Mathematical Biology Seminar Jim Sterling, Keck Graduate Institute Wednesday, Nov. 7, 2018 3:05pm in LCB 225 Models of Mucosal Electrophysiology Abstract: A mathematical model of mucosal surface biophysics is presented that utilizes a form of the Poisson-Boltzmann equation with ion-charged group dissociation constants to marry microscale continuum-electrostatics with ion-specific effects in glycan-rich environments. Ion-pairing or lyotropic effects are best-known in protein solubility (Hofmeister) but are observed in most any biological context in which they are studied. Large negatively-charged polysaccharides in animals serve as seas of carboxylates and sulfates at cell surfaces and in the mucosal glycocalyx where quantitative lyotropy for ion-exchange is reported. In this talk, we will describe a model of a mucosal surface as a tethered brush of i=1,M kinds of fixed charged-groups in which there are j=1,N kinds of free counterions that interact with the layer through an adjacent salt solution. The model is based on a balance of electrophoresis and diffusion but does not assume the Einstein electrical mobility relationship because the crowded macromolecular environment may allow substantial gel-like electrophoresis but maintain very low diffusivity. The model is used to simulate experimental work on the electrokinetics of soft-diffuse layers of in-vitro biohydrogels on a surface.