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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-1459
DTSTART:20090331T170500Z
DURATION:PT1H0M0S
DTSTAMP:20260420T041703Z
LAST-MODIFIED:20090216T143926Z
LOCATION: 4274 Chamberlin
SUMMARY:The origins of emergent behavior in bacterial communities\, Ch
 aos & Complex Systems Seminar\, Douglas B. Weibel\, UW Department of B
 iochemistry
DESCRIPTION:Bacteria sense surfaces and undergo physiological changes\
 , which programs their growth and motility and coordinates their behav
 ior. The resulting bacterial communities display 'emergent' properties
  in which the coordination of the behavior of cells is not predictable
  from the sum of the individual components (e.g. cells). The resulting
  structures behave as multicellular organisms and collectively coloniz
 e niches in search of nutrients and other growth factors. The transiti
 on of a group of 'individual' bacterial cells to collective\, multicel
 lular behavior is accompanied by the upregulation of pathogenic factor
 s\, suggesting that in this state the organisms are preparing to invad
 e a host. An understanding of the mechanisms that control and regulate
  the switch from individual behavior to multicellular behavior will id
 entify mechanisms and targets that may play a role in preventing and t
 reating microbial pathogenesis. We are particularly fascinated by the 
 mechanisms that cells use to coordinate their movement on surfaces. In
  contrast to our understanding of the biophysics involved in the motil
 ity of bacterial cells (e.g. Escherichia coli) in bulk fluids\, almost
  nothing is known about the mechanisms that play a role in cell motili
 ty on surfaces. We are exploring two physical mechanisms that may play
  a role in the coordination of cellular movement on surfaces based on:
  i) physical interactions between cells mediated by bundling between f
 lagella on adjacent cells\; and ii) physical interactions between cell
 s in close proximity to each other that are produced by the disturbanc
 e in the local fluid field by the rotation of the cells during motilit
 y. In this talk I present recent work from our group on both mechanism
 s and demonstrate that bacterial 'swarming' may be one of the most tra
 ctable experimental systems for identifying the mechanisms that drive 
 systems toward emergent behavior. These experiments may shed light on 
 systems that extend far beyond microbial systems\, and include financi
 al markets\, weather\, and population dynamics.
URL:https://www.physics.wisc.edu/events/?id=1459
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