Focus Topic Descriptions, 1.1.1 to 4.1.23

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1: POLYMERS AND SOFT MATTER PHYSICS (DPOLY)

1.1.1: Block Copolymer Thin Films: Directed Assembly

This focus session highlights recent experimental and theoretical developments that relate to the design, characterization, and processing of block copolymer thin films. Contributions related to the directed assembly and templated growth of hybrid materials in block copolymer systems are particularly encouraged. Additional areas of interest include phase separation in thin films, mechanics/dynamics in copolymer layers, and the thermodynamics/kinetics of thin co-polymer film processing.

Organizers: Ryan Hayward (rhayward@mail.pse.umass.edu) and Gilla Stein (gestein@central.uh.edu)

1.1.2: Where Simulation, Theory and Experiments Meet Across Time and Length Scales. [Same as 2.1.16]

Modeling polymers and soft materials, with phenomena ranging from the from assembly of nanoparticles to the rheology of entangled macromolecules, presents unique computational challenges stemming from strong coupling of microscopic physical phenomena to macroscopic time and length scales through multiple mechanisms.  This session will focus on recent developments in bridging time and length scales in computation and theory of polymers, as well as on in-depth understanding spanning multiple length- and time-scales obtained from theory and simulations in polymers, bio polymers and soft matter.

Organizers: David Simmons (dsimmon@uakron.edu) and Gary S. Grest (gsgrest@sandia.gov)

1.1.3: Biopolymers and Biohybrid Polymers (DPOLY/DBIO) (DPOLY) [Same as 2.1.17 and 4.1.2]

Unlike traditional polymers, proteins and peptides have sequence-specific monomer arrangements that enable the formation of a wide variety of chain folds and specific interactions. The incorporation of these hierarchically structured molecules into materials poses new challenges in understanding the emergent physics of such biopolymer systems. This session will provide a forum for contributions on the latest advances in theory and experiment related to characterizing the self-assembly, solution properties, mechanics and other dynamic properties, and biophysical properties of protein materials and biohybrid systems.

Organizers: Brad Olsen (bdolsen@mit.edu), Muzhou Wang (@NIST.gov)

1.1.4: Polymers in Batteries and Electrochemical Capacitors (DPOLY/GERA) (DPOLY)

Polymers are poised to play an integral role in batteries and electrochemical capacitors, acting as the electrode or the electrolyte. Advances in polymeric materials are opening doors towards economical, sustainable, and flexible energy storage platforms. Contributions are solicited for research related to polymers utilized in batteries (e.g., ion-conducting polymers, solid polymer electrolytes and their composites, hybrid composite electrodes) and electrochemical capacitors (e.g., electron-conducting polymers, redox-active polymers). Theoretical, computational, or experimental approaches are welcome.

Organizers: Daniel Hallinan (dhallinan@fsu.edu), Jodie Lutkenhaus (jodie.lutkenhaus@che.tamu.edu)

1.1.5: Polymers for Solar Energy Conversion (DPOLY)

Advances in the development of polymeric materials and polymer based devices for energy applications have generated new knowledge, concepts and strategies for energy conversion and generation of light. This symposium covers recent progress in these fields. Contributions are solicited for research related to the above topics such as polymer-based devices for solar energy conversion or light emission, and polymer – nanofillers for energy capture and conversion schemes including thermoelectrics. Theoretical, computational, or experimental approaches are welcome.

Organizer: Michael Mackay (mem@udel.edu)

1.1.6: Organic Electronics and Photonics (DPOLY/DMP) (DPOLY)

Advances in our fundamental knowledge of organic materials, including small molecules and polymers, have enabled improvement of electronic and photonic devices. This focus topic covers recent progress in understanding the physical behavior of organic semiconducting materials. Contributions are solicited for research related to organic optoelectronic materials such as charge injection and transport; field-effect, light emitting, photovoltaic or thermoelectric devices; exciton dynamics and photophysics; and processing-structure-property-function relationships. Contributions on theoretical, computational, and experimental approaches are welcome.

Organizer: Mark Dadmun (dad@utk.edu)

1.1.7: Renewable and Sustainable Polymers (DPOLY)

Recently there has been a surge of activity in the development of alternative, sustainable resources for the derivation of polymers. Biomass and other renewable resources are attractive substitutes for petroleum sources, resulting in polymers with a reduced environmental impact. This focus session highlights recent advances in the physics and physical chemistry of polymers derived from a variety of sources, including, but not limited to, plant sugars, vegetable oils, fatty acids, lignin, cellulose and other polysaccharides, terpenes, and rosin.

Organizers: Megan Robertson (mlrobertson@uh.edu)

1.1.8: Assembly of Polymers, Soft Nanoparticles and Colloids in Solution (DPOLY/GSOFT/DBIO) (DPOLY) [Same as 2.1.18]

This focus session invites a combination of experimental, theoretical, and simulations contributions related to new methods for manipulating and characterizing the hierarchical self-assembly of block copolymers and soft nanoparticles in aqueous media toward the development of complex materials morphologies. By developing new molecular architectures or physical processing methods, experimental approaches for controlling these self-assembly processes may lead to scalable approaches to nanostructured materials with myriad useful applications. Theory and simulations studies of these materials continue to unveil the mechanisms governing these self-assembly process, while also driving the development of new and innovative methods for designing and processing materials to achieve specific morphologies. Topics of interesting include, yet are not limited to: path-dependent micellar assembly of synthetic and bio-based (e.g., peptide) copolymers, polymersomes, polymer/polymer and polymer/small molecule complexes, peptide-based materials, responsive and dynamic nanostructured assemblies, new characterization methods, anisotropic nanoparticles with specific/directional interactions, therapeutic encapsulation therein.

Organizers: Chang Y. Ryu (ryuc@rpi.edu), Du Yeol Ryu (dyryu@yonsei.ac.kr)

1.1.9: The Physics of Confined Structured Fluids (DPOLY)

This session will focus on the fundamentals that underline the behavior of complex fluids at confined spaces and interfaces. These include the role of interfaces in shaping the structure and dynamics of complex fluids, their responses to external forces and environmental constraints. Of particular interest, but not limited, are contributions that outline interfacial effects from scattering techniques, computer simulations and theory. A broad range of complex fluids studies including polymers, biological complexes, liquid crystals, and colloids confined to interfaces are encouraged.

Organizers: Jaroslaw Majewski (jarek@lanl.gov), Erik Watkins (ebw@lanl.gov)

1.1.10: Glasses Altered by Interfaces (DPOLY)

Glasses are nonequilibrium materials whose properties are easily altered by perturbing influences like interfaces. Properties of glasses in confined geometries and near interfaces are becoming more prevalent as new materials include more fillers and multiple-component systems. This focus session is mainly focused on how different interfaces perturb glassy dynamics, structure, and properties. Explorations of commonalities or differences across different types of interfaces such as substrates, nanofiller, free surfaces, or glassy-rubbery phases are particularly welcome.

Organizers: Connie Roth (cbroth@emory.edu), Andrew Croll (andrew.croll@ndsu.edu)

1.1.11: Small Molecule Transport in Polymers and Polymer Nanocomposites

This session will provide a forum to present recent developments in the area of small molecule transport in polymers and polymer nanocomposites. Topics of interest will be: membrane based separation of small molecules (including but not limited to gas separation and water filtration), gas and moisture barrier films and block copolymer membranes. Contributions related to the fundamental studies on the physics of small molecule transport in polymers and polymer nanocomposites are also encouraged. Experimental, computational or theoretical contributions are requested from industrial and academic researchers.

Organizers: Praveen Agarwal (pagarwal@dow.com); Chinedum Osuji (chinedum.osuji@yale.edu); William Phillip (William.A.Phillip.1@nd.edu)

1.1.12: Nanocomposites From Nano to Meso (DPOLY/FIAP)

This focus session highlights new developments in polymer nanocomposites: use of active nanoparticles and study of dynamics. Experimental, modeling and theoretical contributions that address these topics are welcome. Polymer nanocomposites are particularly interesting when active nanoparticles are responsive to an external field (e.g., light, magnetic, or electric) which includes schemes such as inductive heating by magnetic nanoparticles, photothermal heating of metal nanoparticles, and heating from light-sensitization of polymers by embedding carbon nanotubes. Nanoparticles have sizes intermediate between the monomeric unit and the macromolecular dimension (Rg). Thus, the dynamics of polymer nanocomposites are inherently complex because the time/length scales of the polymer and nanoparticle mobility vary by orders of magnitude within a given nanocomposite. The polymer and nanoparticle dynamics are influenced by the polymer conformation, nanoparticle dispersion, and miscibility, and possess great diversity due to repulsive or attractive polymer-nanoparticle interactions, hard or soft nanoparticles, and unentangled or entangled polymer matrices.

Organizers: Laura Clarke (liclarke@ncsu.edu) and Amelie L. Frishcknecht (alfrisc@sandia.gov)

1.1.13: Polymer Dynamics: Insight from In Situ Scattering

Polymer dynamics takes place on multiple time and length scales and is responsible for fascinating physics and numerous applications.  The development of new scattering techniques and in situ measurements offer a new venue to probe dynamics of polymers on multiple length scales. This session will focus on recent developments in scattering techniques that probe polymer dynamics as well as from new approaches including in situ measurements. Dynamic studies from quasi elastic neutron techniques (QENS and NSE), x-ray correlation photon spectroscopy (XPCS), rheo-small angle neutron scattering and any additional in-situ scattering techniques and  results from scattering-simulation/ theory are especially encouraged.

Organizers: Chris Soles (christopher.soles@nist.gov)

1.1.14: Polymer Architecture: Control of Structure in Poly Olefins

The session will focus on recent development in understanding the structure of poly olefins. Of particular interests are studies on controlling crystallization and the resulting crystalline morphologies in poly olefins. These include studies of the interplay between phase separation and crystallization in blends containing poly olefins, crystallization under constraints such as confinement by interfaces, and memory effects related to crystallization in polyolefin melts. Contributions on exploration of the fundamental physics of crystallization and resulting morphologies of these materials as well the effects of crystallization on properties, such as mechanical properties, gas diffusion rates, or optical properties, are and novel structures that take advantage of these properties. Invited Speakers: Rufina Alamo (FAMU-Florida State University), or Chris Macosko (University of Minnesota), John Torkelson (Northwestern)

Organizer: Wilbur, Jeffrey (JDWilbur@dow.com)

1.1.15: Mechanics of Bio Polymers: From Single Molecules to Active Assemblies.

Biopolymers including DNA, F-actin, and microtubules and others are not only semiflexible filaments spanning a wide range of thermal persistence lengths, but also interact with a complex set of biomolecules. Their interaction with molecular motors for example, generates a novel active state of matter with large strain fluctuations and motor-dependent elasticity. These interactions could be exploited to provide new controls to explore fundamental questions in polymer physics that would impact biological systems.  This session will focus on the rheology and mechanics of semiflexible bio polymers, from a single molecule to networks coupled by transient or active cross linkers. Experimental, computational and theoretical studies that capture the mechanical behavior of active bio-polymers and their assembly are encouraged.

Organizers: Alex Levine (alevine@chem.ucla.edu), Megan Valentine (Valentine@engineering.ucsb.edu)

1.1.16: Biopolymers in Confinement (DBIO/DPOLY)
[Same as 4.1.1]

The configurations and function of large biological molecules, and specifically DNA, can be manipulated through confinement in nanofluidic volumes. In relatively tight confinement, these devices can be used to obtain genomic information. Furthermore, the influence of the spatial organization of the nucleic material on its genetic function can be studied through nanoconfinement. These phenomena will be addressed by this focus session, spanning from application of these devices in the genetic sciences to the exploration of the underlying physics. The session will integrate experiment, theory, and computational approaches. Researchers in biophysics, polymer physics, materials physics, and computational physics will participate.

Organizer: Kevin Dorfman (U Minnesota) dorfman@umn.edu

1.1.17: Physics Of Genome Organization: From DNA To Chromatin (DBIO/DPOLY)
[Same as 3.1.19 and 4.1.5]

Information needed by all cells to survive and proliferate is encoded in the sequence of nucleotides in genomic DNA. In eukaryotes, DNA is packaged into chromatin – a complex multi-scale structure that ensures that all chromosomes fit into the tight confines of the cell nucleus. Chromatin has recently attracted a lot of attention from the biological physics community, with methods from polymer physics, statistical mechanics, condensed matter, and computational physics being applied to understand DNA folding and dynamics, as well as chromatin structure and function. These new developments will be explored in this Focus Session.

Organizers: Alexandre Morozov (Rutgers U) morozov@physics.rutgers.edu and Leonid Mirny (MIT) leonid@mit.edu

1.1.18: Physics of Proteins: From Experiments and Computation to Structure, Dynamics, and Functional Mechanisms (DBIO/DPOLY)
[Same as 4.1.3]

The Focus Session proposed here will bring together leading experts on the physics of proteins, particularly protein structure, dynamics, and functional mechanisms. It will provide a platform for presenting and discussing novel insights on the physics of proteins obtained through both computational and experimental approaches.

Organizers: Wouter Hoff (Oklahoma State U) wouter.hoff@okstate.edu; Andrea Markelz (U Buffalo) amarkelz@buffalo.edu; Corey O'Hearn (Yale U) corey.ohern@yale.edu; Wei Wang (Nanjing) wangwei@nju.edu.cn; and others.

2: SOFT CONDENSED MATTER (GSOFT)

2.1.1: Active Matter: From Colloidal Bots to Reconstituted Networks (GSOFT/DBIO/GSNP) (GSOFT)
[Same as 3.1.10 and 4.1.12]

Active materials are out of equilibrium systems composed of many interacting units that dissipate energy at the local scale and collectively generate motion or mechanical stress. This session focuses on the emergent behavior of engineered active systems, including active colloids, swimming droplets and other microswimmers, vibrated granular matter, and in-vitro networks of cytoskeletal proteins and motor proteins.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

2.1.2: Active Matter: Collective Phenomena in Living Systems (GSOFT/DBIO/GSNP) (GSOFT)
[Same as 3.1.11 and 4.1.13]

This session focuses on the rich variety of collective behavior found in living systems on many scales that can be described under the paradigm of active matter. This ranges from individual cell motility to multicellular phenomena, such as coordinated cell migration, mechanical properties of tissues, pattern formation in bacterial suspensions, and biofilms, to collective animal behavior, such as bird flocking, insect swarming and the behavior of crowds.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

2.1.3: Physics of Bioinspired Materials (GSOFT/DBIO) (GSOFT)
[Same as 4.1.17]

Recent years have witnessed a wave of renewed interest in designing bioinspired materials and structures especially accompanying with the rapid development of modern fabrication technology, such as nanofabrication and 3D printing. Understanding the physics governing formation of novel bioinspired structures and their stimuli-responsive behaviors is the key challenge to advance their design and uncover their potential. The goal of this session is to create a platform for experts working on bioinspired materials, to discuss about the novel physics problems across different length scales and properties. The session will become a unique forum that not only provides the physical understanding of bioinspired materials, but also offers physical insights to advance the design of future bioinspired systems for broad applications by addressing the current scientific and technological challenges.

Organizers: Qiming Wang (University of Southern California) qimingw@usc.edu and Sung Hoon Kang (Johns Hopkins University) shkang@jhu.edu

2.1.4: Clustering and Gelation With Competing Interactions (GSOFT)

This Focus Session deals with clustering phenomena and their origin in colloidal dispersions in presence of various forces (electrostatic or entropic in nature, and/or kinetic barriers of different origins) competing with attractive interactions (from van der Waals to depletion). The themes encompass a wide range of problems from model colloidal dispersions to emerging complex systems, such as protein solutions and gels, proteins in membranes, colloid-polymer nanocomposites, multi-species dispersions and cement gels.

Organizers: Emanuela Del Gado (Georgetown University) ed610@georgetown.edu and Yun Liu (NIST) yun.liu@nist.gov

2.1.5: Continuum Descriptions of Discrete Materials (GSOFT/GSNP) (GSOFT)

Many materials of interest in basic and applied physics have a coarse microstructure, such as granular materials, foams, suspensions, emulsions, and glasses. To model these materials at the large-scale, continuum formulations have been sought after to represent the homogenized effects of a large number of microscopic interactions. While extremely useful and expeditious for simulation purposes, the derivation of valid continuum models for particulate media remains challenging. Issues such as jamming, non-locality, intermittency, temperature analogies, homogenization scales, and shear banding have proven to be complex and important topics when constructing continuum descriptions for these materials. This focus session shall discuss the current state of research in continuum approaches for discrete materials, mixing aspects of statistical, fluid, and solid mechanics with discrete particle physics.

Organizers: Ken Kamrin (MIT) kkamrin@mit.edu and David Henann (Brown) david_henann@brown.edu

2.1.6: Simulating Long Timescale Dynamics of Soft Condensed Matter (GSOFT)

The accurate simulation of material behavior of soft matter at experimentally relevant timescales has been a long standing challenge, owing in part to the many orders of magnitude separating the macroscale from the microscale. The purpose of this session is to provide a forum for the discussion of recent advances in simulation techniques that can reach conventionally inaccessible timescales, with a particular focus on applications to soft matter.

Organizer: Gopinath Subramanian (University of Southern Mississippi) Gopinath.Subramanian@usm.edu

2.1.7: Robophysics (GSOFT/DBIO/GSNP) (GSOFT)
[Same as 4.1.16]

Robots are moving from the factory floor and into our lives (autonomous cars, homecare assistants, search and rescue devices, etc). However, despite the fascinating questions such future “living systems” pose for scientists, the study of such systems has been dominated by engineers and computer scientists. I propose that interaction of researchers studying dynamical systems, soft materials and living systems can help discover principles which will allow physical robotic devices interact with the real world in qualitatively different ways than they do now. And I propose that a Focus session at the APS March meeting that brings together leaders in this emerging area (most of whom are not physicists) will demonstrate the need for a physics of robotics, and reveal interesting problems at the interface of nonlinear dynamics, soft matter, control and biology.

Organizer: Daniel Goldman (Georgia Tech) daniel.goldman@physics.gatech.edu

2.1.8: Sediment Transport, Geological Flows, and Avalanches (GSOFT/GSNP) (GSOFT)

The physics of soft matter is responsible for shaping much of the natural world. Granular materials, soils, mud, and other disordered solids cover a large fraction of Earth’s surface, and the flow of these materials in response to gravitational or fluid driving are important for many environmental, industrial, and public safety applications. Additionally, disordered solids also reside beneath the surface, where they can experience very large forces on very long time scales. How and when these materials flow is often thought to be responsible for earthquakes, sinkholes, or other avalanche-like behavior. This session will cover recent advances in geophysical processes where the physics of soft matter is crucial, such as aeolian and subaqueous sediment transport, earthquakes, mudslides, sinkhole formation, avalanches, and other topics.

Organizers: Corey O'Hern (Yale) corey.ohern@yale.edu, Mark Shattuck (The City College of the City University of New York) shattuck@sci.ccny.cuny.edu, and Nick Ouellette (Stanford) nto@stanford.edu

2.1.9: Soft Matter at Interfaces (GSOFT)
[Same as 4.1.14]

This session considers soft matter questions where the behavior at or of an interface is studied. This includes Pickering emulsions, bijels, particle motion in membranes, studies of capillary waves, problems related to wetting and surface tension, surfactants at interfaces, soap films, lipid bilayers, etc. Note that macroscopic fluid mechanics at interfaces is covered by sorting category 20.6, although speakers with topics that fit with soft matter or involve microscale/macroscale questions are welcome in this focus session.

Organizer: Eric Weeks (Emory University) erweeks@emory.edu

2.1.10: Phase Transitions and Self-assembly in Biological Systems (DBIO/GSOFT) (GSOFT)

There is increasing interest in the assembly of proteins and DNA into complex structures such as virus capsids, amyloid materials or protein crystals. Different disciplines, including statistical, computational and colloid physics, collaborate to examine the role of entropy, molecular symmetry, anisotropic shape, valence and specificity of interaction for the emergence of order, and how this process is affected by slow kinetics, metastability and frustration. We invite experimental, theoretical and computational papers contributing to the understanding of these collective phenomena.

Organizers: Jens Glaser (University of Michigan) jsglaser@umich.edu and Michael Hagan (Brandeis University) hagan@brandeis.edu

2.1.11: Cell Motility: From Single Cell to Collective Dynamics (GSOFT/DBIO) (GSOFT)
[Same as 4.1.10]

This Focus Session addresses cellular motility broadly, from fundamental mechanisms governing single cell motion to the emerging collective dynamics of populations of cells. The speakers will ask and answer diverse questions that span systems and scales within this broad theme.

Organizers: Sima Setayeshgar (Indiana U) simas@indiana.edu; Thomas Gregor (Princeton U) tg2@princeton.edu

2.1.12: Soft Mechanics in Biological Systems (GSOFT/DBIO) (GSOFT)
[Same as 4.1.15]

The session would focus on the interplay between structure, mechanics, and statistical mechanics in biological matter across lengthscales - from subcellular systems to cells to whole tissues, and how this interplay influences the transfer of mechanical information, and emergent collective behavior in these systems.

Organizer: Jen Schwarz (Syracuse U) jschwarz@physics.syr.edu

2.1.13: Physics of Cancer and Development (GSOFT/DBIO) (GSOFT)
[Same as 4.1.11]

Physics is key to a wide range of biological processes in development and the malignant transformation that underlie tumorigenesis. Tumor cells employ cellular processes that drive organogenesis during embryonic deployment such as the epithelial-mesenchymal transition, collective cell migration and tissue remodeling during several steps of the malignant transformation. Thus on the cellular and tissue scale, development and disease are closely related. In these processes, defining the physical properties are critical to understand how cells move, remodel, and exert stresses and strains on their local microenvironment.

Organizers: Kandice Tanner (National Cancer Institute) kandice.tanner@nih.gov; Arpita Upadhyaya (U Maryland, College Park) arpitau@umd.edu

2.1.14: Geometric and Dynamical Nonlinear Mechanics of Slender Structures (GSNP/GSOFT) (GSOFT)

This session will highlight and celebrate recent work at the intersection of geometry, classical mechanics, and nonlinear physics. Slender structures such as cables and membranes are of interest as ubiquitous material structures whose primary nonlinearities are of geometric, rather than material/constitutive origin. Topics to be covered include experimental and theoretical investigations of the mechanics and physics of thin bodies, including dynamics and symmetries, buckling and post-buckling behavior as well as formation of other shapes and patterns.

Organizers: James Hanna (Virginia Tech) hannaj@vt.edu and Dominic Vella (Oxford University) dominic.vella@maths.ox.ac.uk

2.1.15: Soft Colloids: From Single Particle Properties to Bulk Phase Behavior and Dynamics (GSOFT)

Interdisciplinary research on soft colloids - porous networks of cross-linked polymers, swollen by a solvent - is driven by fundamental interest in the unusual properties of elastic particles, both individually and collectively, as well as by practical applications in the chemical, biomedical, food, consumer care, petroleum, and pharmaceutical industries. For example, microgels and microcapsules, which can encapsulate dye or drug molecules, are especially useful as chemical sensors and drug delivery vehicles. Swelling of elastic, compressible, and interpenetrable gel particles can be highly responsive to changes in temperature, pH, and other environmental conditions, leading to unique thermal, mechanical, optical, and rheological properties, especially at concentrations near and above close packing. With the aim of promoting interactions among diverse groups working on soft colloids, this focus session welcomes experimental, theoretical, and computational contributions.

Organizers: Alan Denton (North Dakota State University) alan.denton@ndsu.edu and Alberto Fernandez-Nieves (Georgia Tech) alberto.fernandez@physics.gatech.edu

2.1.16: Where Simulation, Theory and Experiments Meet Across Time and Length Scales. [Same as 1.1.2]

Modeling polymers and soft materials, with phenomena ranging from the from assembly of nanoparticles to the rheology of entangled macromolecules, presents unique computational challenges stemming from strong coupling of microscopic physical phenomena to macroscopic time and length scales through multiple mechanisms.  This session will focus on recent developments in bridging time and length scales in computation and theory of polymers, as well as on in-depth understanding spanning multiple length- and time-scales obtained from theory and simulations in polymers, bio polymers and soft matter.

Organizers: David Simmons (dsimmon@uakron.edu) and Gary S. Grest (gsgrest@sandia.gov)

2.1.17: Biopolymers and Biohybrid Polymers (DPOLY/DBIO) (DPOLY) [Same as 1.1.3 and 4.1.2]

Unlike traditional polymers, proteins and peptides have sequence-specific monomer arrangements that enable the formation of a wide variety of chain folds and specific interactions. The incorporation of these hierarchically structured molecules into materials poses new challenges in understanding the emergent physics of such biopolymer systems. This session will provide a forum for contributions on the latest advances in theory and experiment related to characterizing the self-assembly, solution properties, mechanics and other dynamic properties, and biophysical properties of protein materials and biohybrid systems.

Organizers: Brad Olsen (bdolsen@mit.edu), Muzhou Wang (@NIST.gov)

2.1.18: Assembly of Polymers, Soft Nanoparticles and Colloids in Solution (DPOLY/GSOFT/DBIO) (DPOLY) [Same as 1.1.8]

This focus session invites a combination of experimental, theoretical, and simulations contributions related to new methods for manipulating and characterizing the hierarchical self-assembly of block copolymers and soft nanoparticles in aqueous media toward the development of complex materials morphologies. By developing new molecular architectures or physical processing methods, experimental approaches for controlling these self-assembly processes may lead to scalable approaches to nanostructured materials with myriad useful applications. Theory and simulations studies of these materials continue to unveil the mechanisms governing these self-assembly process, while also driving the development of new and innovative methods for designing and processing materials to achieve specific morphologies. Topics of interesting include, yet are not limited to: path-dependent micellar assembly of synthetic and bio-based (e.g., peptide) copolymers, polymersomes, polymer/polymer and polymer/small molecule complexes, peptide-based materials, responsive and dynamic nanostructured assemblies, new characterization methods, anisotropic nanoparticles with specific/directional interactions, therapeutic encapsulation therein.

Organizers: Chang Y. Ryu (ryuc@rpi.edu), Du Yeol Ryu (dyryu@yonsei.ac.kr)

2.1.19: Aging in the Jammed State [Same as 3.1.2]

This session intends to highlight recent experiments, simulations, and theories that explore the dynamics deep in the aging regime, when materials are completely jammed and any equilibration is beyond reach. Such a state can be reached by materials as diverse as colloids and frustrated magnets. Their dynamics is characterized by activated events, which may be driven by internal (thermal) fluctuations or are due to some external drive (e.g., shear, vibrations, gravity, magnetic fields, etc.). These studies are complementary to those regarding the approach to the jamming transition, and the increasing difficulty in reaching equilibrium in colloidal and magnetic materials, which have received considerable attention over the years. Presentations in this session will inform the community of recent developments, demonstrate the insights gained from experiments, and highlight some of the ideas that have been proposed to explain and unify the observed behaviors.

2.1.20: Avalanches in Granular and Other Particle-based Materials [Same as 3.1.6]

Avalanches in granular media have been studied in sand piles, rotating drums, and during shear flow for a number of years. Many of the previous studies of slips have focused on measuring the critical angle for the initiation of avalanches rather than avalanche size statistics and waiting times. An interesting open question is whether the avalanche statistics in driven granular systems are similar to those for bulk metallic glasses and other amorphous thermal systems. Granular materials interact via purely repulsive contact forces, whereas atomic and molecular potentials include both repulsive and attractive interactions. Granular materials are also highly frictional, which introduces rotational degrees of freedom and strong dissipation of energy. The coupling between the translational and rotational degrees of freedom may influence the initiation of avalanches in granular media. Further, previous studies have shown that the under- and over-damped limits give different scaling exponents for the slip events in the steady state of ductile amorphous systems, which suggests a lack of universality. In this session we seek to feature theoretical, computational, and experimental contributions that investigate the statistics of particle rearrangements and avalanches in granular and other athermal particulate media so that we can understand the extent to which avalanche properties are universal across athermal and thermal glassy systems.

3: STATISTICAL AND NONLINEAR PHYSICS (GSNP)

3.1.1: Mechanical Metamaterials

The field of Mechanical Metamaterials lies at the cusp between physics, engineering and mathematics. The earliest examples of mechanical metamaterials date back to the late 80's, when auxetic (negative Poisson ratio) materials where discovered and created. But it is only in the last few years that the field has seen an explosion of activities, including the creation of materials with negative compressibility, switchable materials, acoustic cloaking and topologically protected mechanical states. Besides presenting an overview of current ideas and efforts, this session aims at bringing together researchers from diverse backgrounds to forge new interdisciplinary connections.

Organizers: Katia Bertoldi (Harvard University), Martin van Hecke (Leiden University), Vincenzo Vitelli (Leiden University)

3.1.2: Aging in the Jammed State [Same as 2.1.19]

This session intends to highlight recent experiments, simulations, and theories that explore the dynamics deep in the aging regime, when materials are completely jammed and any equilibration is beyond reach. Such a state can be reached by materials as diverse as colloids and frustrated magnets. Their dynamics is characterized by activated events, which may be driven by internal (thermal) fluctuations or are due to some external drive (e.g., shear, vibrations, gravity, magnetic fields, etc.). These studies are complementary to those regarding the approach to the jamming transition, and the increasing difficulty in reaching equilibrium in colloidal and magnetic materials, which have received considerable attention over the years. Presentations in this session will inform the community of recent developments, demonstrate the insights gained from experiments, and highlight some of the ideas that have been proposed to explain and unify the observed behaviors.

Organizers: Stefan Boettcher (Emory University), Paolo Sibani (University of Southern Denmark)

3.1.3: Wave Chaos: Theory and Applications

Nowadays, chaotic dynamics plays a crucial role in tackling the increasing complexity in electronics circuits, mechanical structures, and quantum systems. Chaos theory offers a unique platform for modeling wave systems with an arbitrary number of degrees of freedom. Two-dimensional microwave billiards constitutes a well-established framework for studying universal properties of wave systems in theory and experiments. These studies of chaos in analogous billiards are currently used to unveil the properties of complex electromagnetics systems. More recently, novel theoretical models have been developed describing fields through 3D electromagnetic cavities, also accounting for coupling and losses. A huge amount of numerical simulations has been carried out in the electromagnetics engineering community, dealing with mode-stirred enclosures, reverberation chambers, and random sources. In this session, speakers will discuss state-of-the-art mathematical methods in semiclassics and random matrix theory, also focusing on applications to electromagnetic compatibility, optics, and quantum mechanics.

Organizers: Gabriele Gradoni (University of Nottingham), Steven M. Anlage (University of Maryland), Thomas M. Antonsen (University of Maryland)

3.1.4: Fluids & Elasticity

Fluid-structure interactions occur across many length scales within synthetic and biological systems. At large scales, inertial flows and fluid weight can cause substantial structural deformations, while at small length scales, surface forces may dominate a material's deformation. If the elastic material is permeable to the surrounding fluid, stresses that arise from swelling the elastic network can also induce significant deformations to the structure. The coupling of fluids within and around deformable bodies has direct relevance to pattern formation, growth of soft tissues, emergence of geometric nonlinearities, morphable structures, and fluid transport. In a more general sense, interesting phenomena will emerge when materials with large separations of compliance interact. Recent research in this area has explored extremely deformable solids interacting with rigid structures, the interactions of nontrivial fluids with flexible membranes, and the behavior of a fluid within a swollen elastomer. This research has highlighted the importance of understanding the roles of the elastic material and the slender structure in these coupled interactions. This session aims to bring together researchers from diverse backgrounds in structural mechanics, fluid mechanics, applied mathematics, materials science, soft matter physics, and biomechanics, to open new areas of interdisciplinary research.

Organizer: Douglas P. Holmes (Boston University)

3.1.5: Nonlinear Dynamics in Networks

The study of nonlinear dynamical phenomena in networks of coupled dynamical systems has transformed a number of application areas of physics, including the study of synchronization and cascading processes, the modeling of biological and socio-technological systems, and the development of approaches for the optimization and control of complex systems. This focus session will bring together a number of recent contributions in this broad and rapidly developing field of interdisciplinary research in which methods from nonlinear and statistical physics play a central role. Presentations will include theoretical, computational, and experimental work from experts as well as early career researchers.

Organizer: Adilson E. Motter (Northwestern University)

3.1.6: Avalanches in Granular and Other Particle-based Materials [Same as 2.1.20]

Avalanches in granular media have been studied in sand piles, rotating drums, and during shear flow for a number of years. Many of the previous studies of slips have focused on measuring the critical angle for the initiation of avalanches rather than avalanche size statistics and waiting times. An interesting open question is whether the avalanche statistics in driven granular systems are similar to those for bulk metallic glasses and other amorphous thermal systems. Granular materials interact via purely repulsive contact forces, whereas atomic and molecular potentials include both repulsive and attractive interactions. Granular materials are also highly frictional, which introduces rotational degrees of freedom and strong dissipation of energy. The coupling between the translational and rotational degrees of freedom may influence the initiation of avalanches in granular media. Further, previous studies have shown that the under- and over-damped limits give different scaling exponents for the slip events in the steady state of ductile amorphous systems, which suggests a lack of universality. In this session we seek to feature theoretical, computational, and experimental contributions that investigate the statistics of particle rearrangements and avalanches in granular and other athermal particulate media so that we can understand the extent to which avalanche properties are universal across athermal and thermal glassy systems.

Organizers: Robert Behringer (Duke University), Bulbul Chakraborty (Brandeis University), Corey S. O’Hern (Yale University)

3.1.7: Non-equilibrium Systems with Large Fluctuations and Strong Correlations

Gaining a better understanding of systems far from equilibrium remains among the greatest challenges of contemporary physics. One of the generic lessons we have learned about non-equilibrium systems is that the effects of stochastic fluctuations and emerging spatio-temporal correlations tend to be markedly more prominent than in typical thermal equilibrium situations. Whereas remarkable progress has been achieved for specific systems, a general unifying theoretical framework for non-equilibrium systems remains elusive. Many of the intriguing aspects of fluctuations and correlations far from equilibrium remain incompletely understood, and constitute a highly active field of current research, both in experimental studies as well as in analytical theory and numerical investigations. This session intends to gather frontline research in various areas of non-equilibrium statistical physics with emphasis on fluctuations and correlations.

Organizers: Uwe C. Täuber (Virginia Tech), Michel Pleimling (Virginia Tech)

3.1.8: Geometric and Dynamic Nonlinear Mechanics of Slender Structures (GSNP/GSOFT)

This session will highlight and celebrate recent work at the intersection of geometry, classical mechanics, and nonlinear physics. Slender structures such as cables and membranes are of interest as ubiquitous material structures whose primary nonlinearities are of geometric, rather than material or constitutive origin. Topics to be covered include experimental and theoretical investigations of the mechanics and physics of thin bodies, including dynamics and symmetries, buckling and post-buckling behavior as well as formation of other shapes and patterns.

Organizers: James Hanna (Virginia Tech), Dominic Vella (Oxford University)

3.1.9: Robophysics: Physics Meets Robotics (GSNP/DBIO/GSOFT)

Robots are moving from the factory floor into our lives (autonomous cars, homecare assistants, search and rescue devices, etc.). However, despite the fascinating questions such future “living systems” pose for scientists from various domains, the study of such systems has been dominated by engineers and computer scientists. We propose that interaction of researchers studying dynamical systems, soft materials and living systems can help discover principles that will allow physical robotic devices to interact with the real world in qualitatively different ways than they do now. This session, which will bring together leaders in this emerging area (most of whom are not physicists), is expected to demonstrate the need for a “physics of robotics” and to reveal interesting problems at the interface of nonlinear dynamics, soft matter, control, and biology.

Organizer: Dan Goldman (Georgia Tech)

3.1.10: Active Matter: From Colloidal Bots to Reconstituted Networks (GSNP/GSOFT/DBIO)
[Same as 2.1.1 and 4.1.12]

Active materials are out of equilibrium systems composed of many interacting units that dissipate energy at the local scale and collectively generate motion or mechanical stress. This session focuses on the emergent behavior of engineered active systems, including active colloids, swimming droplets and other microswimmers, vibrated granular matter, and in-vitro networks of cytoskeletal proteins and motor proteins.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

3.1.11: Active Matter: Collective Phenomena in Living Systems (GSNP/DBIO/GSOFT)
[Same as 2.1.2 and 4.1.13]

This session focuses on the rich variety of collective behavior found in living systems on many scales that can be described under the paradigm of active matter. This ranges from individual cell motility to multicellular phenomena, such as coordinated cell migration, mechanical properties of tissues, pattern formation in bacterial suspensions, and biofilms, to collective animal behavior, such as bird flocking, insect swarming and the behavior of crowds.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

3.1.12: Continuum Descriptions of Discrete Materials (GSNP/GSOFT)
[Same as 2.1.5]

Many materials of interest in basic and applied physics have a coarse microstructure, such as granular materials, foams, suspensions, emulsions, and glasses. To model these materials at the large-scale, continuum formulations have been sought after to represent the homogenized effects of a large number of microscopic interactions. While extremely useful and expeditious for simulation purposes, the derivation of valid continuum models for particulate media remains challenging. Issues such as jamming, non-locality, intermittency, temperature analogies, homogenization scales, and shear banding have proven to be complex and important topics when constructing continuum descriptions for these materials. This focus session shall discuss the current state of research in continuum approaches for discrete materials, mixing aspects of statistical, fluid, and solid mechanics with discrete particle physics.

Organizers: Ken Kamrin (MIT) kkamrin@mit.edu and David Henann (Brown) david_henann@brown.edu

3.1.13: Sediment Transport, Geological Flows, and Avalanches (GSNP/GSOFT)
[Same as 2.1.8]

The physics of soft matter is responsible for shaping much of the natural world. Granular materials, soils, mud, and other disordered solids cover a large fraction of Earth’s surface, and the flow of these materials in response to gravitational or fluid driving are important for many environmental, industrial, and public safety applications. Additionally, disordered solids also reside beneath the surface, where they can experience very large forces on very long time scales. How and when these materials flow is often thought to be responsible for earthquakes, sinkholes, or other avalanche-like behavior. This session will cover recent advances in geophysical processes where the physics of soft matter is crucial, such as aeolian and subaqueous sediment transport, earthquakes, mudslides, sinkhole formation, avalanches, and other topics.

Organizers: Corey O'Hern (Yale) corey.ohern@yale.edu, Mark Shattuck (The City College of the City University of New York) shattuck@sci.ccny.cuny.edu, and Nick Ouellette (Stanford) nto@stanford.edu

3.1.14: Information Processing in Cellular Signaling and Gene Regulation (GSNP/DBIO)
[Same as 4.1.6]

This Focus Session will investigate probabilistic modeling and data analysis related to cellular information processing phenomena, such as gene regulation and signal transduction. The recent years have enjoyed breakthroughs in the field, such as the ability to quantify activity of many molecular species at the same time and for a long time, to track individual molecules involved in cellular computations, and to study effects of molecular stochasticity in information processing. Methods of nonequilibrium statistical physics, information theory, and control theory are used to model these data and will be featured prominently in the session. This allows applications of more advanced network information theory ideas to biological systems, which we are going to explore.

Organizer: Ilya Nemenman (Emory U) ilya.nemenman@emory.edu

3.1.15: Stochastic Evolutionary and Population Dynamics (GSNP/DBIO)
[Same as 4.1.18]

Over the past years, mathematical and computational tools from statistical physics have been increasingly and quite successfully applied to ecological problems. More recently, novel analytical developments have allowed additional complexity to be added to such spatial and stochastic evolutionary and population dynamics models, rendering them increasingly more realistic and relevant to actual biological systems and ecological problems. The Focus Session will explore these recent developments.

Organizers: Michel Pleimling (Virginia Tech) pleim@vt.edu and Uwe Täuber (Virginia Tech) tauber@vt.edu

3.1.16: Maximum Entropy Models: A Promising Link Between Statistical Physics, Inference, and Biology (GSNP/DBIO)
[Same as 4.1.22]

Maximum entropy (ME) models have recently come to the fore as a method for inferring the underlying interactions of a system's components from data, with particular successes in diverse areas of biophysics. Most of these successes were possible because ME models provided a bridge between pre-existing foundations in statistical physics and large and diverse new datasets. At the same time, ME methods have a long history as general-purpose probabilistic modeling techniques, with strong links to statistics and machine learning. Unfortunately, conceptual and methodological advances reached within one application domain or discipline have often not percolated to others. The Focus Session will explore ME modeling, from new fundamental questions about statistical mechanics foundations of the method, to applications to biological data, and to modern statistical inference (e.g. Boltzmann machine learning).

Organizer: Gasper Tkacik (Institute of Science and Technology Austria) gtkacik@ist.ac.at

3.1.17: Principles of Cell-to-Cell Communication (GSNP/DBIO)
[Same as 4.1.9]

Populations of cells cooperate to perform elaborate functions, such as the growth of tissues and immune surveillance in multicellular organisms, or niche colonization by communities of microbes. These feats of cooperation are made possible by cell-to-cell communication. Understanding the physical principles that make such communication possible in the face of noise, interference, and unpredictable conditions requires an integrated approach stretching from molecules to intracellular networks to cell populations. This Focus Session will bring together a collection of talks at the interface of biology and physics, focusing on cell-to-cell communication and information processing.

Organizers: Ned Wingreen (Princeton U) wingreen@princeton.edu; Thibaud Taillefumier (Princeton U) ttaillef@princeton.edu

3.1.18: Critical Transitions in Biological Systems (GSNP/DBIO)
[Same as 4.1.23]

This Focus Session will bring biophysicists, statistical physicists, and scientists studying nonlinear dynamic systems together to present their work in understanding the dynamics and the critical phase transitions in several model biological systems; and how they apply the results in genetics of complex disease, the driving network identification, and disease progression risk prediction.

Organizer: Chen Zeng (George Washington University) chenz@gwu.edu

3.1.19: Physics and Genome Organization: From DNA to Chromatin (GSNP/DBIO)
[Same as 1.1.17 and 4.1.5]

Information needed by all cells to survive and proliferate is encoded in the sequence of nucleotides in genomic DNA. In eukaryotes, DNA is packaged into chromatin – a complex multi-scale structure that ensures that all chromosomes fit into the tight confines of the cell nucleus. Chromatin has recently attracted a lot of attention from the biological physics community, with methods from polymer physics, statistical mechanics, condensed matter, and computational physics being applied to understand DNA folding and dynamics, as well as chromatin structure and function. These new developments will be explored in this Focus Session.

Organizers: Alexandre Morozov (Rutgers U) morozov@physics.rutgers.edu and Leonid Mirny (MIT) leonid@mit.edu

4: BIOLOGICAL PHYSICS (DBIO)

4.1.1: Biopolymers in Confinement (DBIO/DPOLY/DCOMP)
[Same as 1.1.16]

The configurations and function of large biological molecules, and specifically DNA, can be manipulated through confinement in nanofluidic volumes. In relatively tight confinement, these devices can be used to obtain genomic information. Furthermore, the influence of the spatial organization of the nucleic material on its genetic function can be studied through nanoconfinement. These phenomena will be addressed by this focus session, spanning from application of these devices in the genetic sciences to the exploration of the underlying physics. The session will integrate experiment, theory, and computational approaches. Researchers in biophysics, polymer physics, materials physics, and computational physics will participate.

Organizer: Kevin Dorfman (U Minnesota) dorfman@umn.edu

4.1.2: Biopolymers and Biohybrid Polymers (DPOLY/DBIO) (DPOLY) [Same as 1.1.3 and 2.1.17]

Unlike traditional polymers, proteins and peptides have sequence-specific monomer arrangements that enable the formation of a wide variety of chain folds and specific interactions. The incorporation of these hierarchically structured molecules into materials poses new challenges in understanding the emergent physics of such biopolymer systems. This session will provide a forum for contributions on the latest advances in theory and experiment related to characterizing the self-assembly, solution properties, mechanics and other dynamic properties, and biophysical properties of protein materials and biohybrid systems.

Organizers: Brad Olsen (bdolsen@mit.edu), Muzhou Wang (@NIST.gov)

4.1.3: Physics of Proteins: From Experiments and Computation to Structure, Dynamics, and Functional Mechanisms (DBIO/DPOLY/DCOMP)
[Same as 1.1.18]

The Focus Session proposed here will bring together leading experts on the physics of proteins, particularly protein structure, dynamics, and functional mechanisms. It will provide a platform for presenting and discussing novel insights on the physics of proteins obtained through both computational and experimental approaches.

Organizers: Wouter Hoff (Oklahoma State U) wouter.hoff@okstate.edu; Andrea Markelz (U Buffalo) amarkelz@buffalo.edu; Corey O'Hearn (Yale U) corey.ohern@yale.edu; Wei Wang (Nanjing) wangwei@nju.edu.cn; and others.

4.1.4: DNA: From Understanding Mechanics to Assembly Tool (DPOLY/DBIO) (DPOLY)

4.1.5: Physics of Genome Organization: From DNA to Chromatin (DBIO/DPOLY/DCOMP/GSNP)
[Same as 1.1.17 and 3.1.19]

Information needed by all cells to survive and proliferate is encoded in the sequence of nucleotides in genomic DNA. In eukaryotes, DNA is packaged into chromatin – a complex multi-scale structure that ensures that all chromosomes fit into the tight confines of the cell nucleus. Chromatin has recently attracted a lot of attention from the biological physics community, with methods from polymer physics, statistical mechanics, condensed matter, and computational physics being applied to understand DNA folding and dynamics, as well as chromatin structure and function. These new developments will be explored in this Focus Session.

Organizers: Alexandre Morozov (Rutgers U) morozov@physics.rutgers.edu and Leonid Mirny (MIT) leonid@mit.edu

4.1.6: Information Processing in Cellular Signaling and Gene Regulation (DBIO/GSNP)

This Focus Session will investigate probabilistic modeling and data analysis related to cellular information processing phenomena, such as gene regulation and signal transduction. The recent years have enjoyed breakthroughs in the field, such as the ability to quantify activity of many molecular species at the same time and for a long time, to track individual molecules involved in cellular computations, and to study effects of molecular stochasticity in information processing. Methods of nonequilibrium statistical physics, information theory, and control theory are used to model these data and will be featured prominently in the session. This allows applications of more advanced network information theory ideas to biological systems, which we are going to explore.

Organizer: Ilya Nemenman (Emory U) ilya.nemenman@emory.edu

4.1.7: Evolutionary Design Principles of Bio-Networks

The Focus Session will focus on how evolution shapes the properties of biochemical and gene-regulatory networks. Are there any constraints on the dynamical systems behavior of the networks that evolutionary population dynamics impose? What makes the dynamical behaviors of biochemical networks robust to mutations? How fast do networks evolve and through what mechanisms? Is the evolution of networks predictable? And how does all of this depend on the environment (constant versus fluctuating, beneficial versus harmful, etc)?

Organizers: Oleg Igoshin (Rice U) igoshin@rice.edu and G�bor Bal�zsi (Stony Brook U) gabor.balazsi@stonybrook.edu

4.1.8: The Physics of Cellular Organization

This session will bring together talks on the role and physics of organization in different cellular systems. From large protein waves to single cellular components, organization is essential for proper cellular function. The physics of how cellular systems organize to accomplish their tasks for different roles will be discussed.

Organizers: Michael Gramlich (Washington University, St. Loius) michael.gramlich@wustl.edu; S.M. Ali Tabei (University of Northern Iowa) smatabei@gmail.com

4.1.9: Principles of Cell-to-Cell Communication (DBIO/GSNP)

Populations of cells cooperate to perform elaborate functions, such as the growth of tissues and immune surveillance in multicellular organisms, or niche colonization by communities of microbes. These feats of cooperation are made possible by cell-to-cell communication. Understanding the physical principles that make such communication possible in the face of noise, interference, and unpredictable conditions requires an integrated approach stretching from molecules to intracellular networks to cell populations. This Focus Session will bring together a collection of talks at the interface of biology and physics, focusing on cell-to-cell communication and information processing.

Organizers: Ned Wingreen (Princeton U) wingreen@princeton.edu; Thibaud Taillefumier (Princeton U) ttaillef@princeton.edu

4.1.10: Cell Motility: From Single Cell to Collective Dynamics (DBIO/GSOFT)

This Focus Session addresses cellular motility broadly, from fundamental mechanisms governing single cell motion to the emerging collective dynamics of populations of cells. The speakers will ask and answer diverse questions that span systems and scales within this broad theme.

Organizers: Sima Setayeshgar (Indiana U) simas@indiana.edu; Thomas Gregor (Princeton U) tg2@princeton.edu

4.1.11: Physics of Cancer and Development (DBIO/GSOFT)

Physics is key to a wide range of biological processes in development and the malignant transformation that underlie tumorigenesis. Tumor cells employ cellular processes that drive organogenesis during embryonic deployment such as the epithelial-mesenchymal transition, collective cell migration and tissue remodeling during several steps of the malignant transformation. Thus on the cellular and tissue scale, development and disease are closely related. In these processes, defining the physical properties are critical to understand how cells move, remodel, and exert stresses and strains on their local microenvironment.

Organizers: Kandice Tanner (National Cancer Institute) kandice.tanner@nih.gov; Arpita Upadhyaya (U Maryland, College Park) arpitau@umd.edu

4.1.12: Active Matter: From Colloidal Bots to Reconstituted Networks (GSOFT/DBIO/GSNP)
[Same as 2.1.1 and 3.1.10]

Active materials are out of equilibrium systems composed of many interacting units that dissipate energy at the local scale and collectively generate motion or mechanical stress. This session focuses on the emergent behavior of engineered active systems, including active colloids, swimming droplets and other microswimmers, vibrated granular matter, and in-vitro networks of cytoskeletal proteins and motor proteins.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

4.1.13: Active Matter: Collective Phenomena in Living Systems (DBIO/GSOFT/GSNP)
[Same as 2.1.2 and 3.1.11]

This session focuses on the rich variety of collective behavior found in living systems on many scales that can be described under the paradigm of active matter. This ranges from individual cell motility to multicellular phenomena, such as coordinated cell migration, mechanical properties of tissues, pattern formation in bacterial suspensions, and biofilms, to collective animal behavior, such as bird flocking, insect swarming and the behavior of crowds.

Organizers: Cristina Marchetti (Syracuse University) mcmarche@syr.edu and Yuhai Tu (IBM) yuhai@us.ibm.com

4.1.14: Phase Transitions and Self-Assembly in Biological Systems (GSOFT/DBIO)
[Same as 2.1.9]

There is increasing interest in the assembly of proteins and DNA into complex structures such as virus capsids, amyloid materials or protein crystals. Different disciplines, including statistical, computational and colloid physics, collaborate to examine the role of entropy, molecular symmetry, anisotropic shape, valence and specificity of interaction for the emergence of order, and how this process is affected by slow kinetics, metastability and frustration. We invite experimental, theoretical and computational papers contributing to the understanding of these collective phenomena.

Organizers: Jens Glaser (University of Michigan) jsglaser@umich.edu and Michael Hagan (Brandeis University) hagan@brandeis.edu

4.1.15: Soft mechanics in biological systems (GSOFT/DBIO)

The session would focus on the interplay between structure, mechanics, and statistical mechanics in biological matter across lengthscales - from subcellular systems to cells to whole tissues, and how this interplay influences the transfer of mechanical information, and emergent collective behavior in these systems.

Organizer: Jen Schwarz (Syracuse U) jschwarz@physics.syr.edu

4.1.16: Robophysics: Physics Meets Robotics (GSOFT/DBIO/GSNP)
[Same as 2.1.7]

Robots are moving from the factory floor and into our lives (autonomous cars, homecare assistants, search and rescue devices, etc). However, despite the fascinating questions such future “living systems” pose for scientists, the study of such systems has been dominated by engineers and computer scientists. I propose that interaction of researchers studying dynamical systems, soft materials and living systems can help discover principles which will allow physical robotic devices interact with the real world in qualitatively different ways than they do now. And I propose that a Focus session at the APS March meeting that brings together leaders in this emerging area (most of whom are not physicists) will demonstrate the need for a physics of robotics, and reveal interesting problems at the interface of nonlinear dynamics, soft matter, control and biology.

Organizer: Daniel Goldman (Georgia Tech) daniel.goldman@physics.gatech.edu

4.1.17: Physics of Bioinspired Materials (GSOFT/DBIO)
[Same as 2.1.3]

Recent years have witnessed a wave of renewed interest in designing bioinspired materials and structures especially accompanying with the rapid development of modern fabrication technology, such as nanofabrication and 3D printing. Understanding the physics governing formation of novel bioinspired structures and their stimuli-responsive behaviors is the key challenge to advance their design and uncover their potential. The goal of this session is to create a platform for experts working on bioinspired materials, to discuss about the novel physics problems across different length scales and properties. The session will become a unique forum that not only provides the physical understanding of bioinspired materials, but also offers physical insights to advance the design of future bioinspired systems for broad applications by addressing the current scientific and technological challenges.

Organizers: Qiming Wang (University of Southern California) qimingw@usc.edu and Sung Hoon Kang (Johns Hopkins University) shkang@jhu.edu

4.1.18: Stochastic Evolutionary and Population Dynamics (DBIO/GSNP)

Over the past years, mathematical and computational tools from statistical physics have been increasingly and quite successfully applied to ecological problems. More recently, novel analytical developments have allowed additional complexity to be added to such spatial and stochastic evolutionary and population dynamics models, rendering them increasingly more realistic and relevant to actual biological systems and ecological problems. The Focus Session will explore these recent developments.

Organizers: Michel Pleimling (Virginia Tech) pleim@vt.edu and Uwe T�uber (Virginia Tech) tauber@vt.edu

4.1.19: Neither Shaken or Stirred: Population Dynamics in 3+1 Dimensions

A great deal of biological population dynamics occurs not in the 2-D world of the agar plate, or the well-stirred world of the chemostat, but rather in a 3-D world of complex structures and linkages. Further, this 3-D world is constantly changing with time, adding a 4th dimension, which is critical. There is a two-fold challenge we face: (1) Fabrication of complex 3-D structures for studying such complex population dynamics, and (2) Imaging and analysis of interacting cells in 3+1 dimensions. These will be the discussed in the Focus Session.

Organizer: Robert Austin (Princeton U) austin@princeton.edu

4.1.20: Physics of Sensorimotor Neural Circuits

This session will discuss the physical constraints shape the interaction between neural circuits and the sensory environment. This topic includes adaptation to the statistics of natural environments, as well as between different circuit components, such as between sensory and motor circuits.

Organizer: Tatyana Sharpee (Salk Institute) sharpee@salk.edu

4.1.21: Neural Control of Behavior

How animals move has been a decades-long focus in biomechanics, which attempts to link organism-scale dynamics to the control strategies that actuate them. Lacking however, have been direct connections between these motions and their underlying neural mechanisms. The recent advent of minimally invasive tools for measuring and manipulating neurons in freely behaving animals is providing new insights to the neural basis of control, and physicists are making important contributions to these advances. The Focus Session will address a diverse range of these efforts – from the development of novel microscopy and data analysis tools to the building of theoretical, computational, and robotic models.

Organizers: Gordon Berman (Emory U) gordon.berman@gmail.com and Greg Stephens (Vrije Universiteit Amsterdam & Okinawa Institute of Science and Technology) gjstephens@gmail.com

4.1.22: Maximum Entropy Models: A Promising Link Between Statistical Physics, Inference, and Biology (DBIO/GSNP)

Maximum entropy (ME) models have recently come to the fore as a method for inferring the underlying interactions of a system's components from data, with particular successes in diverse areas of biophysics. Most of these successes were possible because ME models provided a bridge between pre-existing foundations in statistical physics and large and diverse new datasets. At the same time, ME methods have a long history as general-purpose probabilistic modeling techniques, with strong links to statistics and machine learning. Unfortunately, conceptual and methodological advances reached within one application domain or discipline have often not percolated to others. The Focus Session will explore ME modeling, from new fundamental questions about statistical mechanics foundations of the method, to applications to biological data, and to modern statistical inference (e.g. Boltzmann machine learning).

Organizer: Gasper Tkacik (Institute of Science and Technology Austria) gtkacik@ist.ac.at

4.1.23: Critical Transitions in Biological Systems (DBIO/GSNP)

This Focus Session will bring biophysicists, statistical physicists, and scientists studying nonlinear dynamic systems together to present their work in understanding the dynamics and the critical phase transitions in several model biological systems; and how they apply the results in genetics of complex disease, the driving network identification, and disease progression risk prediction.

Organizer: Chen Zeng (George Washington University) chenz@gwu.edu