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CATEGORIES:CUED Control Group Seminars
SUMMARY:Limits of precision in stochastic cell biology - G
lenn Vinnicombe\, University of Cambridge
DTSTART;TZID=Europe/London:20190523T140000
DTEND;TZID=Europe/London:20190523T150000
UID:TALK123778AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/123778
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. Secondly\, Opti
mal clocks: How do you make accurate clocks from s
mall numbers of independent random events (such as
the production\, degradation or modification of
a molecule). If the number of events/molecules is
fixed then the answer is well known - you line up
the events\, one after the other\, all with the sa
me rate. If the number of events is itself random
then the optimal topology can be much more complex
. However\, for many distributions the optimal ans
wer is well approximated by a simple mechanism\, o
ne which we have implemented as part of a syntheti
c oscillator in E-coli.
LOCATION:Cambridge University Engineering Department\, Lect
ure Theatre 6
CONTACT:Alberto Padoan
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