We study a stochastic two-species chemical reaction system with two mechanisms. One mechanism consists of chemical interactions which governs the overall drift of species amounts in the system; the other mechanism consists of resampling, branching or splitting which makes unbiased perturbative changes to species amounts. Our results show that in a system with a large but bounded capacity, certa...

Biological systems are typically very complex and need to be reduced before they are amenable to a thorough analysis. Also, they often possess functionally important dynamic features like bistability. In model reduction, it is sometimes more desirable to preserve the dynamic features only than to recover a good quantitative approximation. We present an approach to reduce the order of a bistable...

A two-component model is developed consisting of a discrete loop of cardiac cells that circulates action potentials as well as a pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of conduction velocity are given via experimentally measured functions. The dynamics of circulating pulses and the pacer's action are regulated by two threshold relations. P...

We report on Kerr nonlinearity and dispersive optical bistability of a Fabry-Perot optical resonator due to the displacement of ultracold atoms trapped within. In the driven resonator, such collective motion is induced by optical forces acting upon up to 10(5) 87Rb atoms prepared in the lowest band of a one-dimensional intracavity optical lattice. The longevity of atomic motional coherence allo...

The speed of memory structures is considerably slower than that of logic thus permitting a variety of approaches to achieving and using bistability. We used the bistability of a doubly clamped beam to attain two states that can potentially be used in the implementation of a nonvolatile memory [1]. The device is designed such that a bistable beam acts as the gate of an air gap transistor. In the...

High-resolution conductance measurements in niobium nanowires below the superconducting transition temperature are presented. Results are shown for a complete multistage elongation-compression cycle of a nanoscale contact. We focus on a bistability region which manifests itself as random telegraph noise. Density functional structural optimizations and conductance calculations using the non-equi...

We explore the rate-dependent dynamic response of periodically paced bullfrog (Rana catesbeiana) cardiac muscle. Alternans (2:2 behavior) occur in 35% of animals and 2:1 $ 1:1 bistability in 74% of animals. In addition, we observe 2:2 $ 2:1 bistablility. We discuss the implications of these results for two map-based models of cardiac dynamics. The high prevalence of bistability suggests that th...

We study a stochastic two-species chemical reaction system with two mechanisms. One mechanism consists of chemical interactions which govern the overall drift of species amounts in the system; the other mechanism consists of resampling, branching or splitting which makes unbiased perturbative changes to species amounts. Our results show that in a system with a large but bounded capacity, certai...

We present a catastrophe-based graphic model for understanding the optical bistability (OB) of an aqueous aerosol particle detected in light scattering. The model is shown to be in good agreement with hidden resonance experiments and indicates that OB in such particles can occur at an incident power level of <50 x 10(-9) W. This threshold is controlled principally by the quality factor of morph...

We investigate a type of bistability occurring in population systems where noise not only causes transitions between stable states, but also constructs the states themselves. We focus on the experimentally well-studied system of ants choosing between two food sources to illustrate the essential points, but the ideas are more general. The mean time for switching between the two bistable states o...