for one temperature from simulations run at other temperatures and/or at different adaptively varying importance weights. They refer to these as canonical transition probabilities (CTPs). System properties are estimated from CTPs. Statistics on CTPs are gathered by inserting a low-cost easily-implemented bookkeeping step into the Metropolis algorithm for non-Boltzmann sampling. The CTP method is inherently adaptive, can take advantage of partitioning of the state space into small regions using either serial or (embarrassingly) parallel architectures, and reduces variance by avoiding histogramming. They also demonstrate how system properties may be extrapolated in temperature from CTPs without the extra memory required by using energy as a microstate label. Nor does it require the solution of non-linear equations used in histogram methods.

Fitzgerald, M.; Picard, R.R.; Silver, R.N.

1998-06-01T23:59:59.000Z

449

Adaptive Radiotherapy for Prostate Cancer Using Kilovoltage Cone-Beam Computed Tomography: First Clinical Results  

SciTech Connect (OSTI)

Purpose: To evaluate the first clinical results of an off-line adaptive radiotherapy (ART) protocol for prostate cancer using kilovoltage cone-beam computed tomography (CBCT) in combination with a diet and mild laxatives. Methods and Materials: Twenty-three patients began treatment with a planning target volume (PTV) margin of 10 mm. The CBCT scans acquired during the first six fractions were used to generate an average prostate clinical target volume (AV-CTV), and average rectum (AV-Rect). Using these structures, a new treatment plan was generated with a 7-mm PTV margin. Weekly CBCT scans were used to monitor the CTV coverage. A diet and mild laxatives were introduced to improve image quality and reduce prostate motion. Results: Twenty patients were treated with conform ART protocol. For these patients, 91% of the CBCT scans could be used to calculate the AV-CTV and AV-Rect. In 96% of the follow-up CBCT scans, the CTV was located within the average PTV. In the remaining 4%, the prostate extended the PTV by a maximum of 1 mm. Systematic and random errors for organ motion were reduced by a factor of two compared with historical data without diet and laxatives. An average PTV reduction of 29% was achieved. The volume of the AV-Rect that received >65 Gy was reduced by 19%. The mean dose to the anal wall was reduced on average by 4.8 Gy. Conclusions: We safely reduced the high-dose region by 29%. The reduction in irradiated volume led to a significant reduction in the dose to the rectum. The diet and laxatives improved the image quality and tended to reduce prostate motion.

Nijkamp, Jasper [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Pos, Floris J. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)], E-mail: f.pos@nki.nl; Nuver, Tonnis T.; Jong, Rianne de; Remeijer, Peter; Sonke, Jan-Jakob; Lebesque, Joos V. [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

2008-01-01T23:59:59.000Z

450

adaptations impaired oxidative: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

learning of phonetic consistency and generalized neural adaptation deficits in dyslexia MIT - DSpace Summary: Developmental dyslexia is a neurological condition that...

451

Applying Climate Information for Adaptation Decision-Making:...  

Open Energy Info (EERE)

Applying Climate Information for Adaptation Decision-Making: A Guidance and Resource Document Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Applying Climate...

452

adaptive phase tracking: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

de 107 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, VOL. 9, NO. 7, OCTOBER 1999 1025 Adaptive Motion Tracking Block Matching Algorithms for Video Coding...

453

USE OF QUADRATIC MODELS WITH MESH ADAPTIVE DIRECT ...  

E-Print Network [OSTI]

Mar 6, 2011 ... differences remain: the mesh adaptive direct search (MADS [6, ... implicit filtering method described in [19] may also be viewed as a hybrid...

Le Digabel

2011-03-06T23:59:59.000Z

454

Development based climate change adaptation and mitigation-conceptual...  

Open Energy Info (EERE)

countries AgencyCompany Organization: Lawrence Berkeley National Laboratory (LBNL) Sector: Climate, Energy, Land, Water Topics: Adaptation, Co-benefits assessment, -...

455

adaptive learning environments: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

In Saarbrucken we are developing the web-based, user-adaptive, interactive learning environment Active 69 Medium-based design: Extending a medium to create and exploratory...

456

Modeling and adaptive control of indoor unmanned aerial vehicles  

E-Print Network [OSTI]

The operation of unmanned aerial vehicles (UAVs) in constrained indoor environments presents many unique challenges in control and planning. This thesis investigates modeling, adaptive control and trajectory optimization ...

Michini, Bernard (Bernard J.)

2009-01-01T23:59:59.000Z

457

Optimization Online - An Adaptive Partition-based Approach for ...  

E-Print Network [OSTI]

Dec 2, 2014 ... Our computational results show that the proposed adaptive partition-based approach converges very fast to a small partition for our test...

Yongjia Song

2014-12-02T23:59:59.000Z

458

adaptive signal model: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Michael Richard 1990-11-13 2 UNCORRECTED 2 Stochastic adaptive control model for traffic signal systems Environmental Sciences and Ecology Websites Summary: process. The model...

459

adaptive social immunity: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to climate risk in the coffee sector of Chiapas, Mexico Environmental Sciences and Ecology Websites Summary: Social identity, perception and motivation in adaptation to...

460

adaptive control scheme: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

systems concepts. Based Alpcan, Tansu 5 Adaptive predictive lighting controllers for daylight artificial light integrated schemes. Open Access Theses and Dissertations Summary:...

Note: This page contains sample records for the topic "dose radiation-induced adaptive" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.