J. Tailleur and M. E. Cates 2009 EPL 86 60002 doi:10.1209/0295-5075/86/60002
J. Tailleur and M. E. Cates
Show affiliationsThe run-and-tumble dynamics of bacteria, as exhibited by E. coli, offers a simple experimental realization of non-Brownian, yet diffusive, particles. Here we present some analytic and numerical results for models of the ideal (low-density) limit in which the particles have no hydrodynamic or other interactions and hence undergo independent motions. We address three cases: sedimentation under gravity; confinement by a harmonic external potential; and rectification by a strip of "funnel gates" which we model by a zone in which tumble rate depends on swim direction. We compare our results with recent experimental and simulation literature and highlight similarities and differences with the diffusive motion of colloidal particles.
87.17.Jj Cell locomotion, chemotaxis
05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion
Issue 6 (June 2009)
Received 27 March 2009, accepted for publication 26 May 2009
Published 30 June 2009
J. Tailleur and M. E. Cates 2009 EPL 86 60002
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