Dr. Julie Simons from California State University Maritime Academy
Abstract: The motion of thin structures like cilia and flagella is vital for many biological systems. In this talk, we will use reproduction and sperm motility as a primary motivator for studying the motion of flagella in 3D fluid environments. Mathematically, we can model a flagellum as a curve in space and approximate the fluid environment as a Stokesian, inertialess world. Many models for flagellar motion in such settings have been developed over the span of many decades, starting with early works using 2D approximations. More recent advancements--technologically, mathematically and computationally--have allowed for exploration of motion in fully three-dimensional contexts and some surprising results. We will describe the mathematical framework for recent work involving the Method of Regularized Stokeslets and preferred curvature and then present results involving individual swimmers near surfaces, groups of swimmers, and cooperative swimmers. We hypothesize that some species of animals have developed cellular structures that enable sperm to swim faster and more efficiently, perhaps in response to sperm competition due to mating behavior.
Bio: Professor Julie Simons is an applied mathematician who specializes in problems involving cellular motility. After earning her Ph.D. from the University of Wisconsin while studying bacterial chemotaxis, she transitioned to studying problems related to reproduction and flagellar motility at Tulane University. This work is at the interface of mathematical modeling, computational simulation, fluid dynamics, and biology. Now at CSU Maritime Academy, she continues to focus on problems in fertility and cellular biomechanics, and promote undergraduate research.