Topology in Biology by Julia Yeomans

Explore the fascinating intersection of topology and biology in this 52-minute lecture by Julia Yeomans at the International Centre for Theoretical Sciences. Delve into the world of active matter, stochastic thermodynamics, and driven systems, focusing on how topological concepts apply to biological phenomena. Learn about active turbulence in dense matter, liquid crystal hydrodynamics, and the role of topological defects in cell behavior. Discover how confinement can harness active energy and influence cell division processes. Examine the transition to turbulence, vortex lattice formation, and the application of topological microfluidics in biological systems. Gain insights into cutting-edge research connecting statistical physics with living biological matter, and understand how these concepts contribute to our understanding of complex biological processes.

Stochastic Thermodynamics, Active Matter and Driven Systems
Topology in Biology
Active particles convert energy to motion Energy enters the system on a single particle level
Active turbulence
Active turbulence of cells?
Dense active matter and active turbulence
Liquid crystals
Continuum equations of liquid crystal hydrodynamics
Hydrodynamics of active systems
Continuum equations of active liquid crystal hydrodynamics
1. Active stress =active turbulence
Instabilities in active nematic
Active turbulence is characterized by
Active turbulence: topological defects are created and destroyed
Unidirectional Alignment of the Active Nematic
States of an Active Nematic in a Channel
Ceilidh Dance
Vortex lattice and active topological microfluidics
Transition to Turbulence
Vorticity distribution
Enstrophy kymograph
Directed percolation
Turbulent fraction as a function of activity
Confinement is a way of harnessing active energy
Cell division
2. Division acts as extensible stress
Flow field around +1/2 defect
Extrusion of dead cells - correlated to topological defects
Confinement by walls can lead to regular vortex lattices in active systems & topological microfluidics
Q&A