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Full-Text Articles in Physics
Substrate Rigidity Deforms And Polarizes Active Gels, Shiladitya Banerjee, M. C. Marchetti
Substrate Rigidity Deforms And Polarizes Active Gels, Shiladitya Banerjee, M. C. Marchetti
Physics - All Scholarship
We present a continuum model of the coupling between cells and substrate that accounts for some of the observed substrate-stiffness dependence of cell properties. The cell is modeled as an elastic active gel, adapting recently developed continuum theories of active viscoelastic fluids. The coupling to the substrate enters as a boundary condition that relates the cell's deformation field to local stress gradients. In the presence of activity, the coupling to the substrate yields spatially inhomogeneous contractile stresses and deformations in the cell and can enhance polarization, breaking the cell's front-rear symmetry.
Active Jamming: Self-Propelled Soft Particles At High Density, Silke Henkes, Yaouen Fily, M. Christina Marchetti
Active Jamming: Self-Propelled Soft Particles At High Density, Silke Henkes, Yaouen Fily, M. Christina Marchetti
Physics - All Scholarship
We study numerically the phases and dynamics of a dense collection of self-propelled particles with soft repulsive interactions in two dimensions. The model is motivated by recent in vitro experiments on confluent monolayers of migratory epithelial and endothelial cells. The phase diagram exhibits a liquid phase with giant number fluctuations at low packing fraction and high self-propulsion speed and a jammed phase at high packing fraction and low self-propulsion speed. The dynamics of the jammed phase is controlled by the low frequency modes of the jammed packing.
Hydrodynamic And Rheology Of Active Polar Filaments, Tanniemola B. Liverpool, M. Cristina Marchetti
Hydrodynamic And Rheology Of Active Polar Filaments, Tanniemola B. Liverpool, M. Cristina Marchetti
Physics - All Scholarship
The cytoskeleton provides eukaryotic cells with mechanical support and helps them perform their biological functions. It is a network of semiflexible polar protein filaments and many accessory proteins that bind to these filaments, regulate their assembly, link them to organelles and continuously remodel the network. Here we review recent theoretical work that aims to describe the cytoskeleton as a polar continuum driven out of equilibrium by internal chemical reactions. This work uses methods from soft condensed matter physics and has led to the formulation of a general framework for the description of the structure and rheology of active suspension of …