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Title: Nonlinear dynamics of dipoles in microtubules: Pseudospin model

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Publication Date:
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
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Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review E
Additional Journal Information:
Journal Volume: 93; Journal Issue: 6; Related Information: CHORUS Timestamp: 2016-06-23 11:08:30; Journal ID: ISSN 2470-0045
American Physical Society
Country of Publication:
United States

Citation Formats

Nesterov, Alexander I., Ramírez, Mónica F., Berman, Gennady P., and Mavromatos, Nick E. Nonlinear dynamics of dipoles in microtubules: Pseudospin model. United States: N. p., 2016. Web. doi:10.1103/PhysRevE.93.062412.
Nesterov, Alexander I., Ramírez, Mónica F., Berman, Gennady P., & Mavromatos, Nick E. Nonlinear dynamics of dipoles in microtubules: Pseudospin model. United States. doi:10.1103/PhysRevE.93.062412.
Nesterov, Alexander I., Ramírez, Mónica F., Berman, Gennady P., and Mavromatos, Nick E. 2016. "Nonlinear dynamics of dipoles in microtubules: Pseudospin model". United States. doi:10.1103/PhysRevE.93.062412.
title = {Nonlinear dynamics of dipoles in microtubules: Pseudospin model},
author = {Nesterov, Alexander I. and Ramírez, Mónica F. and Berman, Gennady P. and Mavromatos, Nick E.},
abstractNote = {},
doi = {10.1103/PhysRevE.93.062412},
journal = {Physical Review E},
number = 6,
volume = 93,
place = {United States},
year = 2016,
month = 6

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevE.93.062412

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  • The mechanical and electrical properties, and information processing capabilities of microtubules are the permanent subject of interest for carrying out experiments in vitro and in silico, as well as for theoretical attempts to elucidate the underlying processes. In this paper, we developed a new model of the mechano–electrical waves elicited in the rows of very flexible C–terminal tails which decorate the outer surface of each microtubule. The fact that C–terminal tails play very diverse roles in many cellular functions, such as recruitment of motor proteins and microtubule–associated proteins, motivated us to consider their collective dynamics as the source of localizedmore » waves aimed for communication between microtubule and associated proteins. Our approach is based on the ferroelectric liquid crystal model and it leads to the effective asymmetric double-well potential which brings about the conditions for the appearance of kink–waves conducted by intrinsic electric fields embedded in microtubules. These kinks can serve as the signals for control and regulation of intracellular traffic along microtubules performed by processive motions of motor proteins, primarly from kinesin and dynein families. On the other hand, they can be precursors for initiation of dynamical instability of microtubules by recruiting the proper proteins responsible for the depolymerization process.« less
  • We describe the behavior of two coupled Bose-Einstein condensates in time-dependent (TD) trap potentials and TD Rabi (or tunneling) frequency using the two-mode approach. Starting from Bloch states, we succeed in obtaining analytical solutions for the TD Schroedinger equation and present a detailed analysis of the relative and geometric phases acquired by the wave function of the condensates, as well as their population imbalance. We also establish a connection between the geometric phases and constants of motion which characterize the dynamic of the system. Besides analyzing the affects of temporality on condensates that differ by hyperfine degrees of freedom (internalmore » Josephson effect), we also do present a brief discussion of a one-species condensate in a double-well potential (external Josephson effect)« less
  • The tubulins of Antarctic fishes, purified from brain tissue and depleted of microtubule-associated proteins (MAPs), polymerized efficiently in vitro to yield microtubules at near-physiological and supraphysiological temperatures (5, 10, and 20{degree}C). The dynamics of the microtubules at these temperatures were examined through the use of labeled guanosine 5{prime}-triphosphate (GTP) as a marker for the incorporation, retention, and loss of tubulin dimers. Following attainment of a steady state in microtubule mass at 20{degree}C, the rate of incorporation of ({sup 3}H)GTP (i.e., tubulin dimers) during pulses of constant duration decreased asymptotically toward a constant, nonzero value as the interval prior to labelmore » addition to the microtubule solution increased. Concomitant with the decreasing rate of label incorporation, the average length of the microtubules increased, and the number concentration of microtubules decreased. Thus, redistribution of microtubule lengths appears to be responsible for the time-dependent decrease in the rate of tubulin uptake. At each temperature, most of the incorporated label was retained by the microtubules during a subsequent chase with excess unlabeled GTP. In contrast, when microtubules were assembled do novo in the presence of ({alpha}-{sup 32}P)GTP at 5{degree}C and then exposed to a pulse of ({sup 3}H)GTP, the {sup 32}P label was lost over time during a subsequent chase with unlabeled GTP, whereas the {sup 3}H label was retained. Together, these results indicate that the microtubules of Antarctic fishes exhibit, at low temperatures, behaviors consistent both with subunit treadmilling and with dynamic instability and/or microtubule annealing.« less
  • The Hubbard model possesses a SU(2) pseudospin symmetry, which contains the U(1) phase symmetry as a subgroup. The existence of such symmetry leads to interesting experimental consequences if the U(1) phase symmetry is spontaneously broken, i.e., if the ground state is superconducting. In this case, there must exist a pair of {ital massive} collective modes which together with the usual Goldstone mode form a triplet representation of the psuedospin group. These collective modes are collisionless and couple directly to external charge disturbances with wave number {pi} and can therefore be detected experimentally as sharp resonances.
  • A two-sublattice peudospin model with distance-dependent interaction parameters is constructed for the ferroelectric phase transition at 307 K and for the isomorphous anomaly at 180 K in pentakis (methylammonium) undecachlorodibismuthate (III) (CH{sub 3}NH{sub 3}){sub 5}Bi{sub 2}Cl{sub 11}. A series of Monte Carlo simulations involving continuous degrees of freedom of deformation is performed for the model. The critical temperatures turn out about 23% lower than those resulting from the mean-field treatment for the three-dimensional fcc lattice in the absence of coupling with strain. An upward shift in the critical temperature then is found due to the coupling with the strain. Themore » multiple histogram method is used to obtain the theoretical predictions for the temperature dependence of the spontaneous polarization, dielectric susceptibility, and specific heat. The existence of a narrow peak in the specific heat and the ratio of the Curie constants close to 4 are confirmed. Evidence is given of the usefulness of the Monte Carlo method with fairly small simulation boxes for the studies of isomorphous anomalies.« less