Showing papers by "Bidhan Chandra Bag published in 2012"
TL;DR: The simulation results show that mean protein folding time first increases with driving frequency and then decreases passing through a maximum, whereas unlike one-dimensional barrier crossing problems, the external oscillating force field induces both stabilization or destabilization of the denatured state of a protein.
Abstract: We have studied the effects of an external sinusoidal force in protein folding kinetics. The externally applied force field acts on the each amino acid residues of polypeptide chains. Our simulation results show that mean protein folding time first increases with driving frequency and then decreases passing through a maximum. With further increase of the driving frequency the mean folding time starts increasing as the noise-induced hoping event (from the denatured state to the native state) begins to experience many oscillations over the mean barrier crossing time period. Thus unlike one-dimensional barrier crossing problems, the external oscillating force field induces both \emph{stabilization or destabilization of the denatured state} of a protein. We have also studied the parametric dependence of the folding dynamics on temperature, viscosity, non-Markovian character of bath in presence of the external field.
13 citations
TL;DR: In this paper, a correlation between two noise processes driving the thermally activated particles in a symmetric triple well potential, may cause a symmetry breaking and a difference in relative stability of the two side wells with respect to the middle one.
Abstract: A correlation between two noise processes driving the thermally activated particles in a symmetric triple well potential, may cause a symmetry breaking and a difference in relative stability of the two side wells with respect to the middle one. This leads to an asymmetric localization of population and splitting of Kramers' rate of escape from the middle well, ensuring a preferential distribution of the products in the course of a parallel reaction.
3 citations
TL;DR: In this article, the authors studied the relaxation of the incoherent state to the coherent state of coupled phase oscillators with time delay in terms of lifetime both in the presence and absence of noise.
Abstract: In this paper we have studied the relaxation of the incoherent state to the coherent state of coupled phase oscillators with time delay in terms of lifetime of the incoherent state both in the presence and absence of noise. To make the present study general we have considered both Gaussian and non Gaussian noises. Our investigation shows that the mean lifetime (MLT) decreases exponentially as the coupling strength among the oscillators grows. It also shows that MLT changes non monotonically with an increase in time delay. Another observation is that the mean lifetime increases exponentially as a function of noise strength for white noise. However, for colour noise, it grows linearly with an increase in noise strength. Enhancement of the correlation time of the coloured noise suppresses MLT. The rate of suppression is faster for non-Gaussian noise compared to the Gaussian case. Finally, we have observed that the mean lifetime increases exponentially as the noise behaviour deviates more from the Gaussian characteristics.
3 citations
TL;DR: In this paper, an upper bound of rate of change of information entropy with time and its deviation from the time derivative of the entropy was derived based on the Fokker-Planck description of the stochastic processes and the Schwarz inequality principle.
Abstract: In this paper we have studied information dynamics of both internal and external noises driven harmonic oscillator. Based on the Fokker–Planck description of the stochastic processes and the Schwarz inequality principle we have calculated upper bound of rate of change of information entropy with time and its deviation from the time derivative of the entropy. The bound and the deviation monotonically decreases to zero during the relaxation of a given nonequilibrium state to a stationery state. The relaxation time increase with increase of noise correlation time of the internal colored thermal noise but it is independent on the correlation time of the external colored noise. However, an extremum behavior appears in the variation of the bound as a function of parameter of the system such as damping strength, noise correlation time of thermal and nonthermal noises etc.
2 citations