The Orientation of Swimming Biflagellates in Shear Flows
The Orientation of Swimming Biflagellates in Shear Flows
复制标题
双鞭毛虫在剪切流中游动的方向
DOI：
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发表时间：
2011
影响因子：
3.5
通讯作者：
M. Bees
中科院分区：
文献类型：
--
作者：
Stephen O’Malley;M. Bees
双鞭毛藻游动的方向是由它们的环境决定的。例如，许多藻类可以通过各种机制平均向上游动（重力轴）和向下游（陀螺仪）。流体中细胞的积累可引起流体动力学的不稳定性，导致模式和流动，称为生物对流，这可能与藻类生物反应器和浮游生物动力学特别相关。此外，了解单个游泳细胞受施加水流影响的行为是充分理解海洋和湖泊中细胞的放大体积行为和种群动态的先决条件；游泳行为和斑块将影响相互作用的机会，这是人口模型的核心。因此，更好地估计种群水平参数需要详细了解细胞游动偏差。采用正则化stokeslet方法，研究了具有五种不同鞭毛跳动的回旋长形球形双鞭毛虫的游动行为及其周围的流体流动。特别是，我们探索了与底部重量和沉积相关的细胞重定向机制，并发现它们是相称和互补的。此外，利用实验测量的莱茵衣藻鞭毛跳动，我们发现游泳细胞的有效细胞偏心比无生命体的小得多，这表明细胞可以令人满意地建模为自我推进的球体。最后，我们提出了一种方法来估计有效细胞偏心的任何双鞭毛搏动图像随机获得。
Biflagellated algae swim in mean directions that are governed by their environments. For example, many algae can swim upward on average (gravitaxis) and toward downwelling fluid (gyrotaxis) via a variety of mechanisms. Accumulations of cells within the fluid can induce hydrodynamic instabilities leading to patterns and flow, termed bioconvection, which may be of particular relevance to algal bioreactors and plankton dynamics. Furthermore, knowledge of the behavior of an individual swimming cell subject to imposed flow is prerequisite to a full understanding of the scaled-up bulk behavior and population dynamics of cells in oceans and lakes; swimming behavior and patchiness will impact opportunities for interactions, which are at the heart of population models. Hence, better estimates of population level parameters necessitate a detailed understanding of cell swimming bias. Using the method of regularized Stokeslets, numerical computations are developed to investigate the swimming behavior of and fluid flow around gyrotactic prolate spheroidal biflagellates with five distinct flagellar beats. In particular, we explore cell reorientation mechanisms associated with bottom-heaviness and sedimentation and find that they are commensurate and complementary. Furthermore, using an experimentally measured flagellar beat for Chlamydomonas reinhardtii, we reveal that the effective cell eccentricity of the swimming cell is much smaller than for the inanimate body alone, suggesting that the cells may be modeled satisfactorily as self-propelled spheres. Finally, we propose a method to estimate the effective cell eccentricity of any biflagellate when flagellar beat images are obtained haphazardly.
影响因子：
8.6
作者：
Drescher, Knut;Goldstein, Raymond E.;Tuval, Idan
通讯作者：
Tuval, Idan