Science / Technology - Colloquium
Wednesday, February 11, 2009
4:00 PM-5:00 AM
Olin Hall
107
The dynamic behavior of complex liquids and soft materials is of great importance in a wide
range of disciplines. Computational studies of these phenomena are particularly demanding because
of the presence of disparate length and energy scales, the complicated coupling between the embedded
objects, and the hydrodynamic
ow eld and thermal
uctuations. In the rst part of this presen-
tation, I will introduce one such recently introduced particle-based mesoscale algorithm|stochastic
rotation dynamics|which solves the hydrodynamic equations by following the discrete time dynamics
of particles with continuous coordinates and velocities, using ecient multi-particle collisions. It will
be shown how the algorithm can be generalized to model dense
uids, immiscible binary and am-
phiphilic mixtures. The phase diagram of the entropically driven de-mixing transition and a detailed
analysis of the capillary wave spectrum for binary droplets will be presented. The second part of
my talk will focus on mesoscale modeling microtubule-motor interactions in gliding assays and living
cells. In living cells microtubules are often viewed as mechanically rigid compressive struts that help
maintain cell shape and aid in the transport of cellular cargo by serving as tracks for the molecular
motors. However, recent experiments on LLC-PK1 epithelial cells strongly suggest that microtubules
are often dynamic and deforming continuously and dominantly being transported anterogradely by
molecular motors. Surprisingly, quantitative analysis of these deformations exhibit striking similari-
ties to in vitro gliding assays. Motivated by these experiments, we have modeled microtubule-motor
interactions using coarse-grained simulations. Simulation results support our experimental ndings
and further elucidate on the interplay between molecular motors and passive cross-linkers. Our results
suggest that molecular motors are not necessarily just cargo carriers, but can play a dynamic role in
the deformation and positioning the microtubule array.
Cost: FREE
Sponsored by: WPI Physics Department, Dr. Izabela Stroe
Suggested Audiences: Adult
E-mail:
izabela@wpi.edu
Phone: 508-831-5249
Last Modified: January 29, 2009 at 1:52 PM
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