Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 6: Poster I

BP 6.27: Poster

Montag, 1. April 2019, 17:30–19:30, Poster B2

Fluid flow control on morphological changes — •Noah Ziethen and Karen Alim — Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany

The morphology of biological transport networks is often regarded as a result of optimization under a given demand. As demands may change rapidly in life, biological flow networks continuously adapt. One particular way of adaptation is the simplification of the network by erosion of specific vessels (pruning). Interestingly, pruning controlled by local flow shear rate is equivalent to global optimization towards minimal dissipation at a fixed network volume.

Here, the model organism Physarum polycephalum allows to directly test causality between flow shear rate change and vessel pruning. P. polycephalum forms a network of connected tubes exhibiting a complex oscillatory shuttle streaming inside them. We image and quantify the time evolution of single vessel junctions in P. polycephalum. We extract the vessel diameters evolution and the corresponding flow field using particle image velocimetry (PIV). We determine the flow profiles for different vessel thicknesses which show surprisingly good agreement with Poiseuille flow. The flow profiles are used to calculate the local shear rate acting on the tube walls. Additionally, we measured the flow rate, the maximum and the variation of the flow velocity. All these above-mentioned quantities are then correlated with the event of pruning.