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UBC Math Dept
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Mathematical Biology and related seminars

February, 2018
Wednesday,
February 21
Tommi Muller -- 3:15 pm in ESB 4127
UBC
TBA
Abstract
TBA
Wednesday,
February 28
Amit Apte -- 3:15 pm in ESB 4127
ICTS, Bangalore
Data assimilation and parameter estimation
Abstract
The problems of estimation of state of a high dimensional chaotic system such as the atmosphere or estimation of parameters of models of highly nonlinear real life phenomena involving multiple parameters can both be considered in the Bayesian framework as problems of the study of the posterior distributions of the state or the parameters, conditioned on the observed data. The former is commonly known as data assimilation in the earth sciences. This talk will focus on discussing the connection between the properties of this posterior distribution and the characteristics of the dynamics of the system, in particular the unstable subspace (in the context of data assimilation [1,2]) and the bifurcations of the system as well as the characteristics of the data sets (in the context of parameter estimation [3]). Ref: [1] doi:10.1137/15M1025839, [2] doi:10.1137/16M1068712, [3] arXiv:1705.03868
Comment:https://home.icts.res.in/~apte/
March, 2018
Wednesday,
March 7
Andrew Bernoff -- 3:15 pm in ESB 4127
Harvey Mudd College
TBA
Abstract
TBA
Comment:https://www.math.hmc.edu/~ajb/
Wednesday,
March 14
Alexandra Jilkine -- 2:00 pm in PIMS Seminar Room
Notre Dame University
Modeling the Dynamics of Cdc42 Oscillation in Fission Yeast
Abstract
We present a mathematical model of the core mechanism responsible for the regulation of polarized growth dynamics by the small GTPase Cdc42. The model is based on the competition of growth zones of Cdc42 localized at the cell tips for a common substrate (inactive Cdc42) that diffuses in the cytosol. We consider several potential ways of implementing negative feedback between Cd42 and its GEF in this model that would be consistent with the observed oscillations of Cdc42 in fission yeast. We analyze the bifurcations in this model as the cell length increases, and total amount of Cdc42 and GEF increase. Symmetric antiphase oscillations at two tips emerge via saddle-homoclinic bifurcations or Hopf bifurcations. We find that a stable oscillation and a stable steady state can coexist, which is consistent with the experimental finding that only 50% of bipolar cells oscillate. Our model suggests that negative feedback is more likely to be acting through inhibition of GEF association rather than upregulation of GEF dissociation.
Wednesday,
March 28
Somdatta Sinha -- 3:15 pm in ESB 5104
April, 2018
Wednesday,
April 4
Josh Scurll -- 3:15 pm in ESB 4127
UBC, Math
TBA
Abstract
TBA

Seminar series sponsored by PIMS.

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