ABSTRACT
We study the nonlinear response of a stochastic bistable system driven by both a weak periodic signal and a dichotomic noise in terms of stochastic phase synchronization. We show that the effect of noise-induced phase synchronization can be significantly enhanced by the addition of a dichotomic noise.
ABSTRACT
Juvenile paddlefish prey upon single zooplankton by detecting a weak electric signature resulting from its feeding and swimming motions. Moreover, it has recently been shown that paddlefish make use of stochastic resonance near the threshold for prey detection: a process termed behavioral stochastic resonance. But this process depends upon an external source of electric noise. A swarm of plankton, for example, Daphnia, can provide this noise. Assuming that juvenile paddlefish attack single Daphnia as outliers in the vicinity of the swarm, making use of noise from the swarm, we calculate the spatial distribution of the average phase locking period for the subthreshold signals acting at the paddlefish rostrum. Numeric evaluation of analytic formulas supports the notion of a noise-induced widening of the capture area quantitatively.
Subject(s)
Animal Communication , Daphnia/physiology , Fishes/physiology , Models, Biological , Population Dynamics , Predatory Behavior/physiology , Stochastic Processes , Algorithms , Animals , Computer Simulation , Electric Organ/physiology , Models, StatisticalABSTRACT
The phenomenon of noise-induced transport in ratchet devices offers an explanation for directed motion on the molecular scale observed in many biological systems. Net transport through a series of discrete states, occurring in cyclic processes or reactions, can be related to widely investigated continuous ratchet models in the context of thermally activated transitions. The transport process can be described effectively in terms of two characteristic coefficients: velocity and diffusion. Their relation to model parameters and limitations for the ratchet mechanism are discussed in this paper. As an application we consider a four-state model for uphill transmembrane transport and compare theoretical results with existing data from a related experiment.
