Mathematical Biology Seminar

Christel Hohenegger
Wednesday Jan. 15, 2010
3:05pm in LCB 215
Modeling Biological Fluids

Abstract: Cystic fibrosis is a common but lethal hereditary disease. One of its symptoms is the dehydration and increased stickiness of lung mucus, which results in frequent lung infections. Recent experimental approaches, termed microrheology, have attempted to extract the pertinent mechanical properties -- viscous and elastic material response -- from very small volumes of material by measuring statistical quantities such as auto- and cross-correlations of optically tracked beads. However, microrheology still lacks good understanding, and consequent technical tools, from basic physical modeling. Using the physical picture of two-point microrheology, I have developed and analyzed a Langevin-based model of the fluctuations of two beads in a viscoelastic fluid, allowing a direct mapping of statistical observables to mechanical properties. One application of this model is the study of mean passage time of a tracer through a mucosal layer which is relevant to the design of drug treatments.

I will also briefly introduce the topics of active suspensions. The dynamics of such suspensions -- bacterial baths are an important example -- has been the focus of much experimental and simulational work in recent years. Here I will describe and discuss a recent kinetic PDE model which has been the basis for my theoretical work on stability -- given in detail in my colloquium talk -- focusing on its underlying assumptions, structure, and some of its deficiencies.