Regensburg 2002 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 10: Statistische Physik in biologischen Systemen
DY 10.2: Vortrag
Montag, 11. März 2002, 10:00–10:15, H2
Ripple formation in Myxobacterial aggregates — •Uwe Börner1, Andreas Deutsch2 und Markus Bär1 — 1Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden — 2Zentrum für Hochleistungsrechnen TU Dresden, Zellescher Weg 12, 01069 Dresden
Pattern formation due to collective motion is a wide-spread phenomenon in nature. Emerging multicellular structures are often reaction-diffusion patterns. They usually stem from the interplay of transport by chemotaxis and diffusion and ,,reactive” processes like production and consumption of nutrients and chemoattractants. Experiments with myxobacterial aggregates reveal standing wave oscillations of the cell density (rippling). We show that these structures are based on a contact interaction instead of a non-local interaction meadiated through a diffusible chemical. Based on recent experimental work, a simple discrete model is proposed describing migration and interactions of cells. Head-to-head collisions of cells result in cell reversals triggered by a membrane-bound protein called C-factor. Spatial and temporal synchronization is due to a refractory period during which cells act in a different way. Detailed insight is obtained by a combination of cellular automaton simulation and a mean-field theory based on the microscopic rules of the automaton.