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TZID:Europe/Paris
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BEGIN:VEVENT
UID:1-136@lptms.universite-paris-saclay.fr
DTSTART:20131105T110000Z
DTEND:20131105T120000Z
DTSTAMP:20131022T050337Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm
 s-2/
SUMMARY:Séminaire du LPTMS: Anders Carlsson - LPTMS\, salle 201\, 2ème é
 tage\, Bât 100\, Campus d'Orsay - 5 Nov 13 11:00
DESCRIPTION:Self-Organizing Waves and Patterns of Proteins in Biological Ce
 lls\n Anders Carlsson (Washington University)\nSelf-organized patterns\, 
 such as traveling waves and symmetry-breaking distributions of chemical sp
 ecies\, demonstrate how simple laws of motion can lead to complex behavior
 s in physical systems. Such patterns result from a combination of positive
  and negative feedback effects with different time scales. The talk will d
 iscuss the example of waves of the protein actin in biological cells. Acti
 n\, the most abundant intracellular protein in mammals\, occurs either as 
 an isolated protein in solution\, or in the form of filaments which have m
 echanical rigidity and are crosslinked into a gel. Recent experiments have
  shown that filamentous actin forms spontaneous waves that cause protrusio
 n of the cell membrane. Such waves may serve as a “clock” that helps a
  cell explore its environment. A theoretical model of actin waves will be 
 presented\, based on the three-dimensional structure of the gel formed by 
 actin filaments\, interacting reciprocally with proteins in the cell membr
 ane. Implementation of this model shows that positive feedback is inherent
  in the growth process of the actin gel\, while negative feedback arises f
 rom the actin-membrane interaction. As the concentration of key proteins i
 n the cell is varied\,  the  model predicts phase transitions between di
 fferent phases including traveling waves or patches\, and static symmetry-
 breaking polarization of the cell.
LOCATION:LPTMS\, salle 201\, 2ème étage\, Bât 100\, Campus d'Orsay\, 15 
 Rue Georges Clemenceau\, Orsay\, 91405\, France
GEO:48.698185;2.181768
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=15 Rue Georges Clemenceau\,
  Orsay\, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=LPTMS\, salle 201\, 2è
 me étage\, Bât 100\, Campus d'Orsay:geo:48.698185,2.181768
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