7 research outputs found
Existence, Uniqueness, Regularity and Long-term Behavior for Dissipative Systems Modeling Electrohydrodynamics
We study a dissipative system of nonlinear and nonlocal equations modeling
the flow of electrohydrodynamics. The existence, uniqueness and regularity of
solutions is proven for general initial data in two space
dimensions and for small data in data in three space dimensions. The existence
in three dimensions is established by studying a linearization of a relative
entropy functional. We also establish the convergence to the stationary
solution with a rate
Local Changes in Lipid Composition to Match Membrane Curvature
A continuum mechanical model based on the Helfrich Hamiltonian is devised to investigate the
coupling between lipid composition and membrane curvature. Each monolayer in the bilayer is modeled as a
freely deformable surface with a director field for lipid orientation. A scalar field for the mole fraction of two
lipid types accounts for local changes in composition. It allows lipids to access monolayer regions favorable
to their intrinsic curvature at the expense of increasing entropic free energy. Hemifusion is one of the key fusion
intermediates with regions of both positive and negative membrane curvature and where proteins must
supply energy in order to bring about large elastic distortions. Using a numerical gradient descent scheme,
minimal energy axisymmetric shapes of hemifusion diaphragms are calculated for varying radii. Previous
studies assumed a fixed, weighted average for spontaneous curvature. Allowing for local changes in spontaneous
curvature yields energies and forces of expansion significantly lower than those obtained from a fixed
composition