Spatiotemporal regulation of chemical reactions by active cytoskeletal remodeling

Condensed Matter lunchtime seminar

Spatiotemporal regulation of chemical reactions by active cytoskeletal remodeling

  • Event time: 1:00pm
  • Event date: 1st November 2010
  • Speaker: Abhishek Chaudhuri (University of Oxford)
  • Location: Room 2511,

Event details

We propose that the active local remodeling of the cytoskeleton which pervades the cell can spatiotemporally regulate biochemical reactions. Using an active hydrodynamics approach, we show how the interplay between active contractility and remodeling of the cytoskeleton can give rise to a dynamic clustering of passive molecules and consequently a dramatic increase in the reaction efficiency and output levels. } }

%@meeting{html, % date = {1 November 2010}, % speaker = {Bartek Waclaw}, % title={A dynamical phase transition in a model for evolution with migration}, % abstract={Biological dispersal---the movement of organisms between habitats---is a ubiquitous %phenomenon with important and wide-ranging consequences. In the natural environment, %organisms expand their ranges, colonise new habitats, and can undergo speciation if they %become spatially isolated. Therefore, dispersal plays a key role in determining spatial %and temporal patterns of genetic diversity. It has been pointed out recently, that %migration from a favourable habitat to an unfavourable one can explain the genetics of %some pathogenic microbes and viruses. However, despite its importance, a general %understanding of how migration affects mutation-selection balance in microbial systems is %lacking. In particular, one would like to know how migration changes the proportions of %different genotypes in the evolving population. Here I will discuss a simple model for %evolution of asexual organisms in two different habitats, with different fitness %landscapes, coupled through one-way migration. The key finding is a dynamical phase %transition at a critical value of the migration rate. The time to reach steady state %diverges at this critical migration rate. Above the transition, the population is %dominated by immigrants from the primary habitat. Below the transition, the genetic %composition of the population is highly non-trivial, with multiple coexisting %quasi-species which are not native to either habitat. Using results from localization %theory, I will show that the critical migration rate may be very small --- demonstrating %that evolutionary outcomes can be very sensitive to even a small amount of migration. %

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

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