Active Forces and Stresses in Living Matter

BIOENGINEERING SEMINAR
 
Abstract:
A key feature of living systems is their ability to consume chemical energy to actively generate the forces they use to move and change shape. These forces are typically generated at the nanometer scale by motor proteins, and transmitted to larger scales by networks of fibers. I will first discuss how these forces emerge from Brownian noise at the sub-micron scale. From an observer's point of view, there is a fundamental bound to the amount of information that can be recovered by monitoring the dynamics of such systems. I will propose a practical method, Stochastic Force Inference, that efficiently utilizes this limited information to reconstruct force fields and infer dissipative currents in Brownian systems. Moving to a larger scale, I will then discuss the transmission of these active forces through the cytoskeleton and the extracellular matrix. I will show how the nonlinear mechanical properties of these biopolymers crucially affect force transmission by selecting and amplifying contractile stresses. We experimentally confirm these results using a novel stress measurement technique, Nonlinear Stress Inference Microscopy.

Bio:
2016–current    Postdoctoral scholar, Princeton Center for Theoretical Science, Princeton University, Princeton, NJ, USA
2013–2016   Ph. D. in Theoretical Physics, Université Paris-Sud, Paris, France
2011–2012   M.S. summa cum laude in Theoretical Physics, École Normale Supérieure, Paris, France
2009–2011   B.S. summa cum laude in Physics, École Normale Supérieure, Paris, France
2009–2010   B.S. magna cum laude in Mathematics, École Normale Supérieure, Paris, France


Zoom link for attending remotely:  https://epfl.zoom.us/j/978102563