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2015-04-20

Kouritzin, Michael A.

A large class of discrete-time branching particle filters with Bayesian model selection ca-pabilities and effective resampling is introduced in algorithmic form, shown empirically to outperform the popular bootstrap algorithm and analyzed mathematically. The particles interact weakly in the...

2007-01-01

Nisbet, Roger, Anderson, Kurt E., McCauley, Edward, Lewis, Mark A.

Much ecological research involves identifying connections between abiotic forcing and population densities or distributions. We present theory that describes this relationship for populations in media with strong unidirectional flow (e.g., aquatic organisms in streams and rivers). Typically,...

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...

2019-01-01

Mark A. Lewis, Zhisheng Shuai, P. van den Driessche

A general framework for threshold parameters in population dynamics is developed using the concept of target reproduction numbers. This framework identies reproduction numbers and other threshold parameters in the literature in terms of their roles in population control. The framework is applied...

2001-01-01

M. R. OWEN, M. A. LEWIS

Observations on Mount St Helens indicate that the spread of recolonizing lupin plants has been slowed due to the presence of insect herbivores and it is possible that the spread of lupins could be reversed in the future by intense insect herbivory [Fagan, W. F. and J. Bishop (2000). Trophic...

2001-01-01

Clark, James S., Lewis, Mark A., Horvath, Lajos

For populations having dispersal described by fat‐tailed kernels (kernels with tails that are not exponentially bounded), asymptotic population spread rates cannot be estimated by traditional models because these models predict continually accelerating (asymptotically infinite) invasion. The...

2004-01-01

Lewis, Mark A., Potapov, A.

Predictions for climate change include movement of temperature isoclines up to 1000 meters per year, and this is supported by recent empirical studies. This paper considers effects of a rapidly changing environment on competitive outcomes between species. The model is formulated as a system of...

2002-01-01

Lewis, Mark A., Weinberger, H.F., Li, B.T.

The discrete-time recursion system \un+1=Q[\un] with \un(x) a vector of population distributions of species and Q an operator which models the growth, interaction, and migration of the species is considered. Previously known results are extended so that one can treat the local invasion of an...

2020-01-14

Nathan G. Marculis, Mark A. Lewis

The method of inside dynamics provides a theory that can track the dynamics of neutral gene fractions in spreading populations. However, the role of mutations has so far been absent in the study of the gene flow of neutral fractions via inside dynamics. Using integrodifference equations, we...