RUI: Molecular Tracer Diffusion Measurements Within the Biomixing Generated by Swimming E. Coli

在这个项目中，PI将与三一大学的本科生合作，使用激光诱导光栅实验技术--强迫瑞利散射(FRS)--测量大肠杆菌浴液中的分子示踪剂扩散系数，以查看微米尺度上的扩散系数是否随着细菌浓度的增加而增加。PI还将使用简单的傅立叶概念显示，如果示踪剂分子确实被游泳者驱入L飞行，则傅立叶反射可以唯一地用于直接测量和量化Lévy与高斯扩散的偏差。这项关于极小雷诺数下分子输运的工作将有助于全面理解描述所有海洋生物的游泳者驱动的小分子通量在游泳者长度尺度和雷诺数范围内的变化。PI还将与三一微生物学家合作开发一项本科生实验室实验，在该实验中，学生们将研究大肠杆菌是如何进化的，以便在趋化过程中超越分子扩散。

In this project the PI will work with Trinity undergraduates to employ the laser-induced-grating experimental technique, forced Rayleigh scattering (FRS), for measurements of molecular-tracer diffusion coefficients within E. coli baths to see if the diffusion coefficients on micron length scales increase with the bacterial concentration. The PI will also show using simple Fourier concepts that FRS can be uniquely employed to directly measure and quantify Lévy deviations from Gaussian diffusion if the tracer molecules are indeed driven into Lévy flights by the swimmers. This work on molecular transport at the very small Reynolds number will help significantly in a complete comprehension of swimmer-driven small-molecule flux over ranges of swimmer length scales and Reynolds numbers that describe all marine organisms. The PI will also collaborate with a Trinity microbiologist to develop an undergraduate laboratory experiment in which students investigate the manner in which E. coli have evolved so that they outrun molecular diffusion during chemotaxis.