This paper studies population models which have the following three ingredients: populations are divided into local subpopulations, local population dynamics are noniinear and random events occur locally in space. In this setting local stochastic phenomena have a systematic effect on average population density and this effect does not disappear in large populations. This result is an outcome of...

1. As plant invasions pose one of the greatest threats to biodiversity, it is critical to improve both our understanding of invasiveness and strategies for control. Much research into plant invasions and their management, including biological control, assumes strong demographic effects by natural enemies, including herbivores. However, the importance of natural enemies in the regulation of plan...

We study the dynamics of phenotypically structured populations in environments with fluctuations. In particular, using novel arguments from the theories of Hamilton-Jacobi equations with constraints and homogenization, we obtain results about the evolution of populations in environments with time oscillations, the development of concentrations in the form of Dirac masses, the location of the do...

Salmon farming has become a prosperous international industry over the last decades. Along with growth in the production farmed salmon, however, an increasing threat by pathogens has emerged. Of special concern is the propagation and spread of the salmon louse, Lepeophtheirus salmonis. In order to gain insight into this parasites population dynamics in large scale salmon farming system, we pres...

The intratumor heterogeneity has been recognized to characterize cancer cells impairing the efficacy of cancer treatments. We here propose an extension of constraint-based modeling approach in order to simulate metabolism of cell populations with the aim to provide a more complete characterization of these systems, especially focusing on the relationships among their components. We tested our m...

Title of Thesis: ASSESSMENT OF POPULATIONS WITH SPATIALLY EXPLICIT DYNAMICS AND THE CONSEQUENCES FOR MARINE PROTECTED AREAS Jennifer Barkman, Master of Science, 2011 Thesis directed by: Assistant Professor Michael Wilberg Center for Environmental Science Spatial processes can have important consequences in the population dynamics of fishes and marine invertebrates. Therefore fisheries managemen...

in this paper, a five–dimensional mathematical model is proposed for the transmission dynamics of hiv/aids within a population of varying size. in writing the model, we have divided the population under consideration into five sub classes of susceptible, infective, pre-aids, aids related complex and that of aids patients. the model has two non- negative equilibria namely, a disease free and the...

In this paper, we investigate a nonlocal periodic reaction-diffusion population model with stage structure. In the case of unbounded spatial domain, we establish the existence of the asymptotic speed of spread and show that it coincides with the minimal wave speed for monotone periodic traveling waves. In the case of bounded spatial domain, we obtain a threshold result on the global attractivit...