美国自然科学基金摘要

美国自然科学基金摘要Dynamics of Double-Stranded DNA in Confined GeometriesNSF Org: DMRDivision of Materials ResearchInitial Amendment Date: September 9, 2011Latest Amendment Date: September 9, 2011A ward Number: 1106044A ward Instrument: Continuing grantProgram Manager: David A. BrantDMR Division of Materials ResearchMPS Directorate for Mathematical & Physical SciencesStart Date: September 15, 2011Expires: August 31, 2014 (Estimated)A warded Amount to Date: $223087Investigator(s): Helmut Strey Helmut.Strey@ (Principal Investigator)Sponsor: SUNY at Stony BrookWEST 5510 FRK MEL LIBSTONY BROOK, NY 11794 631/632-9949NSF Program(s): BIOMA TERIALS PROGRAM,POLYMERSField Application(s):Program Reference Code(s): AMPP, 9161, 7573, 7237Program Element Code(s): 7623, 1773ABSTRACTID: MPS/DMR/BMA T(7623) 1106044 PI: Strey, Helmut ORG: SUNY Stony BrookTitle: Dynamics of double-stranded DNA in confined geometriesINTELLECTUAL MERIT: This proposal is motivated by previous work from the PI's lab on the diffusion of double-stranded DNA (ds-DNA) molecules in 2-dimensional cavity arrays. This work investigated by fluorescence imaging the diffusion of linear DNA through a medium of precisely controlled (and known) pore structure. This structure was a periodic, two-dimensional hexagonal array of spherical cavities interconnected by short circular holes. Tracking many single molecule trajectories, it was found that, for DNA radius of gyration approaching the cavity diameter, diffusion is dominated by the sporadic hopping of DNA between cavities, a mechanism predicted by the entropic barriers transport theory. Hopping corresponds to configurational fluctuations that allow passage of a flexible polymer through a pore constriction smaller than the average coil size. The diffusion of relaxed ds-DNA circles has recently been compared with that of linear DNA of the same length. It is observed that circular molecules diffuse from 2.5 to 5.6 times slower than corresponding linear molecules of the same molecular weight, and 3.7 to 10.6 times slower than corresponding linear molecules of the same average dimension. Such results qualitatively reveal that linear molecules may form loops during translocation through holes between cavities, but the probability of such events is low. The predominant mode of diffusion for linear molecules is end first. This proposal addresses this passage in more detail. Does a polymer thread by one of its ends or loop by one of its mid-segments or do both processes occur with equal facility? This question is addressed in several stages that independently address important fundamental questions in polymer dynamics: (1) Create 2-color end-labeled molecules of varying molecular weights that will enable the study of internal and solution polymer dynamics using fluorescence correlation spectroscopy. (2) Study internal polymer dynamics in slit-like nanochannels to deepen our understanding of laterally confined polymers using FCS and optical microscopy. (3) Measure partitioning and hopping frequencies of linear ds-DNA and nicked circular DNA between cavities and connecting channels as a function DNA length and the array dimensions (height, cavity diameter, constriction width, and length). (4) Characterize the threading dynamics of double-labeled DNA in cavity arrays.BROADER IMPACTS: Many technologies for macromolecular manipulation, purification, and separation rely on an environment of molecular level constraints to create selective macromolecular motion. It is proposed to develop a deeper understanding of the thermodynamics and dynamics of nanoscale polymer confinement by preparing fluidic devices and cavity arrays in which macromolecules can be examined by single molecule fluorescence visualization. The project will also address a very important technological area of separating different polymer topologies (e.g. linear vs. circular). The main educational goal is to train and mentor graduate and undergraduate students to enable them to pursue their career in research and engineering. This research effort will produce students that have a rigorous science background, are independent thinkers, and have an understanding of intellectual property and real world applications. Inaddition, the PI will continue to reach out to high-school students through the Stony Brook Simons program as mentor and science judge. Some of those students, after their lab experience, have been very successful in science competitions such as LISF and the Intel competition. In addition, the PI will host and design a website that allows sharing of techniques and tricks in nanofabrication and nano/microfluidics with the research community. Such a website will enable researchers and students to learn and share the intricacies of nano- and microfluidics.Please report errors in award information by writing to: awardsearch@.Collaborative Research : Emerging Issues in the Sciences Involving Non-Standard Diffusion NSF Org: DMSDivision of Mathematical SciencesInitial Amendment Date: August 5, 2011Latest Amendment Date: August 5, 2011A ward Number: 1065979A ward Instrument: Continuing grantProgram Manager: Kevin F. ClanceyDMS Division of Mathematical SciencesMPS Directorate for Mathematical & Physical SciencesStart Date: August 15, 2011Expires: July 31, 2016 (Estimated)A warded Amount to Date: $157766Investigator(s): Luis Silvestre luis@ (Principal Investigator)Henri Berestycki (Co-Principal Investigator)Sponsor: University of Chicago5801 South Ellis A venueChicago, IL 60637 773/702-8602NSF Program(s): ANALYSIS PROGRAMField Application(s):Program Reference Code(s): 1616Program Element Code(s): 1281ABSTRACTThe mathematical description and understanding of "diffusive processes" is central to many areas of science, from geometry and probability to continuum mechanics, fluid dynamics, population dynamics and game theory to name a few. Ricci flows, the Navier Stokes equation, non linear elasticity, futures options, all carry an element of diffusion, viscosity, uncertainty that correspond to a similar mathematical description. An extensive theory already permeates, under different circumstances and goals, wide areas of analysis, geometry and applied mathematics. The investigators perceive, however, that there are new, emerging areas of added complexity. It is expected that through the collaborative effort, new general methods will emerge providing some sort of unification and cohesion like the one existing today for classical infinitesimal diffusion processes and their role in the sciences (modeling, simulation, prediction).Problems which are to be studied include reaction diffusion phenomena in random environments, phase transition problems, non local diffusion processes and other applications motivated by questions of population dynamics, congestion issues in transportation, diffusion and segregation phenomena in social sciences, formation and dynamics of hotspots of criminal activity, phase transition problems involving nonlocal (long range) interactions and surface diffusion related to electric fluid droplets and complex fluids in nano technology and biology. The project involves a system of personnel exchanges between the home institutions, designed to provide a rich training experience for students and postdocs. In addition, there will be an emphasis month every year of the project in one of the home universities and a summer school designed to bring members of the group - including graduate students and postdocs - together to stimulate scientific progress. In this way the fruits of the research will be exposed to a broader audience, thereby, helping educate and attract a new generation of researchers to these exciting emerging mathematical challenges and ideasEmerging issues in the sciences involving non standard diffusionNSF Org: DMSDivision of Mathematical SciencesInitial Amendment Date: August 5, 2011Latest Amendment Date: August 5, 2011A ward Number: 1065971A ward Instrument: Standard GrantProgram Manager: Kevin F. ClanceyDMS Division of Mathematical SciencesMPS Directorate for Mathematical & Physical SciencesStart Date: August 15, 2011Expires: July 31, 2014 (Estimated)A warded Amount to Date: $150001Investigator(s): Y anyan Li yyli@ (Principal Investigator)Sponsor: Rutgers University New Brunswick3 RUTGERS PLAZANEW BRUNSWICK, NJ 08901 848/932-0150NSF Program(s): ANALYSIS PROGRAMField Application(s):Program Reference Code(s): 1616Program Element Code(s): 1281ABSTRACTThe mathematical description and understanding of "diffusive processes" is central to many areas of science, from geometry and probability to continuum mechanics, fluid dynamics, population dynamics and game theory to name a few. Ricci flows, the Navier Stokes equation, non linear elasticity, futures options, all carry an element of diffusion, viscosity, uncertainty that correspond to a similar mathematical description. An extensive theory already permeates, under different circumstances and goals, wide areas of analysis, geometry and applied mathematics. The investigators perceive, however, that there are new, emerging areas of added complexity. It is expected that through the collaborative effort, new general methods will emerge providing some sort of unification and cohesion like the one existing today for classical infinitesimal diffusion processes and their role in the sciences (modeling, simulation, prediction).Problems which are to be studied include reaction diffusion phenomena in random environments, phase transition problems, non local diffusion processes and other applications motivated byquestions of population dynamics, congestion issues in transportation, diffusion and segregation phenomena in social sciences, formation and dynamics of hotspots of criminal activity, phase transition problems involving nonlocal (long range) interactions and surface diffusion related to electric fluid droplets and complex fluids in nano technology and biology. The project involves a system of personnel exchanges between the home institutions, designed to provide a rich training experience for students and postdocs. In addition, there will be an emphasis month every year of the project in one of the home universities and a summer school designed to bring members of the group - including graduate students and postdocs - together to stimulate scientific progress. In this way the fruits of the research will be exposed to a broader audience, thereby, helping educate and attract a new generation of researchers to these exciting emerging mathematical challenges and ideas.Emerging issues in the sciences involving non standard diffusionNSF Org: DMSDivision of Mathematical SciencesInitial Amendment Date: August 5, 2011Latest Amendment Date: August 5, 2011A ward Number: 1065964A ward Instrument: Standard GrantProgram Manager: Kevin F. ClanceyDMS Division of Mathematical SciencesMPS Directorate for Mathematical & Physical SciencesStart Date: August 15, 2011Expires: July 31, 2014 (Estimated)A warded Amount to Date: $239999Investigator(s): Fang-Hua Lin linf@ (Principal Investigator)Sponsor: New Y ork University70 W ASHINGTON SQUARE SNEW YORK, NY 10012 212/998-2121NSF Program(s): ANALYSIS PROGRAMField Application(s):Program Reference Code(s): 1616Program Element Code(s): 1281ABSTRACTThe mathematical description and understanding of "diffusive processes" is central to many areas of science, from geometry and probability to continuum mechanics, fluid dynamics, population dynamics and game theory to name a few. Ricci flows, the Navier Stokes equation, non linear elasticity, futures options, all carry an element of diffusion, viscosity, uncertainty that correspond to a similar mathematical description. An extensive theory already permeates, under different circumstances and goals, wide areas of analysis, geometry and applied mathematics. The investigators perceive, however, that there are new, emerging areas of added complexity. It is expected that through the collaborative effort, new general methods will emerge providing some sort of unification and cohesion like the one existing today for classical infinitesimal diffusion processes and their role in the sciences (modeling, simulation, prediction).Problems which are to be studied include reaction diffusion phenomena in random environments, phase transition problems, non local diffusion processes and other applications motivated by questions of population dynamics, congestion issues in transportation, diffusion and segregation phenomena in social sciences, formation and dynamics of hotspots of criminal activity, phase transition problems involving nonlocal (long range) interactions and surface diffusion related to electric fluid droplets and complex fluids in nano technology and biology. The project involves a system of personnel exchanges between the home institutions, designed to provide a rich training experience for students and postdocs. In addition, there will be an emphasis month every year of the project in one of the home universities and a summer school designed to bring members of the group - including graduate students and postdocs - together to stimulate scientific progress. In this way the fruits of the research will be exposed to a broader audience, thereby, helping educate and attract a new generation of researchers to these exciting emerging mathematical challenges and ideas.Emerging issues in the sciences involving non standard diffusionNSF Org: DMSDivision of Mathematical SciencesInitial Amendment Date: August 5, 2011Latest Amendment Date: August 5, 2011A ward Number: 1065926A ward Instrument: Standard GrantProgram Manager: Kevin F. ClanceyDMS Division of Mathematical SciencesMPS Directorate for Mathematical & Physical SciencesStart Date: August 15, 2011Expires: July 31, 2014 (Estimated)A warded Amount to Date: $230000Investigator(s): Luis Caffarelli caffarel@ (Principal Investigator)Sponsor: University of Texas at AustinP.O Box 7726Austin, TX 78713 512/471-6424NSF Program(s): ANALYSIS PROGRAMField Application(s):Program Reference Code(s): 1616Program Element Code(s): 1281ABSTRACTThe mathematical description and understanding of "diffusive processes" is central to many areas of science, from geometry and probability to continuum mechanics, fluid dynamics, population dynamics and game theory to name a few. Ricci flows, the Navier Stokes equation, non linearelasticity, futures options, all carry an element of diffusion, viscosity, uncertainty that correspond to a similar mathematical description. An extensive theory already permeates, under different circumstances and goals, wide areas of analysis, geometry and applied mathematics. The investigators perceive, however, that there are new, emerging areas of added complexity. It is expected that through the collaborative effort, new general methods will emerge providing some sort of unification and cohesion like the one existing today for classical infinitesimal diffusion processes and their role in the sciences (modeling, simulation, prediction).Problems which are to be studied include reaction diffusion phenomena in random environments, phase transition problems, non local diffusion processes and other applications motivated by questions of population dynamics, congestion issues in transportation, diffusion and segregation phenomena in social sciences, formation and dynamics of hotspots of criminal activity, phase transition problems involving nonlocal (long range) interactions and surface diffusion related to electric fluid droplets and complex fluids in nano technology and biology. The project involves a system of personnel exchanges between the home institutions, designed to provide a rich training experience for students and postdocs. In addition, there will be an emphasis month every year of the project in one of the home universities and a summer school designed to bring members of the group - including graduate students and postdocs - together to stimulate scientific progress. In this way the fruits of the research will be exposed to a broader audience, thereby, helping educate and attract a new generation of researchers to these exciting emerging mathematical challenges and ideas.Initial Amendment Date: November 5, 2009Latest Amendment Date: November 5, 2009A ward Number: 1004908A ward Instrument: Standard GrantProgram Manager: Bruce P. PalkaDMS Division of Mathematical SciencesMPS Directorate for Mathematical & Physical SciencesStart Date: August 20, 2009Expires: June 30, 2011 (Estimated)A warded Amount to Date: $72558Investigator(s): Danijela Damjanovic ddamjano@ (Principal Investigator)Sponsor: William Marsh Rice University6100 MAIN STHOUSTON, TX 77005 713/348-4820NSF Program(s): ANALYSIS PROGRAMField Application(s):Program Reference Code(s): OTHR, 1281, 0000Program Element Code(s): 1281ABSTRACTThe proposed research is in the area of smooth dynamics and ergodic theory. The main focus of the proposed research is the study of dynamical systems with multidimensional time. Intensive research during the past two decades proved that wide variety of such systems which display certain degree of chaotic behavior, are remarkably rigid. These results induced fast progress towards some long standing conjectures in number theory and quantum mechanics. Rigidity of such systems stands in sharp contrast with flexibility of chaotic systems with one-dimensional time. There are two main themes within the proposed research. The first is to explore further stability and rigidity of algebraic multidimensional-time systems with less chaotic behavior: existence and local rigidity (i.e. differentiable stability) of partially hyperbolic abelian actions on nilmanifolds, and local rigidity of parabolic abelian actions on certain classes of locally symmetric spaces. In this direction the proposed research involves the KAM theory approach and thus requires a detailed study of the corresponding infinitesimal problem: the description of the first cohomology over these actions. The second theme is to explore the existence and stability properties of non-algebraic systems which are strongly partially hyperbolic. Such systems have specific structure of invariant foliations which on one hand imposes restrictions for the manifold of the action, and on the other hand it tends to be robust under small perturbations thus leading to certain degree of stability for the action. The research in this direction leads towards global classification of strongly partially hyperbolic multidimensional-time systems.Dynamical systems and chaos are the areas of mathematics which have flourished during past years while maintaining a strong connection with their roots which lie in the study of various phenomena in domains like cell biology, nano technology, meteorology and engineering. The studies of evolution of nature systems in time represent one of the core scientific interests today. The problem of stability of systems is one of the main issues which arises in the study of nature systems as mathematical models are merely approximations of the natural phenomena. In celestial mechanics, stability of the solar system is one important topic, and the KAM theory turned out to be a powerful tool towards better understanding of the system's long term behavior. Systems withmulti-dimensional time appear in quantum mechanics, where rigidity of such systems is present in the form of uniform distribution of quantum states. Multidimensional-(lattice) time systems also appear in the mathematical formalism for quasicrystals, whose physical properties and generation have been intensively studied. In hardware architecture one of the recently explored venues is extending the classical methodology to multidimensional time (multidimensional scheduling). The principal investigator will continue to encourage undergraduate students, female in particular, to take active part in the research process and will make an effort to expose them to various aspects and applications of this research. These activities will benefit from the grant.Light-Induced NO Release from Zeolite-Nitrosyl Composites: A New Biomaterial for the Prevention of Wound InfectionsNSF Org: DMRDivision of Materials ResearchInitial Amendment Date: September 1, 2011Latest Amendment Date: September 1, 2011A ward Number: 1105296A ward Instrument: Continuing grantProgram Manager: Joseph A. AkkaraDMR Division of Materials ResearchMPS Directorate for Mathematical & Physical SciencesStart Date: September 1, 2011Expires: August 31, 2014 (Estimated)A warded Amount to Date: $130000Investigator(s): Pradip Mascharak pradip@ (Principal Investigator)Scott Oliver (Co-Principal Investigator)Sponsor: University of California-Santa Cruz1156 High StreetSANTA CRUZ, CA 95064 831/459-5278NSF Program(s): BIOMA TERIALS PROGRAMField Application(s):Program Reference Code(s): AMPP, 9161, 7573, 7237Program Element Code(s): 7623ABSTRACTThis award by the Biomaterials Program of the Division of Materials Research to the University of California Santa Cruz supports the collaborative research efforts in developing a novel zeolite-based nitric oxide (NO) delivery platform to combat and prevent infections arising from various drug-resistant pathogens. Several photoactive NO complexes of metals (such as Mn, Fe and Ru) developed in the PIs' laboratory will be first loaded into nano/mesoporous aluminosilicates selected on the basis of their pore size and shape. The research approach will be guided by computer-aided design to better fit the NO-complexes into the pores, and their effective caging will be determined by powder X-ray diffraction, infrared spectroscopy, scanning electron microscopy and energy dispersive elemental mapping. The NO release from these composites will then be determined by various techniques employing NO-sensitive electrodes. The effects of the photoreleased NO from the composites on various bacterial colonies will be carefully monitored to determine the dose effects by colony-counting techniques and microscopy. Finally, different bandage material prototypes will be developed by impregnating mats of biocompatible materials such as carboxymethyl cellulose with the zeolite-nitrosyl powders. The advantages of these designed NO-delivery biomaterials will include: a) site-selective NO delivery to biological targets upon demand via light-triggering; b) entrapment of the photoproducts within the cavities of the biocompatible zeolite host thus avoiding their side-effects; and c) effective eradication of bacterial loads of various drug-resistant strains (since pathogens seldom exhibit resistance to NO as the antibiotic). Close interaction of the two PIs and the involvement of their graduate and undergraduate students in the project are expected to lead in interdisciplinary training at the interface of biology and materials chemistry. Both PI groups regularly bring in underrepresented minority students as well as Univ. California-bound community college minority students in science to work in their laboratories, and these activities are expected to continue with this project.The emergence of Staph-related infections in the surgical units of hospitals and complications due to bacterial fouling of implants and prosthetics in patients have reached an alarming level, demanding new antimicrobial platforms with greater efficiency. Although the strong antimicrobial effects of nitric oxide (NO) have been established, delivery of high fluxes of NO to a biological target (such as an infected wound) has not been possible due to lack of delivery platforms that work upon demand. Recently, several photoactive NO complexes of metals (metal nitrosyls) have been synthesized in the PI?s laboratory. Nitrosyl complexes loaded into the nanopores of the silica-base mineral zeolites would be novel NO-delivery systems to be triggered with low-powervisible light. Such materials could be applied either directly as powders or within bandage materials on infected sites and the bacterial loads could be reduced with photoreleased NO (from the nitrosyls) under the control of light. The proposed zeolite-nitrosyl composites will therefore be a new treatment platform, especially designed for antibiotic-resistant bacteria for which no other treatments are currently available. Broader impacts with respect to teaching, training and outreach programs of this project are in interdisciplinary training of a large number of graduate and undergraduate students at the interface of biology and materials research. The PIs have a strong track record in recruiting summer students through different funded programs such as NSF REU/SURF, NIH ACCESS and others that promote participation of students from underrepresented groups. The dissemination plan provides details for publication in peer reviewed journals, meeting presentations and other channels.DNA Origami Nanostructures with Complex Curvatures in 3D SpaceNSF Org: DMRDivision of Materials ResearchInitial Amendment Date: September 9, 2011Latest Amendment Date: September 9, 2011A ward Number: 1104373A ward Instrument: Standard GrantProgram Manager: David A. BrantDMR Division of Materials ResearchMPS Directorate for Mathematical & Physical SciencesStart Date: September 15, 2011Expires: August 31, 2014 (Estimated)A warded Amount to Date: $400000Investigator(s): Hao Y an hao.yan@ (Principal Investigator)Y an Liu (Co-Principal Investigator)Sponsor: Arizona State UniversityORSPATEMPE, AZ 85281 480/965-5479NSF Program(s): BIOMA TERIALS PROGRAM,CROSS-EF ACTIVITIESField Application(s):Program Reference Code(s): AMPP, 9162, 8007, 7573, 7237Program Element Code(s): 7623, 7275ABSTRACTID: MPS/DMR/BMA T(7623) 1104373 PI: Y an, Hao ORG: Arizona State UniversityTitle: DNA Origami Nanostructures with Complex Curvatures in 3D SpaceINTELLECTUAL MERIT: A grand challenge in the fields of nanotechnology and biomaterials is to assemble arbitrary, three-dimensional (3D) nanostructures with complete control of the material shape. To address this challenge, the PI will develop various novel strategies to construct self-assembling DNA nanostructures that possess complex curvatures in 3D space. More specifically, he proposes to develop a self-assembling system to: (1) Produce 3D DNA nanostructures that contain intricate, complex curvatures using the DNA origami folding technique.(2) Create a set of geometric, wedge-like DNA nanostructures to direct the curvature of preformed, planar DNA nanostructures using targeted insertion and deletion. (3) Utilize curved, 3D DNA origami nanostructures as scaffolds to mimic the role of histone proteins in gene packaging and create artificial nucleosomes for subsequent study. This new technology will exploit the exceptional addressability and spatial control associated with structural DNA nanotechnology to produce an artificial structural platform that resembles the conformational complexity that exists in biological structures, thus creating unprecedented opportunities for engineering novel bioinspired, biomimetic, and biokleptic materials. The design strategies included in this proposal present fundamental steps toward meeting this challenge. The proposal aims to achieve self-assembly of 3D nanostructures with high programmability and complexity, and subsequently use them as scaffolds to mimic the functionality of nucleosomes. Furthermore, the proposed research will provide various new and significant approaches to DNA-based nanofabrication. This project ultimately seeks to go beyond the evident limits of current top-down techniques for the fabrication of arbitrary shaped 3D nanostructures. This will lead to smaller, faster, and more diverse nanoscale structures for a wide range of applications from energy to bio-diagnostic devices.BROADER IMPACTS: There are broad societal implications for this research. As the PIs advance nanoscale techniques for the development of novel technologies, their research leads to。