[Show abstract][Hide abstract] ABSTRACT: In this paper, the dynamics of the coupled Hodgkin-Huxley neurons (HHn)
is investigated. At first, appropriate initial values and reasonable
parameters are used to induce spiral wave in the coupled HHn. The
temperature and channel noise are also considered to induce the birth
and transition of spiral wave, respectively. It is found that the spiral
wave can be generated in the absence of channel noise, and the seed of
spiral wave cannot grow up when the intensity of channel noise exceeds
the threshold (the noise is distributed on all the channels and s
describes the membrane patch, the threshold is suggested with s = 3.2).
The spiral wave disappears and all the coupled HHn become homogeneous
when the temperature exceeds the threshold about T = 22°C.
Full-text · Article · Sep 2010 · International Journal of Modern Physics B
[Show abstract][Hide abstract] ABSTRACT: A stochastic cytosolic calcium oscillation model simultaneously driven by external noise and internal noise has been investigated by using the chemical Langevin equation method. When the extracellular stimulation is subthreshold, it is found that the internal-noise coherence resonance can be suppressed by the external noise, while the external-noise coherence resonance can be enhanced by modulating the internal-noise intensity. Besides a qualitative analysis with a competitive mechanism is given for the results, a further explanation is also provided theoretically by using the small noise approximation and bifurcation analysis.
[Show abstract][Hide abstract] ABSTRACT: Based on a copy number control model of bacterial plasmid, the internal noise near a given steady state is investigated by using the linear noise approximation. All the parameters are restricted to a certain region so that the time spent near the steady state is long enough and the absorbing state can be neglected. For the noise in the plasmid molecules, a transition occurs with increasing the noise in the signal molecules under certain conditions. A noise-reduction mechanism, noise suppression by noise, is found. More importantly, the critical condition for the occurrence of the noise-reduction effect is given in our theoretical treatment.
Full-text · Article · Mar 2008 · Physical Review E
[Show abstract][Hide abstract] ABSTRACT: Based on a coupled circadian oscillators model in mammals, the effects of the structural diversity, the external noise, and the internal noise on synchronization are discussed, respectively. It is found (i) the coupling plays a constructive role in the enhancement of synchronization, while the structural diversity plays a destructive role in the process of synchronous rhythm output. (ii) The synchronization can be enhanced by modulation of the external noise, while it can be suppressed by the internal noise.