June, 11 2008 - from 12 to 13

                               Aula Gerace  - Department of Computer Science

                                               Speaker: Prof. DAN GILLESPIE

                                         Title:  "Stochastic Chemical Kinetics"


                     The time evolution of a well-stirred chemically reacting system
           is traditionally modeled by a set of coupled ordinary differential equations
                 called the reaction rate equation (RRE).  The resulting picture of
               continuous deterministic evolution is, however, valid only for infinitely
             large systems.  That condition is usually well approximated in laboratory
             test tube systems.  But in biological systems formed by single living cells,
                the small population numbers of some reactant species can result in
            dynamical behavior that is noticeably discrete rather than continuous, and
                 stochastic rather than deterministic.  In that case, a more physically
          accurate mathematical modeling is obtained by using the machinery of Markov
              process theory, specifically, the chemical master equation (CME) and the
              stochastic simulation algorithm (SSA).  After reviewing the theoretical
               foundations of stochastic chemical kinetics, we will describe a way to
         approximate the SSA by a faster simulation procedure, and then show how this
           way also provides a logical bridge between the CME/SSA description and the
                                                                 RRE description.

                                      Department of Computer Science
                                   Largo Bruno Pontecorvo 3, 56127 Pisa