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CATEGORIES:DAMTP BioLunch
SUMMARY:Limits in stochastic cell biology - Glenn Vinnicom
be (Engineering\, University of Cambridge)
DTSTART;TZID=Europe/London:20190314T130000
DTEND;TZID=Europe/London:20190314T140000
UID:TALK121306AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/121306
DESCRIPTION:We look at two related problems where noise and sm
all numbers provide limitations on the behaviour o
f cells.\nFirstly "The Poisson box”: For a simple
birth death process (constant birth rate\, exponen
tial deaths) it is well known that the variance eq
uals the mean. We conjecture that for two coupled
birth death processes it is not possible for both
processes to simultaneously beat this bound. That
is\, if X is controlling Y\, and vice versa\, then
in order for the variance in Y to be reduced belo
w the Poisson limit then the variance in X must be
above it. For cell biology\, this suggests that l
arge fluctuations in the population of one molecul
ar species might be a natural consequence of it be
ing implicated in regulating a second. The conject
ure is known to hold in some circumstances - a gen
eral proof remains elusive though.\nSecondly\, Opt
imal clocks: How do you make accurate clocks from
independent random events (such as the production\
, degradation or modification of a molecule). If
the number of events/molecules is fixed then the a
nswer is well known - you line up the events\, one
after the other\, all with the same rate. If the
number of events is itself random then the optimal
topology can be much more complex. However\, for
many distributions the optimal answer is well appr
oximated by a simple mechanism\, which we have imp
lemented as part of a synthetic oscillator in E-co
li. \n
LOCATION:MR11\, Centre for Mathematical Sciences\, Wilberfo
rce Road\, Cambridge
CONTACT:Anne Herrmann
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