题目：Extended mean-field models for collective behavior in cell populations
报告人：Lei-Han Tang（Hong Kong Baptist University）
地点：紫金港西区海纳苑8幢215报告厅
时间：2023年3月24日（周五），下午14：00
摘要：Mean-field models have significantly advanced our understanding of ordering phenomena in condensed matter systems. In this talk, I will argue that they can also be employed to study dynamic self-organisation in biological systems, where the behavior of individual components is often more complex. As an example, I will discuss spontaneous rhythmic behavior in cell populations. A quantitative description of this oscillatory phenomenon has thus far been hampered by incomplete knowledge of the underlying intracellular processes, particularly when isolated cells appear to be quiescent. However, by analysing the temporal response of a cell to environmental signals, it is possible to associate certain behavioural trait, such as adaption, with collective oscillations in the cell population[1]. As the cell density increases beyond a threshold, an oscillating signal in a suitable frequency range becomes self-sustained due to active feedback from individual cells. We find that this overarching principle is at work in several natural and synthetic oscillatory systems where cells communicate through a chemical signal. Applying the theoretical scheme to 2D bacterial suspensions, we found that run-and-tumble cells of sufficiently high density spontaneously develop weak circular motion with a laminar flow profile in the thin fluid layer. The theoretical results are compared with weak collective oscillations discovered earlier in Yilin Wu’s lab[2], which can be considered as a vector version of our fundamental theory.
[1] Shou-Wen Wang and Lei-Han Tang, Emergence of collective oscillations in adaptive cells, Nature Communications 10, 5613 (2019).
[2] Chong Chen, Song Liu, Xia-qing Shi, Hugues Chaté & Yilin Wu, Weak synchronization and large-scale collective oscillation in dense bacterial suspensions, Nature 542, 210-214 (2017).
个人简介：
汤雷翰，香港浸会大学物理系教授，计算与理论研究所主任。1981年本科毕业于中国科技大学，经CUSPEA项目赴美，1987年获得Carnegie Mellon 大学博士学位。2010年当选为美国物理学会会士。主要从事统计物理理论及其在凝聚态和细胞生物学中的应用研究。现担任韩国基础科学院甄拔与评价委员会委员，ICAM-I2CAM执行委员，亚洲生物物理协会执行委员及多个统计物理国际期刊的编委。
欢迎老师和同学参加！
