Conveners
How mixing generates spatial gradients significant to signalling, waste removal, and the distribution of microorganisms
- Laura Miller (University of North Carolina at Chapel Hill)
Description
Spatial gradients of chemicals and microorganisms generated by their advection and diffusion in a fluid have important consequences for signalling, waste removal, feeding, and behaviour. Modelling these systems often requires a combination of multiscale and multiphysics approaches, including solving the equations of fluid motion, describing the advection and diffusion of a (chemical) species, and modelling the behaviour of a cell or a microorganism. In nearly all cases, experimental validation is necessary to check whether or not all of the important elements of the biological and physical systems have been correctly considered. In this minisymposium, we provide examples of such systems that span the level of single-cell dynamics to the behaviour and distribution of groups of organisms. Specific examples include the pumping and mixing of fluid by flagella, spatial gradients of calcium during development, the movement of chemicals through hair arrays for the purpose of sampling, and the movement of zooplankton through beds of vegetation. The mathematical models and numerical methods highlighted in this minisymposium include the Immersed Boundary Method and the Method of Regularized Stokeslets for solving the fully-coupled fluid-structure interaction problem of fluid moving through and around cells, organs and organisms; agent-based models to describe the behaviour and movement of microorganisms; biochemical models to describe the response of cells or microorganisms; and numerical methods for solving the advection and diffusion of a concentration gradient. Challenges in terms of mathematical modelling, numerical simulation, and model validation will be highlighted throughout the presentations.
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