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DY: Fachverband Dynamik und Statistische Physik

DY 48: Pattern Formation / Reaction-Diffusion II (joint session DY/BP)

DY 48.1: Vortrag

Donnerstag, 23. März 2017, 15:00–15:15, ZEU 118

Flow Induced Instabilities in an Advected Dictyostelium Discoideum Model — •Estefania Vidal, Azam Gholami, and Eberhard Bodenschatz — Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, D-37077 Göttingen, Germany

The spirals and concentric waves of cAMP appearing during the aggregation process of the social ameba Dictyostelium Discoideum have been widely studied as an example of pattern formation in biological systems, however in the rain forest soil, the natural environment of these amebas, the constant rain washes away the signalling chemical, thus affecting the pattern formation. To simulate these environmental conditions, we studied numerically and theoretically a Reaction Diffusion model in the presence of a constant flow advection. The model, proposed by Martiel and Goldbeter, describes the dynamics of cAMP by taking its concentration as an activator and the ratio of active receptors in the cell membrane as inhibitor. Depending on the election of parameters this system can be in an oscillatory or an excitable state, and has successfully reproduce many of the experimentally observed features. We show how a Dirichlet boundary condition destabilises the system, creating a continuous influx of waves upstream which grow into train waves that fill the entire system. These phenomena, which appear due to the interaction between the Flow Induced Instability and a Hopf Bifurcation provide a novel mechanism for the creation of continuos waves in Advected Reaction Diffusion systems.