Statistical Mechanics of soft low dimensional structures and dynamical phases of neuronal networks

该奖项支持各种复杂生物系统行为的研究和教育，包括生物聚合物细丝束、细胞膜和相互作用神经元的小网络的力学。PI将探索随机波动和形状对细胞中柔软、弹性结构的相互作用，例如生物聚合物细丝束的力学。这些束是我们细胞结构的组成部分。此外，PI和他的研究小组将探索细胞膜波动与细胞底层几何结构的相互作用。细胞膜的复杂几何结构重新引导和聚焦这些波动，导致细胞具有空间复杂的波动模式。该奖项将支持对控制这些模式的潜在物理原理以及它们如何影响膜相互作用的研究。最后，研究人员将探索相互作用的神经元的小网络的复杂连接如何控制它们的集体电反应和信号产生。该奖项还支持加州大学洛杉矶分校的本科生、研究生和博士后学者的教育。它还将为加州大学洛杉矶分校/加州州立大学多明格斯山分校（CSUDH）的科学交流项目做出贡献，该项目为加州大学洛杉矶分校多明格斯山分校的物理学学生提供了一个在加州大学洛杉矶分校获得研究经验的机会。这项研究对生物系统中几何、连通性和波动的相互作用的更广泛的影响应该包括对细胞力学和力产生原理的更深入的理解。膜上的工作也可以让我们了解石墨烯片和带的波动，这可能在开发纳米技术中发挥重要作用。最后，对神经网络的研究将对哺乳动物呼吸节律产生的研究产生直接影响。技术概述：该奖项支持软、低维结构上波动相互作用的研究和教育，重点是生物衍生系统。这些包括：1)具有瞬态交联的丝束，以及2)具有复杂几何形状的膜。该项目的另一个方面涉及研究神经元在淬灭随机网络上相互作用的集体动力学。该研究的所有三个目标都与研究与猝灭随机变量相互作用的生物学相关波动有关。更具体地说，这个项目的重点可以分为三个部分：1)研究由瞬时交联剂连接的半柔性生物聚合物细丝束（如f -肌动蛋白）。这些连接体表现出长距离的卡西米尔相互作用，导致它们在束内表现为强相互作用的连接体流体。在这个项目中，研究人员将探索连接流体如何影响成束/解束过渡，以及在各种变形形式的作用下，它如何影响管束的动力学。他们还将研究这些系统响应内源性分子马达的驱动动力学。2)研究小组将研究弯曲细丝的波动力学，以解决弯曲如何改变卡西米尔相互作用。他们将扩展这些研究，探索波动波在弹性膜上的局部曲率变化的散射。利用这些结果，他们将探索具有淬火随机几何形状的壳上波动波的局部化。3)该团队将通过继续研究某些被称为k核的拓扑结构对中心模式生成器的集体动力学的影响，来解决相互作用神经元网络中淬灭随机连接的影响。该奖项还支持加州大学洛杉矶分校的本科生、研究生和博士后学者的教育。它还将为加州大学洛杉矶分校/加州州立大学多明格斯山分校（CSUDH）科学交流计划做出贡献。这项研究对生物系统中几何、连通性和波动的相互作用的更广泛的影响应该包括对细胞力学和力产生原理的更深入的理解。膜上的工作也可能对理解石墨烯片和带的波动产生更广泛的影响。最后，对神经网络的研究将对哺乳动物呼吸节律产生的研究产生直接影响，并可能为控制这一重要中枢模式发生器稳定性的基本原理提供新的见解。

NONTECHNICAL SUMMARYThis award supports research and education into the behavior of a variety of complex biological systems including the mechanics of bundles of biopolymer filaments, cell membranes, and small networks of interacting neurons. The PI will explore the interplay of random fluctuations and shape on soft, elastic structures in the cell, e.g. on the mechanics of bundles of biopolymer filaments. These bundles are integral to the mechanics of our cells. In addition, the PI and his research team will explore the interaction of cell membrane undulations with the cell's underlying geometry. The complex geometry of the cellular membranes redirects and focuses these undulations, leading to cells having a spatially complex pattern of fluctuations. This award will support research into the underlying physical principles that govern these patterns and on how they affect membrane interactions. Finally, the researchers will explore how the complex connectivity of small networks of interacting neurons controls their collective electrical response and signal generation. The award also supports the education of undergraduate, graduate students, and postdoctoral scholars at UCLA. It will also contribute to the UCLA/California State University Dominguez Hills (CSUDH) scientific exchange program, which provides an opportunity for physics students at CSUDH to gain research experience at UCLA. The broader impacts of this research into the interplay of geometry, connectivity, and fluctuations in biological systems should include a deeper understanding of the principles of cellular mechanics and force generation. The work on membranes may also inform our understanding of undulations in graphene sheets and ribbons, which might play an important role in developing nanotechnologies. Finally, the work on neuronal networks should have direct impact on studies of respiratory rhythm generation in mammals. TECHNICAL SUMMARYThe award supports research and education on the interaction of fluctuations on soft, low-dimensional structures with an emphasis on biologically derived systems. These include: 1) filament bundles with transient cross linking, and 2) membranes with complex geometry. Another aspect of the project involves studying the collective dynamics of neurons interacting on quenched random networks. All three aims of the research are related by the study of biologically relevant fluctuations interacting with quenched random variables. More specifically, the focus of this project can be broken down into three parts:1) The study of bundles of semiflexible biopolymer filaments (e.g., F-actin) linked by transient cross linkers. These linkers exhibit long-ranged Casimir interactions resulting in their behaving within the bundle as a strongly-interacting linker fluid. In this project, the researchers will explore how that linker fluid affects the bundling/unbundling transition, and how it affects the dynamics of the bundle under the application of various forms of deformation. They will also study the driven dynamics of such systems in response to endogenous molecular motors.2) The research team will study the mechanics of undulations on curved filaments to address how bending modifies the Casimir interaction. They will expand these studies to explore the scattering of undulatory waves on elastic membranes from local changes in curvature. Using these results, they will explore the localization of undulatory waves on shells with quenched random geometry.3) The team will address the effect of quenched random connectivity in interacting neuronal networks by continuing their studies of the effect of certain topological structure called k-cores on the collective dynamics of central pattern generators.The award also supports the education of undergraduates, graduate students, and postdoctoral scholars at UCLA. It will also contribute to the UCLA/California State University Dominguez Hills (CSUDH) scientific exchange program. The broader impacts of this research into the interplay of geometry, connectivity, and fluctuations in biological systems should include a deeper understanding of the principles of cellular mechanics and force generation. The work on membranes may also have a broader impact on understanding undulations in graphene sheets and ribbons. Finally, the work on neuronal networks should have direct impact on studies of respiratory rhythm generation in mammals and possibly provide new insight into the basic principles controlling the stability of this essential central pattern generator.