15 May 2009
Johan Paulsson
Department of Systems Biology
Harvard Medical School
Life in the cell is a complex battle between randomizing and correcting statistical forces: births and deaths of individual molecules create spontaneous fluctuations in abundances - noise - while many control circuits have evolved to eliminate, tolerate or exploit the noise. The net effect is difficult to predict for a number of reasons: the control circuits in turn consist of probabilistic chemical reactions, many reaction rates are nonlinear, cells grow and divide, many reaction networks are complex, and the kinetic details are poorly characterized. I will present various theoretical advances that allow us to deal with these problems in a more systematic fashion, and that enable us to rigorously analyze broad families of systems, and yet keep the assumptions intelligible and intuitive and keep the conclusions experimentally concrete.