Description:

Title: Response dynamics of complex biophysical systems reveal underlying physics.

Speaker: Yasmine Meroz, Harvard University

Abstract: Einstein's seminal work on Brownian motion tells us that the probabilistic analysis of trajectories of freely diffusing particles sheds light on the physics of the system at hand. However for the dynamics of complex systems similar arguments may not apply directly, and we alternatively consider the response dynamics of the system to an external perturbation. In this talk we study responses of biological organisms to external stimuli, with the aim of uncovering dominant physical mechanisms at the microscopic level, such as stochastic transport, first-passage processes, and mechanical couplings, to name a few. In particular, we focus on the example of cellular chemotaxis - the orientation of a biological cell in the direction of a chemical gradient. We show that a probabilistic coarse-grained model relating whole cell response dynamics to chemical cues, gives a mechanistic understanding of the complex phenomenon of directional memory. Predictions of our model are verified both numerically and experimentally, confirming that this approach is effective in providing crucial insight into the physics of complex biological systems.

Host: Adilson Motter

Keywords: Physics, Astronomy, Complex Systems