Conveners
From solitary swimmers to coordinated groups: Modelling motion in fluids at very low Reynolds number: Part A
- Julia Samson ()
From solitary swimmers to coordinated groups: Modelling motion in fluids at very low Reynolds number: Part B
- Julia Samson ()
Description
Small-scale fluid mechanics play an important role in virtually all living systems. Biological processes taking place at very low Reynolds numbers pertain to individual cells (swimming of bacteria or sperm cells) as well as to cell collectives and even groups of larger, multicellular organisms. Classical theoretical explorations and efforts to model fluid flow at low Reynolds number have long been limited to single cells swimming through a Newtonian fluid. Biological problems, however, often involve complex environments and/or systems containing more than one cell or organism, and traditional models have yielded only approximate answers to these problems. Recently, the development of computational tools has spurred advancement in the study of low Reynolds number fluid mechanics in biological systems.
In this minisymposium, we focus on both locomotion in complex materials (such as soil or viscoelastic fluids) and the emergent collective dynamics observed in organisms at different scales by expanding on existing fluid models, developing better-performing algorithms, and integrating behavioural and fluid mechanical models.
Tissue development requires cells of different types to organise themselves into the appropriate patterns and structures to produce viable, functional tissue. Similar processes occur in tissue repair (e.g. wound healing) or when tissues are grown in vitro (tissue engineering). Understanding how this organisation is coordinated is therefore an important basic problem in biology and medicine.
I...
Many important biological functions depend on microorganisms' ability to move in viscoelastic fluids such as mucus and wet soil. The effects of fluid elasticity on motility remain poorly understood partly because the swimmer strokes depend on the properties of the fluid medium, which obfuscates the mechanisms responsible for observed behavioural changes. We use experimental data on the gaits...
An important aspect in the study of reproduction is how sperm are guided toward an egg for fertilization. One such mechanism is the process of chemotaxis, in which the sperm detect changes in concentration (namely of Ca+) in the fluid environment and utilize these changes to alter the waveform of their flagellar beat. This change in beat form results in changes to the swimming path....
The swimming motion of microorganisms such as sperm and cilia can be modelled by several methods, all of which entail solving equations of fluid-structure interaction. Among them, the Method of Regularized Stokeslets (MRS) and the Rotne-Prager-Yamakawa tensor have the advantage of not requiring a 3D Eulerian grid and using the fundamental solutions to the underlying equations instead. However,...
Xeniid corals, a family of soft corals (Alcyonacea), include species displaying a unique pulsing behaviour. Within a colony, each individual polyp pulses by actively contracting and passively expanding eight tentacles, increasing the local mixing and enhancing nutrient and gas exchange. Using the immersed boundary method with finite elements (IBFE), we constructed a 3D model of a pulsing...
