As we acquire experience with the clinical and pharmacokinetic behavior of a drug, it is very desirable to capture this experience and its related information in the form of a population pharmacokinetic model, and then to relate the behavior of the model to the clinical effects of the drug or to a linked pharmacodynamic model. The purpose of population modeling is thus to describe and capture o...

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We investigate the inverse problem of simultaneously estimating the state and the spatial diffusion coefficient for an age-structured population model. The time evolution of the population is supposed to be known on a subdomain in space and age. We generalize to the infinite dimensional setting an adaptive observer originally proposed for finite dimensional systems.

We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better op...

Article history: Received 12 February 2010 Available online 13 April 2010 Submitted by P. Sacks

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The role of committed minorities in shaping public opinion has been recently addressed with the help of multiagent models. However, previous studies focused on homogeneous populations where zealots stand out only for their stubbornness. Here we consider the more general case in which individuals are characterized by different propensities to communicate. In particular, we correlate commitment w...

A stochastic generalization of the Ricker discrete population model is studied under the assumption that noise impacts the population reproduction rate. The obtained results demonstrate that the demographic-type stochastic noise increases the risk of the population extinction. In particular, the paper establishes conditions on the noise intensity under which the population will extinct even if ...

Introduction Conclusions References