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

非技术总结该奖项支持研究和教育各种复杂的生物系统的行为，包括生物聚合物细丝束，细胞膜和相互作用的神经元的小网络的力学。PI将探索细胞中柔软弹性结构的随机波动和形状的相互作用，例如生物聚合物细丝束的力学。这些纤维束是我们细胞结构不可或缺的一部分。此外，PI和他的研究团队将探索细胞膜波动与细胞基本几何形状的相互作用。细胞膜的复杂几何形状重新定向并聚焦这些波动，导致细胞具有空间复杂的波动模式。该奖项将支持研究控制这些模式的基本物理原理以及它们如何影响膜相互作用。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响应和信号产生。该奖项还支持加州大学洛杉矶分校本科生、研究生和博士后学者的教育。它还将有助于加州大学洛杉矶分校/加州州立大学多明格斯山（CSUDH）的科学交流计划，该计划为CSUDH的物理学学生提供了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影响应该包括对细胞力学和力产生原理的更深入理解。膜上的工作也可以告知我们对石墨烯片和带中波动的理解，这可能在开发纳米技术中发挥重要作用。最后，神经元网络的工作应该对哺乳动物呼吸节律产生的研究产生直接影响。技术总结该奖项支持有关软、低维结构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）具有瞬时交联的丝束，和2）具有复杂几何形状的膜。 该项目的另一个方面涉及研究淬火随机网络上相互作用的神经元的集体动力学。所有这三个目标的研究是相关的生物学相关的波动与淬火随机变量的相互作用的研究。 更具体地说，这个项目的重点可以分为三个部分：1）半柔性生物聚合物长丝束的研究（例如，F-肌动蛋白）通过瞬时交联剂连接。这些连接体表现出长程Casimir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剂流体如何影响捆绑/解捆绑过渡，以及它如何影响各种变形形式下的束动力学。他们还将研究这种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上波动的力学，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，以探索局部曲率变化对弹性膜上波动波的散射。利用这些结果，他们将探索具有猝灭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称为k-核心的某些拓扑结构对中央模式生成器的集体动力学的影响，来解决相互作用的神经元网络中猝灭随机连接的影响。该奖项还支持本科生，研究生，加州大学洛杉矶分校的博士后学者它还将有助于加州大学洛杉矶分校/加州州立大学多明格斯山（CSUDH）的科学交流计划。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影响应该包括对细胞力学和力产生原理的更深入理解。对膜的研究也可能对理解石墨烯片和带中的波动产生更广泛的影响。最后，神经元网络的工作应该有直接的影响，在哺乳动物的呼吸节律生成的研究，并可能提供新的见解的基本原则，控制稳定的这一重要的中央模式发生器。

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.