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21.
N. Kouvaris A. Provata 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,70(4):535-541
Long distance reactive and diffusive coupling is introduced in a spatially extended nonlinear stochastic network of interacting
particles. The network serves as a substrate for Lotka-Volterra dynamics with 3rd order nonlinearities. If the network includes
only local nearest neighbour interactions, the system organizes into a number of local asynchronous oscillators. It is shown
that (a) Introduction of all-to-all coupling in the network leads the system into global, center-type, conservative oscillations
as dictated by the mean-field dynamics. (b) Introduction of reactive coupling to the network leads the system to intermittent
oscillations where the trajectories stick for short times in bounded regions of space, with subsequent jumps between different
bounded regions. (c) Introduction of diffusive coupling to the system does not alter the dynamics for small values of the
diffusive coupling pdiff, while after a critical value pdiff
c the system synchronizes into a limit cycle with specific frequency, deviating non-trivially from the mean-field center-type
behaviour. The frequency of the limit cycle oscillations depends on the reaction rates and on the diffusion coupling. The
amplitude σ of the limit cycle depends on the control parameter pdiff. 相似文献
22.
Instantaneous phase difference, synchronization index and mutual information are considered in order to detect phase transitions, collective behaviours and synchronization phenomena that emerge for different levels of diffusive and reactive activity in stochastic networks. The network under investigation is a spatial 2D lattice which serves as a substrate for Lotka-Volterra dynamics with 3rd order nonlinearities. Kinetic Monte Carlo simulations demonstrate that the system spontaneously organizes into a number of asynchronous local oscillators, when only nearest neighbour interactions are considered. In contrast, the oscillators can be correlated, phase synchronized and completely synchronized when introducing different interactivity rules (diffusive or reactive) for nearby and distant species. The quantitative measures of synchronization show that long distance diffusion coupling induces phase synchronization after a well defined transition point, while long distance reaction coupling induces smeared phase synchronization. 相似文献
23.
We study the size distribution of coding and non-coding regions in DNA sequences. For most organisms we observe that the size distribution P
c(S) of the coding regions of size S shows short range distribution, whereas the size distribution of the non-coding regions follows a power-law decay P
nc(S) S
–1 – , with power exponents indicating clear long-range behavior. We argue, using the Generalized Central Limit Theorem, that the long-range distributions observed in the non-coding are related to the lower level clustering of purines and pyrimidines (1d islands) which follow similar long-range laws. We also address the question of clustering of coding segments in the two complementary strands of DNA. We observe a short-range clustering of coding regions in both strands, expressed by an exponential decay in the clustering size distribution. The decay exponent expresses the degree of short-range correlations and the deviation from random clustering. 相似文献
24.
O. A. Chichigina G. A. Tsekouras A. Provata 《Journal of Experimental and Theoretical Physics》2006,103(4):623-631
A thermodynamic approach is developed for reactive dynamic models restricted to substrates of arbitrary dimensions, including
fractal substrates. The thermodynamic formalism is successfully applied to the lattice Lotka-Volterra (LLV) model of autocatalytic
reactions on various lattice substrates. Different regimes of reactions described as phases, and phase transitions, are obtained
using this approach. The predictions of thermodynamic theory confirm extensive numerical kinetic Monte Carlo simulations on
square and fractal lattices. Extensions of the formalism to multispecies LLV models are also presented.
This article was submitted by the authors in English. 相似文献