In many of the models applied to simulations of turbulent transport and turbulent combustion, the mixing between particles is used to reflect the influence of the continuous diffusion terms in the transport equations. Stochastic particles with properties and mixing can be used not only for simulating turbulent combustion, but also for modeling a large spectrum of physical phenomena. Traditional...

Species extinction occurs regularly and unavoidably in ecological systems. The time scales for extinction can broadly vary and inform on the ecosystem’s stability. We study the spatio-temporal extinction dynamics of a paradigmatic population model where three species exhibit cyclic competition. The cyclic dynamics reflects the nonequilibrium nature of the species interactions. While previous wo...

Noise and spatial degrees of freedom characterize most ecosystems. Some aspects of their influence on the coevolution of populations with cyclic interspecies competition have been demonstrated in recent experiments [e.g., B. Kerr, Nature (London) 418, 171 (2002)10.1038/nature00823]. To reach a better theoretical understanding of these phenomena, we consider a paradigmatic spatial model where th...

catecholamine-induced desensitization of adenylate cyclase in human neutrophils have been investigated as has the ability of hydrocortisone to modify such alterations. Incubation of human neutrophils with isoproterenol for 3 h in vitro resulted in an 86% reduction in the ability of isoproterenol to stimulate cyclic AMP accumulation in the cells. Two types of receptor alterations were documented...

Receptors for VIP in mouse peritoneal macrophages (MPM) were examined using [125I]labeled VIP as ligand. The receptor binding was rapid, reversible, saturable, specific, and dependent on time, pH, temperature and cell concentration. At 15 degrees C, the stoichiometric data suggested the presence of two classes of VIP receptors with Kd values of 1.05 +/- 0.2 and 66.4 +/- 11.0 nM and binding capa...

cAMP-binding ectoprotein (Gce1) and lipoprotein lipase (LPL) are anchored to plasma membranes of rat adipocytes by glycosylphosphatidylinositol (GPI) moieties as demonstrated by cleavage by bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), reactivity with anti-crossreacting determinant antibodies (anti-CRD), and metabolic labeling with radiolabeled palmitic acid and myo-inositol...

Interactions between hosts and parasites have been hypothesized to cause winnerless coevolution, called Red Queen dynamics. The canonical Red Queen dynamics assume that all interacting genotypes of hosts and parasites undergo cyclic changes in abundance through negative frequency-dependent selection, which means that any genotype could become frequent at some stage. However, this prediction can...

Economic (business) cycles are some of the most noted features of market economies, also ranked among the most serious of economic problems. Despite long historical persistence, the nature and the origin of business cycles remain controversial. In this paper we investigate the problem of the nature of business cycles from the positions of the market systems viewed as complex systems of many int...

Forest-insect systems frequently show cyclic dynamics which has been of considerable interest to both experimental and theoretical ecologists. One important issue has been the manner in which density-dependence acting on the host population through resource competition influences the likelihood of population cycles. Existing models make contradictory predictions. Here, we explore two models tha...