We disc uss nonlinear Fokker-Planck models describing diff usion processes with particle interactions. These models are motivated by the study of many particle systems in biology\, and arise as the population- level description of a stochastic particle-based m odel. In particular\, we consider a system of impe netrable diffusing spheres and use the method of m atched asymptotic expansions to obtain a systemati c model reduction. In the second part of the talk\ , we discuss how this method can be used to derive an effective transport equation in heterogeneous domains\, such as porous media or crowded environm ents. A nice feature of this approach is that it c an easily account for macroscopic gradients in por osity or crowding.

LOCATION:Seminar Room 1\, Newton Institute CONTACT:info@newton.ac.uk END:VEVENT END:VCALENDAR