Essential to each other, growth and exploration are jointly observed in populations, be it alive such as animals and cells or inanimate such as goods and money. But their ability to move, crucial to cope with uncertainty and optimize returns, is tempered by the space/time properties of the environment. We investigate how the environment shape optimal growth and population distribution in such c...

In metapopulations, the maintenance of local populations can depend on source–sink dynamics, where populations with positive growth rate seed populations with negative growth rate. The pattern and probability of successful dispersal among habitats can therefore be crucial in determining whether local populations will become rare or increase in abundance. We present here data on the dispersal st...

Motivated by issues arising in population dynamics, we consider the problem of iterating a given analytic function a number of times. We use the celebrated technique known as Carleman linearization that turns (for a certain class of functions) this problem into simply taking the power of a real number. We expand this method, showing in particular that it can be used for population models with i...

This study investigates the effect of competition between individuals on population dynamics when they compete for different resources during different seasons or during different growth stages. Individuals are assumed to compete for a single resource during each of these periods according to one of the following competition types: scramble, contest, or an intermediate between the two. The effe...

background: no study has been conducted yet on the process of adjustment of wives with their husbands’ erectile dysfunction in the transitional stages, and there is lack of understanding of this process in iran. objectives: a qualitative, grounded-theory study was designed to examine the process of adjustment of wives with their husbands’ erectile dysfunction in transitional stages. materials a...

We critically review dissipative particle dynamics ~DPD! as a mesoscopic simulation method. We have established useful parameter ranges for simulations, and have made a link between these parameters and x-parameters in Flory-Huggins-type models. This is possible because the equation of state of the DPD fluid is essentially quadratic in density. This link opens the way to do large scale simulati...

The m-testing of model specification pioneered by Newey (1985) and Tauchen (1985) and extended by White (1987) offers a general framework that unifies many specification tests in the literature. Within the m-testing framework, we consider how to test the hypothesis that a model is correctly specified in each of many groups in the population under study, where each of the groups offers only a fe...