论文标题
半充足的微生物的自弹和自我锻炼
Self-buckling and self-writhing of semi-flexible microorganisms
论文作者
论文摘要
细胞体和相关的机械应力的扭曲和扭曲是对微生物自我推测的限制。当它们在粘性液中游泳时，多弱磁性细菌甚至可以在自己的活动中弯曲和扭动。然后出现了新的平衡构型和稳态动力学，取决于生物体的机械性能以及沿其表面的鞭毛的定向分布。将细胞体建模为半充气的柯chhoff杆，并将力学与动态发展的鞭毛取向场耦合，我们得出了管理系统动态的Euler-Poincar {é}方程，并合理地将牛旋细胞的屈曲和扭曲的实验性观测值合理化。由于屈曲和扭转不稳定性，一系列分叉被确定为身体更合规。这些研究突出了对细菌的刚度的实用要求，在这种刚性下发生自弯曲，细胞运动变得无效。
The twisting and writhing of a cell body and associated mechanical stresses is an underappreciated constraint on microbial self-propulsion. Multi-flagellated bacteria can even buckle and writhe under their own activity as they swim through a viscous fluid. New equilibrium configurations and steady-state dynamics then emerge which depend on the organism's mechanical properties and on the oriented distribution of flagella along its surface. Modeling the cell body as a semi-flexible Kirchhoff rod and coupling the mechanics to a dynamically evolving flagellar orientation field, we derive the Euler-Poincar{é} equations governing dynamics of the system, and rationalize experimental observations of buckling and writhing of elongated swarmer cells of the bacterium {\it Proteus mirabilis}. A sequence of bifurcations is identified as the body is made more compliant, due to both buckling and torsional instabilities. These studies highlight a practical requirement for the stiffness of bacteria below which self-buckling occurs and cell motility becomes ineffective.
