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2013-01-01

Qihua Huang, Laura Parshotam, Hao Wang, Caroline Bampfylde, Mark A. Lewis

Mathematical models have been widely applied to perform chemical risk assessments on biological populations for a variety of ecotoxicological pro- cesses. In this paper, by introducing a dose-dependent mortality rate function, we formulate a toxin-dependent aquatic population model that...

2006-01-01

Chad M. Topaz, Andrea L. Bertozzi, Mark A. Lewis

We construct a continuum model for biological aggregations in which individuals experience long-range social attraction and short range dispersal. For the case of one spatial dimension, we study the steady states analytically and numerically. There exist strongly nonlinear states with compact...

2000

Ballantyne, David, Chan, Hubert, Kouritzin, Michael

Particle approximations are used to track a maneuvering signal given only a noisy, corrupted sequence of observations, as are encountered in target tracking and surveillance. The signal exhibits nonlinearities that preclude the optimal use of a Kalman filter. It obeys a stochastic differential...

2004

Zhao, Xingqiu, Long, Hongwei, McCrosky, Jesse, Kim, Surrey, Kouritzin, Michael

In this paper, we discuss multi-target tracking for a submarine model based on incomplete observations. The submarine model is a weakly interacting stochastic dynamic system with several submarines in the underlying region. Observations are obtained at discrete times from a number of sonobuoys...

2011-01-01

Fagan, W. F., Jin, Y., Bishop, J. G., Marleau, J. M., Lewis, Mark A.

The relative importance of plant facilitation and competition during primary succession depends on the development of ecosystem nutrient pools, yet the interaction of these processes remains poorly understood. To explore how these mechanisms interact to drive successional dynamics, we devised a...

2014-01-01

Jonathan R. Potts, Karl Mokross, Mark A. Lewis

Collective phenomena, whereby agent –agent interactions determine spatial patterns, are ubiquitous in the animal kingdom. On the other hand, movement and space use are also greatly influenced by the interactions between animals and their environment. Despite both types of interaction...

2020-05-19

Stephanie J. Peacock, Martin Krkošek, Mark A. Lewis, Péter K. Molnár

Migrations allow animals to track seasonal changes in resources, find mates, and avoid harsh climates, but these regular, longdistance movements also have implications for parasite dynamics and animal health. Migratory animals have been dubbed “superspreaders” of infection, but migration can also...

2008-01-01

Potapov, A. B., Lewis, Mark A.

We consider the model of invasion prevention in a system of lakes that are connected via traffic of recreational boats. It is shown that, in presence of an Allee effect, the general optimal control problem can be reduced to a significantly simpler stationary optimization problem of optimal...

2013-01-01

Krkošek, M., Ashander, J., Lewis, Mark A., Frazer, N.

The exchange of native pathogens between wild and domesticated animals can lead to novel disease threats to wildlife. However, the dynamics of wild host-parasite systems exposed to a reservoir of domesticated hosts are not well understood. A simple mathematical model reveals that the spill-back...

2012-01-01

Poulin, R., Connors, B. M., Krkosek, M., Lewis, Mark A.

Allee effects are thought to mediate the dynamics of population colonization, particularly for invasive species. However, Allee effects acting on parasites have rarely been considered in the analogous process of infectious disease establishment and spread. We studied the colonization of...