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Sample records for dynamically driven evolution

  1. THE EVOLUTION OF OPEN MAGNETIC FLUX DRIVEN BY PHOTOSPHERIC DYNAMICS

    SciTech Connect

    Linker, Jon A.; Lionello, Roberto; Mikic, Zoran; Titov, Viacheslav S.; Antiochos, Spiro K. E-mail: lionel@predsci.com E-mail: titovv@predsci.com

    2011-04-20

    The coronal magnetic field is of paramount importance in solar and heliospheric physics. Two profoundly different views of the coronal magnetic field have emerged. In quasi-steady models, the predominant source of open magnetic field is in coronal holes. In contrast, in the interchange model, the open magnetic flux is conserved, and the coronal magnetic field can only respond to the photospheric evolution via interchange reconnection. In this view, the open magnetic flux diffuses through the closed, streamer belt fields, and substantial open flux is present in the streamer belt during solar minimum. However, Antiochos and coworkers, in the form of a conjecture, argued that truly isolated open flux cannot exist in a configuration with one heliospheric current sheet-it will connect via narrow corridors to the polar coronal hole of the same polarity. This contradicts the requirements of the interchange model. We have performed an MHD simulation of the solar corona up to 20 R{sub sun} to test both the interchange model and the Antiochos conjecture. We use a synoptic map for Carrington rotation 1913 as the boundary condition for the model, with two small bipoles introduced into the region where a positive polarity extended coronal hole forms. We introduce flows at the photospheric boundary surface to see if open flux associated with the bipoles can be moved into the closed-field region. Interchange reconnection does occur in response to these motions. However, we find that the open magnetic flux cannot be simply injected into closed-field regions-the flux eventually closes down and disconnected flux is created. Flux either opens or closes, as required, to maintain topologically distinct open- and closed-field regions, with no indiscriminate mixing of the two. The early evolution conforms to the Antiochos conjecture in that a narrow corridor of open flux connects the portion of the coronal hole that is nearly detached by one of the bipoles. In the later evolution, a

  2. The Evolution of Open Magnetic Flux Driven by Photospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Linker, Jon A.; Lionello, Roberto; Mikic, Zoran; Titov, Viacheslav S.; Antiochos, Spiro K.

    2010-01-01

    The coronal magnetic field is of paramount importance in solar and heliospheric physics. Two profoundly different views of the coronal magnetic field have emerged. In quasi-steady models, the predominant source of open magnetic field is in coronal holes. In contrast, in the interchange model, the open magnetic flux is conserved, and the coronal magnetic field can only respond to the photospheric evolution via interchange reconnection. In this view the open magnetic flux diffuses through the closed, streamer belt fields, and substantial open flux is present in the streamer belt during solar minimum. However, Antiochos and co-workers, in the form of a conjecture, argued that truly isolated open flux cannot exist in a configuration with one heliospheric current sheet (HCS) - it will connect via narrow corridors to the polar coronal hole of the same polarity. This contradicts the requirements of the interchange model. We have performed an MHD simulation of the solar corona up to 20R solar to test both the interchange model and the Antiochos conjecture. We use a synoptic map for Carrington Rotation 1913 as the boundary condition for the model, with two small bipoles introduced into the region where a positive polarity extended coronal hole forms. We introduce flows at the photospheric boundary surface to see if open flux associated with the bipoles can be moved into the closed-field region. Interchange reconnection does occur in response to these motions. However, we find that the open magnetic flux cannot be simply injected into closed-field regions - the flux eventually closes down and disconnected flux is created. Flux either opens or closes, as required, to maintain topologically distinct open and closed field regions, with no indiscriminate mixing of the two. The early evolution conforms to the Antiochos conjecture in that a narrow corridor of open flux connects the portion of the coronal hole that is nearly detached by one of the bipoles. In the later evolution, a

  3. INSTABILITY-DRIVEN DYNAMICAL EVOLUTION MODEL OF A PRIMORDIALLY FIVE-PLANET OUTER SOLAR SYSTEM

    SciTech Connect

    Batygin, Konstantin; Brown, Michael E.; Betts, Hayden

    2012-01-15

    Over the last decade, evidence has mounted that the solar system's observed state can be favorably reproduced in the context of an instability-driven dynamical evolution model, such as the 'Nice' model. To date, all successful realizations of instability models have concentrated on evolving the four giant planets onto their current orbits from a more compact configuration. Simultaneously, the possibility of forming and ejecting additional planets has been discussed, but never successfully implemented. Here we show that a large array of five-planet (two gas giants + three ice giants) multi-resonant initial states can lead to an adequate formation of the outer solar system, featuring an ejection of an ice giant during a phase of instability. Particularly, our simulations demonstrate that the eigenmodes that characterize the outer solar system's secular dynamics can be closely matched with a five-planet model. Furthermore, provided that the ejection timescale of the extra planet is short, orbital excitation of a primordial cold classical Kuiper Belt can also be avoided in this scenario. Thus, the solar system is one of many possible outcomes of dynamical relaxation and can originate from a wide variety of initial states. This deems the construction of a unique model of solar system's early dynamical evolution impossible.

  4. Comparative genomic paleontology across plant kingdom reveals the dynamics of TE-driven genome evolution.

    PubMed

    El Baidouri, Moaine; Panaud, Olivier

    2013-01-01

    Long terminal repeat-retrotransposons (LTR-RTs) are the most abundant class of transposable elements (TEs) in plants. They strongly impact the structure, function, and evolution of their host genome, and, in particular, their role in genome size variation has been clearly established. However, the dynamics of the process through which LTR-RTs have differentially shaped plant genomes is still poorly understood because of a lack of comparative studies. Using a new robust and automated family classification procedure, we exhaustively characterized the LTR-RTs in eight plant genomes for which a high-quality sequence is available (i.e., Arabidopsis thaliana, A. lyrata, grapevine, soybean, rice, Brachypodium dystachion, sorghum, and maize). This allowed us to perform a comparative genome-wide study of the retrotranspositional landscape in these eight plant lineages from both monocots and dicots. We show that retrotransposition has recurrently occurred in all plant genomes investigated, regardless their size, and through bursts, rather than a continuous process. Moreover, in each genome, only one or few LTR-RT families have been active in the recent past, and the difference in genome size among the species studied could thus mostly be accounted for by the extent of the latest transpositional burst(s). Following these bursts, LTR-RTs are efficiently eliminated from their host genomes through recombination and deletion, but we show that the removal rate is not lineage specific. These new findings lead us to propose a new model of TE-driven genome evolution in plants.

  5. Dynamical evolution of galactic disks driven by interaction with a satellite

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Toshio

    2003-04-01

    Dynamical evolution of galactic disks driven by interaction with satellite galaxies, particularly the problem of the disk warping and thickening is studied numerically. One of the main purpose of the study is to resolve the long standing problem of the origin of the disk warping. A possible cause of the warp is interaction with a satellite galaxy. In the case of the Milky Way, the LMC has been considered as the candidate. Some linear analysis have already given a positive result, but one had to wait for a fully self-consistent simulation as a proof. I have accomplished the numerical simulations with a million particles, by introducing a hybrid algorithm, SCF-TREE. Those simulations give us quantitative estimates for the Milky Way system. We have found an example in which large warp amplitudes are developed. We also found that the warp amplitudes depend on the halo distribution. Among our three models, the most massive and spherical halo is preferable for the observable warp excitation.

  6. Dynamic in situ visualization of voltage-driven magnetic domain evolution in multiferroic heterostructures.

    PubMed

    Gao, Ya; Hu, Jia-Mian; Wu, Liang; Nan, C W

    2015-12-23

    Voltage control of magnetism in multiferroic heterostructures provides a promising solution to the excessive heating in spintronic devices. Direct observation of voltage-modulated magnetic domain evolution dynamics is desirable for studying the mechanism of the voltage control of magnetism at mesoscale, but has remained challenging. Here we explored a characterization method for the dynamic in situ evolution of pure voltage modulated magnetic domains in the heterostructures by employing the scanning Kerr microscopy function in the magneto optic Kerr effect system. The local magnetization reorientation of a Ni/PMN-PT heterostructure were characterized under sweeping applied voltage on the PMN-PT single crystal, and the results show that the magnetization rotation angle in the local regions is much greater than that obtained from macroscopic magnetization hysteresis loops.

  7. Dynamic in situ visualization of voltage-driven magnetic domain evolution in multiferroic heterostructures

    NASA Astrophysics Data System (ADS)

    Gao, Ya; Hu, Jia-Mian; Wu, Liang; Nan, C. W.

    2015-12-01

    Voltage control of magnetism in multiferroic heterostructures provides a promising solution to the excessive heating in spintronic devices. Direct observation of voltage-modulated magnetic domain evolution dynamics is desirable for studying the mechanism of the voltage control of magnetism at mesoscale, but has remained challenging. Here we explored a characterization method for the dynamic in situ evolution of pure voltage modulated magnetic domains in the heterostructures by employing the scanning Kerr microscopy function in the magneto optic Kerr effect system. The local magnetization reorientation of a Ni/PMN-PT heterostructure were characterized under sweeping applied voltage on the PMN-PT single crystal, and the results show that the magnetization rotation angle in the local regions is much greater than that obtained from macroscopic magnetization hysteresis loops.

  8. Evolution of a new chlorophyll metabolic pathway driven by the dynamic changes in enzyme promiscuous activity.

    PubMed

    Ito, Hisashi; Tanaka, Ayumi

    2014-03-01

    Organisms generate an enormous number of metabolites; however, the mechanisms by which a new metabolic pathway is acquired are unknown. To elucidate the importance of promiscuous enzyme activity for pathway evolution, the catalytic and substrate specificities of Chl biosynthetic enzymes were examined. In green plants, Chl a and Chl b are interconverted by the Chl cycle: Chl a is hydroxylated to 7-hydroxymethyl chlorophyll a followed by the conversion to Chl b, and both reactions are catalyzed by chlorophyllide a oxygenase. Chl b is reduced to 7-hydroxymethyl chlorophyll a by Chl b reductase and then converted to Chl a by 7-hydroxymethyl chlorophyll a reductase (HCAR). A phylogenetic analysis indicated that HCAR evolved from cyanobacterial 3,8-divinyl chlorophyllide reductase (DVR), which is responsible for the reduction of an 8-vinyl group in the Chl biosynthetic pathway. In addition to vinyl reductase activity, cyanobacterial DVR also has Chl b reductase and HCAR activities; consequently, three of the four reactions of the Chl cycle already existed in cyanobacteria, the progenitor of the chloroplast. During the evolution of cyanobacterial DVR to HCAR, the HCAR activity, a promiscuous reaction of cyanobacterial DVR, became the primary reaction. Moreover, the primary reaction (vinyl reductase activity) and some disadvantageous reactions were lost, but the neutral promiscuous reaction (NADH dehydrogenase) was retained in both DVR and HCAR. We also show that a portion of the Chl c biosynthetic pathway already existed in cyanobacteria. We discuss the importance of dynamic changes in promiscuous activity and of the latent pathways for metabolic evolution.

  9. An evolution-based DNA-binding residue predictor using a dynamic query-driven learning scheme.

    PubMed

    Chai, H; Zhang, J; Yang, G; Ma, Z

    2016-11-15

    DNA-binding proteins play a pivotal role in various biological activities. Identification of DNA-binding residues (DBRs) is of great importance for understanding the mechanism of gene regulations and chromatin remodeling. Most traditional computational methods usually construct their predictors on static non-redundant datasets. They excluded many homologous DNA-binding proteins so as to guarantee the generalization capability of their models. However, those ignored samples may potentially provide useful clues when studying protein-DNA interactions, which have not obtained enough attention. In view of this, we propose a novel method, namely DQPred-DBR, to fill the gap of DBR predictions. First, a large-scale extensible sample pool was compiled. Second, evolution-based features in the form of a relative position specific score matrix and covariant evolutionary conservation descriptors were used to encode the feature space. Third, a dynamic query-driven learning scheme was designed to make more use of proteins with known structure and functions. In comparison with a traditional static model, the introduction of dynamic models could obviously improve the prediction performance. Experimental results from the benchmark and independent datasets proved that our DQPred-DBR had promising generalization capability. It was capable of producing decent predictions and outperforms many state-of-the-art methods. For the convenience of academic use, our proposed method was also implemented as a web server at .

  10. Driven evolution of a constitutional dynamic library of molecular helices toward the selective generation of [2 x 2] gridlike arrays under the pressure of metal ion coordination.

    PubMed

    Giuseppone, Nicolas; Schmitt, Jean-Louis; Lehn, Jean-Marie

    2006-12-27

    Constitutional dynamics, self-assembly, and helical-folding control are brought together in the efficient Sc(OTf)3/microwave-catalyzed transimination of helical oligohydrazone strands, yielding highly diverse dynamic libraries of interconverting constituents through assembly, dissociation, and exchange of components. The transimination-type mechanism of the ScIII-promoted exchange, as well as its regioselectivity, occurring only at the extremities of the helical strands, allow one to perform directional terminal polymerization/depolymerization processes when starting with dissymmetric strands. A particular library is subsequently brought to express quantitatively [2 x 2] gridlike metallosupramolecular arrays in the presence of ZnII ions by component recombination generating the correct ligand from the dynamic set of interconverting strands. This behavior represents a process of driven evolution of a constitutional dynamic chemical system under the pressure (coordination interaction) of an external effector (metal ions).

  11. Stochastic Evolution Equations Driven by Fractional Noises

    DTIC Science & Technology

    2016-11-28

    Stochastic Evolution Equations Driven by Fractional Noises We have introduced a modification of the classical Euler numerical scheme for stochastic...of Papers published in peer-reviewed journals: Final Report: Stochastic Evolution Equations Driven by Fractional Noises Report Title We have introduced...case the evolution form of the equation will involve a Stratonovich integral (or path-wise Young integral). The product can also be interpreted as a

  12. Metamodel-Driven Evolution with Grammar Inference

    NASA Astrophysics Data System (ADS)

    Bryant, Barrett R.; Liu, Qichao; Mernik, Marjan

    2010-10-01

    Domain-specific modeling (DSM) has become one of the most popular techniques for incorporating model-driven engineering (MDE) into software engineering. In DSM, domain experts define metamodels to describe the essential problems in a domain. A model conforms to a schema definition represented by a metamodel in a similar manner to a programming language conforms to a grammar. Metamodel-driven evolution is when a metamodel undergoes evolutions to incorporate new concerns in the domain. However, this results in losing the ability to use existing model instances. Grammar inference is the problem of inferring a grammar from sample strings which the grammar should generate. This paper describes our work in solving the problem of metamodel-driven evolution with grammar inference, by inferring the metamodel from model instances.

  13. The evolution of agricultural intensification and environmental degradation in the UK: a data-driven systems dynamics approach

    NASA Astrophysics Data System (ADS)

    Armstrong McKay, David I.; Dearing, John A.; Dyke, James G.; Poppy, Guy; Firbank, Les

    2016-04-01

    The world's population continues to grow rapidly, yet the current demand for food is already resulting in environmental degradation in many regions. As a result, an emerging challenge of the 21st century is how agriculture can simultaneously undergo sustainable intensification and be made more resilient to accelerating climate change. Key to this challenge is: a) finding the "safe and just operating space" for the global agri-environment system that both provides sufficient food for humanity and avoids crossing dangerous planetary boundaries, and b) downscaling this framework from a planetary to a regional scale in order to better inform decision making and incorporate regional dynamics within the planetary boundaries framework. Regional safe operating spaces can be defined and explored using a combination of metrics that indicate the changing status of ecosystem services (both provisioning and regulating), statistical techniques that reveal early warning signals and breakpoints, and dynamical system models of the regional agri-environment system. Initial attempts to apply this methodology have been made in developing countries (e.g. China [Dearing et al., 2012, 2014; Zhang et al., 2015]), but have not yet been attempted in more developed countries, for example the UK. In this study we assess the changes in ecosystem services in two contrasting agricultural regions in the UK, arable-dominated East England and pastoral-dominated South-West England, since the middle of the 20th Century. We identify and establish proxies and indices of various provisioning and regulating services in these two regions and analyse how these have changed over this time. We find that significant degradation of regulating services occurred in Eastern England in the early 1980s, reflecting a period of rapid intensification and escalating fertiliser usage, but that regulating services have begun to recover since 2000 mainly as a result of fertiliser usage decoupling from increasing wheat

  14. Dynamics of driven superconducting vortices

    NASA Astrophysics Data System (ADS)

    Reichhardt, Cynthia Olson

    1998-09-01

    Vortices in superconductors exhibit rich dynamical behaviors that are relevant to the physical properties of the material. In this thesis, we use simulations to study the dynamics of flux-gradient-driven vortices in different types of samples. We make connections between the microscopic behavior of the vortices and macroscopic experimentally observable measurements. First, we systematically quantify the effect of the pinning landscape on the macroscopic properties of vortex avalanches and vortex plastic flow. We relate the velocity field, cumulative patterns of vortex flow channels, and voltage noise measurements with statistical quantities, such as distributions of avalanche sizes. Samples with a high density of strong pinning sites produce very broad avalanche distributions. Easy-flow vortex channels appear in samples with a low pinning density, and typical avalanche sizes emerge in an otherwise broad distribution of sizes. We observe a crossover from interstitial motion in narrow channels to pin-to-pin motion in broad channels as the pin density is increased. Second, we also analyze the microscopic dynamics of vortex motion through channels that form river-like fractal networks in a variety of superconducting samples, and relate it to macroscopic measurable quantities such as the power spectrum. As a function of pinning strength, we calculate the fractal dimension, tortuosity, and the corresponding voltage noise spectrum. Above a certain pinning strength, a remarkable universal drop in both tortuosity and noise power occurs when the vortex motion changes from braiding channels to unbraided channels. Third, we also present a new dynamic phase diagram for driven vortices with varying lattice softness that indicates that, at high driving currents, at least two distinct dynamic phases of flux flow appear depending on the vortex-vortex interaction strength. When the flux lattice is soft, the vortices flow in independently moving channels with smectic structure. For

  15. A DATA-DRIVEN MODEL FOR THE GLOBAL CORONAL EVOLUTION

    SciTech Connect

    Feng Xueshang; Jiang Chaowei; Xiang Changqing; Zhao Xuepu; Wu, S. T. E-mail: cwjiang@spaceweather.ac.cn E-mail: xpzhao@sun.stanford.edu

    2012-10-10

    This work is devoted to the construction of a data-driven model for the study of the dynamic evolution of the global corona that can respond continuously to the changing of the photospheric magnetic field. The data-driven model consists of a surface flux transport (SFT) model and a global three-dimensional (3D) magnetohydrodynamic (MHD) coronal model. The SFT model is employed to produce the global time-varying and self-consistent synchronic snapshots of the photospheric magnetic field as the input to drive our 3D numerical global coronal AMR-CESE-MHD model on an overset grid of Yin-Yang overlapping structure. The SFT model and the 3D global coronal model are coupled through the boundary condition of the projected characteristic method. Numerical results of the coronal evolution from 1996 September 4 to October 29 provide a good comparison with multiply observed coronal images.

  16. Dynamics of secular evolution

    NASA Astrophysics Data System (ADS)

    Binney, James

    2013-10-01

    The material in this article was presented in five hours of lectures to the 2011 Canary Islands Winter School. The School’s theme was ‘Secular Evolution of Galaxies’ and my task was to present the underlying stellar-dynamical theory. Other lecturers were speaking on the role of bars and chemical evolution, so these topics are avoided here. The material starts with an account of the connections between isolating integrals, quasiperiodicity and angle-action variables - these variables played a prominent and unifying role throughout the lectures. This leads on to the phenomenon of resonant trap- ping and how this can lead to chaos in cuspy potentials and phase-space mixing in slowly evolving potentials. Surfaces of section and frequency analysis are introduced as diagnostics of phase-space structure. Real galactic potentials include a fluctuating part that drives the system towards unattainable thermal equilibrium. Two-body encounters are only one source of fluctuations, and all fluctuations will drive similar evolution. The orbit-averaged Fokker-Planck equation is derived, as are relations that hold between the second-order diffusion coefficients and both the power spectrum of the fluctuations and the first-order diffusion coefficients. From the observed heating of the solar neighbourhood we show that the second-order diffusion coefficients must scale as ˜ J1/2. We show that periodic spiral structure shifts angular momentum outwards, heating at the Lindblad resonances and mixing at corotation. The equation that would yield the normal modes of a stellar disk is first derived and then used to discuss the propagation of tightly wound spiral waves. The winding up of such waves is described and explains why cool stellar disks are responsive systems that amplify ambient noise. An explanation is offered of why the Lin-Shu-Kalnajs dispersion relation and even global normal-mode calculations provide a very incomplete understanding of the dynamics of stellar disks.

  17. Chemo-Dynamical Evolution of Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Hensler, G.

    Dwarf galaxies are characterized by low masses, by their morphological variety, and by low metallicities on average as well as by their scatter in the gas fraction-to-metallicity relation. Because of the low binding energy even under the assumption of a dark matter halo their evolution should be dominated by supernova-driven galactic-wind mass loss which inherently leads to metallicity depletion with preference of particular abundances. Since the gas phases of the interstellar medium evolve dynamically, energetically and chemically differently, their interactions have to be considered by the chemo-dynamical treatment of their evolution. 1d and recent 2d chemo-dynamical models will be presented and compared with particular concern to star-formation episodes, starbursts, star-formation self-regulation, and structural effects which are caused by different environmental conditions and initial parameters. In addition, it is studied to what amount these will affect the abundance ratios.

  18. Magnetotail dynamics: MHD simulations of driven and spontaneous dynamic changes

    SciTech Connect

    Birn, J.; Schindler, K.; Hesse, M.

    1994-05-01

    The dynamic evolution of the magnetotail during growth phase and expansion phase of a substorm is studied through threedimensional time-dependent MHD simulations. To model growth phase effects, an external electric field with an equatorward inflow is applied at the boundaries over a finite time period. This leads to the formation of a thin current sheet with greatly enhanced current density in the near tail, embedded in the wider plasma/current sheet, which becomes diminished in strength. A faster, spontaneous current sheet formation occurs when entropy conservation is released in an isobaric model, while the ideal MHD constraint persists. This may be a suitable model for the late, explosive part of the growth phase. The transition to the substorm expansive phase is modeled by an increase in anomalous resistivity, using either uniform resistivity or a current density dependent resistivity which is turned on when the current density exceeds a certain threshold. In both cases the violation of ideal MHD leads to resistive instability and the formation of a near-Earth neutral line, fast flow, and plasmoid ejection, together with the dipolarization and current reduction in the region further earthward. The spontaneous increase in total region 1 type field-aligned currents associated with the disruptions of the thin current sheets is less significant than that found in earlier simulations of the disruption of a wider current sheet, whereas the driven increase in the region 1 type current is substantial. The results demonstrate that the same dynamic process which appears spontaneous in the behavior of some quantities might be interpreted as entirely driven from the observation of others.

  19. Oxide driven strength evolution of silicon surfaces

    DOE PAGES

    Grutzik, Scott J.; Milosevic, Erik; Boyce, Brad L.; ...

    2015-11-19

    Previous experiments have shown a link between oxidation and strength changes in single crystal silicon nanostructures but provided no clues as to the mechanisms leading to this relationship. Using atomic force microscope-based fracture strength experiments, molecular dynamics modeling, and measurement of oxide development with angle resolved x-ray spectroscopy we study the evolution of strength of silicon (111) surfaces as they oxidize and with fully developed oxide layers. We find that strength drops with partial oxidation but recovers when a fully developed oxide is formed and that surfaces intentionally oxidized from the start maintain their high initial strengths. MD simulations showmore » that strength decreases with the height of atomic layer steps on the surface. These results are corroborated by a completely separate line of testing using micro-scale, polysilicon devices, and the slack chain method in which strength recovers over a long period of exposure to the atmosphere. Lastly, combining our results with insights from prior experiments we conclude that previously described strength decrease is a result of oxidation induced roughening of an initially flat silicon (1 1 1) surface and that this effect is transient, a result consistent with the observation that surfaces flatten upon full oxidation.« less

  20. Oxide driven strength evolution of silicon surfaces

    SciTech Connect

    Grutzik, Scott J.; Zehnder, Alan T.; Milosevic, Erik; Boyce, Brad L.

    2015-11-21

    Previous experiments have shown a link between oxidation and strength changes in single crystal silicon nanostructures but provided no clues as to the mechanisms leading to this relationship. Using atomic force microscope-based fracture strength experiments, molecular dynamics modeling, and measurement of oxide development with angle resolved x-ray spectroscopy we study the evolution of strength of silicon (111) surfaces as they oxidize and with fully developed oxide layers. We find that strength drops with partial oxidation but recovers when a fully developed oxide is formed and that surfaces intentionally oxidized from the start maintain their high initial strengths. MD simulations show that strength decreases with the height of atomic layer steps on the surface. These results are corroborated by a completely separate line of testing using micro-scale, polysilicon devices, and the slack chain method in which strength recovers over a long period of exposure to the atmosphere. Combining our results with insights from prior experiments we conclude that previously described strength decrease is a result of oxidation induced roughening of an initially flat silicon (1 1 1) surface and that this effect is transient, a result consistent with the observation that surfaces flatten upon full oxidation.

  1. Oxide driven strength evolution of silicon surfaces

    SciTech Connect

    Grutzik, Scott J.; Milosevic, Erik; Boyce, Brad L.; Zehnder, Alan T.

    2015-11-19

    Previous experiments have shown a link between oxidation and strength changes in single crystal silicon nanostructures but provided no clues as to the mechanisms leading to this relationship. Using atomic force microscope-based fracture strength experiments, molecular dynamics modeling, and measurement of oxide development with angle resolved x-ray spectroscopy we study the evolution of strength of silicon (111) surfaces as they oxidize and with fully developed oxide layers. We find that strength drops with partial oxidation but recovers when a fully developed oxide is formed and that surfaces intentionally oxidized from the start maintain their high initial strengths. MD simulations show that strength decreases with the height of atomic layer steps on the surface. These results are corroborated by a completely separate line of testing using micro-scale, polysilicon devices, and the slack chain method in which strength recovers over a long period of exposure to the atmosphere. Lastly, combining our results with insights from prior experiments we conclude that previously described strength decrease is a result of oxidation induced roughening of an initially flat silicon (1 1 1) surface and that this effect is transient, a result consistent with the observation that surfaces flatten upon full oxidation.

  2. Evolution: geometrical and dynamical aspects.

    PubMed

    Freguglia, Paolo; Bazzani, Armando

    2003-01-01

    We develop a possible axiomatic approach to the evolution theory that has been previously discussed in Freguglia [2002]. The axioms synthesize the fundamental ideas of evolution theory and allow a geometrical and dynamical interpretation of the generation law. Using the axioms we derive a simple reaction-diffusion model which introduces the species as self-organized stationary distribution of a finite population and simulates the evolution of a phenotypic character under the effect of an external perturbing action. The dynamical properties of the model are briefly presented using numerical simulations.

  3. Real-time divergent evolution in plants driven by pollinators.

    PubMed

    Gervasi, Daniel D L; Schiestl, Florian P

    2017-03-14

    Pollinator-driven diversification is thought to be a major source of floral variation in plants. Our knowledge of this process is, however, limited to indirect assessments of evolutionary changes. Here, we employ experimental evolution with fast cycling Brassica rapa plants to demonstrate adaptive evolution driven by different pollinators. Our study shows pollinator-driven divergent selection as well as divergent evolution in plant traits. Plants pollinated by bumblebees evolved taller size and more fragrant flowers with increased ultraviolet reflection. Bumblebees preferred bumblebee-pollinated plants over hoverfly-pollinated plants at the end of the experiment, showing that plants had adapted to the bumblebees' preferences. Plants with hoverfly pollination became shorter, had reduced emission of some floral volatiles, but increased fitness through augmented autonomous self-pollination. Our study demonstrates that changes in pollinator communities can have rapid consequences on the evolution of plant traits and mating system.

  4. Real-time divergent evolution in plants driven by pollinators

    PubMed Central

    Gervasi, Daniel D. L.; Schiestl, Florian P

    2017-01-01

    Pollinator-driven diversification is thought to be a major source of floral variation in plants. Our knowledge of this process is, however, limited to indirect assessments of evolutionary changes. Here, we employ experimental evolution with fast cycling Brassica rapa plants to demonstrate adaptive evolution driven by different pollinators. Our study shows pollinator-driven divergent selection as well as divergent evolution in plant traits. Plants pollinated by bumblebees evolved taller size and more fragrant flowers with increased ultraviolet reflection. Bumblebees preferred bumblebee-pollinated plants over hoverfly-pollinated plants at the end of the experiment, showing that plants had adapted to the bumblebees' preferences. Plants with hoverfly pollination became shorter, had reduced emission of some floral volatiles, but increased fitness through augmented autonomous self-pollination. Our study demonstrates that changes in pollinator communities can have rapid consequences on the evolution of plant traits and mating system. PMID:28291771

  5. Non-Born-Oppenheimer Liouville-von Neumann Dynamics. Evolution of a Subsystem Controlled by Linear and Population-Driven Decay of Mixing with Decoherent and Coherent Switching.

    PubMed

    Zhu, Chaoyuan; Jasper, Ahren W; Truhlar, Donald G

    2005-07-01

    Electronic energy flow in an isolated molecular system involves coupling between the electronic and nuclear subsystems, and the coupled system evolves to a statistical mixture of pure states. In semiclassical theories, nuclear motion is treated using classical mechanics, and electronic motion is treated as an open quantal system coupled to a "bath" of nuclear coordinates. We have previously shown how this can be simulated by a time-dependent Schrödinger equation with coherent switching and decay of mixing, where the decay of mixing terms model the dissipative effect of the environment on the electronic subdynamics (i.e., on the reduced dynamics of the electronic subsystem). In the present paper we reformulate the problem as a Liouville-von Neumann equation of motion (i.e., we propagate the reduced density matrix of the electronic subsystem), and we introduce the assumption of first-order linear decay. We specifically examine the cases of equal relaxation times for both longitudinal (i.e., population) decay and transverse decay (i.e., dephasing) and of longitudinal relaxation only, yielding the linear decay of mixing (LDM) and the population-driven decay of mixing (PDDM) schemes, respectively. Because we do not generally know the basis in which coherence decays, that is, the pointer basis, we judge the semiclassical methods in part by their ability to give good results in both the adiabatic and diabatic bases. The accuracy in the prediction of physical observables is shown to be robust not only with respect to basis but also with respect to the way in which demixing is incorporated into the master equation for the density matrix. The success of the PDDM scheme is particularly interesting because it incorporates the least amount of decoherence (i.e., the PDDM scheme is the most similar of the methods discussed to the fully coherent semiclassical Ehrenfest method). For both the new and previous decay of mixing schemes, four kinds of decoherent state switching

  6. The SILCC (SImulating the LifeCycle of molecular Clouds) project - II. Dynamical evolution of the supernova-driven ISM and the launching of outflows

    NASA Astrophysics Data System (ADS)

    Girichidis, Philipp; Walch, Stefanie; Naab, Thorsten; Gatto, Andrea; Wünsch, Richard; Glover, Simon C. O.; Klessen, Ralf S.; Clark, Paul C.; Peters, Thomas; Derigs, Dominik; Baczynski, Christian

    2016-03-01

    The SILCC project (SImulating the Life-Cycle of molecular Clouds) aims at a more self-consistent understanding of the interstellar medium (ISM) on small scales and its link to galaxy evolution. We present three-dimensional (magneto)hydrodynamic simulations of the ISM in a vertically stratified box including self-gravity, an external potential due to the stellar component of the galactic disc, and stellar feedback in the form of an interstellar radiation field and supernovae (SNe). The cooling of the gas is based on a chemical network that follows the abundances of H+, H, H2, C+, and CO and takes shielding into account consistently. We vary the SN feedback by comparing different SN rates, clustering and different positioning, in particular SNe in density peaks and at random positions, which has a major impact on the dynamics. Only for random SN positions the energy is injected in sufficiently low-density environments to reduce energy losses and enhance the effective kinetic coupling of the SNe with the gas. This leads to more realistic velocity dispersions (σ _H I≈ 0.8σ _{300{-}8000 K}˜ 10-20 km s^{-1}, σ _H α ≈ 0.6σ _{8000-3× 10^5 K}˜ 20-30 km s^{-1}), and strong outflows with mass loading factors (ratio of outflow to star formation rate) of up to 10 even for solar neighbourhood conditions. Clustered SNe abet the onset of outflows compared to individual SNe but do not influence the net outflow rate. The outflows do not contain any molecular gas and are mainly composed of atomic hydrogen. The bulk of the outflowing mass is dense (ρ ˜ 10-25-10-24 g cm-3) and slow (v ˜ 20-40 km s-1) but there is a high-velocity tail of up to v ˜ 500 km s-1 with ρ ˜ 10-28-10-27 g cm-3.

  7. Ultrafast laser-driven proton sources and dynamic proton imaging

    SciTech Connect

    Nickles, Peter V.; Schnuerer, Matthias; Sokollik, Thomas; Ter-Avetisyan, Sargis; Sandner, Wolfgang; Amin, Munib; Toncian, Toma; Willi, Oswald; Andreev, Alexander

    2008-07-15

    Ion bursts, accelerated by an ultrafast (40 fs) laser-assisted target normal sheath acceleration mechanism, can be adjusted so as to deliver a nearly pure proton beam. Such laser-driven proton bursts have predominantly a low transverse emittance and a broad kinetic spectrum suitable for continuous probing of the temporal evolution of spatially extended electric fields that arise after laser irradiation of thin foils. Fields with a strength of up to 10{sup 10} V/m were measured with a new streaklike proton deflectometry setup. The data show the temporal and spatial evolution of electric fields that are due to target charge-up and ion-front expansion following intense laser-target interaction at intensities of 10{sup 17}-10{sup 18} W/cm{sup 2}. Measurement of the field evolution is important to gain further insight into lateral electron-transport processes and the influence of field dynamics on ion beam properties.

  8. Genome dynamics during experimental evolution

    PubMed Central

    Barrick, Jeffrey E.; Lenski, Richard E.

    2014-01-01

    Evolutionary changes in organismal traits may occur gradually or suddenly. Until recently, however, there has been little direct information about how phenotypic changes are related to the rate and nature of underlying changes in genotype. Technological advances enabling whole-genome and whole-population sequencing coupled with experiments that watch evolution in action have brought new precision and insights to studies of mutation rates and genome evolution. Here, we discuss the evolutionary forces and ecological processes that govern genome dynamics in various laboratory systems in the context of relevant population genetic theory, and we relate these findings to evolution in natural populations. PMID:24166031

  9. Dynamical Evolution of Stellar Systems

    NASA Astrophysics Data System (ADS)

    Baumgardt, H.

    2016-11-01

    Dynamical simulations have become a powerful tool to study the evolution of star clusters due to hardware and software progresses in recent years. Here, I review the state of the art of N-body and other simulation techniques and show what we have learned from these simulations about the dynamical evolution of star clusters. Special attention is given to the results on the lifetimes of star clusters as a function of their environment, the internal changes of the mass functions, the influence of primordial gas expulsion on the ratio of first to second generation stars in globular clusters, and the possible presence of intermediate-mass black holes in star clusters.

  10. Driven Open Quantum Systems and Floquet Stroboscopic Dynamics

    NASA Astrophysics Data System (ADS)

    Restrepo, S.; Cerrillo, J.; Bastidas, V. M.; Angelakis, D. G.; Brandes, T.

    2016-12-01

    We provide an analytic solution to the problem of system-bath dynamics under the effect of high-frequency driving that has applications in a large class of settings, such as driven-dissipative many-body systems. Our method relies on discrete symmetries of the system-bath Hamiltonian and provides the time evolution operator of the full system, including bath degrees of freedom, without weak-coupling or Markovian assumptions. An interpretation of the solution in terms of the stroboscopic evolution of a family of observables under the influence of an effective static Hamiltonian is proposed, which constitutes a flexible simulation procedure of nontrivial Hamiltonians. We instantiate the result with the study of the spin-boson model with time-dependent tunneling amplitude. We analyze the class of Hamiltonians that may be stroboscopically accessed for this example and illustrate the dynamics of system and bath degrees of freedom.

  11. Dynamic signatures of driven vortex motion.

    SciTech Connect

    Crabtree, G. W.; Kwok, W. K.; Lopez, D.; Olsson, R. J.; Paulius, L. M.; Petrean, A. M.; Safar, H.

    1999-09-16

    We probe the dynamic nature of driven vortex motion in superconductors with a new type of transport experiment. An inhomogeneous Lorentz driving force is applied to the sample, inducing vortex velocity gradients that distinguish the hydrodynamic motion of the vortex liquid from the elastic and-plastic motion of the vortex solid. We observe elastic depinning of the vortex lattice at the critical current, and shear induced plastic slip of the lattice at high Lorentz force gradients.

  12. Dynamics of the L {yields} H transition, VH-mode evolution, edge localized modes and R.F. driven confinement control in tokamaks

    SciTech Connect

    Diamond, P.H.; Lebedev, V.B.; Liang, Y.M.; Gruzinov, A.V.; Gruzinov, I.; Medvedev, M.; Carreras, B.A.; Newman, D.E.; Charlton, L.; Sidikman, K.L.

    1995-02-01

    Several novel theoretical results related to L {yields} H transition physics, VH-mode evolution, Edge Localized Modes and active confinement control are presented. Critical issues are identified, results are discussed and important unresolved questions are listed. The basic physics is discussed in the contexts of current experiments and of ITER.

  13. Target-Driven Evolution of Scorpion Toxins.

    PubMed

    Zhang, Shangfei; Gao, Bin; Zhu, Shunyi

    2015-10-07

    It is long known that peptide neurotoxins derived from a diversity of venomous animals evolve by positive selection following gene duplication, yet a force that drives their adaptive evolution remains a mystery. By using maximum-likelihood models of codon substitution, we analyzed molecular adaptation in scorpion sodium channel toxins from a specific species and found ten positively selected sites, six of which are located at the core-domain of scorpion α-toxins, a region known to interact with two adjacent loops in the voltage-sensor domain (DIV) of sodium channels, as validated by our newly constructed computational model of toxin-channel complex. Despite the lack of positive selection signals in these two loops, they accumulated extensive sequence variations by relaxed purifying selection in prey and predators of scorpions. The evolutionary variability in the toxin-bound regions of sodium channels indicates that accelerated substitutions in the multigene family of scorpion toxins is a consequence of dealing with the target diversity. This work presents an example of atypical co-evolution between animal toxins and their molecular targets, in which toxins suffered from more prominent selective pressure from the channels of their competitors. Our discovery helps explain the evolutionary rationality of gene duplication of toxins in a specific venomous species.

  14. Sustainability of culture-driven population dynamics.

    PubMed

    Ghirlanda, Stefano; Enquist, Magnus; Perc, Matjaz

    2010-05-01

    We consider models of the interactions between human population dynamics and cultural evolution, asking whether they predict sustainable or unsustainable patterns of growth. Phenomenological models predict either unsustainable population growth or stabilization in the near future. The latter prediction, however, is based on extrapolation of current demographic trends and does not take into account causal processes of demographic and cultural dynamics. Most existing causal models assume (or derive from simplified models of the economy) a positive feedback between cultural evolution and demographic growth, and predict unlimited growth in both culture and population. We augment these models taking into account that: (1) cultural transmission is not perfect, i.e., culture can be lost; (2) culture does not always promote population growth. We show that taking these factors into account can cause radically different model behavior, such as population extinction rather than stability, and extinction rather than growth. We conclude that all models agree that a population capable of maintaining a large amount of culture, including a powerful technology, runs a high risk of being unsustainable. We suggest that future work must address more explicitly both the dynamics of resource consumption and the cultural evolution of beliefs implicated in reproductive behavior (e.g., ideas about the preferred family size) and in resource use (e.g., environmentalist stances).

  15. Does eutrophication-driven evolution change aquatic ecosystems?

    PubMed

    Alexander, Timothy J; Vonlanthen, Pascal; Seehausen, Ole

    2017-01-19

    Eutrophication increases primary production and changes the relative abundance, taxonomic composition and spatial distribution of primary producers within an aquatic ecosystem. The changes in composition and location of resources alter the distribution and flow of energy and biomass throughout the food web. Changes in productivity also alter the physico-chemical environment, which has further effects on the biota. Such ecological changes influence the direction and strength of natural and sexual selection experienced by populations. Besides altering selection, they can also erode the habitat gradients and/or behavioural mechanisms that maintain ecological separation and reproductive isolation among species. Consequently, eutrophication of lakes commonly results in reduced ecological specialization as well as genetic and phenotypic homogenization among lakes and among niches within lakes. We argue that the associated loss in functional diversity and niche differentiation may lead to decreased carrying capacity and lower resource-use efficiency by consumers. We show that in central European whitefish species radiations, the functional diversity affected by eutrophication-induced speciation reversal correlates with community-wide trophic transfer efficiency (fisheries yield per unit phosphorus). We take this as an example of how evolutionary dynamics driven by anthropogenic environmental change can have lasting effects on biodiversity and ecosystem functioning.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.

  16. ENVIRONMENTALLY DRIVEN GLOBAL EVOLUTION OF GALAXIES

    SciTech Connect

    Cen Renyue

    2011-11-10

    Utilizing high-resolution large-scale galaxy formation simulations of the standard cold dark matter model, we examine global trends in the evolution of galaxies due to gravitational shock heating by collapse of large halos and large-scale structure. We find two major global trends. (1) The mean specific star formation rate (sSFR) at a given galaxy mass is a monotonically increasing function with increasing redshift. (2) The mean sSFR at a given redshift is a monotonically increasing function of decreasing galaxy mass that steepens with decreasing redshift. The general dimming trend with time merely reflects the general decline of gas inflow rate with increasing time. The differential evolution of galaxies of different masses with redshift is a result of gravitational shock heating of gas due to formation of large halos (groups and clusters) and large-scale structure that moves a progressively larger fraction of galaxies and their satellites into environments where gas has too high an entropy to cool to continue feeding resident galaxies. Overdense regions where larger halos are preferentially located begin to be heated earlier and have higher temperatures than lower density regions at any given time, causing sSFR of larger galaxies to fall below the general dimming trend at higher redshift than less massive galaxies and galaxies with high sSFR to gradually shift to lower density environments at lower redshift. We find that several noted cosmic downsizing phenomena are different manifestations of these general trends. We also find that the great migration of galaxies from blue cloud to red sequence as well as color-density relation, among others, may arise naturally in this picture.

  17. Geometric origin of dynamically induced freezing of quantum evolution

    SciTech Connect

    Matos-Abiague, A.; Berakdar, J.

    2006-02-15

    The phenomenon of dynamical, field-induced freezing of quantum evolution is discussed. It occurs when a time-dependent state is dynamically driven in such a way that the evolution of the corresponding wave function is effectively localized within a small region in the projective Hilbert space. As a consequence, the dynamics of the system is frozen and the expectation values of all physical observables hardly change with time. Necessary and sufficient conditions for inducing dynamical freezing are inferred from a general analysis of the geometry of quantum evolution. The relevance of the dynamical freezing for a sustainable in time, dynamical control is discussed and exemplified by a study of the coherent control of the kicked rotor motion.

  18. The evolution of information-driven safeguards

    SciTech Connect

    Budlong-sylvester, Kory W; Pilat, Joseph F

    2010-10-14

    From the adoption of the Model Additional Protocol and integrated safeguards in the 1990s, to current International Atomic Energy Agency (IAEA) efforts to deal with cases of noncompliance, the question of how the Agency can best utilize all the information available to it remains of great interest and increasing importance. How might the concept of 'information-driven' safeguards (IDS) evolve in the future? The ability of the Agency to identify and resolve anomalies has always been important and has emerged as a core Agency function in recent years as the IAEA has had to deal with noncompliance in Iran and the Democratic People's Republic of Korea (DPRK). Future IAEA safeguards implementation should be designed with the goal of facilitating and enhancing this vital capability. In addition, the Agency should utilize all the information it possesses, including its in-house assessments and expertise, to direct its safeguards activities. At the State level, knowledge of proliferation possibilities is currently being used to guide the analytical activities of the Agency and to develop inspection plans. How far can this approach be extended? Does it apply across State boundaries? Should it dictate a larger fraction of safeguards activities? Future developments in IDS should utilize the knowledge resident within the Agency to ensure that safeguards resources flow to where they are most needed in order to address anomalies first and foremost, but also to provide greater confidence in conclusions regarding the absence of undeclared nuclear activities. The elements of such a system and related implementation issues are assessed in this paper.

  19. Protobinary Evolution Driven By Magnetic Braking

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Zhi-Yun

    2013-07-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  20. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Z.; Kratter, K. M.

    2014-01-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  1. Evolution of cooperation driven by incremental learning

    NASA Astrophysics Data System (ADS)

    Li, Pei; Duan, Haibin

    2015-02-01

    It has been shown that the details of microscopic rules in structured populations can have a crucial impact on the ultimate outcome in evolutionary games. So alternative formulations of strategies and their revision processes exploring how strategies are actually adopted and spread within the interaction network need to be studied. In the present work, we formulate the strategy update rule as an incremental learning process, wherein knowledge is refreshed according to one's own experience learned from the past (self-learning) and that gained from social interaction (social-learning). More precisely, we propose a continuous version of strategy update rules, by introducing the willingness to cooperate W, to better capture the flexibility of decision making behavior. Importantly, the newly gained knowledge including self-learning and social learning is weighted by the parameter ω, establishing a strategy update rule involving innovative element. Moreover, we quantify the macroscopic features of the emerging patterns to inspect the underlying mechanisms of the evolutionary process using six cluster characteristics. In order to further support our results, we examine the time evolution course for these characteristics. Our results might provide insights for understanding cooperative behaviors and have several important implications for understanding how individuals adjust their strategies under real-life conditions.

  2. Birth and evolution of the Rio Grande-Rio Chama fluvial system: The influence of magma-driven dynamic topography on fluvial systems over the last 8 Ma

    NASA Astrophysics Data System (ADS)

    Repasch, M. N.; Karlstrom, K. E.; Heizler, M. T.

    2015-12-01

    The Rio Grande-Rio Chama (RG-RC) fluvial system of southern Colorado and northern New Mexico preserves a record of southern Rocky Mountain erosion and sediment transport over the last 8 Ma. During this time the two rivers have evolved wildly, undergoing channel migrations, drainage capture and integration events, carving and refilling of paleocanyons, lake spill-overs, and reshaping of drainage divides. New 40Ar/39Ar basalt ages coupled with new detrital grain age population data for fluvial sediments are beginning to reconstruct the birth of the RG-RC fluvial system and elucidate the processes that drove its evolution over the last ~8 Ma. Twenty-three detrital grain samples have been collected from RG-RC river deposits ranging in age from ~8 Ma (RC) and 4.5 Ma (RG) to modern fluvial sediment. Detrital zircon age spectra for the RG reveal peaks at 25 Ma, 28 Ma, 30-35 Ma (San Juan volcanic), and 70-90Ma (San Juan Basin) in sediments deposited from 4.5 to 0 Ma. RC spectra are richer in San Juan Basin and San Juan volcanic detritus. A 2.6 Ma Totavi Lentil deposit downstream of today's RG-RC confluence is similar to the ancestral RG, while a 1.6 Ma Totavi Lentil is similar to the combined RG-RC, suggesting northward shift of the RG-RC confluence by 1.6 Ma due to Jemez Mountain volcanism. A 4.5 Ma basalt age from Black Mesa and occurrence of San Juan volcanic detritus in 3 to 5 Ma sediment suggests birth of an ancestral RG as early as 4.5 Ma. There is no record of an ancestral RG north of the Red River confluence for the 3.0 to 0.5 Ma time period, supporting prior work that northern San Luis Basin became integrated after 0.5 Ma spill-over of Lake Alamosa. We plan to add detrital sanidine dating to refine the age spectra and help further delineate drainage patterns. The RG-RC system drains a highly tectonically active region. Changes in the fluvial regime suggest: 1) long-lived source of detritus (some recycled) from the San Juan volcanic field, 2) downstream integration

  3. Ultrafast electronic dynamics driven by nuclear motion

    NASA Astrophysics Data System (ADS)

    Vendrell, Oriol

    2016-05-01

    The transfer of electrical charge on a microscopic scale plays a fundamental role in chemistry, in biology, and in technological applications. In this contribution, we will discuss situations in which nuclear motion plays a central role in driving the electronic dynamics of photo-excited or photo-ionized molecular systems. In particular, we will explore theoretically the ultrafast transfer of a double electron hole between the functional groups of glycine after K-shell ionization and subsequent Auger decay. Although a large energy gap of about 15 eV initially exists between the two electronic states involved and coherent electronic dynamics play no role in the hole transfer, we will illustrate how the double hole can be transferred within 3 to 4 fs between both functional ends of the glycine molecule driven solely by specific nuclear displacements and non-Born-Oppenheimer effects. This finding challenges the common wisdom that nuclear dynamics of the molecular skeleton are unimportant for charge transfer processes at the few-femtosecond time scale and shows that they can even play a prominent role. We thank the Hamburg Centre for Ultrafast Imaging and the Volkswagen Foundation for financial support.

  4. Data driven Langevin modeling of biomolecular dynamics

    NASA Astrophysics Data System (ADS)

    Schaudinnus, Norbert; Rzepiela, Andrzej J.; Hegger, Rainer; Stock, Gerhard

    2013-05-01

    Based on a given time series, the data-driven Langevin equation proposed by Hegger and Stock [J. Chem. Phys. 130, 034106 (2009), 10.1063/1.3058436] aims to construct a low-dimensional dynamical model of the system. Adopting various simple model problems of biomolecular dynamics, this work presents a systematic study of the theoretical virtues and limitations as well as of the practical applicability and performance of the method. As the method requires only local information, the input data need not to be Boltzmann weighted in order to warrant that the Langevin model yields correct Boltzmann-distributed results. Moreover, a delay embedding of the state vector allows for the treatment of memory effects. The robustness of the modeling with respect to wrongly chosen model parameters or low sampling is discussed, as well as the treatment of inertial effects. Given sufficiently sampled input data, the Langevin modeling is shown to successfully recover the correct statistics (such as the probability distribution) and the dynamics (such as the position autocorrelation function) of all considered problems.

  5. Dynamic landscapes: a model of context and contingency in evolution.

    PubMed

    Foster, David V; Rorick, Mary M; Gesell, Tanja; Feeney, Laura M; Foster, Jacob G

    2013-10-07

    Although the basic mechanics of evolution have been understood since Darwin, debate continues over whether macroevolutionary phenomena are driven by the fitness structure of genotype space or by ecological interaction. In this paper we propose a simple model capturing key features of fitness-landscape and ecological models of evolution. Our model describes evolutionary dynamics in a high-dimensional, structured genotype space with interspecies interaction. We find promising qualitative similarity with the empirical facts about macroevolution, including broadly distributed extinction sizes and realistic exploration of the genotype space. The abstraction of our model permits numerous applications beyond macroevolution, including protein and RNA evolution.

  6. Laser-driven nonlinear cluster dynamics

    SciTech Connect

    Fennel, Th.; Meiwes-Broer, K.-H.; Tiggesbaeumker, J.; Reinhard, P.-G.; Dinh, P. M.; Suraud, E.

    2010-04-15

    Laser excitation of nanometer-sized atomic and molecular clusters offers various opportunities to explore and control ultrafast many-particle dynamics. Whereas weak laser fields allow the analysis of photoionization, excited-state relaxation, and structural modifications on these finite quantum systems, large-amplitude collective electron motion and Coulomb explosion can be induced with intense laser pulses. This review provides an overview of key phenomena arising from laser-cluster interactions with focus on nonlinear optical excitations and discusses the underlying processes according to the current understanding. A general survey covers basic cluster properties and excitation mechanisms relevant for laser-driven cluster dynamics. Then, after an excursion in theoretical and experimental methods, results for single-photon and multiphoton excitations are reviewed with emphasis on signatures from time- and angular-resolved photoemission. A key issue of this review is the broad spectrum of phenomena arising from clusters exposed to strong fields, where the interaction with the laser pulse creates short-lived and dense nanoplasmas. The implications for technical developments such as the controlled generation of ion, electron, and radiation pulses will be addressed along with corresponding examples. Finally, future prospects of laser-cluster research as well as experimental and theoretical challenges are discussed.

  7. Microstructural evolution during dynamic deformation of cubic metals: copper

    SciTech Connect

    Cerreta, Ellen K; Koller, Darcie D; Bronkhorst, Curt A; Excobedo, Juan P; Hansen, Benjamin L; Patterson, Brian M; Lebensohn, Ricardo A; Livescu, Veronica; Tonks, Davis; Mourad, Hashem M; Germann, Timothy C; Perez - Bergquist, Alex; Gray Ill, George T

    2010-12-22

    Shockwave shape can influence dynamic damage evolution. Features such as rise time, pulse duration, peak shock pressure, pull back, and release rate are influenced as wave shape changes. However, their individual influence on dynamic damage evolution is not well understood. Specifically, changing from a square to triangular or Taylor wave loading profile can alter the release kinetics from peak shock pressure and the volume of material sampled during release. This creates a spatial influence. In high purity metals, because damage is often linked to boundaries within the microstructure (grain or twin), changing the volume of material sampled during release, can have a drastic influence on dynamic damage evolution as the number of boundaries or defects sampled is altered. In this study, model-driven dynamic experiments have been conducted on eu with four different grain sizes to examine, for a given shockwave shape, how the spatial effect of boundary distribution influences dynamic damage evolution. Both two and three dimensional damage characterization techniques have been utilized. This study shows the critical influence of spatial effects, in this case boundary density, on dynamic damage evolution. As the boundary density decreases, the damage evolution transitions from nucleation controlled to growth controlled. It also shows that specific boundaries, those with high Schmid factor orientations on either side, maybe a necessary condition for void formation.

  8. Evolution of protoplanetary discs with magnetically driven disc winds

    NASA Astrophysics Data System (ADS)

    Suzuki, Takeru K.; Ogihara, Masahiro; Morbidelli, Alessandro; Crida, Aurélien; Guillot, Tristan

    2016-12-01

    Aims: We investigate the evolution of protoplanetary discs (PPDs) with magnetically driven disc winds and viscous heating. Methods: We considered an initially massive disc with 0.1 M⊙ to track the evolution from the early stage of PPDs. We solved the time evolution of surface density and temperature by taking into account viscous heating and the loss of mass and angular momentum by the disc winds within the framework of a standard α model for accretion discs. Our model parameters, turbulent viscosity, disc wind mass-loss, and disc wind torque, which were adopted from local magnetohydrodynamical simulations and constrained by the global energetics of the gravitational accretion, largely depends on the physical condition of PPDs, particularly on the evolution of the vertical magnetic flux in weakly ionized PPDs. Results: Although there are still uncertainties concerning the evolution of the vertical magnetic flux that remains, the surface densities show a large variety, depending on the combination of these three parameters, some of which are very different from the surface density expected from the standard accretion. When a PPD is in a wind-driven accretion state with the preserved vertical magnetic field, the radial dependence of the surface density can be positive in the inner region <1-10 au. The mass accretion rates are consistent with observations, even in the very low level of magnetohydrodynamical turbulence. Such a positive radial slope of the surface density strongly affects planet formation because it inhibits the inward drift or even causes the outward drift of pebble- to boulder-sized solid bodies, and it also slows down or even reversed the inward type-I migration of protoplanets. Conclusions: The variety of our calculated PPDs should yield a wide variety of exoplanet systems.

  9. A combined Event-Driven/Time-Driven molecular dynamics algorithm for the simulation of shock waves in rarefied gases

    SciTech Connect

    Valentini, Paolo Schwartzentruber, Thomas E.

    2009-12-10

    A novel combined Event-Driven/Time-Driven (ED/TD) algorithm to speed-up the Molecular Dynamics simulation of rarefied gases using realistic spherically symmetric soft potentials is presented. Due to the low density regime, the proposed method correctly identifies the time that must elapse before the next interaction occurs, similarly to Event-Driven Molecular Dynamics. However, each interaction is treated using Time-Driven Molecular Dynamics, thereby integrating Newton's Second Law using the sufficiently small time step needed to correctly resolve the atomic motion. Although infrequent, many-body interactions are also accounted for with a small approximation. The combined ED/TD method is shown to correctly reproduce translational relaxation in argon, described using the Lennard-Jones potential. For densities between {rho}=10{sup -4}kg/m{sup 3} and {rho}=10{sup -1}kg/m{sup 3}, comparisons with kinetic theory, Direct Simulation Monte Carlo, and pure Time-Driven Molecular Dynamics demonstrate that the ED/TD algorithm correctly reproduces the proper collision rates and the evolution toward thermal equilibrium. Finally, the combined ED/TD algorithm is applied to the simulation of a Mach 9 shock wave in rarefied argon. Density and temperature profiles as well as molecular velocity distributions accurately match DSMC results, and the shock thickness is within the experimental uncertainty. For the problems considered, the ED/TD algorithm ranged from several hundred to several thousand times faster than conventional Time-Driven MD. Moreover, the force calculation to integrate the molecular trajectories is found to contribute a negligible amount to the overall ED/TD simulation time. Therefore, this method could pave the way for the application of much more refined and expensive interatomic potentials, either classical or first-principles, to Molecular Dynamics simulations of shock waves in rarefied gases, involving vibrational nonequilibrium and chemical reactivity.

  10. Field-driven dynamics of nematic microcapillaries

    NASA Astrophysics Data System (ADS)

    Khayyatzadeh, Pouya; Fu, Fred; Abukhdeir, Nasser Mohieddin

    2015-12-01

    Polymer-dispersed liquid-crystal (PDLC) composites long have been a focus of study for their unique electro-optical properties which have resulted in various applications such as switchable (transparent or translucent) windows. These composites are manufactured using desirable "bottom-up" techniques, such as phase separation of a liquid-crystal-polymer mixture, which enable production of PDLC films at very large scales. LC domains within PDLCs are typically spheroidal, as opposed to rectangular for an LCD panel, and thus exhibit substantially different behavior in the presence of an external field. The fundamental difference between spheroidal and rectangular nematic domains is that the former results in the presence of nanoscale orientational defects in LC order while the latter does not. Progress in the development and optimization of PDLC electro-optical properties has progressed at a relatively slow pace due to this increased complexity. In this work, continuum simulations are performed in order to capture the complex formation and electric field-driven switching dynamics of approximations of PDLC domains. Using a simplified elliptic cylinder (microcapillary) geometry as an approximation of spheroidal PDLC domains, the effects of geometry (aspect ratio), surface anchoring, and external field strength are studied through the use of the Landau-de Gennes model of the nematic LC phase.

  11. Spatiotemporal Dynamics of Calcium-Driven Cardiac Alternans

    PubMed Central

    Skardal, Per Sebastian; Karma, Alain; Restrepo, Juan G.

    2015-01-01

    We investigate the dynamics of spatially discordant alternans (SDA) driven by an instability of intracellular calcium cycling using both amplitude equations [P. S. Skardal, A. Karma, and J. G. Restrepo, Phys. Rev. Lett. 108, 108103 (2012)] and ionic model simulations. We focus on the common case where the bi-directional coupling of intracellular calcium concentration and membrane voltage dynamics produces calcium and voltage alternans that are temporally in phase. We find that, close to the alternans bifurcation, SDA is manifested as a smooth wavy modulation of the amplitudes of both repolarization and calcium transient (CaT) alternans, similarly to the well-studied case of voltage-driven alternans. In contrast, further away from the bifurcation, the amplitude of CaT alternans jumps discontinuously at the nodes separating out-of-phase regions, while the amplitude of repolarization alternans remains smooth. We identify universal dynamical features of SDA pattern formation and evolution in the presence of those jumps. We show that node motion of discontinuous SDA patterns is strongly hysteretic even in homogeneous tissue due to the novel phenomenon of “unidirectional pinning”: node movement can only be induced towards, but not away from, the pacing site in response to a change of pacing rate or physiological parameter. In addition, we show that the wavelength of discontinuous SDA patterns scales linearly with the conduction velocity restitution length scale, in contrast to the wavelength of smooth patterns that scales sub-linearly with this length scale. Those results are also shown to be robust against cell-to-cell fluctuations owing to the property that unidirectional node motion collapses multiple jumps accumulating in nodal regions into a single jump. Amplitude equation predictions are in good overall agreement with ionic model simulations. Finally, we briefly discuss physiological implications of our findings. In particular, we suggest that due to the

  12. Plasma Dynamics of the Arc-Driven Rail Gun

    DTIC Science & Technology

    1980-09-01

    AO-A^JX^1^ TECHNICAL LIBRARY AD TECHNICAL REPORT ARBRL-TR-02267 PLASMA DYNAMICS OF THE ARC-DRIVEN RAIL GUN JohnD. Powell JadH. Batteh...T]T\\.E (and Subtitle) Plasma Dynamics of the Arc-Driven Rail Gun 5. TYPE OF REPORT & PERIOD COVERED 6. PERFORMING ORG. REPORT NUMBER 7. AUTHORfa...Electric gun , rail gun , electromagnetic propulsion, plasma dynamics, fluid mechanics 2Q. ABSTRACT (Conttttue am reverse aid* tf necessary and

  13. Dynamics of driven flow with exclusion in graphenelike structures

    NASA Astrophysics Data System (ADS)

    Stinchcombe, R. B.; de Queiroz, S. L. A.

    2015-05-01

    We present a mean-field theory for the dynamics of driven flow with exclusion in graphenelike structures, and numerically check its predictions. We treat first a specific combination of bond transmissivity rates, where mean field predicts, and numerics to a large extent confirms, that the sublattice structure characteristic of honeycomb networks becomes irrelevant. Dynamics, in the various regions of the phase diagram set by open boundary injection and ejection rates, is then in general identical to that of one-dimensional systems, although some discrepancies remain between mean-field theory and numerical results, in similar ways for both geometries. However, at the critical point for which the characteristic exponent is z =3 /2 in one dimension, the mean-field value z =2 is approached for very large systems with constant (finite) aspect ratio. We also treat a second combination of bond (and boundary) rates where, more typically, sublattice distinction persists. For the two rate combinations, in continuum or late-time limits, respectively, the coupled sets of mean-field dynamical equations become tractable with various techniques and give a two-band spectrum, gapless in the critical phase. While for the second rate combination quantitative discrepancies between mean-field theory and simulations increase for most properties and boundary rates investigated, theory still is qualitatively correct in general, and gives a fairly good quantitative account of features such as the late-time evolution of density profile differences from their steady-state values.

  14. Dynamical evolution of comet pairs

    NASA Astrophysics Data System (ADS)

    Sosa, Andrea; Fernández, Julio A.

    2016-10-01

    Some Jupiter family comets in near-Earth orbits (thereafter NEJFCs) show a remarkable similarity in their present orbits, like for instance 169P/NEAT and P/2003 T12 (SOHO), or 252P/LINEAR and P/2016 BA14 (PANSTARRS). By means of numerical integrations we studied the dynamical evolution of these objects. In particular, for each pair of presumably related objects, we are interested in assessing the stability of the orbital parameters for several thousand years, and to find a minimum of their relative spatial distance, coincident with a low value of their relative velocity. For those cases for which we find a well defined minimum of their relative orbital separation, we are trying to reproduce the actual orbit of the hypothetical fragment by modeling a fragmentation of the parent body. Some model parameters are the relative ejection velocity (a few m/s), the orbital point at which the fragmentation could have happened (e.g. perihelion), and the elapsed time since fragmentation. In addition, some possible fragmentation mechanisms, like thermal stress, rotational instability, or collisions, could be explored. According to Fernández J.A and Sosa A. 2015 (Planetary and Space Science 118,pp.14-24), some NEJFCs might come from the outer asteroid belt, and then they would have a more consolidated structure and a higher mineral content than that of comets coming from the trans-Neptunian belt or the Oort cloud. Therefore, such objects would have a much longer physical lifetime in the near-Earth region, and could become potential candidates to produce visible meteor showers (as for example 169P/NEAT which has been identified as the parent body of the alpha-Capricornid meteoroid stream, according to Jenniskens, P., Vaubaillon, J., 2010 (Astron. J. 139), and Kasuga, T., Balam, D.D., Wiegert, P.A., 2010 (Astron. J. 139).

  15. Dynamical Evolution of Ring-Satellite Systems

    NASA Technical Reports Server (NTRS)

    Ohtsuki, Keiji

    2005-01-01

    The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

  16. Asynchronous networks and event driven dynamics

    NASA Astrophysics Data System (ADS)

    Bick, Christian; Field, Michael

    2017-02-01

    Real-world networks in technology, engineering and biology often exhibit dynamics that cannot be adequately reproduced using network models given by smooth dynamical systems and a fixed network topology. Asynchronous networks give a theoretical and conceptual framework for the study of network dynamics where nodes can evolve independently of one another, be constrained, stop, and later restart, and where the interaction between different components of the network may depend on time, state, and stochastic effects. This framework is sufficiently general to encompass a wide range of applications ranging from engineering to neuroscience. Typically, dynamics is piecewise smooth and there are relationships with Filippov systems. In this paper, we give examples of asynchronous networks, and describe the basic formalism and structure. In the following companion paper, we make the notion of a functional asynchronous network rigorous, discuss the phenomenon of dynamical locks, and present a foundational result on the spatiotemporal factorization of the dynamics for a large class of functional asynchronous networks.

  17. A User Driven Dynamic Circuit Network Implementation

    SciTech Connect

    Guok, Chin; Robertson, David; Chaniotakis, Evangelos; Thompson, Mary; Johnston, William; Tierney, Brian

    2008-10-01

    The requirements for network predictability are becoming increasingly critical to the DoE science community where resources are widely distributed and collaborations are world-wide. To accommodate these emerging requirements, the Energy Sciences Network has established a Science Data Network to provide user driven guaranteed bandwidth allocations. In this paper we outline the design, implementation, and secure coordinated use of such a network, as well as some lessons learned.

  18. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies

    SciTech Connect

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; Beyerlein, Irene J.

    2015-01-23

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Lastly, our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation and dynamics in these systems.

  19. Dynamic phases, pinning, and pattern formation for driven dislocation assemblies

    DOE PAGES

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; ...

    2015-01-23

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Lastly, our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation andmore » dynamics in these systems.« less

  20. Dynamic Phases, Pinning, and Pattern Formation for Driven Dislocation Assemblies

    PubMed Central

    Zhou, Caizhi; Reichhardt, Charles; Olson Reichhardt, Cynthia J.; Beyerlein, Irene J.

    2015-01-01

    We examine driven dislocation assemblies and show that they can exhibit a set of dynamical phases remarkably similar to those of driven systems with quenched disorder such as vortices in superconductors, magnetic domain walls, and charge density wave materials. These phases include pinned-jammed, fluctuating, and dynamically ordered states, and each produces distinct dislocation patterns as well as specific features in the noise fluctuations and transport properties. Our work suggests that many of the results established for systems with quenched disorder undergoing plastic depinning transitions can be applied to dislocation systems, providing a new approach for understanding pattern formation and dynamics in these systems. PMID:25613839

  1. Entropy evolution of a damped harmonic oscillator driven by quasimonochromatic noise and external periodic force

    NASA Astrophysics Data System (ADS)

    Qin, Jie; Ning, Lijuan

    2017-08-01

    This paper addresses the entropy evolution of a damped harmonic oscillator driven by quasimonochromatic noise (QMN). Due to QMN is distinct from white noise, so this paper studied the effect of QMN noise on the upper bound of time derivative of entropy for a damped harmonic oscillator. Through the comparison of probability density function (PDF) and the upper bound for the time derivative of entropy, we find that the entropy evolution is also a useful tool to describe the system dynamic behavior. Then we discuss the interplay of the parameters of QMN, damping constant, the frequency of oscillator and external periodic force and their effects on the upper bound for the rate of entropy change. Finally, some beneficial conclusions are obtained.

  2. Dynamics driven allostery in protein kinases

    PubMed Central

    Kornev, Alexandr P.; Taylor, Susan S.

    2015-01-01

    Protein kinases have very dynamic structures and their functionality strongly depends on their dynamic state. Active kinases reveal a dynamic pattern with residues clustering into semirigid communities that move in µs-ms timescale. Previously detected hydrophobic spines serve as connectors between communities. Communities do not follow the traditional subdomain structure of the kinase core or its secondary structure elements. Instead they are organized around main functional units. Integration of the communities depends on the assembly of the hydrophobic spine and phosphorylation of the activation loop. Single mutations can significantly disrupt the dynamic infrastructure and thereby interfere with long distance allosteric signaling that propagates throughout the whole molecule. Dynamics is proposed to be the underlying mechanism for allosteric regulation in protein kinases. PMID:26481499

  3. The dynamics of driven magnetic reconnection in coronal arcades

    NASA Astrophysics Data System (ADS)

    Rickard, G. J.; Priest, E. R.

    1994-04-01

    The dynamics of interacting coronal loops and arcades have recently been highlighted by observations from the Yohkoh satellite and may represent a viable mechanism for heating the solar corona. Here such an interaction is studied using two-dimensional resistive magnetohydrodynamic (MHD) simulations. Initial potential field structures evolve in response to imposed photospheric flows. In addition to the anticipated current sheet about the X -point separating the colliding flux systems, significant current layers are found to lie all the way along the separatrices that intersect at the X -point and divide the coronal magnetic field into topologically distinct regions. Shear flows across the separatrices are also observed. Both of these features are shown to be compatible with recent analytical studies of two-dimensional linear steady-state magnetic reconnection, even though the driven system that has been simulated is not strictly 'open' in the sense implied by steady-state calculations. The implications for future steady-state models are also discussed. The presence of the neutral point also brings into question any constant-density approximations that have previously been used for such quasi-steady coronal evolution models. This results from the intimate coupling between the neutral point and its separatrices communicated via the gas pressure. In terms of the detailed energetics during the arcade evolution, preliminary results reveal that on the order of 3% of the energy injected by the footpoint motions is lost purely through ohmic dissipation. We would therefore anticipate a local hot spot between the interacting flux systems, and a brightening distributed along the length of any separatrix field lines. Furthermore, as the resistivity eta is reduced, the flux annihilation rate and the ohmic dissipation rate are found to scale independently of eta.

  4. Probabilistic density function method for nonlinear dynamical systems driven by colored noise

    SciTech Connect

    Barajas-Solano, David A.; Tartakovsky, Alexandre M.

    2016-05-01

    We present a probability density function (PDF) method for a system of nonlinear stochastic ordinary differential equations driven by colored noise. The method provides an integro-differential equation for the temporal evolution of the joint PDF of the system's state, which we close by means of a modified Large-Eddy-Diffusivity-type closure. Additionally, we introduce the generalized local linearization (LL) approximation for deriving a computable PDF equation in the form of the second-order partial differential equation (PDE). We demonstrate the proposed closure and localization accurately describe the dynamics of the PDF in phase space for systems driven by noise with arbitrary auto-correlation time. We apply the proposed PDF method to the analysis of a set of Kramers equations driven by exponentially auto-correlated Gaussian colored noise to study the dynamics and stability of a power grid.

  5. Metal-coordination-driven dynamic heteroleptic architectures.

    PubMed

    De, Soumen; Mahata, Kingsuk; Schmittel, Michael

    2010-05-01

    Dynamic heteroleptic coordination at metal centres is quite common in Nature and often related to a specific biological function, such as in zinc finger proteins and in hemoglobin for oxygen transport. To achieve the required high heteroleptic fidelity, representative biological systems avail themselves of "intramolecular" multidentate coordination using the protein backbone as a "superligand". In contrast, dynamic heteroleptic coordination at a single metal centre in solution requires to bind different freely exchanging ligands under thermodynamic control. In this tutorial review we present the emerging principles of how to assemble dissimilar ligands at dynamically exchanging metal centres, with a particular emphasis on using the precepts for the fabrication of heteroleptic supramolecular assemblies in solution.

  6. Dynamical Evolution: Spirals and Bars

    NASA Astrophysics Data System (ADS)

    Combes, F.

    Non-axisymmetric modes like spirals and bars are the main driver of the evolution of disks, in transferring angular momentum, and allowing mass accretion. This evolution proceeds through self-regulation and feedback mechanisms, such as bar destruction or weakening by a central mass concentration, decoupling of a nuclear bar taking over the gas radial flows and mass accretion, etc.. These internal mechanisms can also be triggered by interaction with the environment. Recent problems are discussed, like the influence of counter-rotation in the m=1 and m=2 patterns development and on mass accretion by a central AGN.

  7. Spin dynamics in driven composite multiferroics

    SciTech Connect

    Wang, Zidong Grimson, Malcolm J.

    2015-09-28

    A spin dynamics approach has been used to study the behavior of the magnetic spins and the electric pseudo-spins in a 1-D composite multiferroic chain with a linear magneto-electric coupling at the interface. The response is investigated with either external magnetic or electric fields driving the system. The spin dynamics is based on the Landau-Lifshitz-Gilbert equation. A Gaussian white noise is later added into the dynamic process to include the thermal effects. The interface requires a closer inspection of the magneto-electric effects. Thus, we construct a 2-D ladder model to describe the behavior of the magnetic spins and the electric pseudo-spins with different magneto-electric couplings.

  8. Evolution of Neogene Dynamic Topography in Madagascar

    NASA Astrophysics Data System (ADS)

    Paul, J. D.; Roberts, G.; White, N. J.

    2012-12-01

    Madagascar is located on the fringes of the African superswell. Its position and the existence of a +30 mGal long wavelength free-air gravity anomaly suggest that its present-day topography is maintained by convective circulation of the sub-lithospheric mantle. Residual depth anomalies of oceanic crust encompassing the island imply that Madagascar straddles a dynamic topographic gradient. In June-July 2012, we examined geologic evidence for Neogene uplift around the Malagasy coastline. Uplifted coral reef deposits, fossil beach rock, and terraces demonstrate that the northern and southern coasts are probably being uplifted at a rate of ~0.2 mm/yr. Rates of uplift clearly vary around the coastline. Inland, extensive peneplains occur at elevations of 1 - 2 km. These peneplains are underlain by 10 - 20 m thick laterite deposits, and there is abundant evidence for rapid erosion (e.g. lavaka). Basaltic volcanism also occurred during Neogene times. These field observations can be combined with an analysis of drainage networks to determine the spatial and temporal pattern of convectively driven uplift. ~100 longitudinal river profiles were extracted from a digital elevation model of Madagascar. An inverse model is then used to minimize the misfit between observed and calculated river profiles as a function of uplift rate history. During inversion, the residual misfit decreases from ~20 to ~4. Our results suggest that youthful and rapid uplift of 1-2 km occurred at rates of 0.2-0.4 mm/yr during the last ˜15 Myr. The algorithm resolves distinct phases of uplift which generate localized swells of high topography and relief (e.g. the Hauts Plateaux). Our field observations and modeling indicate that the evolution of drainage networks may contain useful information about mantle convective processes.

  9. Protein Synthesis Driven by Dynamical Stochastic Transcription.

    PubMed

    Innocentini, Guilherme C P; Forger, Michael; Radulescu, Ovidiu; Antoneli, Fernando

    2016-01-01

    In this manuscript, we propose a mathematical framework to couple transcription and translation in which mRNA production is described by a set of master equations, while the dynamics of protein density is governed by a random differential equation. The coupling between the two processes is given by a stochastic perturbation whose statistics satisfies the master equations. In this approach, from the knowledge of the analytical time-dependent distribution of mRNA number, we are able to calculate the dynamics of the probability density of the protein population.

  10. Vibrational- and Laser-Driven Electronic Dynamics in the Molecules

    NASA Astrophysics Data System (ADS)

    Stolow, Albert

    2014-05-01

    Electronic dynamics within molecules can be driven by both motions of the atoms, via non-Born-Oppenheimer coupling, and by applied laser fields, driving electron motions on sub-cycle time scales. The challenging but most general case of Molecular Dynamics is where electronic and vibrational motions are fully coupled, the making and breaking of chemical bonds being the most prominent example. Time-Resolved Coincidence Imaging Spectroscopy (TRCIS) is a ultrafast photoelectron probe of Molecular Frame dynamics in polyatomic molecules. It makes use of full 3D recoil momentum vector determination of coincident photoions and photoelectrons as a function of time, permitting observations of coupled electronic-vibrational dynamics from the Molecular Frame rather than the Lab Frame point of view. Methods in non-resonant quantum control, based on the dynamic Stark effect, have also emerged as important tools for enhancing molecular dynamics studies. In particular, molecular alignment can fix the Molecular Frame within the Lab Frame, avoiding loss of information due to orientational averaging. Provided that the molecular dynamics are fast compared to rotational dephasing, this method also permits time-resolved Molecular Frame observations. As laser fields get stronger, a sub-cycle (attosecond) physics emerges, leading to new probes of driven multi-electron dynamics in polyatomic molecules. Understanding driven multi-electron responses will be central to advancing attosecond science towards polyatomic molecules and complex systems.

  11. Dynamical trapping and chaotic scattering of the harmonically driven barrier.

    PubMed

    Koch, Florian R N; Lenz, Florian; Petri, Christoph; Diakonos, Fotios K; Schmelcher, Peter

    2008-11-01

    A detailed analysis of the classical nonlinear dynamics of a single driven square potential barrier with harmonically oscillating position is performed. The system exhibits dynamical trapping which is associated with the existence of a stable island in phase space. Due to the unstable periodic orbits of the KAM structure, the driven barrier is a chaotic scatterer and shows stickiness of scattering trajectories in the vicinity of the stable island. The transmission function of a suitably prepared ensemble yields results which are very similar to tunneling resonances in the quantum mechanical regime. However, the origin of these resonances is different in the classical regime.

  12. Nonlinear waves: Dynamics and evolution

    NASA Astrophysics Data System (ADS)

    Gaponov-Grekhov, A. V.; Rabinovich, M. I.

    Papers on nonlinear waves are presented, covering topics such as the history of studies on nonlinear dynamics since Poincare, attractors, pattern formation and the dynamics of two-dimensional structures in nonequilibirum dissipative media, the onset of spatial chaos in one-dimensional systems, and self-organization phenomena in laser thermochemistry. Additional topics include criteria for the existence of moving structures in two-component reaction-diffusion systems, space-time structures in optoelectronic devices, stimulated scattering and surface structures, and distributed wave collapse in the nonlinear Schroedinger equation. Consideration is also given to dimensions and entropies in multidimensional systems, measurement methods for correlation dimensions, quantum localization and dynamic chaos, self-organization in bacterial cells and populations, nonlinear phenomena in condensed matter, and the origin and evolutionary dynamics of Uranian rings.

  13. Unidirectional spin-torque driven magnetization dynamics

    NASA Astrophysics Data System (ADS)

    Sklenar, Joseph; Zhang, Wei; Jungfleisch, Matthias B.; Saglam, Hilal; Grudichak, Scott; Jiang, Wanjun; Pearson, John E.; Ketterson, John B.; Hoffmann, Axel

    2017-06-01

    The rich physics associated with magnetism often centers around directional effects. Here we demonstrate how spin-transfer torques in general result in unidirectional ferromagnetic resonance dynamics upon field reversal. The unidirectionality is a direct consequence of both field-like and damping-like dynamic torques simultaneously driving the motion. This directional effect arises from the field-like torque being odd and the damping-like torque being even under field reversal. The directional effect is observed when the magnetization has both an in-plane and out-of-plane component, since then the linear combination of the torques rotates with a different handedness around the magnetization as the magnetization is tipped out-of-plane. The effect is experimentally investigated via spin-torque ferromagnetic resonance measurements with the field applied at arbitrary directions away from the interface normal. The measured asymmetry of the voltage spectra are well explained within a phenomenological torque model.

  14. EUV-driven femtosecond dynamics in ethylene

    NASA Astrophysics Data System (ADS)

    van Tilborg, J.; Allison, T. K.; Wright, T. W.; Hertlein, M. P.; Liu, Y.; Merdji, H.; Falcone, R. W.; Belkacem, A.

    2009-11-01

    We studied ion fragment yields from EUV-pump NIR-probe experiments performed on ethylene molecules (C2H4). Through study of the ion yields as a function of pump-probe delay we resolve molecular dynamics on the excited electronic states of the ion. The breakup channel yielding CH+ and CH+3 indicated photo-isomerization to the ethylidene configuration (HC-CH3)+ on an ultrafast timescale. This configuration is predicted to be a transient configuration for electronic relaxation. We observed this channel, and found that it takes the excited cation (C2H+4)* 50 ± 25 fs to reach the ethylidene configuration. The transient ion yield of C2H24 + at zero delay (in combination with independent synchrotron experiments) indicates other ultra-fast dynamics in short-lived intermediate states are present.

  15. Dynamics of Membranes Driven by Actin Polymerization

    PubMed Central

    Gov, Nir S.; Gopinathan, Ajay

    2006-01-01

    A motile cell, when stimulated, shows a dramatic increase in the activity of its membrane, manifested by the appearance of dynamic membrane structures such as lamellipodia, filopodia, and membrane ruffles. The external stimulus turns on membrane bound activators, like Cdc42 and PIP2, which cause increased branching and polymerization of the actin cytoskeleton in their vicinity leading to a local protrusive force on the membrane. The emergence of the complex membrane structures is a result of the coupling between the dynamics of the membrane, the activators, and the protrusive forces. We present a simple model that treats the dynamics of a membrane under the action of actin polymerization forces that depend on the local density of freely diffusing activators on the membrane. We show that, depending on the spontaneous membrane curvature associated with the activators, the resulting membrane motion can be wavelike, corresponding to membrane ruffling and actin waves, or unstable, indicating the tendency of filopodia to form. Our model also quantitatively explains a variety of related experimental observations and makes several testable predictions. PMID:16239328

  16. Lie transformation method on quantum state evolution of a general time-dependent driven and damped parametric oscillator

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Zhang, Weiping

    2016-10-01

    A variety of dynamics in nature and society can be approximately treated as a driven and damped parametric oscillator. An intensive investigation of this time-dependent model from an algebraic point of view provides a consistent method to resolve the classical dynamics and the quantum evolution in order to understand the time-dependent phenomena that occur not only in the macroscopic classical scale for the synchronized behaviors but also in the microscopic quantum scale for a coherent state evolution. By using a Floquet U-transformation on a general time-dependent quadratic Hamiltonian, we exactly solve the dynamic behaviors of a driven and damped parametric oscillator to obtain the optimal solutions by means of invariant parameters of Ks to combine with Lewis-Riesenfeld invariant method. This approach can discriminate the external dynamics from the internal evolution of a wave packet by producing independent parametric equations that dramatically facilitate the parametric control on the quantum state evolution in a dissipative system. In order to show the advantages of this method, several time-dependent models proposed in the quantum control field are analyzed in detail.

  17. Dynamical Coulomb blockade of tunnel junctions driven by alternating voltages

    NASA Astrophysics Data System (ADS)

    Grabert, Hermann

    2015-12-01

    The theory of the dynamical Coulomb blockade is extended to tunneling elements driven by a time-dependent voltage. It is shown that, for standard setups where an external voltage is applied to a tunnel junction via an impedance, time-dependent driving entails an excitation of the modes of the electromagnetic environment by the applied voltage. Previous approaches for ac driven circuits need to be extended to account for the driven bath modes. A unitary transformation involving also the variables of the electromagnetic environment is introduced which allows us to split off the time dependence from the Hamiltonian in the absence of tunneling. This greatly simplifies perturbation-theoretical calculations based on treating the tunneling Hamiltonian as a perturbation. In particular, the average current flowing in the leads of the tunnel junction is studied. Explicit results are given for the case of an applied voltage with a constant dc part and a sinusoidal ac part. The connection with standard dynamical Coulomb blockade theory for constant applied voltage is established. It is shown that an alternating voltage source reveals significant additional effects caused by the electromagnetic environment. The hallmark of the dynamical Coulomb blockade in ac driven devices is a suppression of higher harmonics of the current by the electromagnetic environment. The theory presented basically applies to all tunneling devices driven by alternating voltages.

  18. Quantum dynamics of light-driven chiral molecular motors.

    PubMed

    Yamaki, Masahiro; Nakayama, Shin-ichiro; Hoki, Kunihito; Kono, Hirohiko; Fujimura, Yuichi

    2009-03-21

    The results of theoretical studies on quantum dynamics of light-driven molecular motors with internal rotation are presented. Characteristic features of chiral motors driven by a non-helical, linearly polarized electric field of light are explained on the basis of symmetry argument. The rotational potential of the chiral motor is characterized by a ratchet form. The asymmetric potential determines the directional motion: the rotational direction is toward the gentle slope of the asymmetric potential. This direction is called the intuitive direction. To confirm the unidirectional rotational motion, results of quantum dynamical calculations of randomly-oriented molecular motors are presented. A theoretical design of the smallest light-driven molecular machine is presented. The smallest chiral molecular machine has an optically driven engine and a running propeller on its body. The mechanisms of transmission of driving forces from the engine to the propeller are elucidated by using a quantum dynamical treatment. The results provide a principle for control of optically-driven molecular bevel gears. Temperature effects are discussed using the density operator formalism. An effective method for ultrafast control of rotational motions in any desired direction is presented with the help of a quantum control theory. In this method, visible or UV light pulses are applied to drive the motor via an electronic excited state. A method for driving a large molecular motor consisting of an aromatic hydrocarbon is presented. The molecular motor is operated by interactions between the induced dipole of the molecular motor and the electric field of light pulses.

  19. Dynamical evolution of near-Sun objects

    NASA Astrophysics Data System (ADS)

    Emel'Yanenko, Vacheslav V.; Shelyakov, Mikhail A.

    2014-07-01

    The dynamical evolution of short-period objects having perihelia at small heliocentric distances is discussed. We have investigated the motion of multiple-apparition members of the Marsden and Kracht sungrazing groups. The orbital evolution of these objects on timescales < 10 Kyr is mainly determined by the Kozai-Lidov secular perturbations. These objects are dynamically connected with high-inclination near-Earth objects. On the other hand, we have found several observed near-Earth objects that evolve in the same way, reaching small perihelion distances on short timescales in the past.

  20. Dynamical transitions of a driven Ising interface

    NASA Astrophysics Data System (ADS)

    Sahai, Manish K.; Sengupta, Surajit

    2008-03-01

    We study the structure of an interface in a three-dimensional Ising system created by an external nonuniform field H(r,t) . H changes sign over a two-dimensional plane of arbitrary orientation. When the field is pulled with velocity ve , [i.e., H(r,t)=H(r-vet) ], the interface undergoes several dynamical transitions. For low velocities it is pinned by the field profile and moves along with it, the distribution of local slopes undergoing a series of commensurate-incommensurate transitions. For large ve the interface depins and grows with Kardar-Parisi-Zhang exponents.

  1. Dynamical transitions of a driven Ising interface.

    PubMed

    Sahai, Manish K; Sengupta, Surajit

    2008-03-01

    We study the structure of an interface in a three-dimensional Ising system created by an external nonuniform field H(r,t) . H changes sign over a two-dimensional plane of arbitrary orientation. When the field is pulled with velocity v(e) , [i.e., H(r,t)=H(r-v(e)t) ], the interface undergoes several dynamical transitions. For low velocities it is pinned by the field profile and moves along with it, the distribution of local slopes undergoing a series of commensurate-incommensurate transitions. For large v(e) the interface depins and grows with Kardar-Parisi-Zhang exponents.

  2. Chaotic and ballistic dynamics in time-driven quasiperiodic lattices.

    PubMed

    Wulf, Thomas; Schmelcher, Peter

    2016-04-01

    We investigate the nonequilibrium dynamics of classical particles in a driven quasiperiodic lattice based on the Fibonacci sequence. An intricate transient dynamics of extraordinarily long ballistic flights at distinct velocities is found. We argue how these transients are caused and can be understood by a hierarchy of block decompositions of the quasiperiodic lattice. A comparison to the cases of periodic and fully randomized lattices is performed.

  3. Chaotic and ballistic dynamics in time-driven quasiperiodic lattices

    NASA Astrophysics Data System (ADS)

    Wulf, Thomas; Schmelcher, Peter

    2016-04-01

    We investigate the nonequilibrium dynamics of classical particles in a driven quasiperiodic lattice based on the Fibonacci sequence. An intricate transient dynamics of extraordinarily long ballistic flights at distinct velocities is found. We argue how these transients are caused and can be understood by a hierarchy of block decompositions of the quasiperiodic lattice. A comparison to the cases of periodic and fully randomized lattices is performed.

  4. Implementing a Dynamic Database-Driven Course Using LAMP

    ERIC Educational Resources Information Center

    Laverty, Joseph Packy; Wood, David; Turchek, John

    2011-01-01

    This paper documents the formulation of a database driven open source architecture web development course. The design of a web-based curriculum faces many challenges: a) relative emphasis of client and server-side technologies, b) choice of a server-side language, and c) the cost and efficient delivery of a dynamic web development, database-driven…

  5. Dynamic quantum tunneling in mesoscopic driven Duffing oscillators.

    PubMed

    Guo, Lingzhen; Zheng, Zhigang; Li, Xin-Qi; Yan, Yijing

    2011-07-01

    We investigate the dynamic quantum tunneling between two attractors of a mesoscopic driven Duffing oscillator. We find that, in addition to inducing a remarkable quantum shift of the bifurcation point, the mesoscopic nature also results in a perfect linear scaling behavior for the tunneling rate with the driving distance to the shifted bifurcation point.

  6. Nonlinear dynamics of three-magnon process driven by ferromagnetic resonance in yttrium iron garnet

    SciTech Connect

    Cunha, R. O.; Holanda, J.; Azevedo, A.; Rezende, S. M.; Vilela-Leão, L. H.; Rodríguez-Suárez, R. L.

    2015-05-11

    We report an investigation of the dynamics of the three-magnon splitting process associated with the ferromagnetic resonance (FMR) in films of the insulating ferrimagnet yttrium iron garnet (YIG). The experiments are performed with a 6 μm thick YIG film close to a microstrip line fed by a microwave generator operating in the 2–6 GHz range. The magnetization precession is driven by the microwave rf magnetic field perpendicular to the static magnetic field, and its dynamics is observed by monitoring the amplitude of the FMR absorption peak. The time evolution of the amplitude reveals that if the frequency is lowered below a critical value of 3.3 GHz, the FMR mode pumps two magnons with opposite wave vectors that react back on the FMR, resulting in a nonlinear dynamics of the magnetization. The results are explained by a model with coupled nonlinear equations describing the time evolution of the magnon modes.

  7. Groundwater hydrochemistry evolution in cyclone driven hydrological regimes, NW Australia

    NASA Astrophysics Data System (ADS)

    Skrzypek, G.; Dogramaci, S.; Grierson, P.

    2013-12-01

    lake that existed in the past, as the dynamic fractionation from brine is much different compared to that in fresh and brackish waters. Therefore, deeper brine groundwater under the Marsh developed under a different climatic regime and that the current salt in the Marsh has accumulated over at least 40,000 years but could have been as long as 700,000 years [2]. Our combined chemical and stable isotope analyses confirm the general dominance of vertical over horizontal flow in the region and decoupling of processes that control water evolution from those that control salt evolution in groundwater. [1] Dogramaci S., Skrzypek G., Dodson W., Grierson P.F., 2012, Stable isotope and hydrochemical evolution of groundwater in the semi-arid Hamersley Basin of sub-tropical northwest Australia. Journal of Hydrology 475: 281-293. [2] Skrzypek G., Dogramaci S., Grierson P.F., 2013, Geochemical and hydrological processes controlling groundwater salinity of a large inland wetland of northwest Australia. Chemical Geology (in press).

  8. Metapopulation dynamics and the evolution of dispersal

    NASA Astrophysics Data System (ADS)

    Parvinen, Kalle

    A metapopulation consists of local populations living in habitat patches. In this chapter metapopulation dynamics and the evolution of dispersal is studied in two metapopulation models defined in discrete time. In the first model there are finitely many patches, and in the other one there are infinitely many patches, which allows to incorporate catastrophes into the model. In the first model, cyclic local population dynamics can be either synchronized or not, and increasing dispersal both synchronizes and stabilizes metapopulation dynamics. On the other hand, the type of dynamics has a strong effect on the evolution of dispersal. In case of non-synchronized metapopulation dynamics, dispersal is much more beneficial than in the case of synchronized metapopulation dynamics. Local dynamics has a substantial effect also on the possibility of evolutionary branching in both models. Furthermore, with an Allee effect in the local dynamics of the second model, even evolutionary suicide can occur. It is an evolutionary process in which a viable population adapts in such a way that it can no longer persist.

  9. Feedback-Driven Dynamic Invariant Discovery

    NASA Technical Reports Server (NTRS)

    Zhang, Lingming; Yang, Guowei; Rungta, Neha S.; Person, Suzette; Khurshid, Sarfraz

    2014-01-01

    Program invariants can help software developers identify program properties that must be preserved as the software evolves, however, formulating correct invariants can be challenging. In this work, we introduce iDiscovery, a technique which leverages symbolic execution to improve the quality of dynamically discovered invariants computed by Daikon. Candidate invariants generated by Daikon are synthesized into assertions and instrumented onto the program. The instrumented code is executed symbolically to generate new test cases that are fed back to Daikon to help further re ne the set of candidate invariants. This feedback loop is executed until a x-point is reached. To mitigate the cost of symbolic execution, we present optimizations to prune the symbolic state space and to reduce the complexity of the generated path conditions. We also leverage recent advances in constraint solution reuse techniques to avoid computing results for the same constraints across iterations. Experimental results show that iDiscovery converges to a set of higher quality invariants compared to the initial set of candidate invariants in a small number of iterations.

  10. Nonadiabatic quantum state engineering driven by fast quench dynamics

    NASA Astrophysics Data System (ADS)

    Herrera, Marcela; Sarandy, Marcelo S.; Duzzioni, Eduardo I.; Serra, Roberto M.

    2014-02-01

    There are a number of tasks in quantum information science that exploit nontransitional adiabatic dynamics. Such a dynamics is bounded by the adiabatic theorem, which naturally imposes a speed limit in the evolution of quantum systems. Here, we investigate an approach for quantum state engineering exploiting a shortcut to the adiabatic evolution, which is based on rapid quenches in a continuous-time Hamiltonian evolution. In particular, this procedure is able to provide state preparation faster than the adiabatic brachistochrone. Remarkably, the evolution time in this approach is shown to be ultimately limited by its "thermodynamical cost," provided in terms of the average work rate (average power) of the quench process. We illustrate this result in a scenario that can be experimentally implemented in a nuclear magnetic resonance setup.

  11. Coupling Dynamical And Collisional Evolution Of Dust In Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Charnoz, Sebastien

    2010-10-01

    Gaseous circumstellar disks are rich in dust and are thought to be both accretionaly and dynamically active. Unfortunately large bodies that could be embedded in these disks are still difficult to observe and their putative properties are indirectly inferred from the observable small dust content. It is why constraining the size distribution coupled with dust-dynamics is so critical. Unfortunately, coupling effects such as a realistic time-dependant dynamics, fragmentation and coagulation, has been recognized as numerically challenging and almost no attempt really succeeded with a generic approach. In these disks, the dust dynamics is driven by a variety of processes (gravity, gas drag, radiation pressure..) inducing a size-dependant dynamics, and, at the same time collisional evolution changes the local size distributions. These two effects are intimately coupled because the local dynamics and size-distribution determines the local collision rates, that, in-turn, determines the size-distribution and modifies the particle's dynamics. Here we report on a new algorithm that overcomes these difficulties by using a hybrid approach extending the work of Charnoz & Morbidelli (Icarus, 2004, 2007). We will briefly present the method and focus on gaseous protoplanetary disks either laminar or turbulent (the time dependant transport and dust evolution will be shown) . We will show how the taking into account of a 3D dynamics helps to determine disantengle the dust size-distribution in the disk's photosphere and in the midplane and thus may provide observational signatures of accretion. We will show how the coupling of turbulence with fragmentation may significantly affect the dust/ratio for the smallest bodies. Finally, we will show that an accurate description of the time dependant dynamics of larger dusts (those with Stokes numbers >= 1) may provide a possible path to the formation of bodies larger than the accretion barrier, through accretion in a transitory regime.

  12. Structure, dynamics, assembly, and evolution of protein complexes.

    PubMed

    Marsh, Joseph A; Teichmann, Sarah A

    2015-01-01

    The assembly of individual proteins into functional complexes is fundamental to nearly all biological processes. In recent decades, many thousands of homomeric and heteromeric protein complex structures have been determined, greatly improving our understanding of the fundamental principles that control symmetric and asymmetric quaternary structure organization. Furthermore, our conception of protein complexes has moved beyond static representations to include dynamic aspects of quaternary structure, including conformational changes upon binding, multistep ordered assembly pathways, and structural fluctuations occurring within fully assembled complexes. Finally, major advances have been made in our understanding of protein complex evolution, both in reconstructing evolutionary histories of specific complexes and in elucidating general mechanisms that explain how quaternary structure tends to evolve. The evolution of quaternary structure occurs via changes in self-assembly state or through the gain or loss of protein subunits, and these processes can be driven by both adaptive and nonadaptive influences.

  13. Nonlinear Phase Dynamics in a Driven Bosonic Josephson Junction

    SciTech Connect

    Boukobza, Erez; Moore, Michael G.; Cohen, Doron; Vardi, Amichay

    2010-06-18

    We study the collective dynamics of a driven two-mode Bose-Hubbard model in the Josephson interaction regime. The classical phase space is mixed, with chaotic and regular components, which determine the dynamical nature of the fringe visibility. For a weak off-resonant drive, where the chaotic component is small, the many-body dynamics corresponds to that of a Kapitza pendulum, with the relative phase {phi} between the condensates playing the role of the pendulum angle. Using a master equation approach we show that the modulation of the intersite potential barrier stabilizes the {phi}={pi} 'inverted pendulum' coherent state, and protects the fringe visibility.

  14. Evolution of a Driven Quantum System Toward a Quasi-Thermal State

    NASA Astrophysics Data System (ADS)

    Fotso, Herbert; Mikelsons, Karlis; Freericks, James; Department of Physics, Georgetown Univeristy Team

    2013-05-01

    We study the relaxation of an interacting system driven out of equilibrium by a constant electric field using Non-Equilibrium Dynamical Mean Field Theory. We use on the one hand a DMFT method which solves the steady state problem directly in frequency space, and on the other hand, a DMFT method that follows the transient time evolution of the system on the Keldysh contour. The system is described by the Falicov Kimball model which we follow across the metal - insulator transition. We find that the retarded Green's function quickly approaches that of the steady state while the lesser Green's function and, as a result the distribution function, slowly approach that of a steady state with an increased temperature due to the additional energy transferred to the system by the electric field. Analyses of this type can help understand the results of some experiments involving ultracold atomic gases.

  15. Is mammalian chromosomal evolution driven by regions of genome fragility?

    PubMed Central

    Ruiz-Herrera, Aurora; Castresana, Jose; Robinson, Terence J

    2006-01-01

    Background A fundamental question in comparative genomics concerns the identification of mechanisms that underpin chromosomal change. In an attempt to shed light on the dynamics of mammalian genome evolution, we analyzed the distribution of syntenic blocks, evolutionary breakpoint regions, and evolutionary breakpoints taken from public databases available for seven eutherian species (mouse, rat, cattle, dog, pig, cat, and horse) and the chicken, and examined these for correspondence with human fragile sites and tandem repeats. Results Our results confirm previous investigations that showed the presence of chromosomal regions in the human genome that have been repeatedly used as illustrated by a high breakpoint accumulation in certain chromosomes and chromosomal bands. We show, however, that there is a striking correspondence between fragile site location, the positions of evolutionary breakpoints, and the distribution of tandem repeats throughout the human genome, which similarly reflect a non-uniform pattern of occurrence. Conclusion These observations provide further evidence that certain chromosomal regions in the human genome have been repeatedly used in the evolutionary process. As a consequence, the genome is a composite of fragile regions prone to reorganization that have been conserved in different lineages, and genomic tracts that do not exhibit the same levels of evolutionary plasticity. PMID:17156441

  16. Relaxation to equilibrium driven via indirect control in Markovian dynamics

    SciTech Connect

    Romano, Raffaele

    2007-11-15

    We prove that it is possible to modify the stationary states of a quantum dynamical semigroup, describing the irreversible evolution of a two-level system, by means of an auxiliary two-level system, a quantum probe that can be suitably prepared. The target system and the probe can be initially entangled or uncorrelated. We find that this indirect control of the stationary states is possible, even if there are no initial correlations, under suitable conditions on the dynamical parameters characterizing the evolution of the joint system.

  17. Thermochemically Driven Gas-Dynamic Fracturing (TDGF)

    SciTech Connect

    Michael Goodwin

    2008-12-31

    This report concerns efforts to increase oil well productivity and efficiency via a method of heating the oil-bearing rock of the well, a technique known as Thermochemical Gas-Dynamic Fracturing (TGDF). The technique uses either a chemical reaction or a combustion event to raise the temperature of the rock of the well, thereby increasing oil velocity, and oil pumping rate. Such technology has shown promise for future application to both older wellheads and also new sites. The need for such technologies in the oil extraction field, along with the merits of the TGDF technology is examined in Chapter 1. The theoretical basis underpinning applications of TGDF is explained in Chapter 2. It is shown that productivity of depleted well can be increased by one order of magnitude after heating a reservoir region of radius 15-20 m around the well by 100 degrees 1-2 times per year. Two variants of thermal stimulation are considered: uniform heating and optimal temperature distribution in the formation region around the perforation zone. It is demonstrated that the well productivity attained by using equal amounts of thermal energy is higher by a factor of 3 to 4 in the case of optimal temperature distribution as compared to uniform distribution. Following this theoretical basis, two practical approaches to applying TDGF are considered. Chapter 3 looks at the use of chemical intiators to raise the rock temperature in the well via an exothermic chemical reaction. The requirements for such a delivery device are discussed, and several novel fuel-oxidizing mixtures (FOM) are investigated in conditions simulating those at oil-extracting depths. Such FOM mixtures, particularly ones containing nitric acid and a chemical initiator, are shown to dramatically increase the temperature of the oil-bearing rock, and thus the productivity of the well. Such tests are substantiated by preliminary fieldwork in Russian oil fields. A second, more cost effective approach to TGDF is considered in

  18. Testing the Accuracy of Data-driven MHD Simulations of Active Region Evolution

    NASA Astrophysics Data System (ADS)

    Leake, James E.; Linton, Mark G.; Schuck, Peter W.

    2017-04-01

    Models for the evolution of the solar coronal magnetic field are vital for understanding solar activity, yet the best measurements of the magnetic field lie at the photosphere, necessitating the development of coronal models which are “data-driven” at the photosphere. We present an investigation to determine the feasibility and accuracy of such methods. Our validation framework uses a simulation of active region (AR) formation, modeling the emergence of magnetic flux from the convection zone to the corona, as a ground-truth data set, to supply both the photospheric information and to perform the validation of the data-driven method. We focus our investigation on how the accuracy of the data-driven model depends on the temporal frequency of the driving data. The Helioseismic and Magnetic Imager on NASA’s Solar Dynamics Observatory produces full-disk vector magnetic field measurements at a 12-minute cadence. Using our framework we show that ARs that emerge over 25 hr can be modeled by the data-driving method with only ∼1% error in the free magnetic energy, assuming the photospheric information is specified every 12 minutes. However, for rapidly evolving features, under-sampling of the dynamics at this cadence leads to a strobe effect, generating large electric currents and incorrect coronal morphology and energies. We derive a sampling condition for the driving cadence based on the evolution of these small-scale features, and show that higher-cadence driving can lead to acceptable errors. Future work will investigate the source of errors associated with deriving plasma variables from the photospheric magnetograms as well as other sources of errors, such as reduced resolution, instrument bias, and noise.

  19. Dynamics and morphology development in electrospun fibers driven by concentration sweeps

    NASA Astrophysics Data System (ADS)

    Dayal, Pratyush; Kyu, Thein

    2007-10-01

    The present article describes the modeling and simulation of the dynamics of the electrospinning process coupled with the spatio-temporal evolution of fiber morphology driven by concentration sweeps. The electrospinning process has been modeled based on an array of beads connected by Maxwell's elements in a cylindrical shell to describe the force balance between Coulombic and viscoelastic forces at the surface of the jet. The phase separation dynamics has been calculated in the framework of the Cahn-Hilliard time-evolution equation by incorporating Flory-Huggins free energy for liquid-liquid demixing in conjunction with solvent evaporation through the fiber surface. The simulations based on the coupling of these two processes have revealed in situ morphology development registering all structural forming processes such as polymer droplets, interconnected spinodal structure, and the porous structure along the spinline. The simulated porous fiber shows a striking resemblance to the experimental finding.

  20. Dynamics of Spinor Condensates Driven by an Inhomogeneous Magnetic Field

    NASA Astrophysics Data System (ADS)

    Zheng, Gong-Ping; Chang, Gao-Zhan; Li, Pin; Li, Ting; Wei, L. F.

    2017-06-01

    A variational wavefunction including the breather, dipole and scissor modes simultaneously is constructed to investigate the collective-excitation dynamics of spin-1 ^{87}Rb condensates driven by a space- and time-dependent magnetic field. When the Dirac point never enters the condensate, it is shown that the dipole, breather and scissor modes will be all excited driven by the sinusoidal oscillation of the Dirac point, due to the coupling of different collective modes from the inhomogeneity of the magnetic field. A resonance-driving phenomenon is observed. If the Dirac point passes through the condensate, our numerical results agree with most experimental observations (Ray et al. in Nature 505:657, 2014) and find that the center of mass of the condensate does not follow the zero point of the magnetic field. Hopefully, our method can be extended to study the similar dynamics for the other spinor condensates.

  1. Dynamics of Spinor Condensates Driven by an Inhomogeneous Magnetic Field

    NASA Astrophysics Data System (ADS)

    Zheng, Gong-Ping; Chang, Gao-Zhan; Li, Pin; Li, Ting; Wei, L. F.

    2017-10-01

    A variational wavefunction including the breather, dipole and scissor modes simultaneously is constructed to investigate the collective-excitation dynamics of spin-1 ^{87}Rb condensates driven by a space- and time-dependent magnetic field. When the Dirac point never enters the condensate, it is shown that the dipole, breather and scissor modes will be all excited driven by the sinusoidal oscillation of the Dirac point, due to the coupling of different collective modes from the inhomogeneity of the magnetic field. A resonance-driving phenomenon is observed. If the Dirac point passes through the condensate, our numerical results agree with most experimental observations (Ray et al. in Nature 505:657, 2014) and find that the center of mass of the condensate does not follow the zero point of the magnetic field. Hopefully, our method can be extended to study the similar dynamics for the other spinor condensates.

  2. THE DYNAMICAL EVOLUTION OF STELLAR BLACK HOLES IN GLOBULAR CLUSTERS

    SciTech Connect

    Morscher, Meagan; Pattabiraman, Bharath; Rodriguez, Carl; Rasio, Frederic A.; Umbreit, Stefan

    2015-02-10

    Our current understanding of the stellar initial mass function and massive star evolution suggests that young globular clusters (GCs) may have formed hundreds to thousands of stellar-mass black holes (BHs), the remnants of stars with initial masses from ∼20-100 M {sub ☉}. Birth kicks from supernova explosions may eject some BHs from their birth clusters, but most should be retained. Using a Monte Carlo method we investigate the long-term dynamical evolution of GCs containing large numbers of stellar BHs. We describe numerical results for 42 models, covering a broad range of realistic initial conditions, including up to 1.6 × 10{sup 6} stars. In almost all models we find that significant numbers of BHs (up to ∼10{sup 3}) are retained all the way to the present. This is in contrast to previous theoretical expectations that most BHs should be ejected dynamically within a few gigayears The main reason for this difference is that core collapse driven by BHs (through the Spitzer {sup m}ass segregation instability{sup )} is easily reverted through three-body processes, and involves only a small number of the most massive BHs, while lower-mass BHs remain well-mixed with ordinary stars far from the central cusp. Thus the rapid segregation of stellar BHs does not lead to a long-term physical separation of most BHs into a dynamically decoupled inner core, as often assumed previously. Combined with the recent detections of several BH X-ray binary candidates in Galactic GCs, our results suggest that stellar BHs could still be present in large numbers in many GCs today, and that they may play a significant role in shaping the long-term dynamical evolution and the present-day dynamical structure of many clusters.

  3. Interface dynamics of capillary driven flow in a tube

    NASA Astrophysics Data System (ADS)

    Ichikawa, Naoki; Satoda, Yoko; Nakada, Takeshi

    This paper describes the dynamics of a liquid driven by capillary force in a tube. The movement of a gas-liquid interface in a horizontal tube as a result of capillary action has been investigated. A theoretical analysis of the interface dynamics is presented where dimensionless numbers representing time and distance scales are introduced, and a unique functional relation is derived. Experiments were carried out with distilled water as the test liquid in glass tubes of inner diameter from 0.5 mm to 4.0 mm. The position of the gas-liquid interface as a function of time was observed. The experimental results agree well with theory.

  4. Nonlinear dynamics of turbulence driven magnetic islands. II. Numerical simulations

    NASA Astrophysics Data System (ADS)

    Agullo, O.; Muraglia, M.; Benkadda, S.; Poyé, A.; Dubuit, N.; Garbet, X.; Sen, A.

    2017-04-01

    The nonlinear dynamics of a turbulence driven magnetic island (TDMI) is investigated numerically in a reduced magnetohydrodynamic fluid model. The significance of identifying a characteristic signature of a TDMI for its experimental observation is discussed. The principal focus of our simulations is on the nature of the pressure profile flattening inside a TDMI, and we show that, in agreement with analytical predictions, a partial flattening occurs when the island size exceeds a critical value that is a function of the small scale interchange dynamics. We also present a model and test it numerically, which links explicitly the interchange turbulence and the island pressure flattening.

  5. Elastically driven intermittent microscopic dynamics in soft solids

    NASA Astrophysics Data System (ADS)

    Bouzid, Mehdi; Colombo, Jader; Barbosa, Lucas Vieira; Del Gado, Emanuela

    2017-06-01

    Soft solids with tunable mechanical response are at the core of new material technologies, but a crucial limit for applications is their progressive aging over time, which dramatically affects their functionalities. The generally accepted paradigm is that such aging is gradual and its origin is in slower than exponential microscopic dynamics, akin to the ones in supercooled liquids or glasses. Nevertheless, time- and space-resolved measurements have provided contrasting evidence: dynamics faster than exponential, intermittency and abrupt structural changes. Here we use 3D computer simulations of a microscopic model to reveal that the timescales governing stress relaxation, respectively, through thermal fluctuations and elastic recovery are key for the aging dynamics. When thermal fluctuations are too weak, stress heterogeneities frozen-in upon solidification can still partially relax through elastically driven fluctuations. Such fluctuations are intermittent, because of strong correlations that persist over the timescale of experiments or simulations, leading to faster than exponential dynamics.

  6. Evolution and Adaptation in Pseudomonas aeruginosa Biofilms Driven by Mismatch Repair System-Deficient Mutators

    PubMed Central

    Yang, Liang; Molin, Søren; Oliver, Antonio; Smania, Andrea M.

    2011-01-01

    Pseudomonas aeruginosa is an important opportunistic pathogen causing chronic airway infections, especially in cystic fibrosis (CF) patients. The majority of the CF patients acquire P. aeruginosa during early childhood, and most of them develop chronic infections resulting in severe lung disease, which are rarely eradicated despite intensive antibiotic therapy. Current knowledge indicates that three major adaptive strategies, biofilm development, phenotypic diversification, and mutator phenotypes [driven by a defective mismatch repair system (MRS)], play important roles in P. aeruginosa chronic infections, but the relationship between these strategies is still poorly understood. We have used the flow-cell biofilm model system to investigate the impact of the mutS associated mutator phenotype on development, dynamics, diversification and adaptation of P. aeruginosa biofilms. Through competition experiments we demonstrate for the first time that P. aeruginosa MRS-deficient mutators had enhanced adaptability over wild-type strains when grown in structured biofilms but not as planktonic cells. This advantage was associated with enhanced micro-colony development and increased rates of phenotypic diversification, evidenced by biofilm architecture features and by a wider range and proportion of morphotypic colony variants, respectively. Additionally, morphotypic variants generated in mutator biofilms showed increased competitiveness, providing further evidence for mutator-driven adaptive evolution in the biofilm mode of growth. This work helps to understand the basis for the specific high proportion and role of mutators in chronic infections, where P. aeruginosa develops in biofilm communities. PMID:22114708

  7. THE MORPHOLOGY AND DYNAMICS OF JET-DRIVEN SUPERNOVA REMNANTS: THE CASE OF W49B

    SciTech Connect

    González-Casanova, Diego F.; De Colle, Fabio; Ramirez-Ruiz, Enrico; Lopez, Laura A.

    2014-02-01

    The circumstellar medium (CSM) of a massive star is modified by its winds before a supernova (SN) explosion occurs, and thus the evolution of the resulting supernova remnant (SNR) is influenced by both the geometry of the explosion as well as the complex structure of the CSM. Motivated by recent work suggesting the SNR W49B was a jet-driven SN expanding in a complex CSM, we explore how the dynamics and the metal distributions in a jet-driven explosion are modified by the interaction with the surrounding environment. In particular, we perform hydrodynamical calculations to study the dynamics and explosive nucleosynthesis of a jet-driven SN triggered by the collapse of a 25 M {sub ☉} Wolf-Rayet star and its subsequent interaction with the CSM up to several hundred years following the explosion. We find that although the CSM has small-scale effects on the structure of the SNR, the overall morphology and abundance patterns are reflective of the initial asymmetry of the SN explosion. Thus, we predict that jet-driven SNRs, such as W49B, should be identifiable based on morphology and abundance patterns at ages up to several hundred years, even if they expand into a complex CSM environment.

  8. Intermittent Turbulence and SOC Dynamics in a 2-D Driven Current-Sheet Model

    NASA Technical Reports Server (NTRS)

    Klimas, A. J.; Uritsky, V.; Vinas, A. F.; Vassiliasdis, D.; Baker, D. N.

    2005-01-01

    Borovsky et al. have shown that Earth's magnetotail plasma sheet is strongly turbulent. More recently, Borovsky and Funsten have shown that eddy turbulence dominates and have suggested that the eddy turbulence is driven by fast flows that act as jets in the plasma. Through basic considerations of energy and magnetic flux conservation, these fast flows are thought to be localized to small portions of the total plasma sheet and to be generated by magnetic flux reconnection that is similarly localized. Angelopoulos et al., using single spacecraft Geotail data, have shown that the plasma sheet turbulence exhibits signs of intermittence and Weygand et al., using four spacecraft Cluster data, have confirmed and expanded on this conclusion. Uritsky et al., using Polar UVI image data, have shown that the evolution of bright, nightside, UV auroral emission regions is consistent with many of the properties of systems in self-organized criticality (SOC). Klimas et al. have suggested that the auroral dynamics is a reflection of the dynamics of the fast flows in the plasma. sheet. Their hypothesis is that the transport of magnetic fludenergy through the magnetotail is enabled by scale-free avalanches of localized reconnection whose SOC dynamics are reflected in the auroral UV emission dynamics. A corollary of this hypothesis is that the strong, intermittent, eddy turbulence of the plasma sheet is closely related to its critical dynamics. The question then arises: Can in situ evidence for the SOC dynamics be found in the properties of the plasma sheet turbulence? A 2-dimensional numerical driven current-sheet model of the central plasma sheet has been developed that incorporates an idealized current-driven instability with a resistive MHD system. It has been shown that the model can evolve into SOC in a physically relevant parameter regime. Initial results from a study of intermittent turbulence in this model and the relationship of this turbulence to the model's known SOC

  9. A data driven nonlinear stochastic model for blood glucose dynamics.

    PubMed

    Zhang, Yan; Holt, Tim A; Khovanova, Natalia

    2016-03-01

    The development of adequate mathematical models for blood glucose dynamics may improve early diagnosis and control of diabetes mellitus (DM). We have developed a stochastic nonlinear second order differential equation to describe the response of blood glucose concentration to food intake using continuous glucose monitoring (CGM) data. A variational Bayesian learning scheme was applied to define the number and values of the system's parameters by iterative optimisation of free energy. The model has the minimal order and number of parameters to successfully describe blood glucose dynamics in people with and without DM. The model accounts for the nonlinearity and stochasticity of the underlying glucose-insulin dynamic process. Being data-driven, it takes full advantage of available CGM data and, at the same time, reflects the intrinsic characteristics of the glucose-insulin system without detailed knowledge of the physiological mechanisms. We have shown that the dynamics of some postprandial blood glucose excursions can be described by a reduced (linear) model, previously seen in the literature. A comprehensive analysis demonstrates that deterministic system parameters belong to different ranges for diabetes and controls. Implications for clinical practice are discussed. This is the first study introducing a continuous data-driven nonlinear stochastic model capable of describing both DM and non-DM profiles.

  10. Geometric phase of a qubit driven by a phase noise laser under non-Markovian dynamics

    NASA Astrophysics Data System (ADS)

    Berrada, K.

    2014-01-01

    Robustness of the geometric phase (GP) with respect to the environmental effects is a basic condition for an effective quantum computation. Here, we study quantitatively the GP of a two-level atom system driven by a phase noise laser under non-Markovian dynamics in terms of different parameters involved in the whole system. We find that with the change of the damping coupling, the GP is very sensitive to its properties exhibiting long collapse and revival phenomena, which play a significant role in enhancing the stabilization and control of the system dynamics. Moreover, we show that the GP can be considered as a tool for testing and characterizing the nature of the qubit-environment coupling. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement dynamics between the qubit with its environment under external classical noise is evaluated and investigated during the time evolution.

  11. Dynamic Phase Transitions in Driven Cyclic Kinetic Networks

    NASA Astrophysics Data System (ADS)

    Gingrich, Todd; Vaikuntanathan, Suriyanarayanan; Geissler, Phillip

    2014-03-01

    Many physical processes can be modeled by Markovian rate processes. When detailed balance is broken, as is generically the case in biological processes, the dynamics exhibits nonvanishing fluxes around cycles and produces entropy. We demonstrate that a particular class of kinetic networks, those with a nearly periodic, pseudo-one-dimensional cyclical character, yield a nontrivial statistics of the large deviations in the observed fluxes. This behavior can be understood analytically in the limit of large networks, where we demonstrate the existence of a dynamic phase transition. The observation suggests that interesting, and potentially useful, large dynamical fluctuations are common even in rate processes with a single degree of freedom. As the analysis holds for networks driven out of equilibrium, potential application to biologically relevant networks is especially intriguing.

  12. The price of anarchy in mobility-driven contagion dynamics

    PubMed Central

    Nicolaides, Christos; Cueto-Felgueroso, Luis; Juanes, Ruben

    2013-01-01

    Public policy and individual incentives determine the patterns of human mobility through transportation networks. In the event of a health emergency, the pursuit of maximum social or individual utility may lead to conflicting objectives in the routing strategies of network users. Individuals tend to avoid exposure so as to minimize the risk of contagion, whereas policymakers aim at coordinated behaviour that maximizes the social welfare. Here, we study agent-driven contagion dynamics through transportation networks, coupled to the adoption of either selfish- or policy-driven rerouting strategies. In analogy with the concept of price of anarchy in transportation networks subject to congestion, we show that maximizing individual utility leads to a loss of welfare for the social group, measured here by the total population infected after an epidemic outbreak. PMID:23904588

  13. Fluctuation loops in noise-driven linear dynamical systems

    NASA Astrophysics Data System (ADS)

    Ghanta, Akhil; Neu, John C.; Teitsworth, Stephen

    2017-03-01

    Understanding the spatiotemporal structure of most probable fluctuation pathways to rarely occurring states is a central problem in the study of noise-driven, nonequilibrium dynamical systems. When the underlying system does not possess detailed balance, the optimal fluctuation pathway to a particular state and relaxation pathway from that state may combine to form a looplike structure in the system phase space called a fluctuation loop. Here, fluctuation loops are studied in a linear circuit model consisting of coupled R C elements, where each element is driven by its own independent noise source. Using a stochastic Hamiltonian approach, we determine the optimal fluctuation pathways, and analytically construct corresponding fluctuation loops. To quantitatively characterize fluctuation loops, we study the time-dependent area tensor that is swept out by individual stochastic trajectories in the system phase space. At long times, the area tensor scales linearly with time, with a coefficient that precisely vanishes when the system satisfies detailed balance.

  14. Pressure evolution in shallow magma chambers upon buoyancy-driven replenishment

    NASA Astrophysics Data System (ADS)

    Papale, P.; Montagna, C. P.; Longo, A.

    2017-03-01

    The invasion of active magma chambers by primitive magma of deeper provenance is a frequent occurrence in volcanic systems, and it is commonly associated with pressurization. Chamber replenishment is driven by pressure and buoyancy forces that cause magma ascent towards shallow depths. We examine the end-member case of pure buoyancy-driven (natural) convection in crustal reservoirs deriving from the presence of degassed, dense magma at shallow level, that can originate a gravitational instability. Space-time-dependent numerical simulations of magma dynamics in composite underground systems reveal highly nonlinear pressure evolution dominated by decompression at shallow depths. This counterintuitive result originates from the compressible nature of multiphase magmas and their complex convection and mixing dynamics. Shallow magma chamber decompression on replenishment is favored by large volatile contents of the uprising magma, resulting in large density contrasts among the resident and the incoming components. These results show that the intuitive concept of magma chamber pressurization upon replenishment may not always hold in real situations dominated by buoyancy, and provide new perspectives for the interpretation of geophysical records at active volcanoes.Plain Language SummaryA common process at active volcanoes worldwide is the arrival of magma from depth of tens of kilometers into shallower (depths of some km) reservoirs ("magma chambers"), containing themselves magma that can be different in terms of gas content and composition. We present numerical simulations that describe this process, with particular reference to the Campi Flegrei volcano in Italy. Our results show that, depending on the specific conditions and the gas contents of the two magma types, this process can lead to a decrease in pressure of the shallow chamber. When interpreting ground deformation signals, very often magma rise toward shallow depths</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IAUS..316..246D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IAUS..316..246D"><span>Early <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of young substructured clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorval, Julien; Boily, Christian</p> <p>2017-03-01</p> <p>Stellar clusters form with a high level of substructure, inherited from the molecular cloud and the star formation process. Evidence from observations and simulations also indicate the stars in such young clusters form a subvirial system. The subsequent <span class="hlt">dynamical</span> <span class="hlt">evolution</span> can cause important mass loss, ejecting a large part of the birth population in the field. It can also imprint the stellar population and still be inferred from observations of evolved clusters. Nbody simulations allow a better understanding of these early twists and turns, given realistic initial conditions. Nowadays, substructured, clumpy young clusters are usually obtained through pseudo-fractal growth and velocity inheritance. We introduce a new way to create clumpy initial conditions through a ''Hubble expansion'' which naturally produces self consistent clumps, velocity-wise. In depth analysis of the resulting clumps shows consistency with hydrodynamical simulations of young star clusters. We use these initial conditions to investigate the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of young subvirial clusters. We find the collapse to be soft, with hierarchical merging leading to a high level of mass segregation. The subsequent <span class="hlt">evolution</span> is less pronounced than the equilibrium achieved from a cold collapse formation scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015HiA....16..318P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015HiA....16..318P"><span>Overview of <span class="hlt">dynamical</span> mechanisms of secular <span class="hlt">evolution</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pfenniger, Daniel</p> <p>2015-03-01</p> <p>Gravity-bound isolated systems, from stars, planetary systems, star clusters to galaxies, share common properties where <span class="hlt">evolution</span> is the rule. Typically if they start forming at a well defined epoch they tend to change significantly over a timescale comparable to their present age. So <span class="hlt">evolution</span> is never truly stopped, it just proceeds slower and slower: after a rapid, violent phase a slower, secular phase follows. In galactic astronomy for many decades the paradigm was rather that after a short violent time galaxies would settle in a stable steady state just consuming gas into stars. Actually today it appears that the progressive appearance of galaxy systematic morphologies and the slowing pace of mergers indicate that common intrinsic <span class="hlt">dynamical</span> factors continue to shape galaxies towards similar properties irrespective of their largely different formation histories and initial conditions. Newtonian physics supplemented by a weakly dissipative component provides an amazing amount of explanations for the galaxy properties, like exponential stellar disks, spirals, bars, and peanut-shaped bulges. The purpose of this talk is to review these mechanisms of <span class="hlt">dynamical</span> secular <span class="hlt">evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.2540S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.2540S"><span>Upper-Mantle Flow <span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Topography in Eastern Anatolia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sengul Uluocak, Ebru; Pysklywec, Russell; Eken, Tuna; Hakan Gogus, Oguz</p> <p>2016-04-01</p> <p>Eastern Anatolia is characterized by 2 km plateau uplift -in the last 10 Myrs-, high surface heat flow distribution, shallow Curie-point depth, anomalous gravity field. Seismological observations indicate relatively high Pn and Sn attenuation and significant low seismic velocity anomalies in the region. Moreover, the surface geology is associated predominantly with volcanic rocks in which melt production through mantle upwelling (following lithospheric delamination) has been suggested. It has been long known that the topographic loading in the region cannot be supported by crustal thickness (~45 km) based on the principle of Airy isostasy. Recent global geodynamic studies carried out for evaluating the post-collisional processes imply that there is an explicit <span class="hlt">dynamic</span> uplift in Eastern Anatolia and its adjacent regions. In this study we investigate the instantaneous <span class="hlt">dynamic</span> topography <span class="hlt">driven</span> by 3-D upper-mantle flow in Eastern Anatolia. For this purpose we conducted numerous thermo-mechanical models using a 2-D Arbitrary Lagrangian Eulerian (ALE) finite element method. The available P-wave tomography data extracted along 10 profiles were used to obtain depth-dependent density anomalies in the region. We present resulting <span class="hlt">dynamic</span> topography maps and estimated 3D mantle flow velocity vectors along these 2-D cross sections for each profile. The residual topography based on crustal thickness and observed topography was calculated and compared with other independent datasets concerning geological deformation and <span class="hlt">dynamic</span> topography predictions. The results indicate an upper mantle <span class="hlt">driven</span> <span class="hlt">dynamic</span> uplift correlated with the under-compensated characteristic in Eastern Anatolia. We discuss our results combined with 3D mantle flow by considering seismic anisotropy studies in the region. Initial results indicate that high <span class="hlt">dynamic</span> uplift and the localized low Pn velocities in concurrence with Pn anisotropy structures show nearly spatial coherence in Eastern Anatolia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......196L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......196L"><span>Field-<span class="hlt">driven</span> magnetization <span class="hlt">dynamics</span> of nanoparticles and nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Jie</p> <p></p> <p>This thesis is about micromagnetism in confined magnetic microstructures. The field-<span class="hlt">driven</span> magnetization <span class="hlt">dynamics</span> of nanoparticles and nanowires is systematically discussed following a clear thread of thought: from "macrospin" to "microspin". At the same time, four topics are raised and investigated. First, inspired by the traditional ferromagnetic resonance technique, two strategies for measuring the Gilbert damping coefficient using the magnetic circular dichroism effect are presented and discussed. The investigation is performed within a framework of the linear response of the macrospin in 2-D magnetic films to external time-dependent fields. The object of the study then turns to Stoner particles, which are single-domain magnetic nanoparticles, that are quasi 0-D systems and still assumed to be macrospins. The field-<span class="hlt">driven</span> magnetization reversal in multi-axial Stoner particles is investigated and the corresponding Eular equations are presented. The Eular equations provide a unified framework for research of this kind. After that, the macrospin assumption itself is examined. The study of when and how it fails results in the famous "nucleation problem" in micromagnetism, thus the discussion then moves into the microspin category. The nucleation problem of single-domain cuboid permalloy nanowires, which are quasi 1-D systems, is investigated and a magnetization reversal mode named "domain formation and domain wall propagation" is revealed. Field-<span class="hlt">driven</span> magnetic domain wall propagation is an excellent example of microspin behavior, and has been a hot issue in recent spintronic research. The effects of transverse magnetic anisotropies on field-<span class="hlt">driven</span> transverse wall propagation in narrow magnetic nanowires are systematically investigated. These results should not only deepen the understanding of the domain wall <span class="hlt">dynamics</span> in magnetic nanowires, but also offer inspiration for further developments of ultrafast nano-devices with higher integration levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24f2510Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24f2510Z"><span>Influence of helical external <span class="hlt">driven</span> current on nonlinear resistive tearing mode <span class="hlt">evolution</span> and saturation in tokamaks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, W.; Wang, S.; Ma, Z. W.</p> <p>2017-06-01</p> <p>The influences of helical <span class="hlt">driven</span> currents on nonlinear resistive tearing mode <span class="hlt">evolution</span> and saturation are studied by using a three-dimensional toroidal resistive magnetohydrodynamic code (CLT). We carried out three types of helical <span class="hlt">driven</span> currents: stationary, time-dependent amplitude, and thickness. It is found that the helical <span class="hlt">driven</span> current is much more efficient than the Gaussian <span class="hlt">driven</span> current used in our previous study [S. Wang et al., Phys. Plasmas 23(5), 052503 (2016)]. The stationary helical <span class="hlt">driven</span> current cannot persistently control tearing mode instabilities. For the time-dependent helical <span class="hlt">driven</span> current with f c d = 0.01 and δ c d < 0.04 , the island size can be reduced to its saturated level that is about one third of the initial island size. However, if the total <span class="hlt">driven</span> current increases to about 7% of the total plasma current, tearing mode instabilities will rebound again due to the excitation of the triple tearing mode. For the helical <span class="hlt">driven</span> current with time dependent strength and thickness, the reduction speed of the radial perturbation component of the magnetic field increases with an increase in the <span class="hlt">driven</span> current and then saturates at a quite low level. The tearing mode is always controlled even for a large <span class="hlt">driven</span> current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPJM9003C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPJM9003C"><span>Plasma <span class="hlt">dynamics</span> and heating/acceleration during <span class="hlt">driven</span> magnetic reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, C. Z.; Inoue, Shizuo; Ono, Yasushi; Horiuchi, Ritoku</p> <p>2015-11-01</p> <p>Highlights of the plasma <span class="hlt">dynamics</span> and energization during <span class="hlt">driven</span> anti-parallel magnetic reconnection are presented. The MHD condition breaks down in the entire reconnection layer (the reconnection current layer, the separatrix region and the whole downstream), and the plasma <span class="hlt">dynamics</span> is significantly different from the results of the Hall-MHD model. In particular, we explain (1) how electron and ion <span class="hlt">dynamics</span> decouple and how the charge separation and electrostatic electric field are produced in the magnetic field reversal region (reconnection current layer and outflow exhaust) and around the separatrix regions, (2) how electrons and ions gain energy in the reconnection current layer, (3) why the electron outflow velocity in the reconnection exhaust reaches super-Alfvenic speed and the ion outflow velocity reaches Alfvenic speed and how the parallel electric field is produced, (4) how electrons are accelerated by the parallel electric field around the separatrix region, and (5) how ions gain energy when they move across the separatrix region into the downstream. Finally we show that electrons and ions gain energy mainly from the inductive reconnection <span class="hlt">driven</span> electric field and less from the electrostatic electric field.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4657918','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4657918"><span>Fluctuation-<span class="hlt">Driven</span> Neural <span class="hlt">Dynamics</span> Reproduce Drosophila Locomotor Patterns</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cruchet, Steeve; Gustafson, Kyle; Benton, Richard; Floreano, Dario</p> <p>2015-01-01</p> <p>The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-<span class="hlt">driven</span> neural network modeling and <span class="hlt">dynamical</span> systems analysis. We generated fluctuation-<span class="hlt">driven</span> network models whose outputs—locomotor bouts—matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. <span class="hlt">Dynamical</span> models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural <span class="hlt">dynamics</span>, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior. PMID:26600381</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25564763','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25564763"><span>Stochastic modeling indicates that aging and somatic <span class="hlt">evolution</span> in the hematopoetic system are <span class="hlt">driven</span> by non-cell-autonomous processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rozhok, Andrii I; Salstrom, Jennifer L; DeGregori, James</p> <p>2014-12-01</p> <p>Age-dependent tissue decline and increased cancer incidence are widely accepted to be rate-limited by the accumulation of somatic mutations over time. Current models of carcinogenesis are dominated by the assumption that oncogenic mutations have defined advantageous fitness effects on recipient stem and progenitor cells, promoting and rate-limiting somatic <span class="hlt">evolution</span>. However, this assumption is markedly discrepant with evolutionary theory, whereby fitness is a <span class="hlt">dynamic</span> property of a phenotype imposed upon and widely modulated by environment. We computationally modeled <span class="hlt">dynamic</span> microenvironment-dependent fitness alterations in hematopoietic stem cells (HSC) within the Sprengel-Liebig system known to govern <span class="hlt">evolution</span> at the population level. Our model for the first time integrates real data on age-dependent <span class="hlt">dynamics</span> of HSC division rates, pool size, and accumulation of genetic changes and demonstrates that somatic <span class="hlt">evolution</span> is not rate-limited by the occurrence of mutations, but instead results from aged microenvironment-<span class="hlt">driven</span> alterations in the selective/fitness value of previously accumulated genetic changes. Our results are also consistent with evolutionary models of aging and thus oppose both somatic mutation-centric paradigms of carcinogenesis and tissue functional decline. In total, we demonstrate that aging directly promotes HSC fitness decline and somatic <span class="hlt">evolution</span> via non-cell-autonomous mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21790566','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21790566"><span>Adaptive chromosomal divergence <span class="hlt">driven</span> by mixed geographic mode of <span class="hlt">evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feder, Jeffrey L; Gejji, Richard; Powell, Thomas H Q; Nosil, Patrik</p> <p>2011-08-01</p> <p>Chromosomal inversions are ubiquitous in nature and of great significance for understanding adaptation and speciation. Inversions were the first markers used to investigate the genetic structure of natural populations, leading to the concept of coadapted gene complexes and theories concerning founder effects and genetic drift in small populations. However, we still lack elements of a general theory accounting for the origins and distribution of inversions in nature. Here, we use computer simulations to show that a "mixed geographic mode" of <span class="hlt">evolution</span> involving allopatric separation of populations followed by secondary contact and gene flow generates chromosomal divergence by natural selection under wider conditions than previous hypotheses. This occurs because inversions arising in allopatry contain a full complement of locally adapted genes. Once gene flow ensues, reduced recombination within inversions keeps these favorable genotypic combinations intact, resulting in inverted genomic regions being favored over collinear regions. This process allows inversions to establish to high frequencies. Our model can account for several classic patterns in the geographic distribution of inversions and highlights how selection on standing genetic variation allows rapid chromosomal <span class="hlt">evolution</span> without the waiting time for new mutations. As inversion differences often separate closely related taxa, mixed modes of divergence could be common. © 2011 The Author(s). <span class="hlt">Evolution</span>© 2011 The Society for the Study of <span class="hlt">Evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2251265D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2251265D"><span>Early <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of substructured stellar clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorval, Julien; Boily, Christian</p> <p>2015-08-01</p> <p>It is now widely accepted that stellar clusters form with a high level of substructure (Kuhn et al. 2014, Bate 2009), inherited from the molecular cloud and the star formation process. Evidence from observations and simulations also indicate the stars in such young clusters form a subvirial system (Kirk et al. 2007, Maschberger et al. 2010). The subsequent <span class="hlt">dynamical</span> <span class="hlt">evolution</span> can cause important mass loss, ejecting a large part of the birth population in the field. It can also imprint the stellar population and still be inferred from observations of evolved clusters. Nbody simulations allow a better understanding of these early twists and turns, given realistic initial conditions. Nowadays, substructured, clumpy young clusters are usually obtained through pseudo-fractal growth (Goodwin et al. 2004) and velocity inheritance. Such models are visually realistics and are very useful, they are however somewhat artificial in their velocity distribution. I introduce a new way to create clumpy initial conditions through a "Hubble expansion" which naturally produces self consistent clumps, velocity-wise. A velocity distribution analysis shows the new method produces realistic models, consistent with the <span class="hlt">dynamical</span> state of the newly created cores in hydrodynamic simulation of cluster formation (Klessen & Burkert 2000). I use these initial conditions to investigate the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of young subvirial clusters, up to 80000 stars. I find an overall soft <span class="hlt">evolution</span>, with hierarchical merging leading to a high level of mass segregation. I investigate the influence of the mass function on the fate of the cluster, specifically on the amount of mass loss induced by the early violent relaxation. Using a new binary detection algorithm, I also find a strong processing of the native binary population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/120914','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/120914"><span>Nonlinear <span class="hlt">dynamics</span> of a <span class="hlt">driven</span> mode near marginal stability</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berk, H.L.; Breizman, B.N.; Pekker, M.</p> <p>1995-09-01</p> <p>The nonlinear <span class="hlt">dynamics</span> of a linearly unstable mode in a <span class="hlt">driven</span> kinetic system is investigated to determine scaling of the saturated fields near the instability threshold. To leading order, this problem reduces to solving an integral equation with a temporally nonlocal cubic term. This equation can exhibit a self-similar solution that blows up in a finite time. When the blow-up occurs, higher nonlinearities become important and the mode saturates due to plateau formation arising from particle trapping in the wave. Otherwise, the simplified equation gives a regular solution that leads to a different saturation scaling reflecting the closeness to the instability threshold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990PhyD...46..317B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990PhyD...46..317B"><span>On the classical <span class="hlt">dynamics</span> of strongly <span class="hlt">driven</span> anharmonic oscillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Breuer, H. P.; Dietz, K.; Holthaus, M.</p> <p>1990-12-01</p> <p>We investigate the <span class="hlt">dynamics</span> of periodically <span class="hlt">driven</span> anharmonic oscillators. In particular, we consider values of the coupling strength which are orders of magnitude higher than those required for the overlap of primary resonances. We observe a division of phase space into a regular and a stochastic region. Both regions are separated by a sharp chaos border which sets an upper limit to the stochastic heating of particles; its dependence on the coupling strength is studied. We construct perpetual adiabatic invariants governing regular motion. A bifurcation mechanism leading to the annihilation of resonances is explained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJMPD..2630017M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJMPD..2630017M"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of globular clusters: Recent developments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merafina, Marco</p> <p></p> <p>We analyze structural parameters of the globular clusters belonging to the Milky Way system which were listed in the latest edition of the Harris Catalogue. We search for observational evidences of the effect of tidal forces induced by the Galaxy on the <span class="hlt">dynamical</span> and thermodynamical <span class="hlt">evolution</span> of a globular cluster. The behavior for the W0 distribution exhibited by the globular cluster population seems to be in contrast with theoretical results in literature about gravothermal instability, and suggest a new limit value smaller than the previous one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20646382','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20646382"><span>Pulse-<span class="hlt">driven</span> near-resonant quantum adiabatic <span class="hlt">dynamics</span>: Lifting of quasidegeneracy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yatsenko, L.P.; Guerin, S.; Jauslin, H.R.</p> <p>2004-10-01</p> <p>We study the quantum <span class="hlt">dynamics</span> of a two-level system <span class="hlt">driven</span> by a pulse that starts near-resonant for small amplitudes, yielding nonadiabatic <span class="hlt">evolution</span>, and induces an adiabatic <span class="hlt">evolution</span> for larger amplitudes. This problem is analyzed in terms of lifting of degeneracy for rising amplitudes. It is solved exactly for the case of linear and exponential rising. Approximate solutions are given in the case of power-law rising. This allows us to determine approximative formulas for the line shape of resonant excitation by various forms of pulses such as truncated trigonometric pulses. We also analyze and explain the various superpositions of states that can be obtained by the half Stark chirped rapid adiabatic passage process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..93a3820Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..93a3820Y"><span><span class="hlt">Dynamic</span> steady state of periodically <span class="hlt">driven</span> quantum systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yudin, V. I.; Taichenachev, A. V.; Basalaev, M. Yu.</p> <p>2016-01-01</p> <p>Using the density matrix formalism, we prove the existence of the periodic steady state for an arbitrary periodically <span class="hlt">driven</span> system described by linear <span class="hlt">dynamic</span> equations. This state has the same period as the modulated external influence, and it is realized as an asymptotic solution (t →+∞ ) due to relaxation processes. The presented derivation simultaneously contains a simple and effective computational algorithm (without using either the Floquet or Fourier formalisms), which automatically guarantees a full account of all frequency components. As a particular example, for three-level Λ system we calculate the line shape and field-induced shift of the dark resonance formed by the field with a periodically modulated phase. Also we have analytically solved a basic theoretical problem of the direct frequency comb spectroscopy, when the two-level system is <span class="hlt">driven</span> by the periodic sequence of rectangular pulses. In this case, the radical dependence of the spectroscopy line shape on pulse area is found. Moreover, the existence of quasiforbidden spectroscopic zones, in which the Ramsey fringes are significantly reduced, is predicted. Our results have a wide area of applications in laser physics, spectroscopy, atomic clocks, and magnetometry. Also they can be useful for any area of quantum physics where periodically <span class="hlt">driven</span> systems are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050223594','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050223594"><span>Collisional and <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Planetary Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weidenschilling, Stuart J.</p> <p>2004-01-01</p> <p>Senior Scientst S. J. Weidenschilling presents his final administrative report in the research program entitled "Collisional and <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Planetary Systems," on which he was the Principal Investigator. This research program produced the following publications: 1) "Jumping Jupiters" in binary star systems. F. Marzari, S. J. Weidenschilling, M. Barbieri and V. Granata. Astrophys. J., in press, 2005; 2) Formation of the cores of the outer planets. To appear in "The Outer Planets" (R. Kallenbach, ED), ISSI Conference Proceedings (Space Sci. Rev.), in press, 2005; 3) Accretion <span class="hlt">dynamics</span> and timescales: Relation to chondrites. S. J. Weidenschilling and J. Cuzzi. In Meteorites and the Early Solar System LI (D. Lauretta et al., Eds.), Univ. of Arizona Press, 2005; 4) Asteroidal heating and thermal stratification of the asteroid belt. A. Ghosh, S. J.Weidenschilling, H. Y. McSween, Jr. and A. Rubin. In Meteorites and the Early Solar System I1 (D. Lauretta et al., Eds.), Univ. of Arizona Press, 2005.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27063737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27063737"><span>A <span class="hlt">dynamic</span>, climate-<span class="hlt">driven</span> model of Rift Valley fever.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leedale, Joseph; Jones, Anne E; Caminade, Cyril; Morse, Andrew P</p> <p>2016-03-31</p> <p>Outbreaks of Rift Valley fever (RVF) in eastern Africa have previously occurred following specific rainfall <span class="hlt">dynamics</span> and flooding events that appear to support the emergence of large numbers of mosquito vectors. As such, transmission of the virus is considered to be sensitive to environmental conditions and therefore changes in climate can impact the spatiotemporal <span class="hlt">dynamics</span> of epizootic vulnerability. Epidemiological information describing the methods and parameters of RVF transmission and its dependence on climatic factors are used to develop a new spatio-temporal mathematical model that simulates these <span class="hlt">dynamics</span> and can predict the impact of changes in climate. The Liverpool RVF (LRVF) model is a new <span class="hlt">dynamic</span>, process-based model <span class="hlt">driven</span> by climate data that provides a predictive output of geographical changes in RVF outbreak susceptibility as a result of the climate and local livestock immunity. This description of the multi-disciplinary process of model development is accessible to mathematicians, epidemiological modellers and climate scientists, uniting <span class="hlt">dynamic</span> mathematical modelling, empirical parameterisation and state-of-the-art climate information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016sofi.prop...52A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016sofi.prop...52A"><span>Testing the Physics and Chemistry of Radiation <span class="hlt">Driven</span> Cloud <span class="hlt">Evolution</span> - [C II] Mapping of IC 59 and IC 63</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andersson, B.-G.</p> <p></p> <p>The interaction of newly formed stars with their natal clouds give rise to a number of <span class="hlt">dynamical</span> and chemical effects, forming H II regions, injecting energy in the surrounding ISM and, potentially giving ride to triggered star formation. When an expanding H II region encounters density enhancements, Bright Rimmed Clouds (BRC) are formed, containing photo-dissociation regions (PDR). These provide valuable laboratories of radiation <span class="hlt">driven</span> <span class="hlt">dynamics</span> both for cloud <span class="hlt">dynamics</span> and the physical and chemical <span class="hlt">evolution</span> of the gas and dust. We propose to map the near-by pair of BRCs IC59 and IC 63, in the [C II] line, a well-known PDR tracer, with the upGREAT LFA array. These observations will complement a significant amount of existing data tracing the molecular gas and dust in the clouds. The parallel CO (J=11-10) data from the L1 channel will provide important information about the dense warm molecular gas to be compared e.g. to existing low-J CO transitions. Although at similar distance from the illuminating star gamma Cas, the two nebulae show dramatic differences in their structure. Because of their relative vicinity ( 190pc), the clouds provide a unique environment to acquire high spatial resolution observation of BRC and PDRs. Because of the high spectral resolution of upGREAT, our observations will provide detailed information about gas flows and turbulent motions, providing important constraints and test for models of radiation <span class="hlt">driven</span> cloud <span class="hlt">evolution</span> and the chemistry and physics of PDRs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21454965','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21454965"><span>THE MERGER-<span class="hlt">DRIVEN</span> <span class="hlt">EVOLUTION</span> OF MASSIVE GALAXIES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Robaina, Aday R.; Van der Wel, Arjen; Skelton, Rosalind E.; Meisenheimer, Klaus; Bell, Eric F.; Somerville, Rachel S.; McIntosh, Daniel H.; Wolf, Christian</p> <p>2010-08-10</p> <p>We explore the rate and impact of galaxy mergers on the massive galaxy population using the amplitude of the two-point correlation function on small scales for M {sub *} > 5 x 10{sup 10} M {sub sun} galaxies from the COSMOS and COMBO-17 surveys. Using a pair fraction derived from the Sloan Digital Sky Survey as a low-redshift benchmark, the large survey area at intermediate redshifts allows us to determine the <span class="hlt">evolution</span> of the close-pair fraction with unprecedented accuracy for a mass-selected sample: we find that the fraction of galaxies more massive than 5 x 10{sup 10} M {sub sun} in pairs separated by less than 30 kpc in three-dimensional space evolves as F(z) = (0.0130 {+-} 0.0019) x (1 + z){sup 1.21{+-}0.25} between z = 0 and z = 1.2. Assuming a merger timescale of 0.5 Gyr, the inferred merger rate is such that galaxies with mass in excess of 10{sup 11} M {sub sun} have undergone, on average, 0.5 (0.7) mergers involving progenitor galaxies both more massive than 5 x 10{sup 10} M {sub sun} since z = 0.6 (1.2). We also study the number density <span class="hlt">evolution</span> of massive red sequence galaxies using published luminosity functions and constraints on the M/L {sub B} <span class="hlt">evolution</span> from the fundamental plane. Moreover, we demonstrate that the measured merger rate of massive galaxies is sufficient to explain this observed number density <span class="hlt">evolution</span> in massive red sequence galaxies since z = 1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJB...88...95M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJB...88...95M"><span>An opinion-<span class="hlt">driven</span> behavioral <span class="hlt">dynamics</span> model for addictive behaviors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, Thomas W.; Finley, Patrick D.; Apelberg, Benjamin J.; Ambrose, Bridget K.; Brodsky, Nancy S.; Brown, Theresa J.; Husten, Corinne; Glass, Robert J.</p> <p>2015-04-01</p> <p>We present a model of behavioral <span class="hlt">dynamics</span> that combines a social network-based opinion <span class="hlt">dynamics</span> model with behavioral mapping. The behavioral component is discrete and history-dependent to represent situations in which an individual's behavior is initially <span class="hlt">driven</span> by opinion and later constrained by physiological or psychological conditions that serve to maintain the behavior. Individuals are modeled as nodes in a social network connected by directed edges. Parameter sweeps illustrate model behavior and the effects of individual parameters and parameter interactions on model results. Mapping a continuous opinion variable into a discrete behavioral space induces clustering on directed networks. Clusters provide targets of opportunity for influencing the network state; however, the smaller the network the greater the stochasticity and potential variability in outcomes. This has implications both for behaviors that are influenced by close relationships verses those influenced by societal norms and for the effectiveness of strategies for influencing those behaviors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1140312','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1140312"><span>An opinion-<span class="hlt">driven</span> behavioral <span class="hlt">dynamics</span> model for addictive behaviors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Moore, Thomas W.; Finley, Patrick D.; Apelberg, Benjamin J.; Ambrose, Bridget K.; Brodsky, Nancy S.; Brown, Theresa J.; Husten, Corinne; Glass, Robert J.</p> <p>2015-04-08</p> <p>We present a model of behavioral <span class="hlt">dynamics</span> that combines a social network-based opinion <span class="hlt">dynamics</span> model with behavioral mapping. The behavioral component is discrete and history-dependent to represent situations in which an individual’s behavior is initially <span class="hlt">driven</span> by opinion and later constrained by physiological or psychological conditions that serve to maintain the behavior. Additionally, individuals are modeled as nodes in a social network connected by directed edges. Parameter sweeps illustrate model behavior and the effects of individual parameters and parameter interactions on model results. Mapping a continuous opinion variable into a discrete behavioral space induces clustering on directed networks. Clusters provide targets of opportunity for influencing the network state; however, the smaller the network the greater the stochasticity and potential variability in outcomes. Furthermore, this has implications both for behaviors that are influenced by close relationships verses those influenced by societal norms and for the effectiveness of strategies for influencing those behaviors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27300844','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27300844"><span>Probabilistic density function method for nonlinear <span class="hlt">dynamical</span> systems <span class="hlt">driven</span> by colored noise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barajas-Solano, David A; Tartakovsky, Alexandre M</p> <p>2016-05-01</p> <p>We present a probability density function (PDF) method for a system of nonlinear stochastic ordinary differential equations <span class="hlt">driven</span> by colored noise. The method provides an integrodifferential equation for the temporal <span class="hlt">evolution</span> of the joint PDF of the system's state, which we close by means of a modified large-eddy-diffusivity (LED) closure. In contrast to the classical LED closure, the proposed closure accounts for advective transport of the PDF in the approximate temporal deconvolution of the integrodifferential equation. In addition, we introduce the generalized local linearization approximation for deriving a computable PDF equation in the form of a second-order partial differential equation. We demonstrate that the proposed closure and localization accurately describe the <span class="hlt">dynamics</span> of the PDF in phase space for systems <span class="hlt">driven</span> by noise with arbitrary autocorrelation time. We apply the proposed PDF method to analyze a set of Kramers equations <span class="hlt">driven</span> by exponentially autocorrelated Gaussian colored noise to study nonlinear oscillators and the <span class="hlt">dynamics</span> and stability of a power grid. Numerical experiments show the PDF method is accurate when the noise autocorrelation time is either much shorter or longer than the system's relaxation time, while the accuracy decreases as the ratio of the two timescales approaches unity. Similarly, the PDF method accuracy decreases with increasing standard deviation of the noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvE..93e2121B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvE..93e2121B"><span>Probabilistic density function method for nonlinear <span class="hlt">dynamical</span> systems <span class="hlt">driven</span> by colored noise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barajas-Solano, David A.; Tartakovsky, Alexandre M.</p> <p>2016-05-01</p> <p>We present a probability density function (PDF) method for a system of nonlinear stochastic ordinary differential equations <span class="hlt">driven</span> by colored noise. The method provides an integrodifferential equation for the temporal <span class="hlt">evolution</span> of the joint PDF of the system's state, which we close by means of a modified large-eddy-diffusivity (LED) closure. In contrast to the classical LED closure, the proposed closure accounts for advective transport of the PDF in the approximate temporal deconvolution of the integrodifferential equation. In addition, we introduce the generalized local linearization approximation for deriving a computable PDF equation in the form of a second-order partial differential equation. We demonstrate that the proposed closure and localization accurately describe the <span class="hlt">dynamics</span> of the PDF in phase space for systems <span class="hlt">driven</span> by noise with arbitrary autocorrelation time. We apply the proposed PDF method to analyze a set of Kramers equations <span class="hlt">driven</span> by exponentially autocorrelated Gaussian colored noise to study nonlinear oscillators and the <span class="hlt">dynamics</span> and stability of a power grid. Numerical experiments show the PDF method is accurate when the noise autocorrelation time is either much shorter or longer than the system's relaxation time, while the accuracy decreases as the ratio of the two timescales approaches unity. Similarly, the PDF method accuracy decreases with increasing standard deviation of the noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatGe...9..140C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatGe...9..140C"><span>Rapid biological speciation <span class="hlt">driven</span> by tectonic <span class="hlt">evolution</span> in New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Craw, Dave; Upton, Phaedra; Burridge, Christopher P.; Wallis, Graham P.; Waters, Jonathan M.</p> <p>2016-02-01</p> <p>Collisions between tectonic plates lead to the rise of new mountain ranges that can separate biological populations and ultimately result in new species. However, the identification of links between tectonic mountain-building and biological speciation is confounded by environmental and ecological factors. Thus, there are surprisingly few well-documented examples of direct tectonic controls on terrestrial biological speciation. Here we present examples from New Zealand, where the rapid <span class="hlt">evolution</span> of 18 species of freshwater fishes has resulted from parallel tectonic landscape <span class="hlt">evolution</span>. We use numerical models to reconstruct changes in the deep crustal structure and surface drainage catchments of the southern island of New Zealand over the past 25 million years. We show that the island and mountain topography evolved in six principal tectonic zones, which have distinct drainage catchments that separated fish populations. We use new and existing phylogenetic analyses of freshwater fish populations, based on over 1,000 specimens from more than 400 localities, to show that fish genomes can retain evidence of this tectonic landscape development, with a clear correlation between geologic age and extent of DNA sequence divergence. We conclude that landscape <span class="hlt">evolution</span> has controlled on-going biological diversification over the past 25 million years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..445...48L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..445...48L"><span><span class="hlt">Evolution</span> of cooperation <span class="hlt">driven</span> by social-welfare-based migration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yan; Ye, Hang; Zhang, Hong</p> <p>2016-03-01</p> <p>Individuals' migration behavior may play a significant role in the <span class="hlt">evolution</span> of cooperation. In reality, individuals' migration behavior may depend on their perceptions of social welfare. To study the relationship between social-welfare-based migration and the <span class="hlt">evolution</span> of cooperation, we consider an evolutionary prisoner's dilemma game (PDG) in which an individual's migration depends on social welfare but not on the individual's own payoff. By introducing three important social welfare functions (SWFs) that are commonly studied in social science, we find that social-welfare-based migration can promote cooperation under a wide range of parameter values. In addition, these three SWFs have different effects on cooperation, especially through the different spatial patterns formed by migration. Because the relative efficiency of the three SWFs will change if the parameter values are changed, we cannot determine which SWF is optimal for supporting cooperation. We also show that memory capacity, which is needed to evaluate individual welfare, may affect cooperation levels in opposite directions under different SWFs. Our work should be helpful for understanding the <span class="hlt">evolution</span> of human cooperation and bridging the chasm between studies of social preferences and studies of social cooperation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998PhDT.......194R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998PhDT.......194R"><span>Nonequilibrium <span class="hlt">dynamic</span> phases in <span class="hlt">driven</span> vortex lattices with periodic pinning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reichhardt, Charles Michael</p> <p>1998-12-01</p> <p>We present the results of an extensive series of simulations of flux-gradient and current <span class="hlt">driven</span> vortices interacting with either random or periodically arranged pinning sites. First, we consider flux-gradient-<span class="hlt">driven</span> simulations of superconducting vortices interacting with strong randomly-distributed columnar pinning defects, as an external field H(t) is quasi-statically swept from zero through a matching field Bsb{phi}. Here, we find significant changes in the behavior of the local flux density B(x, y, H(t)), magnetization M(H(t)), critical current Jsb{c}(B(t)), and the individual vortex flow paths, as the local flux density crosses Bsb{phi}. Further, we find that for a given pin density, Jsb{c}(B) can be enhanced by maximizing the distance between the pins for B < Bsb{phi}. For the case of periodic pinning sites as a function of applied field, we find a rich variety of ordered and partially-ordered vortex lattice configurations. We present formulas that predict the matching fields at which commensurate vortex configurations occur and the vortex lattice orientation with respect to the pinning lattice. Our results are in excellent agreement with recent imaging experiments on square pinning arrays (K. Harada et al., Science 274, 1167 (1996)). For current <span class="hlt">driven</span> simulations with periodic pinning we find a remarkable number of <span class="hlt">dynamical</span> plastic flow phases. Signatures of the transitions between these different <span class="hlt">dynamical</span> phases include sudden jumps in the current-voltage curves, hysteresis, as well as marked changes in the vortex trajectories and vortex lattice order. These phases are outlined in a series of <span class="hlt">dynamic</span> phase diagrams. We show that several of these phases and their phase-boundaries can be understood in terms of analytical arguments. Finally, when the vortex lattice is <span class="hlt">driven</span> at varying angles with respect to the underlying periodic pinning array, the transverse voltage-current V(I) curves show a series of mode-locked plateaus with the overall V(I) forming</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...628904S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...628904S"><span><span class="hlt">Dynamics</span> of dental <span class="hlt">evolution</span> in ornithopod dinosaurs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strickson, Edward; Prieto-Márquez, Albert; Benton, Michael J.; Stubbs, Thomas L.</p> <p>2016-07-01</p> <p>Ornithopods were key herbivorous dinosaurs in Mesozoic terrestrial ecosystems, with a variety of tooth morphologies. Several clades, especially the ‘duck-billed’ hadrosaurids, became hugely diverse and abundant almost worldwide. Yet their evolutionary <span class="hlt">dynamics</span> have been disputed, particularly whether they diversified in response to events in plant <span class="hlt">evolution</span>. Here we focus on their remarkable dietary adaptations, using tooth and jaw characters to examine changes in dental disparity and evolutionary rate. Ornithopods explored different areas of dental morphospace throughout their <span class="hlt">evolution</span>, showing a long-term expansion. There were four major evolutionary rate increases, the first among basal iguanodontians in the Middle-Late Jurassic, and the three others among the Hadrosauridae, above and below the split of their two major clades, in the middle of the Late Cretaceous. These evolutionary bursts do not correspond to times of plant diversification, including the radiation of the flowering plants, and suggest that dental innovation rather than coevolution with major plant clades was a major driver in ornithopod <span class="hlt">evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3909918','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3909918"><span>Integrating influenza antigenic <span class="hlt">dynamics</span> with molecular <span class="hlt">evolution</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bedford, Trevor; Suchard, Marc A; Lemey, Philippe; Dudas, Gytis; Gregory, Victoria; Hay, Alan J; McCauley, John W; Russell, Colin A; Smith, Derek J; Rambaut, Andrew</p> <p>2014-01-01</p> <p>Influenza viruses undergo continual antigenic <span class="hlt">evolution</span> allowing mutant viruses to evade host immunity acquired to previous virus strains. Antigenic phenotype is often assessed through pairwise measurement of cross-reactivity between influenza strains using the hemagglutination inhibition (HI) assay. Here, we extend previous approaches to antigenic cartography, and simultaneously characterize antigenic and genetic <span class="hlt">evolution</span> by modeling the diffusion of antigenic phenotype over a shared virus phylogeny. Using HI data from influenza lineages A/H3N2, A/H1N1, B/Victoria and B/Yamagata, we determine patterns of antigenic drift across viral lineages, showing that A/H3N2 evolves faster and in a more punctuated fashion than other influenza lineages. We also show that year-to-year antigenic drift appears to drive incidence patterns within each influenza lineage. This work makes possible substantial future advances in investigating the <span class="hlt">dynamics</span> of influenza and other antigenically-variable pathogens by providing a model that intimately combines molecular and antigenic <span class="hlt">evolution</span>. DOI: http://dx.doi.org/10.7554/eLife.01914.001 PMID:24497547</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4944125','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4944125"><span><span class="hlt">Dynamics</span> of dental <span class="hlt">evolution</span> in ornithopod dinosaurs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Strickson, Edward; Prieto-Márquez, Albert; Benton, Michael J.; Stubbs, Thomas L.</p> <p>2016-01-01</p> <p>Ornithopods were key herbivorous dinosaurs in Mesozoic terrestrial ecosystems, with a variety of tooth morphologies. Several clades, especially the ‘duck-billed’ hadrosaurids, became hugely diverse and abundant almost worldwide. Yet their evolutionary <span class="hlt">dynamics</span> have been disputed, particularly whether they diversified in response to events in plant <span class="hlt">evolution</span>. Here we focus on their remarkable dietary adaptations, using tooth and jaw characters to examine changes in dental disparity and evolutionary rate. Ornithopods explored different areas of dental morphospace throughout their <span class="hlt">evolution</span>, showing a long-term expansion. There were four major evolutionary rate increases, the first among basal iguanodontians in the Middle-Late Jurassic, and the three others among the Hadrosauridae, above and below the split of their two major clades, in the middle of the Late Cretaceous. These evolutionary bursts do not correspond to times of plant diversification, including the radiation of the flowering plants, and suggest that dental innovation rather than coevolution with major plant clades was a major driver in ornithopod <span class="hlt">evolution</span>. PMID:27412496</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5371421','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5371421"><span><span class="hlt">Dynamic</span> microbiome <span class="hlt">evolution</span> in social bees</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kwong, Waldan K.; Medina, Luis A.; Koch, Hauke; Sing, Kong-Wah; Soh, Eunice Jia Yu; Ascher, John S.; Jaffé, Rodolfo; Moran, Nancy A.</p> <p>2017-01-01</p> <p>The highly social (eusocial) corbiculate bees, comprising the honey bees, bumble bees, and stingless bees, are ubiquitous insect pollinators that fulfill critical roles in ecosystem services and human agriculture. Here, we conduct wide sampling across the phylogeny of these corbiculate bees and reveal a <span class="hlt">dynamic</span> evolutionary history behind their microbiota, marked by multiple gains and losses of gut associates, the presence of generalist as well as host-specific strains, and patterns of diversification <span class="hlt">driven</span>, in part, by host ecology (for example, colony size). Across four continents, we found that different host species have distinct gut communities, largely independent of geography or sympatry. Nonetheless, their microbiota has a shared heritage: The emergence of the eusocial corbiculate bees from solitary ancestors appears to coincide with the acquisition of five core gut bacterial lineages, supporting the hypothesis that host sociality facilitates the development and maintenance of specialized microbiomes. PMID:28435856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28435856','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28435856"><span><span class="hlt">Dynamic</span> microbiome <span class="hlt">evolution</span> in social bees.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwong, Waldan K; Medina, Luis A; Koch, Hauke; Sing, Kong-Wah; Soh, Eunice Jia Yu; Ascher, John S; Jaffé, Rodolfo; Moran, Nancy A</p> <p>2017-03-01</p> <p>The highly social (eusocial) corbiculate bees, comprising the honey bees, bumble bees, and stingless bees, are ubiquitous insect pollinators that fulfill critical roles in ecosystem services and human agriculture. Here, we conduct wide sampling across the phylogeny of these corbiculate bees and reveal a <span class="hlt">dynamic</span> evolutionary history behind their microbiota, marked by multiple gains and losses of gut associates, the presence of generalist as well as host-specific strains, and patterns of diversification <span class="hlt">driven</span>, in part, by host ecology (for example, colony size). Across four continents, we found that different host species have distinct gut communities, largely independent of geography or sympatry. Nonetheless, their microbiota has a shared heritage: The emergence of the eusocial corbiculate bees from solitary ancestors appears to coincide with the acquisition of five core gut bacterial lineages, supporting the hypothesis that host sociality facilitates the development and maintenance of specialized microbiomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21028271','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21028271"><span>Numerical simulation of nonlinear <span class="hlt">dynamical</span> systems <span class="hlt">driven</span> by commutative noise</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Carbonell, F. Biscay, R.J.; Jimenez, J.C.; Cruz, H. de la</p> <p>2007-10-01</p> <p>The local linearization (LL) approach has become an effective technique for the numerical integration of ordinary, random and stochastic differential equations. One of the reasons for this success is that the LL method achieves a convenient trade-off between numerical stability and computational cost. Besides, the LL method reproduces well the <span class="hlt">dynamics</span> of nonlinear equations for which other classical methods fail. However, in the stochastic case, most of the reported works has been focused in Stochastic Differential Equations (SDE) <span class="hlt">driven</span> by additive noise. This limits the applicability of the LL method since there is a number of interesting <span class="hlt">dynamics</span> observed in equations with multiplicative noise. On the other hand, recent results show that commutative noise SDEs can be transformed into a random differential equation (RDE) by means of a random diffeomorfism (conjugacy). This paper takes advantages of such conjugacy property and the LL approach for defining a LL scheme for SDEs <span class="hlt">driven</span> by commutative noise. The performance of the proposed method is illustrated by means of numerical simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.459..171S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.459..171S"><span>The <span class="hlt">dynamics</span> of radiation-<span class="hlt">driven</span>, optically thick winds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, Rong-Feng; Nakar, Ehud; Piran, Tsvi</p> <p>2016-06-01</p> <p>Recent observation of some luminous transient sources with low colour temperatures suggests that the emission is dominated by optically thick winds <span class="hlt">driven</span> by super-Eddington accretion. We present a general analytical theory of the <span class="hlt">dynamics</span> of radiation pressure-<span class="hlt">driven</span>, optically thick winds. Unlike the classical adiabatic stellar wind solution whose <span class="hlt">dynamics</span> are solely determined by the sonic radius, here the loss of the radiation pressure due to photon diffusion also plays an important role. We identify two high mass-loss rate regimes (dot{M} > L_Edd/c^2). In the large total luminosity regime, the solution resembles an adiabatic wind solution. Both the radiative luminosity, L, and the kinetic luminosity, Lk, are super-Eddington with L < Lk and L ∝ L_k^{1/3}. In the lower total luminosity regime, most of the energy is carried out by the radiation with Lk < L ≈ LEdd. In a third, low mass-loss regime (dot{M} < L_Edd/c^2), the wind becomes optically thin early on and, unless gas pressure is important at this stage, the solution is very different from the adiabatic one. The results are independent from the energy generation mechanism at the foot of the wind; therefore, they are applicable to a wide range of mass ejection systems, from black hole accretion, to planetary nebulae, and to classical novae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18791073','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18791073"><span>Prevolutionary <span class="hlt">dynamics</span> and the origin of <span class="hlt">evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nowak, Martin A; Ohtsuki, Hisashi</p> <p>2008-09-30</p> <p>Life is that which replicates and evolves. The origin of life is also the origin of <span class="hlt">evolution</span>. A fundamental question is when do chemical kinetics become evolutionary <span class="hlt">dynamics</span>? Here, we formulate a general mathematical theory for the origin of <span class="hlt">evolution</span>. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active monomers that form random polymers. Prelife is a generative system that can produce information. Prevolutionary <span class="hlt">dynamics</span> have selection and mutation, but no replication. Life marches in with the ability of replication: Polymers act as templates for their own reproduction. Prelife is a scaffold that builds life. Yet, there is competition between life and prelife. There is a phase transition: If the effective replication rate exceeds a critical value, then life outcompetes prelife. Replication is not a prerequisite for selection, but instead, there can be selection for replication. Mutation leads to an error threshold between life and prelife.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567469','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2567469"><span>Prevolutionary <span class="hlt">dynamics</span> and the origin of <span class="hlt">evolution</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nowak, Martin A.; Ohtsuki, Hisashi</p> <p>2008-01-01</p> <p>Life is that which replicates and evolves. The origin of life is also the origin of <span class="hlt">evolution</span>. A fundamental question is when do chemical kinetics become evolutionary <span class="hlt">dynamics</span>? Here, we formulate a general mathematical theory for the origin of <span class="hlt">evolution</span>. All known life on earth is based on biological polymers, which act as information carriers and catalysts. Therefore, any theory for the origin of life must address the emergence of such a system. We describe prelife as an alphabet of active monomers that form random polymers. Prelife is a generative system that can produce information. Prevolutionary <span class="hlt">dynamics</span> have selection and mutation, but no replication. Life marches in with the ability of replication: Polymers act as templates for their own reproduction. Prelife is a scaffold that builds life. Yet, there is competition between life and prelife. There is a phase transition: If the effective replication rate exceeds a critical value, then life outcompetes prelife. Replication is not a prerequisite for selection, but instead, there can be selection for replication. Mutation leads to an error threshold between life and prelife. PMID:18791073</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6563E..0DP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6563E..0DP"><span>Cognitive algorithms: <span class="hlt">dynamic</span> logic, working of the mind, <span class="hlt">evolution</span> of consciousness and cultures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perlovsky, Leonid I.</p> <p>2007-04-01</p> <p>The paper discusses <span class="hlt">evolution</span> of consciousness <span class="hlt">driven</span> by the knowledge instinct, a fundamental mechanism of the mind which determines its higher cognitive functions. <span class="hlt">Dynamic</span> logic mathematically describes the knowledge instinct. It overcomes past mathematical difficulties encountered in modeling intelligence and relates it to mechanisms of concepts, emotions, instincts, consciousness and unconscious. The two main aspects of the knowledge instinct are differentiation and synthesis. Differentiation is <span class="hlt">driven</span> by <span class="hlt">dynamic</span> logic and proceeds from vague and unconscious states to more crisp and conscious states, from less knowledge to more knowledge at each hierarchical level of the mind. Synthesis is <span class="hlt">driven</span> by <span class="hlt">dynamic</span> logic operating in a hierarchical organization of the mind; it strives to achieve unity and meaning of knowledge: every concept finds its deeper and more general meaning at a higher level. These mechanisms are in complex relationship of symbiosis and opposition, which leads to complex <span class="hlt">dynamics</span> of <span class="hlt">evolution</span> of consciousness and cultures. Modeling this <span class="hlt">dynamics</span> in a population leads to predictions for the <span class="hlt">evolution</span> of consciousness, and cultures. Cultural predictive models can be compared to experimental data and used for improvement of human conditions. We discuss existing evidence and future research directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhyD..191..156H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhyD..191..156H"><span>Davydov soliton <span class="hlt">evolution</span> in temperature gradients <span class="hlt">driven</span> by hyperbolic waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herrera, J.; Maza, M. A.; Minzoni, A. A.; Smyth, Noel F.; Worthy, Annette L.</p> <p>2004-04-01</p> <p>In the present work the <span class="hlt">evolution</span> of a Davydov soliton in an inhomogeneous medium will be considered. The Zakharov system of equations, which describes this soliton, consists of a perturbed non-linear Schrödinger (NLS) type equation plus a forced wave equation. This system is not exactly integrable for a homogeneous medium and its Lagrangian is non-local. It has recently been shown that this type of soliton has a long enough lifetime, even for non-zero temperature, so as to be a possible mechanism for the transfer of energy along an α helix. In the present work, the effect of temperature inhomogeneities on the behaviour of this soliton will be studied. As the soliton propagates through such an inhomogeneity, both dispersive and non-dispersive waves are generated. The stability of the soliton to this radiation is studied. The <span class="hlt">evolution</span> of the Davydov soliton solution of the Zakharov equations in an inhomogeneous medium will be studied using an approximate method based on averaged conservation laws, which results in ordinary differential equations for the pulse parameters. It is shown that the inclusion of the effect of the dispersive radiation shed by the soliton for the NLS equation and the non-dispersive (hyperbolic) radiation shed by the soliton for the forced wave equation is vital for an accurate description of the <span class="hlt">evolution</span> of the Davydov soliton. It is found that the soliton is stable even in the presence of hyperbolic radiation and that the temperature gradients have significant effects on the propagation of the soliton, even to the extent of reversing its motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...831..122R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...831..122R"><span>Protoplanetary Disk Heating and <span class="hlt">Evolution</span> <span class="hlt">Driven</span> by Spiral Density Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rafikov, Roman R.</p> <p>2016-11-01</p> <p>Scattered light imaging of protoplanetary disks often reveals prominent spiral arms, likely excited by massive planets or stellar companions. Assuming that these arms are density waves, evolving into spiral shocks, we assess their effect on the thermodynamics, accretion, and global <span class="hlt">evolution</span> of the disk. We derive analytical expressions for the direct (irreversible) heating, angular momentum transport, and mass accretion rate induced by disk shocks of arbitrary amplitude. These processes are very sensitive to the shock strength. We show that waves of moderate strength (density jump at the shock ΔΣ/Σ ∼ 1) result in negligible disk heating (contributing at the ∼1% level to the energy budget) in passive, irradiated protoplanetary disks on ∼100 au scales, but become important within several au. However, shock heating is a significant (or even dominant) energy source in disks of cataclysmic variables, stellar X-ray binaries, and supermassive black hole binaries, heated mainly by viscous dissipation. Mass accretion induced by the spiral shocks is comparable to (or exceeds) the mass inflow due to viscous stresses. Protoplanetary disks featuring prominent global spirals must be evolving rapidly, in ≲0.5 Myr at ∼100 au. A direct upper limit on the <span class="hlt">evolution</span> timescale can be established by measuring the gravitational torque due to the spiral arms from the imaging data. We find that, regardless of their origin, global spiral waves must be important agents of the protoplanetary disk <span class="hlt">evolution</span>. They may serve as an effective mechanism of disk dispersal and could be related to the phenomenon of transitional disks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA189342','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA189342"><span>Stochastic <span class="hlt">Evolution</span> Equations <span class="hlt">Driven</span> by Nuclear Space Valued Martingales.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1987-09-01</p> <p>11TILEI- d cutic eolufctin equations dIriven by nucle ar space valued mart in ial s 12. PER50NAL AUTHOR(S) Kallianpiir, G. and Perez-Ahreu, V. 13a. TYPE...space D where the driving force is a ’-valued martingale. We do this in Section 2 where we obtain an "<span class="hlt">evolution</span>" or "mild solution" in the form of a...2 nuclear space) such that the restriction A(t) of A(t) on D is a continuous linear operator on (. Thus one is led to the question of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8436E..0NC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8436E..0NC"><span>Data-<span class="hlt">driven</span> approach to <span class="hlt">dynamic</span> visual attention modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Culibrk, Dubravko; Sladojevic, Srdjan; Riche, Nicolas; Mancas, Matei; Crnojevic, Vladimir</p> <p>2012-06-01</p> <p>Visual attention deployment mechanisms allow the Human Visual System to cope with an overwhelming amount of visual data by dedicating most of the processing power to objects of interest. The ability to automatically detect areas of the visual scene that will be attended to by humans is of interest for a large number of applications, from video coding, video quality assessment to scene understanding. Due to this fact, visual saliency (bottom-up attention) models have generated significant scientific interest in recent years. Most recent work in this area deals with <span class="hlt">dynamic</span> models of attention that deal with moving stimuli (videos) instead of traditionally used still images. Visual saliency models are usually evaluated against ground-truth eye-tracking data collected from human subjects. However, there are precious few recently published approaches that try to learn saliency from eyetracking data and, to the best of our knowledge, no approaches that try to do so when <span class="hlt">dynamic</span> saliency is concerned. The paper attempts to fill this gap and describes an approach to data-<span class="hlt">driven</span> <span class="hlt">dynamic</span> saliency model learning. A framework is proposed that enables the use of eye-tracking data to train an arbitrary machine learning algorithm, using arbitrary features derived from the scene. We evaluate the methodology using features from a state-of-the art <span class="hlt">dynamic</span> saliency model and show how simple machine learning algorithms can be trained to distinguish between visually salient and non-salient parts of the scene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4660942','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4660942"><span>Nonconservative current-<span class="hlt">driven</span> <span class="hlt">dynamics</span>: beyond the nanoscale</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Todorov, Tchavdar N; Dundas, Daniel</p> <p>2015-01-01</p> <p>Summary Long metallic nanowires combine crucial factors for nonconservative current-<span class="hlt">driven</span> atomic motion. These systems have degenerate vibrational frequencies, clustered about a Kohn anomaly in the dispersion relation, that can couple under current to form nonequilibrium modes of motion growing exponentially in time. Such motion is made possible by nonconservative current-induced forces on atoms, and we refer to it generically as the waterwheel effect. Here the connection between the waterwheel effect and the stimulated directional emission of phonons propagating along the electron flow is discussed in an intuitive manner. Nonadiabatic molecular <span class="hlt">dynamics</span> show that waterwheel modes self-regulate by reducing the current and by populating modes in nearby frequency, leading to a <span class="hlt">dynamical</span> steady state in which nonconservative forces are counter-balanced by the electronic friction. The waterwheel effect can be described by an appropriate effective nonequilibrium <span class="hlt">dynamical</span> response matrix. We show that the current-induced parts of this matrix in metallic systems are long-ranged, especially at low bias. This nonlocality is essential for the characterisation of nonconservative atomic <span class="hlt">dynamics</span> under current beyond the nanoscale. PMID:26665086</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.2534S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.2534S"><span>Upper- Mantle <span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Uplift in Central Anatolia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sengul Uluocak, Ebru; Pysklywec, Russell; Hakan Gogus, Oguz</p> <p>2016-04-01</p> <p>Based on geological and geophysical observations and interpretations of the present-day geodynamics, we propose that mantle structures beneath the crust drive a non-isostatic component of topography in Central Anatolia. Topography residuals for the region were calculated from the isostatic component of topography according to the principle of Airy isostasy while assuming crustal block is in hydrostatic equilibrium in the mantle. For the geodynamic interpretations we ran numerous 2D thermo-mechanical models based on different temperature inputs and viscous creep strength coefficients and using available P-wave tomography data along a N-S directional profile (33oE) through Central Anatolia as an estimate on the regional mantle structure. Our models are uniformly affected by widespread NE-SW oriented mantle flow obtained in the shear-wave azimuthal anisotropy studies and predict <span class="hlt">dynamic</span> topography based on vertical components of density-<span class="hlt">driven</span> flow in the upper mantle mainly induced by 2D temperature variations. The <span class="hlt">dynamic</span> topography results indicate ~1 km instantaneous uplift in concordance with the under-compensated topography in the region. The data and modelling results define the region as a plateau-like uplift, slightly inflated in southern part based on <span class="hlt">dynamic</span> topography patterns. The <span class="hlt">dynamic</span> topography induced by upper-mantle flow provides robust new information about the main geodynamic components by showing broad consistency with independent data sets and observables for the area; such as, asthenospheric source of volcanism, gravity data, and high surface heat flow distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvX...4a1012P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvX...4a1012P"><span><span class="hlt">Driven</span> Nonlinear <span class="hlt">Dynamics</span> of Two Coupled Exchange-Only Qubits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pal, Arijeet; Rashba, Emmanuel I.; Halperin, Bertrand I.</p> <p>2014-01-01</p> <p>Inspired by the creation of a fast exchange-only qubit [Medford et al., Phys. Rev. Lett. 111, 050501 (2013)], we develop a theory describing the nonlinear <span class="hlt">dynamics</span> of two such qubits that are capacitively coupled, when one of them is <span class="hlt">driven</span> resonantly at a frequency equal to its level splitting. We include conditions of strong driving, where the Rabi frequency is a significant fraction of the level splitting, and we consider situations where the splitting for the second qubit may be the same as or different than the first. We demonstrate that coupling between qubits can be detected by reading the response of the second qubit, even when the coupling between them is only of about 1% of their level splittings, and we calculate entanglement between qubits. Patterns of nonlinear <span class="hlt">dynamics</span> of coupled qubits and their entanglement are strongly dependent on the geometry of the system, and the specific mechanism of interqubit coupling deeply influences <span class="hlt">dynamics</span> of both qubits. In particular, we describe the development of irregular <span class="hlt">dynamics</span> in a two-qubit system, explore approaches for inhibiting it, and demonstrate the existence of an optimal range of coupling strength maintaining stability during the operational time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001DPS....33.3107S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001DPS....33.3107S"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of comet nucleus rotation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scheeres, D. J.; Sidorenko, V. V.; Neishtadt, A. I.; Vasiliev, A. A.</p> <p>2001-11-01</p> <p>The rotational <span class="hlt">dynamics</span> of outgassing cometary nuclei are investigated analytically using <span class="hlt">dynamical</span> systems theory. We develop a general theory for the averaged <span class="hlt">evolution</span> of a comet nucleus rotation state assuming that the nucleus is a spheroid (either prolate or oblate) and that the outgassing torques are a function of solar insolation and heliocentric distance. The resulting solutions are a function of the comet outgassing properties, its heliocentric orbit, and the assumed distribution of active regions on its surface. We find that the long-term <span class="hlt">evolution</span> of the comet nucleus rotation is a strong function of the distribution of active regions over its surface. Specifically, we find that a comet nucleus with a uniformly active surface will tend towards a rotation state with a nutation angle of ~ 55 degrees and an angular momentum perpendicular to the sun-perihelion direction. Conversely, a comet nucleus with an isolated active region will tend towards a zero nutation angle with its symmetry axis and angular momentum aligned parallel to the sun-perihelion direction. For active surface regions between these extremes we find 4 qualitatively different <span class="hlt">dynamical</span> outcomes. In all cases, the theory predicts that the comet nucleus angular momentum will have a secular increase, a phenomenon that could contribute to nucleus splitting of active comets. These results can be used to discriminate between competing theories of comet outgassing based on a nucelus' rotation state. They also allow for a range of plausible a priori constraints to be placed on a comet's rotation state to aid in the interpretation of its outgassing structure. This work was supported by the NASA JURRISS program under Grant NAG5-8715. AIN, AAV and VVS acknowledge support from Russian Foundation for Basic research via Grants 00-01-00538 and 00-01-0174 respectively. DJS acknowledges support from the PG&G program via Grant NAG5-9017.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010004104','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010004104"><span>The <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of A Tubular Leonid Persistent Train</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jenniskens, Peter; Nugent, David; Plane, John M. C.; DeVincenzi, Donald L. (Technical Monitor)</p> <p>2000-01-01</p> <p>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the persistent train of a bright Leonid meteor was examined for evidence of the source of the luminosity and the physical conditions in the meteor path. The train consisted of two parallel somewhat diffuse luminous tracks, interpreted as the walls of a tube. A general lack of wind shear along the trail allowed these structures to remain intact for nearly 200 s, from which it was possible to determine that the tubular structure expanded at a near constant 10.5 m/s, independent of altitude between 86 and 97 km. An initial fast decrease of train intensity below 90 km was followed by an increase in intensity and then a gradual decrease at longer times, whereas at high attitudes the integrated intensity was nearly constant with time. These results are compared to a model that describes the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the train by diffusion, following an initial rapid expansion of the hot gaseous trail behind the meteoroid. The train luminosity is produced by O ((sup 1)S) emission at 557 nm, <span class="hlt">driven</span> by elevated atomic O levels produced by the meteor impact, as well as chemiluminescent reactions of the ablated metals Na and Fe with O3. Ozone is rapidly removed within the train, both by thermal decomposition and catalytic destruction by the metallic species. Hence, the brightest emission occurs at the edge of the train between outwardly diffusing metallic species and inwardly diffusing O3. Although the model is able to account plausibly for a number of characteristic features of the train <span class="hlt">evolution</span>, significant discrepancies remain that cannot easily be resolved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000EM%26P...82..471J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000EM%26P...82..471J"><span>The <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of a Tubular Leonid Persistent Train</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jenniskens, Peter; Nugent, David; Plane, John M. C.</p> <p></p> <p>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the persistent train of a bright Leonid meteor was examined for evidence of the source of the luminosity and the physical conditions in the meteor path. The train consisted of two parallel somewhat diffuse luminous tracks, interpreted as the walls of a tube. A general lack of wind shear along the trail allowed these structures to remain intact for nearly 200 s, from which it was possible to determine that the tubular structure expanded at a near constant 10.5 ms^-1, independent of altitude between 86 and 97 km. An initial fast decrease of train intensity below 90 km was followed by an increase in intensity and then a gradual decrease at longer times, whereas at high altitudes the integrated intensity was nearly constant with time. These results are compared to a model that describes the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the train by diffusion, following an initial rapid expansion of the hot gaseous trail behind the meteoroid. The train luminosity is produced by O (^1S) emission at 557 nm, <span class="hlt">driven</span> by elevated atomic O levels produced by the meteor impact, as well as chemiluminescent reactions of the ablated metals Na and Fe with O_3. Ozone is rapidly removed within the train, both by thermal decomposition and catalytic destruction by the metallic species. Hence, the brightest emission occurs at the edge of the train between outwardly diffusing metallic species and inwardly diffusing O_3. Although the model is able to account plausibly for a number of characteristic features of the train <span class="hlt">evolution</span>, significant discrepancies remain that cannot casily be resolved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MARL15005U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARL15005U"><span>Autonomous and <span class="hlt">driven</span> <span class="hlt">dynamics</span> of spin torque nano-oscillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Urazhdin, Sergei</p> <p>2012-02-01</p> <p>Understanding the <span class="hlt">dynamical</span> properties of autonomous spin torque nano-oscillators (STNO) and their response to external perturbations is important for their applications as nanoscale microwave sources. We used spectroscopic measurements to study the <span class="hlt">dynamical</span> characteristics of nanopillar- and point contact-based STNOs incorporating a microstrip in close proximity to the active magnetic layer. By applying microwave current at frequency fext to the microstrip, we were able to generate large microwave fields of more than 30 Oe rms at the location of STNO. We demonstrate that for a wide range of fext, STNO exhibits multiple synchronization regimes with integer and non-integer rational ratios between fext and the oscillation frequency f. We show that the synchronization ranges are determined by the symmetry of the oscillation orbit and the orientation of the driving field relative to the symmetry axis of the orbit. We observe synchronization hysteresis, i.e. a dependence of the synchronization limits on the <span class="hlt">dynamical</span> history caused by the nonlinearity of STNO. We also show that the oscillation can be parametrically excited in the subcritical regime of STNO by a microwave field at twice the frequency of the oscillation. By measuring the threshold and the frequency range of parametric excitation, we determine damping, spin-polarization efficiency, and coupling to the microwave signal. In addition, by measuring the frequency range of parametric synchronization in the auto-oscillation regime, we determine the <span class="hlt">dynamic</span> nonlinearity of the nanomagnet. Thus, analysis of the <span class="hlt">driven</span> oscillations provides complete information about the <span class="hlt">dynamical</span> characteristics of STNO. Finally, we discuss several unusual <span class="hlt">dynamical</span> behaviors of STNO caused by their strong nonlinearity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28166510','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28166510"><span>Hamiltonian-<span class="hlt">Driven</span> Adaptive <span class="hlt">Dynamic</span> Programming for Continuous Nonlinear <span class="hlt">Dynamical</span> Systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Yongliang; Wunsch, Donald; Yin, Yixin</p> <p>2017-02-01</p> <p>This paper presents a Hamiltonian-<span class="hlt">driven</span> framework of adaptive <span class="hlt">dynamic</span> programming (ADP) for continuous time nonlinear systems, which consists of evaluation of an admissible control, comparison between two different admissible policies with respect to the corresponding the performance function, and the performance improvement of an admissible control. It is showed that the Hamiltonian can serve as the temporal difference for continuous-time systems. In the Hamiltonian-<span class="hlt">driven</span> ADP, the critic network is trained to output the value gradient. Then, the inner product between the critic and the system <span class="hlt">dynamics</span> produces the value derivative. Under some conditions, the minimization of the Hamiltonian functional is equivalent to the value function approximation. An iterative algorithm starting from an arbitrary admissible control is presented for the optimal control approximation with its convergence proof. The implementation is accomplished by a neural network approximation. Two simulation studies demonstrate the effectiveness of Hamiltonian-<span class="hlt">driven</span> ADP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27418410','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27418410"><span>Covalent Photosensitizer-Polyoxometalate-Catalyst Dyads for Visible-Light-<span class="hlt">Driven</span> Hydrogen <span class="hlt">Evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schönweiz, Stefanie; Rommel, Sebastian A; Kübel, Joachim; Micheel, Mathias; Dietzek, Benjamin; Rau, Sven; Streb, Carsten</p> <p>2016-08-16</p> <p>A general concept for the covalent linkage of coordination compounds to bipyridine-functionalized polyoxometalates is presented. The new route is used to link an iridium photosensitizer to an Anderson-type hydrogen-<span class="hlt">evolution</span> catalyst. This covalent dyad catalyzes the visible-light-<span class="hlt">driven</span> hydrogen <span class="hlt">evolution</span> reaction (HER) and shows superior HER activity compared with the non-covalent reference. Hydrogen <span class="hlt">evolution</span> is observed over periods >1 week. Spectroscopic, photophysical, and electrochemical analyses give initial insight into the stability, electronic structure, and reactivity of the dyad. The results demonstrate that the proposed linkage concept allows synergistic covalent interactions between functional coordination compounds and reactive molecular metal oxides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10144073','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10144073"><span><span class="hlt">Evolution</span> of the alpha particle <span class="hlt">driven</span> toroidicity induced Alfven mode</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu, Y.; White, R.B.; Cheng, C.Z.</p> <p>1994-04-01</p> <p>The interaction of alpha particles with a toroidicity induced Alfven eigenmode is investigated self-consistently by using a kinetic dispersion relation. All important poloidal harmonics and their radial mode profiles are included. A Hamiltonian guiding center code is used to simulate the alpha particle motion. The simulations include particle orbit width, nonlinear particle <span class="hlt">dynamics</span> and the effects of the modes on the particles. Modification of the particle distribution leading to mode saturation is observed. There is no significant alpha particle loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014FlDyR..46f1413Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014FlDyR..46f1413Y"><span>Quasi-cyclic <span class="hlt">evolution</span> of turbulence <span class="hlt">driven</span> by a steady force in a periodic cube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yasuda, Tatsuya; Goto, Susumu; Kawahara, Genta</p> <p>2014-12-01</p> <p>The quasi-cyclic <span class="hlt">evolution</span> of turbulence <span class="hlt">driven</span> by a steady force in a periodic cube is investigated by means of large-eddy simulations with vanishing kinematic viscosity. By constraining the domain size so that only a single series of energy cascade events can take place, quasi-cyclic motions of multi-scale coherent vortices with a period of about 20T are realized. (Here, T denotes the turnover time of the largest eddies.) The observed cycle is composed of four periods characterized by activities of the largest- and smallest-resolvable-scale eddies. Vigorous energy cascade events, which last for about 2T, are observed between the two moments when large- and small-scale eddies are active. Even though we have examined only a special case of steady forces, such cyclic behavior of turbulence is likely to capture the essential <span class="hlt">dynamics</span> of the regeneration cycle of multi-scale coherent structures, that is, the energy cascade in homogeneous isotropic turbulence at high Reynolds numbers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000JAP....87..695S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000JAP....87..695S"><span>Electromigration-<span class="hlt">driven</span> shape <span class="hlt">evolution</span> of two-dimensional voids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schimschak, M.; Krug, J.</p> <p>2000-01-01</p> <p>We present a detailed numerical study of the electromigration-induced shape <span class="hlt">evolution</span> of quasi-two-dimensional (cylindrical) voids in metallic thin films. The problem is treated within a continuum formulation which takes into account mass transport along surfaces, current crowding, and crystal anisotropy in the surface mobility. Finite strips with periodic boundary conditions in the current direction are treated as well as voids in infinite or semi-infinite films. For the strip geometry, it is shown that the linear instability of the strip edge can induce the release of voids into the interior of the film, while edge voids develop into fatal slits only in the presence of moderate (not too strong) crystalline anisotropy. Distorted voids in an infinite film typically disintegrate, but the breakup scenario is qualitatively different in isotropic and anisotropic media. A rigid boundary attracts voids and may also induce void breakup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3353962','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3353962"><span><span class="hlt">Evolution</span> of Cooperation <span class="hlt">Driven</span> by Reputation-Based Migration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cong, Rui; Wu, Bin; Qiu, Yuanying; Wang, Long</p> <p>2012-01-01</p> <p>How cooperation emerges and is stabilized has been a puzzling problem to biologists and sociologists since Darwin. One of the possible answers to this problem lies in the mobility patterns. These mobility patterns in previous works are either random-like or <span class="hlt">driven</span> by payoff-related properties such as fitness, aspiration, or expectation. Here we address another force which drives us to move from place to place: reputation. To this end, we propose a reputation-based model to explore the effect of migration on cooperation in the contest of the prisoner's dilemma. In this model, individuals earn their reputation scores through previous cooperative behaviors. An individual tends to migrate to a new place if he has a neighborhood of low reputation. We show that cooperation is promoted for relatively large population density and not very large temptation to defect. A higher mobility sensitivity to reputation is always better for cooperation. A longer reputation memory favors cooperation, provided that the corresponding mobility sensitivity to reputation is strong enough. The microscopic perception of the effect of this mechanism is also given. Our results may shed some light on the role played by migration in the emergence and persistence of cooperation. PMID:22615739</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22615739','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22615739"><span><span class="hlt">Evolution</span> of cooperation <span class="hlt">driven</span> by reputation-based migration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cong, Rui; Wu, Bin; Qiu, Yuanying; Wang, Long</p> <p>2012-01-01</p> <p>How cooperation emerges and is stabilized has been a puzzling problem to biologists and sociologists since Darwin. One of the possible answers to this problem lies in the mobility patterns. These mobility patterns in previous works are either random-like or <span class="hlt">driven</span> by payoff-related properties such as fitness, aspiration, or expectation. Here we address another force which drives us to move from place to place: reputation. To this end, we propose a reputation-based model to explore the effect of migration on cooperation in the contest of the prisoner's dilemma. In this model, individuals earn their reputation scores through previous cooperative behaviors. An individual tends to migrate to a new place if he has a neighborhood of low reputation. We show that cooperation is promoted for relatively large population density and not very large temptation to defect. A higher mobility sensitivity to reputation is always better for cooperation. A longer reputation memory favors cooperation, provided that the corresponding mobility sensitivity to reputation is strong enough. The microscopic perception of the effect of this mechanism is also given. Our results may shed some light on the role played by migration in the emergence and persistence of cooperation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009MNRAS.396L..66Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MNRAS.396L..66Y"><span>The merger-<span class="hlt">driven</span> <span class="hlt">evolution</span> of warm infrared luminous galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Younger, Joshua D.; Hayward, Christopher C.; Narayanan, Desika; Cox, T. J.; Hernquist, Lars; Jonsson, Patrik</p> <p>2009-06-01</p> <p>We present a merger-<span class="hlt">driven</span> evolutionary model for the production of luminous (LIRGs) and ultraluminous infrared galaxies (ULIRGs) with warm infrared (IR) colours. Our results show that simulations of gas-rich major mergers including star formation, black hole growth and feedback can produce warm (U)LIRGs. We also find that while the warm evolutionary phase is associated with increased active galactic nucleus (AGN) activity, star formation alone may be sufficient to produce warm IR colours. However, the transition can be suppressed entirely - even when there is a significant AGN contribution - when we assume a single-phase interstellar medium, which maximizes the attenuation. Finally, our evolutionary models are consistent with the 25-to-60 flux density ratio versus LHX/LIR relation for local LIRGs and ULIRGs, and predict the observed scatter in IR colour at fixed LHX/LIR. Therefore, our models suggest a cautionary note in the interpretation of warm IR colours: while associated with periods of active black hole growth, they are probably produced by a complex mix of star formation and AGN activity intermediate between the cold star formation dominated phase and the birth of a bright, unobscured quasar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22167230','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22167230"><span>ORBITAL AND MASS RATIO <span class="hlt">EVOLUTION</span> OF PROTOBINARIES <span class="hlt">DRIVEN</span> BY MAGNETIC BRAKING</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Bo; Li, Zhi-Yun</p> <p>2013-01-20</p> <p>The majority of stars reside in multiple systems, especially binaries. The formation and early <span class="hlt">evolution</span> of binaries is a longstanding problem in star formation that is not yet fully understood. In particular, how the magnetic field observed in star-forming cores shapes the binary characteristics remains relatively unexplored. We demonstrate numerically, using an MHD version of the ENZO AMR hydro code, that a magnetic field of the observed strength can drastically change two of the basic quantities that characterize a binary system: the orbital separation and mass ratio of the two components. Our calculations focus on the protostellar mass accretion phase, after a pair of stellar 'seeds' have already formed. We find that in dense cores magnetized to a realistic level, the angular momentum of the material accreted by the protobinary is greatly reduced by magnetic braking. Accretion of strongly braked material shrinks the protobinary separation by a large factor compared to the non-magnetic case. The magnetic braking also changes the <span class="hlt">evolution</span> of the mass ratio of unequal-mass protobinaries by producing material of low specific angular momentum that accretes preferentially onto the more massive primary star rather than the secondary. This is in contrast with the preferential mass accretion onto the secondary previously found numerically for protobinaries accreting from an unmagnetized envelope, which tends to drive the mass ratio toward unity. In addition, the magnetic field greatly modifies the morphology and <span class="hlt">dynamics</span> of the protobinary accretion flow. It suppresses the traditional circumstellar and circumbinary disks that feed the protobinary in the non-magnetic case; the binary is fed instead by a fast collapsing pseudodisk whose rotation is strongly braked. The magnetic braking-<span class="hlt">driven</span> inward migration of binaries from their birth locations may be constrained by high-resolution observations of the orbital distribution of deeply embedded protobinaries, especially</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.1578P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.1578P"><span><span class="hlt">Evolution</span> of Neogene <span class="hlt">Dynamic</span> Topography in Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paul, Jonathan; Roberts, Gareth; White, Nicky</p> <p>2013-04-01</p> <p>The characteristic basins and swells of Africa's surface topography probably reflect patterns of convective circulation in the sub-lithospheric mantle. We have interrogated drainage networks to determine the spatial and temporal pattern of convectively <span class="hlt">driven</span> uplift. ~560 longitudinal river profiles were extracted from a digital elevation model of Africa. An inverse model is then used to minimise the misfit between observed and calculated river profiles as a function of uplift rate history. During inversion, the residual misfit decreases from ~22 to ~5. Our results suggest that Africa's topography began to grow most rapidly after ~30 Ma at peak uplift rates of 0.1-0.15 mm/yr. The algorithm resolves distinct phases of uplift which generate localized swells of high topography and relief (e.g. the Angolan Dome). Uplift rate histories are shown to vary significantly from swell to swell. The calculated magnitudes, timing, and location of uplift agree well with local independent geological constraints, such as intense volcanism at Hoggar (42-39 Ma) and Afar (31-29 Ma), uplifted marine terraces, and warped peneplains. We have also calculated solid sediment flux histories for major African deltas which have persisted through time. This onshore record provides an important indirect constraint on the history of vertical motions at the surface, and agrees well with the offshore flux record, obtained from mapping isopachs of deltaic sediments. Our modelling and reconstructed sedimentary flux histories indicate that the <span class="hlt">evolution</span> of drainage networks may contain useful information about mantle convective processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/125497','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/125497"><span>Cellular automata and complex <span class="hlt">dynamics</span> of <span class="hlt">driven</span> elastic media</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coppersmith, S.N.; Littlewodd, P.B.; Sibani, P.</p> <p>1995-12-01</p> <p>Several systems of importance in condensed matter physics can be modelled as an elastic medium in a disordered environment and <span class="hlt">driven</span> by an external force. In the simplest cases, the equation of motion involves competition between a local non-linear potential (fluctuating in space) and elastic coupling, as well as relaxational (inertialess) <span class="hlt">dynamics</span>. Despite a simple mathematical description, the interactions between many degrees of freedom lead to the emergence of time and length scales much longer than those set by the microscopic <span class="hlt">dynamics</span>. Extensive computations have improved the understanding of the behavior of such models, but full solutions of the equations of motion for very large systems are time-consuming and may obscure important physical principles in a massive volume of output. The development of cellular automata models has been crucial, both in conceptual simplification and in allowing the collection of data on many replicas of very large systems. We will discuss how the marriage of cellular automata models and parallel computation on a MasPar MP-1216 computer has helped to elucidate the <span class="hlt">dynamical</span> properties of these many-degree-of-freedom systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94b4514Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94b4514Z"><span>Reentrant <span class="hlt">dynamics</span> of <span class="hlt">driven</span> pancake vortices in layered superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, H. J.; Wu, Wenjuan; Zhou, Wei; Shi, Z. X.; Misko, V. R.; Peeters, F. M.</p> <p>2016-07-01</p> <p>The <span class="hlt">dynamics</span> of <span class="hlt">driven</span> pancake vortices in layered superconductors is studied using molecular-<span class="hlt">dynamics</span> simulations. We found that, with increasing driving force, for strong interlayer coupling, the preexisted vortex lines either directly depin or first transform to two-dimensional (2D) pinned states before they are depinned, depending on the pinning strength. In a narrow region of pinning strengths, we found an interesting repinning process, which results in a negative differential resistance. For weak interlayer coupling, individually pinned pancake vortices first form disordered 2D flow and then transform to ordered three-dimensional (3D) flow with increasing driving force. However, for extremely strong pinning, the random pinning-induced thermal-like Langevin forces melt 3D vortex lines, which results in a persistent 2D flow in the fast-sliding regime. In the intermediate regime, the peak effect is found: With increasing driving force, the moving pancake vortices first crystallize to moving 3D vortex lines, and then these 3D vortex lines are melted, leading to the appearance of a reentrant 2D flow state. Our results are summarized in a <span class="hlt">dynamical</span> phase diagram.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27062059','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27062059"><span>Predicting when climate-<span class="hlt">driven</span> phenotypic change affects population <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLean, Nina; Lawson, Callum R; Leech, Dave I; van de Pol, Martijn</p> <p>2016-06-01</p> <p>Species' responses to climate change are variable and diverse, yet our understanding of how different responses (e.g. physiological, behavioural, demographic) relate and how they affect the parameters most relevant for conservation (e.g. population persistence) is lacking. Despite this, studies that observe changes in one type of response typically assume that effects on population <span class="hlt">dynamics</span> will occur, perhaps fallaciously. We use a hierarchical framework to explain and test when impacts of climate on traits (e.g. phenology) affect demographic rates (e.g. reproduction) and in turn population <span class="hlt">dynamics</span>. Using this conceptual framework, we distinguish four mechanisms that can prevent lower-level responses from impacting population <span class="hlt">dynamics</span>. Testable hypotheses were identified from the literature that suggest life-history and ecological characteristics which could predict when these mechanisms are likely to be important. A quantitative example on birds illustrates how, even with limited data and without fully-parameterized population models, new insights can be gained; differences among species in the impacts of climate-<span class="hlt">driven</span> phenological changes on population growth were not explained by the number of broods or density dependence. Our approach helps to predict the types of species in which climate sensitivities of phenotypic traits have strong demographic and population consequences, which is crucial for conservation prioritization of data-deficient species. © 2016 John Wiley & Sons Ltd/CNRS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996APS..DPP.7IA01H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996APS..DPP.7IA01H"><span>Rayleigh-Taylor Instability <span class="hlt">Evolution</span> in Ablatively <span class="hlt">Driven</span> Cylindrical Implosions^*,**</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsing, W. W.</p> <p>1996-11-01</p> <p>The Rayleigh-Taylor instability is an important limitation in ICF capsule designs. Significant work both theoretically and experimentally has been done to demonstrate the stabilizing effects due to material flow through the unstable region. The experimental verification has been done predominantly in planar geometry. Convergent geometry introduces effects not present in planar geometry such as shell thickening and accelerationless growth of modal amplitudes (e.g. Bell-Plesset growth). Amplitude thresholds for the nonlinear regime are reduced, since the wavelength of a mode m decreases with convergence λ ~ r/m, where r is the radius. We have investigated convergent effects using an imploding cylinder <span class="hlt">driven</span> by x-ray ablation on the NOVA laser. By doping sections of the cylinder with high-Z materials, in conjunction with x-ray backlighting, we have measured the growth and feedthrough of the perturbations from the ablation front to the inner surface of the cylinder for various initial modes and amplitudes from early time through stagnation. Mode coupling of illumination asymmetries with material perturbations is observed, as well as phase reversal of the perturbations from near the ablation front to the inner surface of the cylinder. Imaging is performed with an x-ray pinhole camera coupled to a gated microchannel plate detector. In collaboration with C. W. Barnes, J. B. Beck, N. Hoffman (LANL), D. Galmiche, A. Richard (CEA/L-V), J. Edwards, P. Graham, B. Thomas (AWE). ^**This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/971900','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/971900"><span>Describing Story <span class="hlt">Evolution</span> from <span class="hlt">Dynamic</span> Information Streams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rose, Stuart J.; Butner, R. Scott; Cowley, Wendy E.; Gregory, Michelle L.; Walker, Julia</p> <p>2009-10-12</p> <p>Sources of streaming information, such as news syndicates, publish information continuously. Information portals and news aggregators list the latest information from around the world enabling information consumers to easily identify events in the past 24 hours. The volume and velocity of these streams causes information from prior days’ to quickly vanish despite its utility in providing an informative context for interpreting new information. Few capabilities exist to support an individual attempting to identify or understand trends and changes from streaming information over time. The burden of retaining prior information and integrating with the new is left to the skills, determination, and discipline of each individual. In this paper we present a visual analytics system for linking essential content from information streams over time into <span class="hlt">dynamic</span> stories that develop and change over multiple days. We describe particular challenges to the analysis of streaming information and explore visual representations for showing story change and <span class="hlt">evolution</span> over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JAP...110i4510C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JAP...110i4510C"><span><span class="hlt">Dynamics</span> of photothermally <span class="hlt">driven</span> VO2-coated microcantilevers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cabrera, Rafmag; Merced, Emmanuelle; Sepúlveda, Nelson; Fernández, Félix E.</p> <p>2011-11-01</p> <p>The <span class="hlt">dynamic</span> response of VO2-coated silicon microcantilevers thermally <span class="hlt">driven</span> over the film's insulator-to-metal transition was studied using laser light pulses directly incident on the cantilevers. The measured photothermal response revealed very high curvature changes of approximately 2500 m-1 up to pulse frequencies greater than 100 Hz and readily observable vibrations up to frequencies of a few kHz with no amplitude degradation after tens of thousands of pulses. Maximum tip amplitudes for 300-μm-long, 1-μm-thick cantilevers used in these experiments were nearly 120 μm and correspondingly less for 2-μm-thick cantilevers. The main mechanism limiting oscillation amplitude was found to be heat transport response during heating and cooling, which depends mainly on thermal conduction through the cantilever itself to the massive anchor and chip body, which acted as a heat sink at room temperature. For the laser-<span class="hlt">driven</span> oscillations studied, damping by the surrounding air is unimportant in the range of frequencies probed. Large-curvature response is expected to extend to higher pulse frequencies for cantilevers with smaller dimensions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23770726','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23770726"><span>Current-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of chiral ferromagnetic domain walls.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Emori, Satoru; Bauer, Uwe; Ahn, Sung-Min; Martinez, Eduardo; Beach, Geoffrey S D</p> <p>2013-07-01</p> <p>In most ferromagnets the magnetization rotates from one domain to the next with no preferred handedness. However, broken inversion symmetry can lift the chiral degeneracy, leading to topologically rich spin textures such as spin spirals and skyrmions through the Dzyaloshinskii-Moriya interaction (DMI). Here we show that in ultrathin metallic ferromagnets sandwiched between a heavy metal and an oxide, the DMI stabilizes chiral domain walls (DWs) whose spin texture enables extremely efficient current-<span class="hlt">driven</span> motion. We show that spin torque from the spin Hall effect drives DWs in opposite directions in Pt/CoFe/MgO and Ta/CoFe/MgO, which can be explained only if the DWs assume a Néel configuration with left-handed chirality. We directly confirm the DW chirality and rigidity by examining current-<span class="hlt">driven</span> DW <span class="hlt">dynamics</span> with magnetic fields applied perpendicular and parallel to the spin spiral. This work resolves the origin of controversial experimental results and highlights a new path towards interfacial design of spintronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1512088D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1512088D"><span><span class="hlt">Dynamic</span> landscapes in human <span class="hlt">evolution</span> and dispersal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Devès, Maud; King, Geoffrey; Bailey, Geoffrey; Inglis, Robyn; Williams, Matthew; Winder, Isabelle</p> <p>2013-04-01</p> <p>Archaeological studies of human settlement in its wider landscape setting usually focus on climate change as the principal environmental driver of change in the physical features of the landscape, even on the long time scales of early human <span class="hlt">evolution</span>. We emphasize that landscapes evolve <span class="hlt">dynamically</span> due to an interplay of processes occurring over different timescales. Tectonic deformation, volcanism, sea level changes, by acting on the topography, the lithology and on the patterns of erosion-deposition in a given area, can moderate or amplify the influence of climate at the regional and local scale. These processes impose or alleviate physical barriers to movement, and modify the distribution and accessibility of plant and animal resources in ways critical to human ecological and evolutionary success (King and Bailey, JHE 2006; Bailey and King, Antiquity 2011, Winder et al. Antiquity in press). The DISPERSE project, an ERC-funded collaboration between the University of York and the Institut de Physique du Globe de Paris, aims to develop systematic methods for reconstructing landscapes associated with active tectonics, volcanism and sea level change at a variety of scales in order to study their potential impact on patterns of human <span class="hlt">evolution</span> and dispersal. Examples are shown to illustrate the ways in which changes of significance to human settlement can occur at a range of geographical scales and on time scales that range from lifetimes to tens of millennia, creating and sustaining attractive conditions for human settlement and exercising powerful selective pressures on human development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982fps..conf..403B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982fps..conf..403B"><span>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the solar system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burns, J. A.</p> <p></p> <p>The lectures cover orbital <span class="hlt">evolution</span>, radiation forces, tides, the past solar system, the three body problem, and rotational <span class="hlt">dynamics</span> in the solar system. A geometric description is given of an orbit, and it is illustrated how an orbit can change under the action of tiny perturbing forces. Attention is also given to some of the processes that cause orbits to evolve. After considering the radiation forces experienced by a perfectly absorbing particle, an elementary mechanical model is developed to compute the force felt by a particle that scatters, transmits, and absorbs light. The lecture on tides explains how tides have synchronized most satellite rotation periods with their orbital periods and have modified appreciably the rotations of the three inner terrestrial planets. Regarding the past solar system, integrations of the orbital <span class="hlt">evolutions</span> backward in time are considered in order to learn the past form of the solar system. Descriptions are given of the orbital histories of the moon, of hypothetical satellites about Mercury and Venus, of the Martian satellites, and of large moons in the outer solar system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880060410&hterms=dissipative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddissipative','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880060410&hterms=dissipative&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Ddissipative"><span>The <span class="hlt">evolution</span> of cross helicity in <span class="hlt">driven</span>/dissipative two-dimensional magnetohydrodynamics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ghosh, S.; Matthaeus, W. H.; Montgomery, D.</p> <p>1988-01-01</p> <p>The paper presents a series of incompressible two-dimensional simulations of <span class="hlt">driven</span>/dissipative MHD turbulence where the amount of correlation between the kinetic and magnetic forcing is regulated, thereby controlling the amount of cross helicity injection. It is shown that correlated forcing provides a strong source of magnetofluid cross helicity. The clear appearance of the 'minority species effect,' which is the most striking and systematic effect during this <span class="hlt">driven</span> <span class="hlt">dynamic</span> alignment process, is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.110m2404K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.110m2404K"><span>Current-<span class="hlt">driven</span> skyrmion <span class="hlt">dynamics</span> in disordered films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Joo-Von; Yoo, Myoung-Woo</p> <p>2017-03-01</p> <p>A theoretical study of the current-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of magnetic skyrmions in disordered perpendicularly magnetized ultrathin films is presented. The disorder is simulated as a granular structure, in which the local anisotropy varies randomly from grain to grain. The skyrmion velocity is computed for different disorder parameters and ensembles. Similar behavior is seen for spin-torques due to in-plane currents and the spin Hall effect, where a pinning regime can be identified at low currents with a transition towards the disorder-free case at higher currents, similar to domain wall motion in disordered films. Moreover, a current-dependent skyrmion Hall effect and fluctuations in the core radius are found, which result from the interaction with the pinning potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..91a2814Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..91a2814Z"><span>Solving the inverse problem of noise-<span class="hlt">driven</span> <span class="hlt">dynamic</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Zhaoyang; Zheng, Zhigang; Niu, Haijing; Mi, Yuanyuan; Wu, Si; Hu, Gang</p> <p>2015-01-01</p> <p>Nowadays, massive amounts of data are available for analysis in natural and social systems and the tasks to depict system structures from the data, i.e., the inverse problems, become one of the central issues in wide interdisciplinary fields. In this paper, we study the inverse problem of <span class="hlt">dynamic</span> complex networks <span class="hlt">driven</span> by white noise. A simple and universal inference formula of double correlation matrices and noise-decorrelation (DCMND) method is derived analytically, and numerical simulations confirm that the DCMND method can accurately depict both network structures and noise correlations by using available output data only. This inference performance has never been regarded possible by theoretical derivation, numerical computation, and experimental design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...815085C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...815085C"><span>Optical-helicity-<span class="hlt">driven</span> magnetization <span class="hlt">dynamics</span> in metallic ferromagnets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Gyung-Min; Schleife, André; Cahill, David G.</p> <p>2017-04-01</p> <p>Recent observations of switching of magnetic domains in ferromagnetic metals by circularly polarized light, so-called all-optical helicity dependent switching, has renewed interest in the physics that governs the interactions between the angular momentum of photons and the magnetic order parameter of materials. Here we use time-resolved-vectorial measurements of magnetization <span class="hlt">dynamics</span> of thin layers of Fe, Ni and Co <span class="hlt">driven</span> by picosecond duration pulses of circularly polarized light. We decompose the torques that drive the magnetization into field-like and spin-transfer components that we attribute to the inverse Faraday effect and optical spin-transfer torque, respectively. The inverse Faraday effect is approximately the same in Fe, Ni and Co, but the optical spin-transfer torque is strongly enhanced by adding a Pt capping layer. Our work provides quantitative data for testing theories of light-material interactions in metallic ferromagnets and multilayers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22126768','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22126768"><span><span class="hlt">DYNAMICS</span> OF ASTROPHYSICAL BUBBLES AND BUBBLE-<span class="hlt">DRIVEN</span> SHOCKS: BASIC THEORY, ANALYTICAL SOLUTIONS, AND OBSERVATIONAL SIGNATURES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Medvedev, Mikhail V.; Loeb, Abraham</p> <p>2013-05-10</p> <p>Bubbles in the interstellar medium are produced by astrophysical sources, which continuously or explosively deposit large amounts of energy into the ambient medium. These expanding bubbles can drive shocks in front of them, the <span class="hlt">dynamics</span> of which is markedly different from the widely used Sedov-von Neumann-Taylor blast wave solution. Here, we present the theory of a bubble-<span class="hlt">driven</span> shock and show how its properties and <span class="hlt">evolution</span> are determined by the temporal history of the source energy output, generally referred to as the source luminosity law, L(t). In particular, we find the analytical solutions for a <span class="hlt">driven</span> shock in two cases: the self-similar scaling law, L{proportional_to}(t/t{sub s} ) {sup p} (with p and t{sub s} being constants) and the finite activity time case, L{proportional_to}(1 - t/t{sub s} ){sup -p}. The latter with p > 0 describes a finite-time-singular behavior, which is relevant to a wide variety of systems with explosive-type energy release. For both luminosity laws, we derived the conditions needed for the <span class="hlt">driven</span> shock to exist and predict the shock observational signatures. Our results can be relevant to stellar systems with strong winds, merging neutron star/magnetar/black hole systems, and massive stars evolving to supernovae explosions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JNS....25.1307W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JNS....25.1307W"><span>A Data-<span class="hlt">Driven</span> Approximation of the Koopman Operator: Extending <span class="hlt">Dynamic</span> Mode Decomposition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, Matthew O.; Kevrekidis, Ioannis G.; Rowley, Clarence W.</p> <p>2015-12-01</p> <p>The Koopman operator is a linear but infinite-dimensional operator that governs the <span class="hlt">evolution</span> of scalar observables defined on the state space of an autonomous <span class="hlt">dynamical</span> system and is a powerful tool for the analysis and decomposition of nonlinear <span class="hlt">dynamical</span> systems. In this manuscript, we present a data-<span class="hlt">driven</span> method for approximating the leading eigenvalues, eigenfunctions, and modes of the Koopman operator. The method requires a data set of snapshot pairs and a dictionary of scalar observables, but does not require explicit governing equations or interaction with a "black box" integrator. We will show that this approach is, in effect, an extension of <span class="hlt">dynamic</span> mode decomposition (DMD), which has been used to approximate the Koopman eigenvalues and modes. Furthermore, if the data provided to the method are generated by a Markov process instead of a deterministic <span class="hlt">dynamical</span> system, the algorithm approximates the eigenfunctions of the Kolmogorov backward equation, which could be considered as the "stochastic Koopman operator" (Mezic in Nonlinear <span class="hlt">Dynamics</span> 41(1-3): 309-325, 2005). Finally, four illustrative examples are presented: two that highlight the quantitative performance of the method when presented with either deterministic or stochastic data and two that show potential applications of the Koopman eigenfunctions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22224279','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22224279"><span>Geometric phase of a qubit <span class="hlt">driven</span> by a phase noise laser under non-Markovian <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berrada, K.</p> <p>2014-01-15</p> <p>Robustness of the geometric phase (GP) with respect to the environmental effects is a basic condition for an effective quantum computation. Here, we study quantitatively the GP of a two-level atom system <span class="hlt">driven</span> by a phase noise laser under non-Markovian <span class="hlt">dynamics</span> in terms of different parameters involved in the whole system. We find that with the change of the damping coupling, the GP is very sensitive to its properties exhibiting long collapse and revival phenomena, which play a significant role in enhancing the stabilization and control of the system <span class="hlt">dynamics</span>. Moreover, we show that the GP can be considered as a tool for testing and characterizing the nature of the qubit–environment coupling. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement <span class="hlt">dynamics</span> between the qubit with its environment under external classical noise is evaluated and investigated during the time <span class="hlt">evolution</span>. -- Highlights: •Geometric phase under noise phase laser. •<span class="hlt">Dynamics</span> of the geometric phase under non-Markovian <span class="hlt">dynamics</span> in the presence of classical noise. •Solution of master equation of the system in terms atomic inversion. •Nonlocal correlation between the system and its environment under non-Markovianity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860052995&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DOort%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860052995&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DOort%2Bcloud"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of the Oort cloud</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weissman, P. R.</p> <p>1985-01-01</p> <p>New studies of the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of cometary orbits in the Oort cloud are made using a revised version of Weissman's (1982) Monte Carlo simulation model, which more accurately mimics the perturbation of comets by the giant planets. It is shown that perturbations by Saturn and Jupiter provide a substantial barrier to the diffusion of cometary perihelia into the inner solar system. Perturbations by Uranus and Neptune are rarely great enough to remove comets from the Oort cloud, but do serve to scatter the comets in the cloud in initial energy. The new model gives a population of 1.8 to 2.1 x 10 to the 12th comets for the present-day Oort cloud, and a mass of 7 to 8 earth masses. Perturbation of the Oort cloud by giant molecular clouds in the galaxy is discussed, as is evidence for a massive 'inner Oort cloud' internal to the observed one. The possibility of an unseen solar companion orbiting in the Oort cloud and causing periodic comet showers is shown to be <span class="hlt">dynamically</span> plausible but unlikely, based on the observed cratering rate on the earth and moon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1154837','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1154837"><span>Electricity Demand <span class="hlt">Evolution</span> <span class="hlt">Driven</span> by Storm Motivated Population Movement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allen, Melissa R; Fernandez, Steven J; Fu, Joshua S; Walker, Kimberly A</p> <p>2014-01-01</p> <p>Managing the risks posed by climate change to energy production and delivery is a challenge for communities worldwide. Sea Level rise and increased frequency and intensity of natural disasters due to sea surface temperature rise force populations to move locations, resulting in changing patterns of demand for infrastructure services. Thus, Infrastructures will evolve to accommodate new load centers while some parts of the network are underused, and these changes will create emerging vulnerabilities. Combining climate predictions and agent based population movement models shows promise for exploring the universe of these future population distributions and changes in coastal infrastructure configurations. In this work, we created a prototype agent based population distribution model and developed a methodology to establish utility functions that provide insight about new infrastructure vulnerabilities that might result from these patterns. Combining climate and weather data, engineering algorithms and social theory, we use the new Department of Energy (DOE) Connected Infrastructure <span class="hlt">Dynamics</span> Models (CIDM) to examine electricity demand response to increased temperatures, population relocation in response to extreme cyclonic events, consequent net population changes and new regional patterns in electricity demand. This work suggests that the importance of established evacuation routes that move large populations repeatedly through convergence points as an indicator may be under recognized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DDA....4830304B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DDA....4830304B"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of globular clusters in dark matter halos</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Breen, Phil; Varri, Anna Lisa; Penarrubia, Jorge; Heggie, Douglas C.</p> <p>2017-06-01</p> <p>The formation of globular clusters in a cosmological context is a topical open problem. One possible formation scenario is that globular clusters have formed in their own dark matter halos, and, as a result, some clusters may have retained it to the present day. In such a case, collisional processes taking place in the central regions of globulars may lead to the formation of a tenuous stellar envelope extending far beyond the tidal boundary of the parent cluster.The synergy between the astrometric mission Gaia and forthcoming multi-object spectrographs such as WEAVE will allow us to explore, with unprecedented accuracy, the outer regions of selected Galactic globular clusters, therefore it is particularly timely to consider to what extent the presence of dark matter is consistent with their <span class="hlt">dynamics</span> and structure at large distances from the cluster centre.<span class="hlt">Driven</span> by these motivations, we present the results of a series of direct N-body simulations where globular clusters have been evolved self-consistently in a static dark matter potential. Special attention will be given to the exploration of the effects of the dark halo on the traditional phases of the long-term <span class="hlt">evolution</span> of collisional systems and the <span class="hlt">dynamical</span> interplay with other fundamental physical ingredients, such as stellar-mass black holes, will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1140312-opinion-driven-behavioral-dynamics-model-addictive-behaviors','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1140312-opinion-driven-behavioral-dynamics-model-addictive-behaviors"><span>An opinion-<span class="hlt">driven</span> behavioral <span class="hlt">dynamics</span> model for addictive behaviors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Moore, Thomas W.; Finley, Patrick D.; Apelberg, Benjamin J.; ...</p> <p>2015-04-08</p> <p>We present a model of behavioral <span class="hlt">dynamics</span> that combines a social network-based opinion <span class="hlt">dynamics</span> model with behavioral mapping. The behavioral component is discrete and history-dependent to represent situations in which an individual’s behavior is initially <span class="hlt">driven</span> by opinion and later constrained by physiological or psychological conditions that serve to maintain the behavior. Additionally, individuals are modeled as nodes in a social network connected by directed edges. Parameter sweeps illustrate model behavior and the effects of individual parameters and parameter interactions on model results. Mapping a continuous opinion variable into a discrete behavioral space induces clustering on directed networks. Clusters providemore » targets of opportunity for influencing the network state; however, the smaller the network the greater the stochasticity and potential variability in outcomes. Furthermore, this has implications both for behaviors that are influenced by close relationships verses those influenced by societal norms and for the effectiveness of strategies for influencing those behaviors.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95a4305A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95a4305A"><span>Effects of interactions on periodically <span class="hlt">driven</span> <span class="hlt">dynamically</span> localized systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agarwala, Adhip; Sen, Diptiman</p> <p>2017-01-01</p> <p>It is known that there are lattice models in which noninteracting particles get <span class="hlt">dynamically</span> localized when periodic δ -function kicks are applied with a particular strength. We use both numerical and analytical methods to study the effects of interactions in three different models in one dimension. The systems we have considered include spinless fermions with interactions between nearest-neighbor sites, the Hubbard model of spin-1/2 fermions, and the Bose-Hubbard model with on-site interactions. We derive effective Floquet Hamiltonians up to second order in the time period of kicking. Using these we show that interactions can give rise to a variety of interesting results such as two-body bound states in all three models and dispersionless few-particle bound states with more than two particles for spinless fermions and bosons. We substantiate these results by exact diagonalization and stroboscopic time <span class="hlt">evolution</span> of systems with a few particles. We derive a pseudo-spin-1/2 limit of the Bose-Hubbard system in the thermodynamic limit and show that a special case of this has an exponentially large number of degenerate eigenstates of the effective Hamiltonian. Finally, we study the effect of changing the strength of the δ -function kicks slightly away from perfect <span class="hlt">dynamical</span> localization; we find that a single particle remains <span class="hlt">dynamically</span> localized for a long time after which it moves ballistically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22253151','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22253151"><span>Nanoscale structural <span class="hlt">evolution</span> of electrically <span class="hlt">driven</span> insulator to metal transition in vanadium dioxide</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Freeman, Eugene Shukla, Nikhil; Datta, Suman; Stone, Greg; Engel-Herbert, Roman; Gopalan, Venkatraman; Paik, Hanjong; Moyer, Jarrett A.; Cai, Zhonghou; Wen, Haidan; Schlom, Darrell G.</p> <p>2013-12-23</p> <p>The structural <span class="hlt">evolution</span> of tensile strained vanadium dioxide thin films was examined across the electrically <span class="hlt">driven</span> insulator-to-metal transition by nanoscale hard X-ray diffraction. A metallic filament with rutile (R) structure was found to be the dominant conduction pathway for an electrically <span class="hlt">driven</span> transition, while the majority of the channel area remained in the monoclinic M1 phase. The filament dimensions were estimated using simultaneous electrical probing and nanoscale X-ray diffraction. Analysis revealed that the width of the conducting channel can be tuned externally using resistive loads in series, enabling the M1/R phase ratio in the phase coexistence regime to be tuned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22181613','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22181613"><span>Structure-<span class="hlt">driven</span> nonlinear instability as the origin of the explosive reconnection <span class="hlt">dynamics</span> in resistive double tearing modes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Janvier, M; Kishimoto, Y; Li, J Q</p> <p>2011-11-04</p> <p>The onset of abrupt magnetic reconnection events, observed in the nonlinear <span class="hlt">evolution</span> of double tearing modes (DTM), is investigated via reduced resistive magnetohydrodynamic simulations. We have identified the critical threshold for the parameters characterizing the linear DTM stability leading to the bifurcation to the explosive <span class="hlt">dynamics</span>. A new type of secondary instability is discovered that is excited once the magnetic islands on each rational surface reach a critical structure characterized here by the width and the angle rating their triangularization. This new instability is an island structure-<span class="hlt">driven</span> nonlinear instability, identified as the trigger of the subsequent nonlinear <span class="hlt">dynamics</span> which couples flow and flux perturbations. This instability only weakly depends on resistivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJMPB..23.3789M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJMPB..23.3789M"><span>a Unified Description of Time Dependence of Information Entropy Production and Flux in Thermal Broadband Noise-<span class="hlt">Driven</span> <span class="hlt">Dynamical</span> Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Majee, Pradip; Goswami, Gurupada; Barik, Debashis; Bag, Bidhan Chandra</p> <p></p> <p>In this paper we have studied the <span class="hlt">dynamics</span> of thermal broadband noise-<span class="hlt">driven</span> <span class="hlt">dynamical</span> system in terms of information entropy at both the nonstationary and stationary states. Here, a unified description of fluctuating force is considered in a thermodynamically closed system. Based on the Fokker-Planck description of stochastic processes and the entropy balance equation, we have calculated the time-dependence of the information entropy production and entropy flux in the presence and absence of nonequilibrium constraint. Our calculation considers how the time <span class="hlt">evolution</span> of these quantities is affected if the characteristic of noise changes from white to red or green and red to green in a unified scheme.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95w5430P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95w5430P"><span><span class="hlt">Dynamics</span> and control of edge states in laser-<span class="hlt">driven</span> graphene nanoribbons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puviani, M.; Manghi, F.; Bertoni, A.</p> <p>2017-06-01</p> <p>An intense laser field in the high-frequency regime drives carriers in graphene nanoribbons (GNRs) out of equilibrium and creates topologically protected edge states. Using Floquet theory on <span class="hlt">driven</span> GNRs, we calculate the time <span class="hlt">evolution</span> of local excitations of these edge states and show that they exhibit a robust <span class="hlt">dynamics</span> also in the presence of very localized lattice defects (atomic vacancies), which is characteristic of topologically nontrivial behavior. We show how it is possible to control them by a modulated electrostatic potential: They can be fully transmitted on the same edge, reflected on the opposite one, or can be split between the two edges, in analogy with Hall edge states, making them promising candidates for flying-qubit architectures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.1539V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.1539V"><span><span class="hlt">Dynamics</span> and predictability of a low-order wind-<span class="hlt">driven</span> ocean - atmosphere model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vannitsem, Stéphane</p> <p>2013-04-01</p> <p>The <span class="hlt">dynamics</span> of a low order coupled wind-<span class="hlt">driven</span> Ocean-Atmosphere (OA) system is investigated with emphasis on its predictability properties. The low-order coupled deterministic system is composed of a baroclinic atmosphere for which 12 dominant <span class="hlt">dynamical</span> modes are only retained (Charney and Straus, 1980) and a wind-<span class="hlt">driven</span>, quasi-geostrophic and reduced-gravity shallow ocean whose field is truncated to four dominant modes able to reproduce the large scale oceanic gyres (Pierini, 2011). The two models are coupled through mechanical forcings only. The analysis of its <span class="hlt">dynamics</span> reveals first that under aperiodic atmospheric forcings only dominant single gyres (clockwise or counterclockwise) appear. This feature is expected to be related with the specific domain choice over which the coupled system is defined. Second the <span class="hlt">dynamical</span> quantities characterizing the short-term predictability (Lyapunov exponents, Lyapunov dimension, Kolmogorov-Sinaï (KS) entropy) displays a complex dependence as a function of the key parameters of the system, namely the coupling strength and the external thermal forcing. In particular, the KS-entropy is increasing as a function of the coupling in most of the experiments, implying an increase of the rate of loss of information about the localization of the system on his attractor. Finally the <span class="hlt">dynamics</span> of the error is explored and indicates, in particular, a rich variety of short term behaviors of the error in the atmosphere depending on the (relative) amplitude of the initial error affecting the ocean, from polynomial (at2 + bt3 + ct4) up to purely exponential <span class="hlt">evolutions</span>. These features are explained and analyzed in the light of the recent findings on error growth (Nicolis et al, 2009). References Charney J G, Straus DM (1980) Form-Drag Instability, Multiple Equilibria and Propagating Planetary Waves in Baroclinic, Orographically Forced, Planetary Wave Systems. J Atmos Sci 37: 1157-1176. Nicolis C, Perdigao RAP, Vannitsem S (2009) <span class="hlt">Dynamics</span> of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840046142&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DOort%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840046142&hterms=Oort+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DOort%2Bcloud"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of the Oort cometary cloud</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weissman, P. R.</p> <p>1983-01-01</p> <p>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of comets in the Oort cloud under the influence of stellar perturbations has been modeled using Monte Carlo techniques. It is shown that the cloud has been depleted over the history of the solar system. Comets are lost from the cloud by direct ejection due to close stellar encounters, diffusion of aphelia to distances beyond the sun's sphere of influence, or diffusion of perihelia into the planetary region where Jupiter and Saturn perturbations either eject them on hyperbolic trajectories or capture them to short-period orbits. The population of the cloud is estimated to be 1.0 - 1.5 x 10 to the 12th comets and the total mass is on the order of 1.9 earth masses. In addition to random passing stars, less frequent encounters with giant molecular clouds may play a significant role in randomizing the orbits of comets in the cloud and reducing the effective radius of the sun's sphere of influence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARB15002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARB15002G"><span>Computational Fluid <span class="hlt">Dynamics</span> of Acoustically <span class="hlt">Driven</span> Bubble Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glosser, Connor; Lie, Jie; Dault, Daniel; Balasubramaniam, Shanker; Piermarocchi, Carlo</p> <p>2014-03-01</p> <p>The development of modalities for precise, targeted drug delivery has become increasingly important in medical care in recent years. Assemblages of microbubbles steered by acoustic pressure fields present one potential vehicle for such delivery. Modeling the collective response of multi-bubble systems to an intense, externally applied ultrasound field requires accurately capturing acoustic interactions between bubbles and the externally applied field, and their effect on the <span class="hlt">evolution</span> of bubble kinetics. In this work, we present a methodology for multiphysics simulation based on an efficient transient boundary integral equation (TBIE) coupled with molecular <span class="hlt">dynamics</span> (MD) to compute trajectories of multiple acoustically interacting bubbles in an ideal fluid under pulsed acoustic excitation. For arbitrary configurations of spherical bubbles, the TBIE solver self-consistently models transient surface pressure distributions at bubble-fluid interfaces due to acoustic interactions and relative potential flows induced by bubble motion. Forces derived from the resulting pressure distributions act as driving terms in the MD update at each timestep. The resulting method efficiently and accurately captures individual bubble <span class="hlt">dynamics</span> for clouds containing up to hundreds of bubbles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARP18001J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARP18001J"><span>Electrically <span class="hlt">driven</span> magnetization <span class="hlt">dynamics</span> in yttrium iron garnet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jungfleisch, Matthias Benjamin</p> <p></p> <p>Creation and manipulation of magnetization states by spin-orbital torques are important for novel spintronics applications. Magnetic insulators were mostly ignored for this particular purpose, despite their low Gilbert damping, which makes them outstanding materials for magnonic applications and investigation of nonlinear spin-wave phenomena. Here, we demonstrate the propagation of spin-wave modes in micro-structured yttrium iron garnet (Y3Fe5O12,YIG) stripes. Spin waves propagating along the long side of the stripe are detected by means of spatially-resolved Brillouin light scattering (BLS) microscopy. The propagation distance of spin waves is determined in the linear regime, where an exponential decay of 10 μm is observed. We also explored the possibility of driving magnetization <span class="hlt">dynamics</span> with spin Hall effects (SHE) in bilayers of YIG/Pt microstructures. For this purpose we adopted a spin-transfer torque ferromagnetic resonance (ST-FMR) approach. Here a rf charge current is passed through the Pt layer, which generates a spin-transfer torque at the interface from an oscillating spin current via the SHE. This gives rise to a resonant excitation of the magnetization <span class="hlt">dynamics</span>. In all metallic systems the magnetization <span class="hlt">dynamics</span> is detected via the homodyne anisotropic magnetoresistance of the ferromagnetic layer. However, since there is no charge flowing through ferromagnetic insulators there is no anisotropic magnetoresistance. Instead, we show that for the case of YIG/Pt the spin Hall magnetoresistance can be used. Our measured voltage spectra can be well fitted to an analytical model evidencing that the ST-FMR concept can be extended to insulating systems. Furthermore, we employ spatially-resolved BLS spectroscopy to map the ST-FMR <span class="hlt">driven</span> spin <span class="hlt">dynamics</span>. We observe the formation of a strong, self-localized spin-wave intensity in the center of the sample. This spin-wave `bullet' is created due to nonlinear cross coupling of eigenmodes existing in the magnetic</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhLB..718.1176N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhLB..718.1176N"><span>Impact of rotation-<span class="hlt">driven</span> particle repopulation on the thermal <span class="hlt">evolution</span> of pulsars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Negreiros, Rodrigo; Schramm, Stefan; Weber, Fridolin</p> <p>2013-01-01</p> <p><span class="hlt">Driven</span> by the loss of energy, isolated rotating neutron stars (pulsars) are gradually slowing down to lower frequencies, which increases the tremendous compression of the matter inside of them. This increase in compression changes both the global properties of rotating neutron stars as well as their hadronic core compositions. Both effects may register themselves observationally in the thermal <span class="hlt">evolution</span> of such stars, as demonstrated in this Letter. The rotation-<span class="hlt">driven</span> particle process which we consider here is the direct Urca (DU) process, which is known to become operative in neutron stars if the number of protons in the stellar core exceeds a critical limit of around 11% to 15%. We find that neutron stars spinning down from moderately high rotation rates of a few hundred Hertz may be creating just the right conditions where the DU process becomes operative, leading to an observable effect (enhanced cooling) in the temperature <span class="hlt">evolution</span> of such neutron stars. As it turns out, the rotation-<span class="hlt">driven</span> DU process could explain the unusual temperature <span class="hlt">evolution</span> observed for the neutron star in Cas A, provided the mass of this neutron star lies in the range of 1.5 to 1.9M⊙ and its rotational frequency at birth was between 40 (400 Hz) and 70% (800 Hz) of the Kepler (mass shedding) frequency, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/908126','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/908126"><span><span class="hlt">Dynamic</span> Data-<span class="hlt">Driven</span> Event Reconstruction for Atmospheric Releases</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kosovic, B; Belles, R; Chow, F K; Monache, L D; Dyer, K; Glascoe, L; Hanley, W; Johannesson, G; Larsen, S; Loosmore, G; Lundquist, J K; Mirin, A; Neuman, S; Nitao, J; Serban, R; Sugiyama, G; Aines, R</p> <p>2007-02-22</p> <p>Accidental or terrorist releases of hazardous materials into the atmosphere can impact large populations and cause significant loss of life or property damage. Plume predictions have been shown to be extremely valuable in guiding an effective and timely response. The two greatest sources of uncertainty in the prediction of the consequences of hazardous atmospheric releases result from poorly characterized source terms and lack of knowledge about the state of the atmosphere as reflected in the available meteorological data. In this report, we discuss the development of a new event reconstruction methodology that provides probabilistic source term estimates from field measurement data for both accidental and clandestine releases. Accurate plume dispersion prediction requires the following questions to be answered: What was released? When was it released? How much material was released? Where was it released? We have developed a <span class="hlt">dynamic</span> data-<span class="hlt">driven</span> event reconstruction capability which couples data and predictive models through Bayesian inference to obtain a solution to this inverse problem. The solution consists of a probability distribution of unknown source term parameters. For consequence assessment, we then use this probability distribution to construct a ''''composite'' forward plume prediction which accounts for the uncertainties in the source term. Since in most cases of practical significance it is impossible to find a closed form solution, Bayesian inference is accomplished by utilizing stochastic sampling methods. This approach takes into consideration both measurement and forward model errors and thus incorporates all the sources of uncertainty in the solution to the inverse problem. Stochastic sampling methods have the additional advantage of being suitable for problems characterized by a non-Gaussian distribution of source term parameters and for cases in which the underlying <span class="hlt">dynamical</span> system is non-linear. We initially developed a Markov Chain Monte</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4569562','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4569562"><span>Diversity Waves in Collapse-<span class="hlt">Driven</span> Population <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Maslov, Sergei; Sneppen, Kim</p> <p>2015-01-01</p> <p>Populations of species in ecosystems are often constrained by availability of resources within their environment. In effect this means that a growth of one population, needs to be balanced by comparable reduction in populations of others. In neutral models of biodiversity all populations are assumed to change incrementally due to stochastic births and deaths of individuals. Here we propose and model another redistribution mechanism <span class="hlt">driven</span> by abrupt and severe reduction in size of the population of a single species freeing up resources for the remaining ones. This mechanism may be relevant e.g. for communities of bacteria, with strain-specific collapses caused e.g. by invading bacteriophages, or for other ecosystems where infectious diseases play an important role. The emergent <span class="hlt">dynamics</span> of our system is characterized by cyclic ‘‘diversity waves’’ triggered by collapses of globally dominating populations. The population diversity peaks at the beginning of each wave and exponentially decreases afterwards. Species abundances have bimodal time-aggregated distribution with the lower peak formed by populations of recently collapsed or newly introduced species while the upper peak - species that has not yet collapsed in the current wave. In most waves both upper and lower peaks are composed of several smaller peaks. This self-organized hierarchical peak structure has a long-term memory transmitted across several waves. It gives rise to a scale-free tail of the time-aggregated population distribution with a universal exponent of 1.7. We show that diversity wave <span class="hlt">dynamics</span> is robust with respect to variations in the rules of our model such as diffusion between multiple environments, species-specific growth and extinction rates, and bet-hedging strategies. PMID:26367172</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26367172','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26367172"><span>Diversity Waves in Collapse-<span class="hlt">Driven</span> Population <span class="hlt">Dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maslov, Sergei; Sneppen, Kim</p> <p>2015-09-01</p> <p>Populations of species in ecosystems are often constrained by availability of resources within their environment. In effect this means that a growth of one population, needs to be balanced by comparable reduction in populations of others. In neutral models of biodiversity all populations are assumed to change incrementally due to stochastic births and deaths of individuals. Here we propose and model another redistribution mechanism <span class="hlt">driven</span> by abrupt and severe reduction in size of the population of a single species freeing up resources for the remaining ones. This mechanism may be relevant e.g. for communities of bacteria, with strain-specific collapses caused e.g. by invading bacteriophages, or for other ecosystems where infectious diseases play an important role. The emergent <span class="hlt">dynamics</span> of our system is characterized by cyclic ''diversity waves'' triggered by collapses of globally dominating populations. The population diversity peaks at the beginning of each wave and exponentially decreases afterwards. Species abundances have bimodal time-aggregated distribution with the lower peak formed by populations of recently collapsed or newly introduced species while the upper peak--species that has not yet collapsed in the current wave. In most waves both upper and lower peaks are composed of several smaller peaks. This self-organized hierarchical peak structure has a long-term memory transmitted across several waves. It gives rise to a scale-free tail of the time-aggregated population distribution with a universal exponent of 1.7. We show that diversity wave <span class="hlt">dynamics</span> is robust with respect to variations in the rules of our model such as diffusion between multiple environments, species-specific growth and extinction rates, and bet-hedging strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1214532-diversity-waves-collapse-driven-population-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1214532-diversity-waves-collapse-driven-population-dynamics"><span>Diversity waves in collapse-<span class="hlt">driven</span> population <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Maslov, Sergei; Sneppen, Kim</p> <p>2015-09-14</p> <p>Populations of species in ecosystems are often constrained by availability of resources within their environment. In effect this means that a growth of one population, needs to be balanced by comparable reduction in populations of others. In neutral models of biodiversity all populations are assumed to change incrementally due to stochastic births and deaths of individuals. Here we propose and model another redistribution mechanism <span class="hlt">driven</span> by abrupt and severe collapses of the entire population of a single species freeing up resources for the remaining ones. This mechanism may be relevant e.g. for communities of bacteria, with strain-specific collapses caused e.g.more » by invading bacteriophages, or for other ecosystems where infectious diseases play an important role. The emergent <span class="hlt">dynamics</span> of our system is cyclic ‘‘diversity waves’’ triggered by collapses of globally dominating populations. The population diversity peaks at the beginning of each wave and exponentially decreases afterwards. Species abundances are characterized by a bimodal time-aggregated distribution with the lower peak formed by populations of recently collapsed or newly introduced species while the upper peak - species that has not yet collapsed in the current wave. In most waves both upper and lower peaks are composed of several smaller peaks. This self-organized hierarchical peak structure has a long-term memory transmitted across several waves. It gives rise to a scale-free tail of the time-aggregated population distribution with a universal exponent of 1.7. We show that diversity wave <span class="hlt">dynamics</span> is robust with respect to variations in the rules of our model such as diffusion between multiple environments, species-specific growth and extinction rates, and bet-hedging strategies.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM22B..02K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM22B..02K"><span>Radiation Belt Transport <span class="hlt">Driven</span> by Solar Wind <span class="hlt">Dynamic</span> Pressure Fluctuations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kress, B. T.; Hudson, M. K.; Ukhorskiy, A. Y.; Mueller, H.</p> <p>2012-12-01</p> <p>The creation of the Earth's outer zone radiation belts is attributed to earthward transport and adiabatic acceleration of electrons by drift-resonant interactions with electromagnetic fluctuations in the magnetosphere. Three types of radial transport <span class="hlt">driven</span> by solar wind <span class="hlt">dynamic</span> pressure fluctuations that have been identified are: (1) radial diffusion [Falthammer, 1965], (2) significant changes in the phase space density radial profile due to a single or few ULF drift-resonant interactions [Ukhorskiy et al., 2006; Degeling et al., 2008], and (3) shock associated injections of radiation belt electrons occurring in less than a drift period [Li et al., 1993]. A progress report will be given on work to fully characterize different forms of radial transport and their effect on the Earth's radiation belts. The work is being carried out by computing test-particle trajectories in electric and magnetic fields from a simple analytic ULF field model and from global MHD simulations of the magnetosphere. Degeling, A. W., L. G. Ozeke, R. Rankin, I. R. Mann, and K. Kabin (2008), Drift resonant generation of peaked relativistic electron distributions by Pc 5 ULF waves, textit{J. Geophys. Res., 113}, A02208, doi:10.1029/2007JA012411. Fälthammar, C.-G. (1965), Effects of Time-Dependent Electric Fields on Geomagnetically Trapped Radiation, J. Geophys. Res., 70(11), 2503-2516, doi:10.1029/JZ070i011p02503. Li, X., I. Roth, M. Temerin, J. R. Wygant, M. K. Hudson, and J. B. Blake (1993), Simulation of the prompt energization and transport of radiation belt particles during the March 24, 1991 SSC, textit{Geophys. Res. Lett., 20}(22), 2423-2426, doi:10.1029/93GL02701. Ukhorskiy, A. Y., B. J. Anderson, K. Takahashi, and N. A. Tsyganenko (2006), Impact of ULF oscillations in solar wind <span class="hlt">dynamic</span> pressure on the outer radiation belt electrons, textit{Geophys. Res. Lett., 33}(6), L06111, doi:10.1029/2005GL024380.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1214532','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1214532"><span>Diversity waves in collapse-<span class="hlt">driven</span> population <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Maslov, Sergei; Sneppen, Kim</p> <p>2015-09-14</p> <p>Populations of species in ecosystems are often constrained by availability of resources within their environment. In effect this means that a growth of one population, needs to be balanced by comparable reduction in populations of others. In neutral models of biodiversity all populations are assumed to change incrementally due to stochastic births and deaths of individuals. Here we propose and model another redistribution mechanism <span class="hlt">driven</span> by abrupt and severe collapses of the entire population of a single species freeing up resources for the remaining ones. This mechanism may be relevant e.g. for communities of bacteria, with strain-specific collapses caused e.g. by invading bacteriophages, or for other ecosystems where infectious diseases play an important role. The emergent <span class="hlt">dynamics</span> of our system is cyclic ‘‘diversity waves’’ triggered by collapses of globally dominating populations. The population diversity peaks at the beginning of each wave and exponentially decreases afterwards. Species abundances are characterized by a bimodal time-aggregated distribution with the lower peak formed by populations of recently collapsed or newly introduced species while the upper peak - species that has not yet collapsed in the current wave. In most waves both upper and lower peaks are composed of several smaller peaks. This self-organized hierarchical peak structure has a long-term memory transmitted across several waves. It gives rise to a scale-free tail of the time-aggregated population distribution with a universal exponent of 1.7. We show that diversity wave <span class="hlt">dynamics</span> is robust with respect to variations in the rules of our model such as diffusion between multiple environments, species-specific growth and extinction rates, and bet-hedging strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2254601N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2254601N"><span>Companion-<span class="hlt">driven</span> <span class="hlt">dynamics</span> in hot Jupiter systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ngo, Henry; Batygin, Konstantin; Knutson, Heather A.; Lewis, Nikole K.; de Wit, Julien</p> <p>2015-08-01</p> <p>Hot Jupiters are giant planets found on orbits that lie in close proximity to their host stars. In this region, the process of tidal dissipation is believed to be generally efficient, and should act to circularize planetary orbits on timescales much shorter than the inferred ages of the observed stars. However, at time of writing, one in six known hot Jupiters have eccentricities inconsistent with zero at the three sigma level and about one in twelve have eccentricities greater than 0.2. This discrepancy hints at the existence of a <span class="hlt">dynamical</span> mechanism that acts to maintain hot Jupiter eccentricities in face of tidal dissipation for extended periods of time. Our recent radial velocity (RV) and direct imaging surveys find that 70% of hot Jupiter systems are expected to host a distant planetary or stellar mass companion. In this work, we examine whether <span class="hlt">dynamical</span> interactions with these long period companions could be responsible for the excited hot Jupiter eccentricities. Specifically, we consider the one of the most eccentric known hot Jupiter systems, HAT-P-2, as a case study. The inner planet in this system has a mass approximately ten times that of Jupiter, a semi-major axis of 0.07 AU, and an orbital eccentricity of 0.5. Long-term radial velocity monitoring has revealed the presence of an even more massive outer companion located beyond 4 AU with a partially constrained orbit. We examine different <span class="hlt">dynamical</span> scenarios for this system in order to determine whether or not this outer companion might be responsible for the inner planet's unusually large orbital eccentricity, and make predictions for the short-term orbital <span class="hlt">evolution</span> of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...121m5104L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...121m5104L"><span>Temperature dependent <span class="hlt">evolution</span> of <span class="hlt">dynamic</span> heterogeneity in metallic glass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luo, P.; Li, M. X.; Jiang, H. Y.; Wen, P.; Bai, H. Y.; Wang, W. H.</p> <p>2017-04-01</p> <p>Substantial efforts in theoretical and experimental studies have demonstrated that the <span class="hlt">dynamics</span> in supercooled liquids is spatially heterogeneous. However, a complete description concerning the <span class="hlt">dynamic</span> heterogeneity <span class="hlt">evolution</span> from liquid to rigid glass is still lacking. Here, by a combining study of the <span class="hlt">dynamic</span> and static mechanical responses, we quantify the characterization of <span class="hlt">dynamic</span> heterogeneity and its temperature <span class="hlt">evolution</span> spanning an unprecedented broad temperature range in metallic glass. We show that the <span class="hlt">dynamic</span> heterogeneity persists from the warm liquid state into the rigid glassy state and becomes progressively pronounced with cooling, accompanied by increasing breadth of the relaxation rate dispersion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9205E..02N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9205E..02N"><span><span class="hlt">Dynamic</span> data <span class="hlt">driven</span> bidirectional reflectance distribution function measurement system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nauyoks, Stephen E.; Freda, Sam; Marciniak, Michael A.</p> <p>2014-09-01</p> <p>The bidirectional reflectance distribution function (BRDF) is a fitted distribution function that defines the scatter of light off of a surface. The BRDF is dependent on the directions of both the incident and scattered light. Because of the vastness of the measurement space of all possible incident and reflected directions, the calculation of BRDF is usually performed using a minimal amount of measured data. This may lead to poor fits and uncertainty in certain regions of incidence or reflection. A <span class="hlt">dynamic</span> data <span class="hlt">driven</span> application system (DDDAS) is a concept that uses an algorithm on collected data to influence the collection space of future data acquisition. The authors propose a DDD-BRDF algorithm that fits BRDF data as it is being acquired and uses on-the-fly fittings of various BRDF models to adjust the potential measurement space. In doing so, it is hoped to find the best model to fit a surface and the best global fit of the BRDF with a minimum amount of collection space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19708755','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19708755"><span>Molecular <span class="hlt">dynamics</span> study of thermal-<span class="hlt">driven</span> methane hydrate dissociation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>English, Niall J; Phelan, Gráinne M</p> <p>2009-08-21</p> <p>Nonequilibrium molecular <span class="hlt">dynamics</span> simulations have been performed to investigate the thermal-<span class="hlt">driven</span> breakup of both spherical methane hydrate nanocrystallites (with radii of approximately 18 and 21 A) and planar methane hydrate interfaces in liquid water at 280-340 K. The melting temperatures of each cluster were estimated, and dissociation was observed to be strongly dependent on temperature, with higher dissociation rates at larger overtemperatures vis-a-vis melting. For the 18 and 21 A radius nanocrystals, breakup was also seen to be dependent on cluster size, and different methane compositions (85%, 95%, and 100% of maximum theoretical occupation) in the planar case also lead to slight differences in the initial dissociation rate. In all cases, the diffusion of the methane into the surrounding liquid water was found to be an important step limiting the overall rate of breakup. A simple coupled mass and heat transfer model has been devised for both the spherical and planar hydrate systems that explains these findings, and distinguishes between the role of the overall thermal driving force and methane diffusional mass transfer in controlling the break-up rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1011663','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1011663"><span>Data-<span class="hlt">driven</span> optimization of <span class="hlt">dynamic</span> reconfigurable systems of systems.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tucker, Conrad S.; Eddy, John P.</p> <p>2010-11-01</p> <p>This report documents the results of a Strategic Partnership (aka University Collaboration) LDRD program between Sandia National Laboratories and the University of Illinois at Urbana-Champagne. The project is titled 'Data-<span class="hlt">Driven</span> Optimization of <span class="hlt">Dynamic</span> Reconfigurable Systems of Systems' and was conducted during FY 2009 and FY 2010. The purpose of this study was to determine and implement ways to incorporate real-time data mining and information discovery into existing Systems of Systems (SoS) modeling capabilities. Current SoS modeling is typically conducted in an iterative manner in which replications are carried out in order to quantify variation in the simulation results. The expense of many replications for large simulations, especially when considering the need for optimization, sensitivity analysis, and uncertainty quantification, can be prohibitive. In addition, extracting useful information from the resulting large datasets is a challenging task. This work demonstrates methods of identifying trends and other forms of information in datasets that can be used on a wide range of applications such as quantifying the strength of various inputs on outputs, identifying the sources of variation in the simulation, and potentially steering an optimization process for improved efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7176191','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7176191"><span>Investigation of the <span class="hlt">dynamic</span> behavior of laser-<span class="hlt">driven</span> flyers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Trott, W.M. )</p> <p>1994-07-10</p> <p>Various aspects of the <span class="hlt">dynamic</span> behavior of laser-accelerated flyer plates (e.g., planarity, cohesion, thickness, etc.) have been examined using several high-speed optical techniques. Images of accelerating flyers have been obtained by means of fast-framing photography and with an electronic image converter streak camera operated in an image motion configuration. These data are compared to records of flyer velocity vs. time as a function of laser fluence as well as impact particle velocity measurements on lithium fluoride witness plates.'' Flyer materials examined include pure aluminum and a composite material containing a thin layer of aluminum oxide. Composite flyers exhibit superior performance due to better planarity and cohesion, increased thickness vs. displacement, and significantly higher velocity for a given driving energy. With proper tailoring of flyer properties and driving laser parameters, laser-<span class="hlt">driven</span> acceleration of thin flyer plates offers a promising, laboratory-scale approach to quantitative studies requiring well-controlled, short-pulse shcok compression. [copyright]American Institute of Physics</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJMPC..2450081X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJMPC..2450081X"><span><span class="hlt">Dynamic</span> <span class="hlt">Evolution</span> Model Based on Social Network Services</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Xi; Gou, Zhi-Jian; Zhang, Shi-Bin; Zhao, Wen</p> <p>2013-11-01</p> <p>Based on the analysis of evolutionary characteristics of public opinion in social networking services (SNS), in the paper we propose a <span class="hlt">dynamic</span> <span class="hlt">evolution</span> model, in which opinions are coupled with topology. This model shows the clustering phenomenon of opinions in <span class="hlt">dynamic</span> network <span class="hlt">evolution</span>. The simulation results show that the model can fit the data from a social network site. The <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of networks accelerates the opinion, separation and aggregation. The scale and the number of clusters are influenced by confidence limit and rewiring probability. <span class="hlt">Dynamic</span> changes of the topology reduce the number of isolated nodes, while the increased confidence limit allows nodes to communicate more sufficiently. The two effects make the distribution of opinion more neutral. The <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of networks generates central clusters with high connectivity and high betweenness, which make it difficult to control public opinions in SNS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27457095','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27457095"><span>Locally dispersing populations in heterogeneous <span class="hlt">dynamic</span> landscapes with spatiotemporal correlations. II. Habitat <span class="hlt">driven</span> by voter <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hiebeler, David E; Hill, Jack L</p> <p>2016-10-21</p> <p>We examine a spatially explicit population model on a <span class="hlt">dynamic</span> landscape with suitable and unsuitable habitat <span class="hlt">driven</span> by voter or contagion <span class="hlt">dynamics</span>. We consider four cases, consisting of all combinations of local and global interactions for both population dispersal and habitat <span class="hlt">dynamics</span>. For both local and global population dispersal, using local habitat <span class="hlt">dynamics</span> always increases population density relative to the case with global habitat <span class="hlt">dynamics</span>, due to the resulting segregation of habitat turnover, decrease in effective habitat turnover rate, and presence of stable habitat corridors. With global habitat <span class="hlt">dynamics</span>, a population using local dispersal exhibits lower density than one with global dispersal due to local crowding as well as frequent disturbance due to habitat transitions. On the other hand, with local habitat <span class="hlt">dynamics</span>, a population using local dispersal can exploit suitable habitat patches and use <span class="hlt">dynamic</span> corridors to colonize new regions. The latter effect is not seen with static landscapes, where clustered habitat can lead to the isolation of suitable patches due to surrounding unsuitable habitat. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AnMP....3...97B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AnMP....3...97B"><span>Construction of a state <span class="hlt">evolution</span> for Kawasaki <span class="hlt">dynamics</span> in continuum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berns, Christoph; Kondratiev, Yuri; Kutoviy, Oleksandr</p> <p>2013-06-01</p> <p>We consider conservative, non-equilibrium stochastic jump <span class="hlt">dynamics</span> of interacting particles in continuum. These <span class="hlt">dynamics</span> have a (grand canonical) Gibbs measure as invariant measure. The problem of existence of these <span class="hlt">dynamics</span> is studied. The corresponding time <span class="hlt">evolution</span> of correlation functions is constructed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002DDA....33.1504S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002DDA....33.1504S"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of comet nucleus rotation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scheeres, D. J.; Sidorenko, V. V.; Neishtadt, A. I.; Vasiliev, A. A.</p> <p>2002-09-01</p> <p>The rotational <span class="hlt">dynamics</span> of outgassing cometary nuclei are investigated analytically. We develop a general theory for the <span class="hlt">evolution</span> of a comet nucleus' rotation state using averaging theory and assuming that the outgassing torques are a function of solar insolation and heliocentric distance. The resulting solutions are a function of the nucleus inertia ellipsoid, its outgassing properties, its heliocentric orbit, and the assumed distribution of active regions on its surface. We find that the long-term <span class="hlt">evolution</span> of the comet nucleus rotation is a strong function of the distribution of active regions over its surface. In particular, we find that nuclei with nearly axisymmetric inertia ellipsoids and a uniformly active surface will tend towards a rotation state that has a nutation angle of ~ 55 degrees and its angular momentum perpendicular to the sun-perihelion direction. If such a comet nucleus has only one isolated active region, it will tend towards a zero nutation angle with its approximate symmetry axis and rotational angular momentum aligned parallel to the sun-perihelion direction. In the general case for an inertia ellipsoid that is not close to being axisymmetric we find a much richer set of possible steady-state solutions that are stable, ranging from rotation about the maximum moment of the inertia axis, to SAM and LAM non-principal axis rotation states. The resulting stable rotation states are a strong function of outgassing activity distribution, which we show using a simplified model of the comet Halley nucleus. Also, we demonstrate that comet Borrely observations are consistent with a stable rotation state. Our results can be used to discriminate between competing theories of comet outgassing based on a nucelus' rotation state. They also allow for a range of plausible a priori constraints to be placed on a comet's rotation state to aid in the interpretation of its outgassing structure. This work was supported by the NASA JURRISS program under Grant NAG5</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhDT.......185F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhDT.......185F"><span><span class="hlt">Dynamics</span> and <span class="hlt">evolution</span> of dense stellar systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fregeau, John M.</p> <p>2004-10-01</p> <p>The research presented in this thesis comprises a theoretical study of several aspects relating to the <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of dense stellar systems such as globular clusters. First, I present the results of a study of mass segregation in two-component star clusters, based on a large number of numerical N-body simulations using our Monte-Carlo code. Heavy objects, which could represent stellar remnants such as neutron stars or black holes, exhibit behavior that is in quantitative agreement with simple analytical arguments. Light objects, which could represent free-floating planets or brown dwarfs, are predominantly lost from the cluster, as expected from simple analytical arguments, but may remain in the halo in larger numbers than expected. Using a recent null detection of planetary-mass microlensing events in M22, I find an upper limit of ˜25% at the 63% confidence level for the current mass fraction of M22 in the form of very low-mass objects. Turning to more realistic clusters, I present a study of the <span class="hlt">evolution</span> of clusters containing primordial binaries, based on an enhanced version of the Monte-Carlo code that treats binary interactions via cross sections and analytical prescriptions. All models exhibit a long-lived “binary burning” phase lasting many tens of relaxation times. The structural parameters of the models during this phase match well those of most observed Galactic globular clusters. At the end of this phase, clusters that have survived tidal disruption undergo deep core collapse, followed by gravothermal oscillations. The results clearly show that the presence of even a small fraction of binaries in a cluster is sufficient to support the core against collapse significantly beyond the normal core collapse time predicted without the presence of binaries. For tidally truncated systems, collapse is delayed sufficiently that the cluster will undergo complete tidal disruption before core collapse. Moving a step beyond analytical prescriptions, I</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADP011162','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADP011162"><span>Prediction of Combustion-<span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Instability for High Performance Gas Turbine Combustors: Part I</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2001-06-01</p> <p>Hsiao, G., Pandalai, R., Hura, H., and Mongia , H. C., "Chropulsio a p e -Vol. o mbustor, 1998. " Combustion <span class="hlt">Dynamic</span> Modeling for Gas Turbine...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO 11162 TITLE: Predicton of Combustion -<span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Instability for...UNCLASSIFIED , Click here to view PowerPoint presentation; Press Esc to exit ,: Prediction of Combustion -<span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Instability For High Performance Gas</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11502126','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11502126"><span>The <span class="hlt">Dynamics</span> of Marangoni-<span class="hlt">Driven</span> Local Film Drainage between Two Drops.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yeo, Leslie Y.; Matar, Omar K.; de Ortiz, E. Susana Perez; Hewitt, Geoffrey F.</p> <p>2001-09-01</p> <p>A study of Marangoni-<span class="hlt">driven</span> local continuous film drainage between two drops induced by an initially nonuniform interfacial distribution of insoluble surfactant is reported. Using the lubrication approximation, a coupled system of fourth-order nonlinear partial differential equations was derived to describe the spatio-temporal <span class="hlt">evolution</span> of the continuous film thickness and surfactant interfacial concentration. Numerical solutions of these governing equations were obtained using the Numerical Method of Lines with appropriate initial and boundary conditions. A full parametric study was undertaken to explore the effect of the viscosity ratio, background surfactant concentration, the surface Péclet number, and van der Waals interaction forces on the <span class="hlt">dynamics</span> of the draining film for the case where surfactant is present in trace amounts. Marangoni stresses were found to cause large deformations in the liquid film: Thickening of the film at the surfactant leading edge was accompanied by rapid and severe thinning far upstream. Under certain conditions, this severe thinning leads directly to film rupture due to the influence of van der Waals forces. Time scales for rupture, promoted by Marangoni-<span class="hlt">driven</span> local film drainage were compared with those associated with the dimpling effect, which accompanies the approach of two drops, and implications of the results of this study on drop coalescence are discussed. Copyright 2001 Academic Press.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22805093','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22805093"><span>Arms race co-<span class="hlt">evolution</span> of Magnaporthe oryzae AVR-Pik and rice Pik genes <span class="hlt">driven</span> by their physical interactions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kanzaki, Hiroyuki; Yoshida, Kentaro; Saitoh, Hiromasa; Fujisaki, Koki; Hirabuchi, Akiko; Alaux, Ludovic; Fournier, Elisabeth; Tharreau, Didier; Terauchi, Ryohei</p> <p>2012-12-01</p> <p>Attack and counter-attack impose strong reciprocal selection on pathogens and hosts, leading to development of arms race evolutionary <span class="hlt">dynamics</span>. Here we show that Magnaporthe oryzae avirulence gene AVR-Pik and the cognate rice resistance (R) gene Pik are highly variable, with multiple alleles in which DNA replacements cause amino acid changes. There is tight recognition specificity of the AVR-Pik alleles by the various Pik alleles. We found that AVR-Pik physically binds the N-terminal coiled-coil domain of Pik in a yeast two-hybrid assay as well as in an in planta co-immunoprecipitation assay. This binding specificity correlates with the recognition specificity between AVR and R genes. We propose that AVR-Pik and Pik are locked into arms race co-<span class="hlt">evolution</span> <span class="hlt">driven</span> by their direct physical interactions. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28753335','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28753335"><span>Generation and <span class="hlt">Evolution</span> of High-Mach-Number Laser-<span class="hlt">Driven</span> Magnetized Collisionless Shocks in the Laboratory.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaeffer, D B; Fox, W; Haberberger, D; Fiksel, G; Bhattacharjee, A; Barnak, D H; Hu, S X; Germaschewski, K</p> <p>2017-07-14</p> <p>We present the first laboratory generation of high-Mach-number magnetized collisionless shocks created through the interaction of an expanding laser-<span class="hlt">driven</span> plasma with a magnetized ambient plasma. Time-resolved, two-dimensional imaging of plasma density and magnetic fields shows the formation and <span class="hlt">evolution</span> of a supercritical shock propagating at magnetosonic Mach number M_{ms}≈12. Particle-in-cell simulations constrained by experimental data further detail the shock formation and separate <span class="hlt">dynamics</span> of the multi-ion-species ambient plasma. The results show that the shocks form on time scales as fast as one gyroperiod, aided by the efficient coupling of energy, and the generation of a magnetic barrier between the piston and ambient ions. The development of this experimental platform complements present remote sensing and spacecraft observations, and opens the way for controlled laboratory investigations of high-Mach number collisionless shocks, including the mechanisms and efficiency of particle acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.119b5001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.119b5001S"><span>Generation and <span class="hlt">Evolution</span> of High-Mach-Number Laser-<span class="hlt">Driven</span> Magnetized Collisionless Shocks in the Laboratory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schaeffer, D. B.; Fox, W.; Haberberger, D.; Fiksel, G.; Bhattacharjee, A.; Barnak, D. H.; Hu, S. X.; Germaschewski, K.</p> <p>2017-07-01</p> <p>We present the first laboratory generation of high-Mach-number magnetized collisionless shocks created through the interaction of an expanding laser-<span class="hlt">driven</span> plasma with a magnetized ambient plasma. Time-resolved, two-dimensional imaging of plasma density and magnetic fields shows the formation and <span class="hlt">evolution</span> of a supercritical shock propagating at magnetosonic Mach number Mms≈12 . Particle-in-cell simulations constrained by experimental data further detail the shock formation and separate <span class="hlt">dynamics</span> of the multi-ion-species ambient plasma. The results show that the shocks form on time scales as fast as one gyroperiod, aided by the efficient coupling of energy, and the generation of a magnetic barrier between the piston and ambient ions. The development of this experimental platform complements present remote sensing and spacecraft observations, and opens the way for controlled laboratory investigations of high-Mach number collisionless shocks, including the mechanisms and efficiency of particle acceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38..771Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38..771Z"><span>Mercury's Thermal <span class="hlt">Evolution</span>, <span class="hlt">Dynamical</span> Topography and Geoid</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ziethe, Ruth; Benkhoff, Johannes</p> <p></p> <p> stagnant lid comprises roughly half the mantle after only 0.5Ga. Since the rigid lithosphere does not take part in the convection anymore, the heat coming from the interior (due to the cooling of the large core) can only be transported through the lithosphere by thermal conduction. This is a significantly less effective mechanism of heat transport than convection and hence the lithosphere forms an insulating layer. As a result, the interior is kept relatively warm.Because the mantle is relatively shallow compared to the planet's radius, and additionally the thick stagnant lid is formed relatively rapid, the convection is confined to a layer of only about 200km to 300km. Convection structures are therefore relatively small structured. The flow patterns in the early <span class="hlt">evolution</span> show that mantle convection is characterized by numerous upwelling plumes, which are fed by the heat flow from the cooling core. These upwellings are relatively stable regarding their spatial position. As the core cools down the temperature anomalies become colder and less pronounced but not less numerous. In our calculations, a region of partial melt in the mantle forms immediately after the start of the model at a depths of roughly 220km. While in the entire lower mantle the temperature exceeds the solidus, the highest melt degrees can be found in the upwelling plumes. The partial molten region persists a significant time (up to 2.5Ga). How long the partial molten zone actually survives depends strongly on the initial conditions of the model. For instance, an outer layer with a reduced thermal conductivity would keep the lower mantle significantly warmer and a molten layer survives longer. The hot upwellings cause a surface deformation (<span class="hlt">dynamical</span> topography) which itself causes a gravity anomaly. Due to the weak constraints of important parameters (e.g. sulfur content of the core, mantle rheology, amount and distribution of radiogenic heat sources, planetary contraction, thermal conductivity, etc</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21451052','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21451052"><span><span class="hlt">EVOLUTION</span> OF MASSIVE STARS WITH PULSATION-<span class="hlt">DRIVEN</span> SUPERWINDS DURING THE RED SUPERGIANT PHASE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yoon, Sung-Chul</p> <p>2010-07-01</p> <p>Pulsations <span class="hlt">driven</span> by partial ionization of hydrogen in the envelope are often considered important for driving winds from red supergiants (RSGs). In particular, it has been suggested by some authors that the pulsation growth rate in an RSG can be high enough to trigger an unusually strong wind (or a superwind), when the luminosity-to-mass ratio becomes sufficiently large. Using both hydrostatic and hydrodynamic stellar <span class="hlt">evolution</span> models with initial masses ranging from 15 to 40 M{sub sun}, we investigate (1) how the pulsation growth rate depends on the global parameters of supergiant stars and (2) what would be the consequences of a pulsation-<span class="hlt">driven</span> superwind, if it occurred, for the late stages of massive star <span class="hlt">evolution</span>. We suggest that such a superwind history would be marked by a runaway increase, followed by a sudden decrease, of the wind's mass-loss rate. The impact on the late <span class="hlt">evolution</span> of massive stars would be substantial, with stars losing a huge fraction of their H-envelope even with a significantly lower initial mass than previously predicted. This might explain the observed lack of Type II-P supernova (SN) progenitors having initial mass higher than about 17 M{sub sun}. We also discuss possible implications for a subset of Type IIn SNe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1046103','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1046103"><span><span class="hlt">Dynamic</span> Data-<span class="hlt">Driven</span> Event Reconstruction for Atmospheric Releases</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mirin, A A; Kosovic, B</p> <p>2007-03-29</p> <p>Accidental or terrorist releases of hazardous materials into the atmosphere can impact large populations and cause significant loss of life or property damage. Plume predictions have been shown to be extremely valuable in guiding an effective and timely response. The two greatest sources of uncertainty in the prediction of the consequences of hazardous atmospheric releases result from poorly characterized source terms and lack of knowledge about the state of the atmosphere as reflected in the available meteorological data. We have developed a new event reconstruction methodology that provides probabilistic source term estimates from field measurement data for both accidental and clandestine releases. Accurate plume dispersion prediction requires the following questions to be answered: What was released? When was it released? How much material was released? Where was it released? We have developed a <span class="hlt">dynamic-data-driven</span> event reconstruction capability that couples data and predictive methods through Bayesian inference to obtain a solution to this inverse problem. The solution consists of a probability distribution of unknown source term parameters. For consequence assessment, we then use this probability distribution to construct a 'composite' forward plume prediction that accounts for the uncertainties in the source term. Since in most cases of practical significance it is impossible to find a closed form solution, Bayesian inference is accomplished by utilizing stochastic sampling methods. This approach takes into consideration both measurement and forward model errors and thus incorporates all the sources of uncertainty in the solution to the inverse problem. Stochastic sampling methods have the additional advantage of being suitable for problems characterized by a non-Gaussian distribution of source term parameters and for cases in which the underlying <span class="hlt">dynamical</span> system is nonlinear. We initially developed a Markov Chain Monte Carlo (MCMC) stochastic methodology</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...8a4035K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...8a4035K"><span>Complex Pattern Formation from Current-<span class="hlt">Driven</span> <span class="hlt">Dynamics</span> of Single-Layer Homoepitaxial Islands on Crystalline Conducting Substrates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Ashish; Dasgupta, Dwaipayan; Maroudas, Dimitrios</p> <p>2017-07-01</p> <p>We report a systematic study of complex pattern formation resulting from the <span class="hlt">driven</span> <span class="hlt">dynamics</span> of single-layer homoepitaxial islands on surfaces of face-centered-cubic (fcc) crystalline conducting substrates under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-<span class="hlt">driven</span> <span class="hlt">evolution</span> of rounded islands for an electric field oriented along the fast edge diffusion direction. For larger-than-critical island sizes on {110 } and {100 } fcc substrates, we show that multiple necking instabilities generate complex island patterns, including not-simply-connected void-containing islands mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the <span class="hlt">evolution</span> of the number of daughter islands and their average size and uniformity. The <span class="hlt">evolution</span> of the average island size follows a universal power-law scaling relation, and the <span class="hlt">evolution</span> of the total edge length of the islands in the complex pattern follows Kolmogorov-Johnson-Mehl-Avrami kinetics. Our study makes a strong case for the use of electric fields, as precisely controlled macroscopic forcing, toward surface patterning involving complex nanoscale features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25549018','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25549018"><span>Kinetics and cluster morphology <span class="hlt">evolution</span> of shear-<span class="hlt">driven</span> aggregation of well-stabilized colloids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meng, Xia; Wu, Hua; Morbidelli, Massimo</p> <p>2015-01-27</p> <p>We investigate the shear-<span class="hlt">driven</span> aggregation of polystyrene colloids that are stabilized by both fixed and surfactant charges, using a microchannel device, in various particle volume fractions. The objective is to understand how the primary particles evolve to clusters with shearing time, how the cluster morphology develops along the aggregation with the effect of breakage and restructuring, and whether non-Derjaguin-Landau-Verwey-Overbeek (DLVO) interactions are present, affecting the kinetics. The time <span class="hlt">evolution</span> of the primary particle conversion to big clusters is characterized by an induction time, followed by an explosive increase when the cluster size reaches a certain critical value, which confirms the self-acceleration kinetics developed in the literature. The size of the critical clusters has been quantified for the first time, and its scaling with the shear rate follows the literature prediction well. Moreover, analysis of the shear-<span class="hlt">driven</span> kinetics confirms the presence of substantial non-DLVO interactions in the given system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..467..307S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..467..307S"><span>Study of the critical behavior of the <span class="hlt">driven</span> lattice gas model with limited nonequilibrium <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saracco, Gustavo P.; Rubio Puzzo, M. Leticia; Bab, Marisa A.</p> <p>2017-02-01</p> <p>In this paper the nonequilibrium critical behavior is investigated using a variant of the well-known two-dimensional <span class="hlt">driven</span> lattice gas (DLG) model, called modified <span class="hlt">driven</span> lattice gas (MDLG). In this model, the application of the external field is regulated by a parameter p ɛ [ 0 , 1 ] in such a way that if p = 0, the field is not applied, and it becomes the Ising model, while if p = 1, the DLG model is recovered. The behavior of the model is investigated for several values of p by studying the <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of the system within the short-time regime in the neighborhood of a phase transition. It is found that the system experiences second-order phase transitions in all the interval of p for the density of particles ρ = 0.5. The determined critical temperatures Tc(p) are greater than the critical temperature of the Ising model TcI, and increase with p up to the critical temperature of the DLG model in the limit of infinite driving fields. The dependence of Tc(p) on p is compatible with a power-law behavior whose exponent is ψ = 0.27(3) . Furthermore, the complete set of the critical and the anisotropic exponents is estimated. For the smallest value of p, the ​<span class="hlt">dynamics</span> and β exponents are close to that calculated for the Ising model, and the anisotropic exponent Δ is near zero. As p is increased, the exponents and Δ change, meaning that the anisotropy effects increase. For the largest value investigated, the set of exponents approaches to that reported by the most recent theoretical framework developed for the DLG model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760030040&hterms=stellar+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstellar%2Bevolution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760030040&hterms=stellar+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstellar%2Bevolution"><span>Galactic <span class="hlt">evolution</span>. I - Single-zone models. [encompassing stellar <span class="hlt">evolution</span> and gas-star <span class="hlt">dynamic</span> theories</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thuan, T. X.; Hart, M. H.; Ostriker, J. P.</p> <p>1975-01-01</p> <p>The two basic approaches of physical theory required to calculate the <span class="hlt">evolution</span> of a galactic system are considered, taking into account stellar <span class="hlt">evolution</span> theory and the <span class="hlt">dynamics</span> of a gas-star system. Attention is given to intrinsic (stellar) physics, extrinsic (<span class="hlt">dynamical</span>) physics, and computations concerning the fractionation of an initial mass of gas into stars. The characteristics of a 'standard' model and its variants are discussed along with the results obtained with the aid of these models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760030040&hterms=evolution+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Devolution%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760030040&hterms=evolution+theory&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Devolution%2Btheory"><span>Galactic <span class="hlt">evolution</span>. I - Single-zone models. [encompassing stellar <span class="hlt">evolution</span> and gas-star <span class="hlt">dynamic</span> theories</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thuan, T. X.; Hart, M. H.; Ostriker, J. P.</p> <p>1975-01-01</p> <p>The two basic approaches of physical theory required to calculate the <span class="hlt">evolution</span> of a galactic system are considered, taking into account stellar <span class="hlt">evolution</span> theory and the <span class="hlt">dynamics</span> of a gas-star system. Attention is given to intrinsic (stellar) physics, extrinsic (<span class="hlt">dynamical</span>) physics, and computations concerning the fractionation of an initial mass of gas into stars. The characteristics of a 'standard' model and its variants are discussed along with the results obtained with the aid of these models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ClDy...42.1981V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ClDy...42.1981V"><span><span class="hlt">Dynamics</span> and predictability of a low-order wind-<span class="hlt">driven</span> ocean-atmosphere coupled model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vannitsem, Stéphane</p> <p>2014-04-01</p> <p>The <span class="hlt">dynamics</span> of a low-order coupled wind-<span class="hlt">driven</span> ocean-atmosphere system is investigated with emphasis on its predictability properties. The low-order coupled deterministic system is composed of a baroclinic atmosphere for which 12 dominant <span class="hlt">dynamical</span> modes are only retained (Charney and Straus in J Atmos Sci 37:1157-1176, 1980) and a wind-<span class="hlt">driven</span>, quasi-geostrophic and reduced-gravity shallow ocean whose field is truncated to four dominant modes able to reproduce the large scale oceanic gyres (Pierini in J Phys Oceanogr 41:1585-1604, 2011). The two models are coupled through mechanical forcings only. The analysis of its <span class="hlt">dynamics</span> reveals first that under aperiodic atmospheric forcings only dominant single gyres (clockwise or counterclockwise) appear, while for periodic atmospheric solutions the double gyres emerge. In the present model domain setting context, this feature is related to the level of truncation of the atmospheric fields, as indicated by a preliminary analysis of the impact of higher wavenumber ("synoptic" scale) modes on the development of oceanic gyres. In the latter case, double gyres appear in the presence of a chaotic atmosphere. Second the <span class="hlt">dynamical</span> quantities characterizing the short-term predictability (Lyapunov exponents, Lyapunov dimension, Kolmogorov-Sinaï (KS) entropy) displays a complex dependence as a function of the key parameters of the system, namely the coupling strength and the external thermal forcing. In particular, the KS-entropy is increasing as a function of the coupling in most of the experiments, implying an increase of the rate of loss of information about the localization of the system on its attractor. Finally the <span class="hlt">dynamics</span> of the error is explored and indicates, in particular, a rich variety of short term behaviors of the error in the atmosphere depending on the (relative) amplitude of the initial error affecting the ocean, from polynomial ( at 2 + bt 3 + ct 4) up to exponential-like <span class="hlt">evolutions</span>. These features are explained</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5183323','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5183323"><span>Experimental investigation of the nonlinear <span class="hlt">evolution</span> of an impurity-<span class="hlt">driven</span> drift wave</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allen, G.R.; Yamada, M.; Rewoldt, G.; Tang, W.M.</p> <p>1982-04-01</p> <p>An impurity-<span class="hlt">driven</span> drift wave is observed to be destabilized by the reversed density gradient of a singly-ionized heavy-impurity-ion population in a Q-machine plasma. The <span class="hlt">evolution</span> of the instability is investigated as it progresses from the initial linear exponential growth phase, into a nonlinear saturated state, whereupon strong radially outward anomalous diffusion is observed. The relationship between the anomalous diffusion coefficient and the wave amplitude is in agreement with estimates obtained from the nonlinear drift-wave turbulence theory of Dupree.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JSP...154..751D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JSP...154..751D"><span><span class="hlt">Evolution</span> of the Distribution of Wealth in an Economic Environment <span class="hlt">Driven</span> by Local Nash Equilibria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Degond, Pierre; Liu, Jian-Guo; Ringhofer, Christian</p> <p>2014-02-01</p> <p>We present and analyze a model for the <span class="hlt">evolution</span> of the wealth distribution within a heterogeneous economic environment. The model considers a system of rational agents interacting in a game theoretical framework, through fairly general assumptions on the cost function. This <span class="hlt">evolution</span> drives the <span class="hlt">dynamic</span> of the agents in both wealth and economic configuration variables. We consider a regime of scale separation where the large scale <span class="hlt">dynamics</span> is given by a hydrodynamic closure with a Nash equilibrium serving as the local thermodynamic equilibrium. The result is a system of gas <span class="hlt">dynamics</span>-type equations for the density and average wealth of the agents on large scales. We recover the inverse gamma distribution as an equilibrium in the particular case of quadratic cost functions which has been previously considered in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990054647','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990054647"><span>Reduction of Large <span class="hlt">Dynamical</span> Systems by Minimization of <span class="hlt">Evolution</span> Rate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Girimaji, Sharath S.</p> <p>1999-01-01</p> <p>Reduction of a large system of equations to a lower-dimensional system of similar <span class="hlt">dynamics</span> is investigated. For <span class="hlt">dynamical</span> systems with disparate timescales, a criterion for determining redundant dimensions and a general reduction method based on the minimization of <span class="hlt">evolution</span> rate are proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4739...28V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4739...28V"><span>Evolutionary programming for goal-<span class="hlt">driven</span> <span class="hlt">dynamic</span> planning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vaccaro, James M.; Guest, Clark C.; Ross, David O.</p> <p>2002-03-01</p> <p>Many complex artificial intelligence (IA) problems are goal- <span class="hlt">driven</span> in nature and the opportunity exists to realize the benefits of a goal-oriented solution. In many cases, such as in command and control, a goal-oriented approach may be the only option. One of many appropriate applications for such an approach is War Gaming. War Gaming is an important tool for command and control because it provides a set of alternative courses of actions so that military leaders can contemplate their next move in the battlefield. For instance, when making decisions that save lives, it is necessary to completely understand the consequences of a given order. A goal-oriented approach provides a slowly evolving tractably reasoned solution that inherently follows one of the principles of war: namely concentration on the objective. Future decision-making will depend not only on the battlefield, but also on a virtual world where military leaders can wage wars and determine their options by playing computer war games much like the real world. The problem with these games is that the built-in AI does not learn nor adapt and many times cheats, because the intelligent player has access to all the information, while the user has access to limited information provided on a display. These games are written for the purpose of entertainment and actions are calculated a priori and off-line, and are made prior or during their development. With these games getting more sophisticated in structure and less domain specific in scope, there needs to be a more general intelligent player that can adapt and learn in case the battlefield situations or the rules of engagement change. One such war game that might be considered is Risk. Risk incorporates the principles of war, is a top-down scalable model, and provides a good application for testing a variety of goal- oriented AI approaches. By integrating a goal-oriented hybrid approach, one can develop a program that plays the Risk game effectively and move</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23687064','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23687064"><span>Photoinduced biphasic hydrogen <span class="hlt">evolution</span>: decamethylosmocene as a light-<span class="hlt">driven</span> electron donor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ge, Peiyu; Olaya, Astrid J; Scanlon, Micheál D; Hatay Patir, Imren; Vrubel, Heron; Girault, Hubert H</p> <p>2013-07-22</p> <p>Excitation of the weak electron donor decamethylosmocene on illumination with white light produces an excited-state species capable of reducing organically solubilized protons under biphasic conditions. Insight into the mechanism and kinetics of light-<span class="hlt">driven</span> biphasic hydrogen <span class="hlt">evolution</span> are obtained by analysis with gas chromatography, cyclic voltammetry, and UV/Vis and (1)H NMR spectroscopy. Formation of decamethylosmocenium hydride, which occurs prior to hydrogen <span class="hlt">evolution</span>, is a rapid step relative to hydrogen release and takes place independently of light activation. Remarkably, hydride formation occurs with greater efficiency (ca. 90% conversion) under biphasic conditions than when the reaction is carried out in an acidified single organic phase (ca. 20% conversion). Cyclic voltammetry studies reveal that decamethylosmocene has a higher proton affinity than either decamethylferrocene or osmocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24670947','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24670947"><span>Footprints of directional selection in wild Atlantic salmon populations: evidence for parasite-<span class="hlt">driven</span> <span class="hlt">evolution</span>?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zueva, Ksenia J; Lumme, Jaakko; Veselov, Alexey E; Kent, Matthew P; Lien, Sigbjørn; Primmer, Craig R</p> <p>2014-01-01</p> <p>Mechanisms of host-parasite co-adaptation have long been of interest in evolutionary biology; however, determining the genetic basis of parasite resistance has been challenging. Current advances in genome technologies provide new opportunities for obtaining a genome-scale view of the action of parasite-<span class="hlt">driven</span> natural selection in wild populations and thus facilitate the search for specific genomic regions underlying inter-population differences in pathogen response. European populations of Atlantic salmon (Salmo salar L.) exhibit natural variance in susceptibility levels to the ectoparasite Gyrodactylus salaris Malmberg 1957, ranging from resistance to extreme susceptibility, and are therefore a good model for studying the <span class="hlt">evolution</span> of virulence and resistance. However, distinguishing the molecular signatures of genetic drift and environment-associated selection in small populations such as land-locked Atlantic salmon populations presents a challenge, specifically in the search for pathogen-<span class="hlt">driven</span> selection. We used a novel genome-scan analysis approach that enabled us to i) identify signals of selection in salmon populations affected by varying levels of genetic drift and ii) separate potentially selected loci into the categories of pathogen (G. salaris)-<span class="hlt">driven</span> selection and selection acting upon other environmental characteristics. A total of 4631 single nucleotide polymorphisms (SNPs) were screened in Atlantic salmon from 12 different northern European populations. We identified three genomic regions potentially affected by parasite-<span class="hlt">driven</span> selection, as well as three regions presumably affected by salinity-<span class="hlt">driven</span> directional selection. Functional annotation of candidate SNPs is consistent with the role of the detected genomic regions in immune defence and, implicitly, in osmoregulation. These results provide new insights into the genetic basis of pathogen susceptibility in Atlantic salmon and will enable future searches for the specific genes involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3966780','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3966780"><span>Footprints of Directional Selection in Wild Atlantic Salmon Populations: Evidence for Parasite-<span class="hlt">Driven</span> <span class="hlt">Evolution</span>?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zueva, Ksenia J.; Lumme, Jaakko; Veselov, Alexey E.; Kent, Matthew P.; Lien, Sigbjørn; Primmer, Craig R.</p> <p>2014-01-01</p> <p>Mechanisms of host-parasite co-adaptation have long been of interest in evolutionary biology; however, determining the genetic basis of parasite resistance has been challenging. Current advances in genome technologies provide new opportunities for obtaining a genome-scale view of the action of parasite-<span class="hlt">driven</span> natural selection in wild populations and thus facilitate the search for specific genomic regions underlying inter-population differences in pathogen response. European populations of Atlantic salmon (Salmo salar L.) exhibit natural variance in susceptibility levels to the ectoparasite Gyrodactylus salaris Malmberg 1957, ranging from resistance to extreme susceptibility, and are therefore a good model for studying the <span class="hlt">evolution</span> of virulence and resistance. However, distinguishing the molecular signatures of genetic drift and environment-associated selection in small populations such as land-locked Atlantic salmon populations presents a challenge, specifically in the search for pathogen-<span class="hlt">driven</span> selection. We used a novel genome-scan analysis approach that enabled us to i) identify signals of selection in salmon populations affected by varying levels of genetic drift and ii) separate potentially selected loci into the categories of pathogen (G. salaris)-<span class="hlt">driven</span> selection and selection acting upon other environmental characteristics. A total of 4631 single nucleotide polymorphisms (SNPs) were screened in Atlantic salmon from 12 different northern European populations. We identified three genomic regions potentially affected by parasite-<span class="hlt">driven</span> selection, as well as three regions presumably affected by salinity-<span class="hlt">driven</span> directional selection. Functional annotation of candidate SNPs is consistent with the role of the detected genomic regions in immune defence and, implicitly, in osmoregulation. These results provide new insights into the genetic basis of pathogen susceptibility in Atlantic salmon and will enable future searches for the specific genes involved. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/894329','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/894329"><span><span class="hlt">Evolution</span> of a storm-<span class="hlt">driven</span> cloudy boundary layer in the Arctic</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Inoue, J; Kosovic, B; Curry, J A</p> <p>2003-10-24</p> <p>The cloudy boundary layer under stormy conditions during the summertime Arctic has been studied using observation from the SHEBA experiment and large-eddy simulations (LES). On 29 July 1998, a stable Arctic cloudy boundary layer event was observed after passage of a synoptic low. The local <span class="hlt">dynamic</span> and thermodynamic structure of the boundary layer was determined from aircraft measurement including analysis of turbulence, cloud microphysics and radiative properties. After the upper cloud layer advected over the existing cloud layer, the turbulent kinetic energy budget indicated that the cloud layer below 200 m was maintained predominantly by shear production. Observations of longwave radiation showed that cloud top cooling at the lower cloud top has been suppressed by radiative effects of the upper cloud layer. Our LES results demonstrate the importance of the combination of shear mixing near the surface and radiative cooling at the cloud top in the storm-<span class="hlt">driven</span> cloudy boundary layer. Once the low-level cloud reaches a certain height, depending on the amount of cloud-top cooling, the two sources of TKE production begin to separate in space under continuous stormy conditions, suggesting one possible mechanism for the cloud layering. The sensitivity tests suggest that the storm-<span class="hlt">driven</span> cloudy boundary layer is flexibly switched to the shear-<span class="hlt">driven</span> system due to the advection of upper clouds or the buoyantly <span class="hlt">driven</span> system due to the lack of the wind shear. A comparison is made of this storm-<span class="hlt">driven</span> boundary layer with the buoyantly <span class="hlt">driven</span> boundary layer previously described in the literature.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23306058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23306058"><span><span class="hlt">Evolution</span> of specialization under non-equilibrium population <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nurmi, Tuomas; Parvinen, Kalle</p> <p>2013-03-21</p> <p>We analyze the <span class="hlt">evolution</span> of specialization in resource utilization in a mechanistically underpinned discrete-time model using the adaptive <span class="hlt">dynamics</span> approach. We assume two nutritionally equivalent resources that in the absence of consumers grow sigmoidally towards a resource-specific carrying capacity. The consumers use resources according to the law of mass-action with rates involving trade-off. The resulting discrete-time model for the consumer population has over-compensatory <span class="hlt">dynamics</span>. We illuminate the way non-equilibrium population <span class="hlt">dynamics</span> affect the evolutionary <span class="hlt">dynamics</span> of the resource consumption rates, and show that <span class="hlt">evolution</span> to the trimorphic coexistence of a generalist and two specialists is possible due to asynchronous non-equilibrium population <span class="hlt">dynamics</span> of the specialists. In addition, various forms of cyclic evolutionary <span class="hlt">dynamics</span> are possible. Furthermore, evolutionary suicide may occur even without Allee effects and demographic stochasticity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatCo...6E6998R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatCo...6E6998R"><span>Volcano seismicity and ground deformation unveil the gravity-<span class="hlt">driven</span> magma discharge <span class="hlt">dynamics</span> of a volcanic eruption</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ripepe, Maurizio; Donne, Dario Delle; Genco, Riccardo; Maggio, Giuseppe; Pistolesi, Marco; Marchetti, Emanuele; Lacanna, Giorgio; Ulivieri, Giacomo; Poggi, Pasquale</p> <p>2015-05-01</p> <p>Effusive eruptions are explained as the mechanism by which volcanoes restore the equilibrium perturbed by magma rising in a chamber deep in the crust. Seismic, ground deformation and topographic measurements are compared with effusion rate during the 2007 Stromboli eruption, drawing an eruptive scenario that shifts our attention from the interior of the crust to the surface. The eruption is modelled as a gravity-<span class="hlt">driven</span> drainage of magma stored in the volcanic edifice with a minor contribution of magma supplied at a steady rate from a deep reservoir. Here we show that the discharge rate can be predicted by the contraction of the volcano edifice and that the very-long-period seismicity migrates downwards, tracking the residual volume of magma in the shallow reservoir. Gravity-<span class="hlt">driven</span> magma discharge <span class="hlt">dynamics</span> explain the initially high discharge rates observed during eruptive crises and greatly influence our ability to predict the <span class="hlt">evolution</span> of effusive eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25980642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25980642"><span>Volcano seismicity and ground deformation unveil the gravity-<span class="hlt">driven</span> magma discharge <span class="hlt">dynamics</span> of a volcanic eruption.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ripepe, Maurizio; Donne, Dario Delle; Genco, Riccardo; Maggio, Giuseppe; Pistolesi, Marco; Marchetti, Emanuele; Lacanna, Giorgio; Ulivieri, Giacomo; Poggi, Pasquale</p> <p>2015-05-18</p> <p>Effusive eruptions are explained as the mechanism by which volcanoes restore the equilibrium perturbed by magma rising in a chamber deep in the crust. Seismic, ground deformation and topographic measurements are compared with effusion rate during the 2007 Stromboli eruption, drawing an eruptive scenario that shifts our attention from the interior of the crust to the surface. The eruption is modelled as a gravity-<span class="hlt">driven</span> drainage of magma stored in the volcanic edifice with a minor contribution of magma supplied at a steady rate from a deep reservoir. Here we show that the discharge rate can be predicted by the contraction of the volcano edifice and that the very-long-period seismicity migrates downwards, tracking the residual volume of magma in the shallow reservoir. Gravity-<span class="hlt">driven</span> magma discharge <span class="hlt">dynamics</span> explain the initially high discharge rates observed during eruptive crises and greatly influence our ability to predict the <span class="hlt">evolution</span> of effusive eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhEn...6d6501L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhEn...6d6501L"><span>Visible-light-<span class="hlt">driven</span> hydrogen <span class="hlt">evolution</span> with polyoxometalate as electron relay</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Xing; Li, Yuexiang; Peng, Shaoqin; Lai, Hua; Yi, Zhengji</p> <p>2016-10-01</p> <p>A visible-light-<span class="hlt">driven</span> hydrogen <span class="hlt">evolution</span> system was constructed in one step with xanthene dye as photosensitizer, triethanolamine (TEOA) as electron donor, Pt as cocatalyst, and Keggin-type silicon-tungsten polyoxometalate (POM) as electron relay. The average rate of hydrogen <span class="hlt">evolution</span> from the eosin Y-POM-TEOA-PtCl62- systems is 51.8 μmol h-1, and the apparent quantum yield is 8.9% during 20 h irradiation (λ>420 nm, a high-pressure Hg lamp was used as the light source). Ultraviolet-visible absorption spectra and fluorescence spectra were used to study the mechanism of charge transfer. A radical anion Dye, which generates from quenching of the triplet-excited state Dye3* by sacrificial electron donor, was considered the main species for transmitting electrons to POM and then to Pt. SiW9O3410-, derived from SiW12O404-, is the main form of POM in our reaction system, which can mediate the electron transfer from Dye to Pt, so an enhanced hydrogen <span class="hlt">evolution</span> was realized. The present study highlights POM as electron relay in the photocatalytic hydrogen <span class="hlt">evolution</span> process, which is expected to contribute to the development of functional and efficient artificial photosynthetic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15836265','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15836265"><span>Current oscillation and chaotic <span class="hlt">dynamics</span> in superlattices <span class="hlt">driven</span> by crossed electric and magnetic fields.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, C; Cao, J C</p> <p>2005-03-01</p> <p>We have theoretically studied current oscillation and chaotic <span class="hlt">dynamics</span> in doped GaAsAlAs superlattices <span class="hlt">driven</span> by crossed electric and magnetic fields. When the superlattice system is <span class="hlt">driven</span> by a dc voltage, a stationary or <span class="hlt">dynamic</span> electric-field domain can be obtained. We carefully studied the electric-field-domain <span class="hlt">dynamics</span> and current self-oscillation which both display different modes with the change of magnetic field. When an ac electric field is also applied to the superlattice, a typical nonlinear <span class="hlt">dynamic</span> system is constructed with the ac amplitude, ac frequency, and magnetic field as the control parameters. Different nonlinear behaviors show up when we tune the control parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2841172','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2841172"><span>Parallel <span class="hlt">evolution</span> of character displacement <span class="hlt">driven</span> by competitive selection in terrestrial salamanders</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2010-01-01</p> <p>Background Parallel <span class="hlt">evolution</span> can occur when common environmental factors exert similar selective forces on morphological variation in populations in different geographic localities. Competition can also generate morphological shifts, and if competing species co-occur in multiple geographic regions, then repeated instances of competitively-<span class="hlt">driven</span> morphological divergence (character displacement) can occur. Despite the importance of character displacement for inferring the role of selection in morphological <span class="hlt">evolution</span> however, replicated instances of sympatric morphological divergence are understudied. Results I tested the hypothesis that interspecific competition generated patterns of parallel morphological divergence in multiple geographic locations where two competing salamander species, Plethodon jordani and P. teyahalee, come into contact. I used geometric morphometrics to characterize head shape and found ecological character displacement in sympatric localities on each of three distinct mountains (geographic transects), where sympatric specimens displayed greater cranial differences and an increase in cranial robustness as compared to allopatric specimens. Using a recently developed analytical procedure, I also found that the observed morphological <span class="hlt">evolution</span> within each species was consistent among transects; both in the total amount of morphological change as well as the direction of <span class="hlt">evolution</span> in the morphological data space. This provided strong statistical evidence of parallel morphological <span class="hlt">evolution</span> within species across replicate geographic transects. Conclusions The results presented here reveal that the morphological <span class="hlt">evolution</span> of each species followed a common evolutionary path in each transect. Because dispersal between sympatric locations among transects is unlikely, these findings suggest that the repeated instances of character displacement have evolved in situ. They also suggest that selection from competitive interactions plays an important role</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4186249','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4186249"><span><span class="hlt">Evolution</span> of wealth in a non-conservative economy <span class="hlt">driven</span> by local Nash equilibria</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Degond, Pierre; Liu, Jian-Guo; Ringhofer, Christian</p> <p>2014-01-01</p> <p>We develop a model for the <span class="hlt">evolution</span> of wealth in a non-conservative economic environment, extending a theory developed in Degond et al. (2014 J. Stat. Phys. 154, 751–780 (doi:10.1007/s10955-013-0888-4)). The model considers a system of rational agents interacting in a game-theoretical framework. This <span class="hlt">evolution</span> drives the <span class="hlt">dynamics</span> of the agents in both wealth and economic configuration variables. The cost function is chosen to represent a risk-averse strategy of each agent. That is, the agent is more likely to interact with the market, the more predictable the market, and therefore the smaller its individual risk. This yields a kinetic equation for an effective single particle agent density with a Nash equilibrium serving as the local thermodynamic equilibrium. We consider a regime of scale separation where the large-scale <span class="hlt">dynamics</span> is given by a hydrodynamic closure with this local equilibrium. A class of generalized collision invariants is developed to overcome the difficulty of the non-conservative property in the hydrodynamic closure derivation of the large-scale <span class="hlt">dynamics</span> for the <span class="hlt">evolution</span> of wealth distribution. The result is a system of gas <span class="hlt">dynamics</span>-type equations for the density and average wealth of the agents on large scales. We recover the inverse Gamma distribution, which has been previously considered in the literature, as a local equilibrium for particular choices of the cost function. PMID:25288808</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25288808','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25288808"><span><span class="hlt">Evolution</span> of wealth in a non-conservative economy <span class="hlt">driven</span> by local Nash equilibria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Degond, Pierre; Liu, Jian-Guo; Ringhofer, Christian</p> <p>2014-11-13</p> <p>We develop a model for the <span class="hlt">evolution</span> of wealth in a non-conservative economic environment, extending a theory developed in Degond et al. (2014 J. Stat. Phys. 154, 751-780 (doi:10.1007/s10955-013-0888-4)). The model considers a system of rational agents interacting in a game-theoretical framework. This <span class="hlt">evolution</span> drives the <span class="hlt">dynamics</span> of the agents in both wealth and economic configuration variables. The cost function is chosen to represent a risk-averse strategy of each agent. That is, the agent is more likely to interact with the market, the more predictable the market, and therefore the smaller its individual risk. This yields a kinetic equation for an effective single particle agent density with a Nash equilibrium serving as the local thermodynamic equilibrium. We consider a regime of scale separation where the large-scale <span class="hlt">dynamics</span> is given by a hydrodynamic closure with this local equilibrium. A class of generalized collision invariants is developed to overcome the difficulty of the non-conservative property in the hydrodynamic closure derivation of the large-scale <span class="hlt">dynamics</span> for the <span class="hlt">evolution</span> of wealth distribution. The result is a system of gas <span class="hlt">dynamics</span>-type equations for the density and average wealth of the agents on large scales. We recover the inverse Gamma distribution, which has been previously considered in the literature, as a local equilibrium for particular choices of the cost function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARB12001W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARB12001W"><span>Exploring the <span class="hlt">Dynamics</span> of <span class="hlt">Evolution</span> and Ecology of Biological Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jin</p> <p>2014-03-01</p> <p>We established the potential and flux landscape theory for <span class="hlt">evolution</span>. We found explicitly the conventional Wright's gradient adaptive landscape based on the mean fitness is inadequate to describe the general evolutionary <span class="hlt">dynamics</span>. We show the intrinsic potential as being Lyapunov function (monotonically decreasing in time) does exist and can define the adaptive landscape for general <span class="hlt">evolution</span> <span class="hlt">dynamics</span> for studying global stability. The driving force determining the <span class="hlt">dynamics</span> can be decomposed into gradient of potential landscape and curl probability flux. Non-zero flux causes detailed balance breaking and measures how far the <span class="hlt">evolution</span> from equilibrium state. The gradient of intrinsic potential and curl flux are perpendicular to each other in zero fluctuation limit resembling electric and magnetic forces on electrons. We quantified intrinsic energy, entropy and free energy of <span class="hlt">evolution</span> and constructed non-equilibrium thermodynamics. The intrinsic non-equilibrium free energy is a Lyapunov function. Both intrinsic potential and free energy can be used to quantify the global stability and robustness of <span class="hlt">evolution</span>. We investigated an example of three allele evolutionary <span class="hlt">dynamics</span> with frequency dependent selection (detailed balance broken). We uncovered the underlying single, triple, and limit cycle attractor landscapes. We found quantitative criterions for stability through landscape topography. We also quantified <span class="hlt">evolution</span> pathways and found paths do not follow potential gradient and are irreversible due to non-zero flux. We generalized the original Fisher's fundamental theorem to the general (i.e., frequency dependent selection) regime of <span class="hlt">evolution</span> by linking the adaptive rate with not only genetic variance related to the potential but also the flux. We show there is an optimum potential where curl flux resulting from biotic interactions of individuals within a species or between species can sustain an endless <span class="hlt">evolution</span> even if the physical environment is unchanged. We</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015FrP.....3...67G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FrP.....3...67G"><span><span class="hlt">Dynamics</span> of hydrofracturing and permeability <span class="hlt">evolution</span> in layered reservoirs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghani, Irfan; Koehn, Daniel; Toussaint, Renaud; Passchier, Cees</p> <p>2015-09-01</p> <p>A coupled hydro-mechanical model is presented to model fluid <span class="hlt">driven</span> fracturing in layered porous rocks. In the model the solid elastic continuum is described by a discrete element approach coupled with a fluid continuum grid that is used to solve Darcy based pressure diffusion. The model assumes poro-elasto-plastic effects and yields real time <span class="hlt">dynamic</span> aspects of the fracturing and effective stress <span class="hlt">evolution</span> under the influence of excess fluid pressure gradients. We show that the formation and propagation of hydrofractures are sensitive to mechanical and tectonic conditions of the system. In cases where elevated fluid pressure is the sole driving agent in a stable tectonic system, sealing layers induce permutations between the principal directions of the local stress tensor, which regulate the growth of vertical fractures and may result in irregular pattern formation or sub-horizontal failure below the seal. Stiffer layers tend to concentrate differential stresses and lead to vertical fracture growth, whereas the layer-contact tends to fracture if the strength of the neighboring rock is comparably high. If the system has remained under extension for a longer time period, the developed hydrofractures propagate by linking up confined tensile fractures in competent layers. This leads to the growth of large-scale normal faults in the layered systems, so that subsequently the effective permeability is highly variable over time and the faults drain the system. The simulation results are shown to be consistent with some of the field observations carried out in the Oman Mountains, where abnormal fluid pressure is reported to be a significant factor in the development of several generations of local and regional fracture and fault sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28761438','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28761438"><span>Differential Cloud Particles <span class="hlt">Evolution</span> Algorithm Based on Data-<span class="hlt">Driven</span> Mechanism for Applications of ANN.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Wei</p> <p>2017-01-01</p> <p>Computational scientists have designed many useful algorithms by exploring a biological process or imitating natural <span class="hlt">evolution</span>. These algorithms can be used to solve engineering optimization problems. Inspired by the change of matter state, we proposed a novel optimization algorithm called differential cloud particles <span class="hlt">evolution</span> algorithm based on data-<span class="hlt">driven</span> mechanism (CPDD). In the proposed algorithm, the optimization process is divided into two stages, namely, fluid stage and solid stage. The algorithm carries out the strategy of integrating global exploration with local exploitation in fluid stage. Furthermore, local exploitation is carried out mainly in solid stage. The quality of the solution and the efficiency of the search are influenced greatly by the control parameters. Therefore, the data-<span class="hlt">driven</span> mechanism is designed for obtaining better control parameters to ensure good performance on numerical benchmark problems. In order to verify the effectiveness of CPDD, numerical experiments are carried out on all the CEC2014 contest benchmark functions. Finally, two application problems of artificial neural network are examined. The experimental results show that CPDD is competitive with respect to other eight state-of-the-art intelligent optimization algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5518518','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5518518"><span>Differential Cloud Particles <span class="hlt">Evolution</span> Algorithm Based on Data-<span class="hlt">Driven</span> Mechanism for Applications of ANN</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2017-01-01</p> <p>Computational scientists have designed many useful algorithms by exploring a biological process or imitating natural <span class="hlt">evolution</span>. These algorithms can be used to solve engineering optimization problems. Inspired by the change of matter state, we proposed a novel optimization algorithm called differential cloud particles <span class="hlt">evolution</span> algorithm based on data-<span class="hlt">driven</span> mechanism (CPDD). In the proposed algorithm, the optimization process is divided into two stages, namely, fluid stage and solid stage. The algorithm carries out the strategy of integrating global exploration with local exploitation in fluid stage. Furthermore, local exploitation is carried out mainly in solid stage. The quality of the solution and the efficiency of the search are influenced greatly by the control parameters. Therefore, the data-<span class="hlt">driven</span> mechanism is designed for obtaining better control parameters to ensure good performance on numerical benchmark problems. In order to verify the effectiveness of CPDD, numerical experiments are carried out on all the CEC2014 contest benchmark functions. Finally, two application problems of artificial neural network are examined. The experimental results show that CPDD is competitive with respect to other eight state-of-the-art intelligent optimization algorithms. PMID:28761438</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E3654W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E3654W"><span>Analyses of Magnetic Structures of Active Region 11117 <span class="hlt">Evolution</span> using a 3D Data-<span class="hlt">Driven</span> Magnetohydrodynamic Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Shi; Jiang, Chaowei; Feng, Xueshang</p> <p></p> <p>We use the photospheric vector magnetograms obtained by Helioseismic and Magnetic Image (HMI) on-board the Solar <span class="hlt">Dynamic</span> Observatory (SDO) as the boundary conditions for a Data-<span class="hlt">Driven</span> CESE-MHD model (Jiang et al. 2012) to investigate the physical characteristics and <span class="hlt">evolution</span> of magnetic field configurations in the corona before and after a solar eruptive event. Specifically, the <span class="hlt">evolution</span> of AR11117 characteristics such as length of magnetic shear along the neutral line, current helicity, magnetic free energy and the energy flux across the photosphere due to flux emergence and surface flow are presented. The computed 3D magnetic field configuration are compared with AIA (Atmosphere Image Assembly) which shows remarkable resemblance. A topological analyses reveals that the small flare is correlated with a bald patch (BP, where the magnetic field is tangent to the photosphere), suggesting that the energy release of the flare is caused by magnetic reconnection associated with the BP separatrices. The total magnetic flux and energy keep increasing slightly in spite of flare, while the computed magnetic free energy drops during the flare by 10 (30) ergs which is adequate in providing the energy budget of a minor C-class confined flare as observed. Jiang, Chaowei, Xueshang, Feng, S. T Wu and Qiang Hu, Ap. J., 759:85, 2012 Nov 10</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26650485','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26650485"><span>Iron-Doped Carbon Nitride-Type Polymers as Homogeneous Organocatalysts for Visible Light-<span class="hlt">Driven</span> Hydrogen <span class="hlt">Evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Lin-Feng; Wen, Ting; Xu, Jing-Yin; Zhai, Xin-Ping; Zhao, Min; Hu, Guo-Wen; Chen, Peng; Wang, Qiang; Zhang, Hao-Li</p> <p>2016-01-13</p> <p>Graphitic carbon nitrides have appeared as a new type of photocatalyst for water splitting, but their broader and more practical applications are oftentimes hindered by the insolubility or difficult dispersion of the material in solvents. We herein prepared novel two-dimensional (2D) carbon nitride-type polymers doped by iron under a mild one-pot method through preorganizing formamide and citric acid precursors into supramolecular structures, which eventually polycondensed into a homogeneous organocatalyst for highly efficient visible light-<span class="hlt">driven</span> hydrogen <span class="hlt">evolution</span> with a rate of ∼16.2 mmol g(-1) h(-1) and a quantum efficiency of 0.8%. Laser photolysis and electrochemical impedance spectroscopic measurements suggested that iron-doping enabled strong electron coupling between the metal and the carbon nitride and formed unique electronic structures favoring electron mobilization along the 2D nanomaterial plane, which might facilitate the electron transfer process in the photocatalytic system and lead to efficient H2 <span class="hlt">evolution</span>. In combination with electrochemical measurements, the electron transfer <span class="hlt">dynamics</span> during water reduction were depicted, and the earth-abundant Fe-based catalyst may open a sustainable strategy for conversion of sunlight into hydrogen energy and cope with current challenging energy issues worldwide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..465..662W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..465..662W"><span>Predicting the <span class="hlt">evolution</span> of complex networks via similarity <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Tao; Chen, Leiting; Zhong, Linfeng; Xian, Xingping</p> <p>2017-01-01</p> <p>Almost all real-world networks are subject to constant <span class="hlt">evolution</span>, and plenty of them have been investigated empirically to uncover the underlying <span class="hlt">evolution</span> mechanism. However, the <span class="hlt">evolution</span> prediction of <span class="hlt">dynamic</span> networks still remains a challenging problem. The crux of this matter is to estimate the future network links of <span class="hlt">dynamic</span> networks. This paper studies the <span class="hlt">evolution</span> prediction of <span class="hlt">dynamic</span> networks with link prediction paradigm. To estimate the likelihood of the existence of links more accurate, an effective and robust similarity index is presented by exploiting network structure adaptively. Moreover, most of the existing link prediction methods do not make a clear distinction between future links and missing links. In order to predict the future links, the networks are regarded as <span class="hlt">dynamic</span> systems in this paper, and a similarity updating method, spatial-temporal position drift model, is developed to simulate the evolutionary <span class="hlt">dynamics</span> of node similarity. Then the updated similarities are used as input information for the future links' likelihood estimation. Extensive experiments on real-world networks suggest that the proposed similarity index performs better than baseline methods and the position drift model performs well for <span class="hlt">evolution</span> prediction in real-world evolving networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000A%26A...364L..75K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000A%26A...364L..75K"><span>Assisted stellar suicide: the wind-<span class="hlt">driven</span> <span class="hlt">evolution</span> of the recurrent nova T Pyxidis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knigge, Ch.; King, A. R.; Patterson, J.</p> <p>2000-12-01</p> <p>We show that the extremely high luminosity of the short-period recurrent nova T Pyx in quiescence can be understood if this system is a wind-<span class="hlt">driven</span> supersoft x-ray source (SSS). In this scenario, a strong, radiation-induced wind is excited from the secondary star and accelerates the binary <span class="hlt">evolution</span>. The accretion rate is therefore much higher than in an ordinary cataclysmic binary at the same orbital period, as is the luminosity of the white dwarf primary. In the steady state, the enhanced luminosity is just sufficient to maintain the wind from the secondary. The accretion rate and luminosity predicted by the wind-<span class="hlt">driven</span> model for T Pyx are in good agreement with the observational evidence. X-ray observations with Chandra or XMM may be able to confirm T Pyx's status as a SSS. T Pyx's lifetime in the wind-<span class="hlt">driven</span> state is on the order of a million years. Its ultimate fate is not certain, but the system may very well end up destroying itself, either via the complete evaporation of the secondary star, or in a Type Ia supernova if the white dwarf reaches the Chandrasekhar limit. Thus either the primary, the secondary, or both may currently be committing assisted stellar suicide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPNO7010N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPNO7010N"><span>Investigating shock-<span class="hlt">driven</span> Richtmyer-Meshkov ripple <span class="hlt">evolution</span> before and after re-shock</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagel, S. R.; Huntington, C. M.; MacLaren, S. A.; Raman, K. S.; Baumann, T.; Benedetti, L. R.; Doane, D. M.; Islam, T. S.; Felker, S.; Holder, J. P.; Seugling, R. M.; Wang, P.; Zhou, Y. K.; Doss, F. W.; Flippo, K. A.; Perry, T. S.</p> <p>2015-11-01</p> <p>Late-time Rayleigh-Taylor/Richtmyer-Meshkov(RM) ripple growth in an opposing-shock geometry is investigated using x-ray area backlit imaging of a shock-tube with indirectly <span class="hlt">driven</span> shocks. The shocks are <span class="hlt">driven</span> from opposing sides of the tube. The ablator layer on one side has pre-imposed ripples in the form of a sine wave with two amplitudes and a single wavelength. This ablator includes an opaque tracer layer that is used to track the perturbed interface as it is <span class="hlt">driven</span> into a lower density foam. The ablator on the opposing side of the tube is flat, and is used to launch the shock that re-shocks the rippled interface. A large-area backlighter and gated x-ray radiography is used to capture images at different times during the RM instability growth. Here, first measurements obtained with this experimental platform at the NIF, including the optimization of the platform are presented. The RM ripple <span class="hlt">evolution</span> before and after re-shock, including a possible loss of initial conditions are, also discussed. The data that informs the codes is compared to simulation results Work supported by U.S. Department of Energy under Contract DE- AC52-06NA27279. LLNL-ABS-674941.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJMPD..2650029B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJMPD..2650029B"><span><span class="hlt">Dynamical</span> variables and <span class="hlt">evolution</span> of the universe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhatti, M. Zaeem-Ul-Haq; Yousaf, Z.</p> <p></p> <p>One of the striking feature of inhomogeneous matter distribution under the effects of fourth-order gravity and electromagnetic field have been discussed in this manuscript. We have considered a compact spherical celestial star undergoing expansion due to the presence of higher curvature invariants of f(R) gravity and imperfect fluid. We have explored the <span class="hlt">dynamical</span> equations and field equations in f(R) gravity. An explicit expression have been found for Weyl tensor and material variables under the dark <span class="hlt">dynamical</span> effects. Using a viable f(R) model, some <span class="hlt">dynamical</span> variables have been explored from splitting the Riemann curvature tensor. These dark <span class="hlt">dynamical</span> variables are also studied for charged dust cloud with and without the constraint of constant Ricci scalar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11970264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11970264"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of sand ripples under water.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stegner, A; Wesfreid, J E</p> <p>1999-10-01</p> <p>We have performed an experimental study on the <span class="hlt">evolution</span> of sand ripples formed under the action of an oscillatory flow. An annular sand-water cell was used in order to investigate a wide range of parameters. The sand ripples follow an irreversible condensation mechanism from small to large wavelength until a final state is reached. The wavelength and the shape of these stable sand patterns are mainly governed by the fluid displacement and the static angle of the granular media. A strong hysteresis affects the <span class="hlt">evolution</span> of steep ripples. When the acceleration of the sand bed reaches a critical value, the final pattern is modified by the superficial fluidization of the sand layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3315450','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3315450"><span>Collective <span class="hlt">Dynamics</span> Differentiates Functional Divergence in Protein <span class="hlt">Evolution</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Glembo, Tyler J.; Farrell, Daniel W.; Gerek, Z. Nevin; Thorpe, M. F.; Ozkan, S. Banu</p> <p>2012-01-01</p> <p>Protein <span class="hlt">evolution</span> is most commonly studied by analyzing related protein sequences and generating ancestral sequences through Bayesian and Maximum Likelihood methods, and/or by resurrecting ancestral proteins in the lab and performing ligand binding studies to determine function. Structural and <span class="hlt">dynamic</span> <span class="hlt">evolution</span> have largely been left out of molecular <span class="hlt">evolution</span> studies. Here we incorporate both structure and <span class="hlt">dynamics</span> to elucidate the molecular principles behind the divergence in the evolutionary path of the steroid receptor proteins. We determine the likely structure of three evolutionarily diverged ancestral steroid receptor proteins using the Zipping and Assembly Method with FRODA (ZAMF). Our predictions are within ∼2.7 Å all-atom RMSD of the respective crystal structures of the ancestral steroid receptors. Beyond static structure prediction, a particular feature of ZAMF is that it generates protein <span class="hlt">dynamics</span> information. We investigate the differences in conformational <span class="hlt">dynamics</span> of diverged proteins by obtaining the most collective motion through essential <span class="hlt">dynamics</span>. Strikingly, our analysis shows that evolutionarily diverged proteins of the same family do not share the same <span class="hlt">dynamic</span> subspace, while those sharing the same function are simultaneously clustered together and distant from those, that have functionally diverged. <span class="hlt">Dynamic</span> analysis also enables those mutations that most affect <span class="hlt">dynamics</span> to be identified. It correctly predicts all mutations (functional and permissive) necessary to evolve new function and ∼60% of permissive mutations necessary to recover ancestral function. PMID:22479170</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008ChPhL..25..798F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008ChPhL..25..798F"><span><span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Modified Chaplygin Gas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Ming-Hui; Wu, Ya-Bo; He, Jing</p> <p>2008-02-01</p> <p>Based our previous work [Mod. Phys. Lett. A 22 (2007) 783, Gen. Relat. Grav. 39 (2007) 653], some properties of modified Chaplygin gas (MCG) as a dark energy model continue to be studied mainly in two aspects: one is the change rates of the energy density and energy transfer, and the other is the <span class="hlt">evolution</span> of the growth index. It is pointed that the density of dark energy undergoes the change from decrease to increase no matter whether the interaction between dark energy and dark matter exists or not, but the corresponding transformation points are different from each other. Furthermore, it is stressed that the MCG model even supports the existence of interaction between dark energy and dark matter, and the energy of transfer flows from dark energy to dark matter. The <span class="hlt">evolution</span> of the interaction term with an ansatz 3Hc2 ρ is discussed with the MCG model. Moreover, the <span class="hlt">evolution</span> of the growth index f in the MCG model without interaction is illustrated, from which we find that the evolutionary trajectory of f overlaps with that of the ΣCDM model when a > 0.7 and its theoretical value f ≈ 0.566 given by us at z = 0.15 is consistent with the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSMG14A1910S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSMG14A1910S"><span>Lidar observations of wind- and wave-<span class="hlt">driven</span> morphological <span class="hlt">evolution</span> of coastal foredunes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spore, N.; Brodie, K. L.; Kershner, C. M.</p> <p>2016-02-01</p> <p>Coastal foredunes are continually evolving geomorphic features that are slowly built up by wind-blown sand and rapidly eroded during storms by large waves and swash. Landward aeolian transport removes sediment from the active beach and surf-zone, trapping it in the dune, where as coastal erosion both removes sediment from the dune and can decrease the overall fetch and sediment supply available to the dune. Understanding how wave and wind-<span class="hlt">driven</span> process interact with each other and the dune-beach system itself is a critical component of improving predictions of coastal <span class="hlt">evolution</span>. To investigate these processes, two 50 m alongshore by 25 m cross-shore patches of dune along an open coast beach fronting the Atlantic Ocean in Duck, NC were scanned with a high resolution terrestrial lidar scanner ( 5000 points per m^2) every three weeks over the last year to observe detailed morphological <span class="hlt">evolution</span> of the dune and upper beach. Sequential scans were co-registered to each other using fixed objects in the field of view, significantly increasing precision and accuracy of the observations. The north study site featured a 7.5 m tall scarped foredune system, where as the southern study site featured a 6 m tall, hummocky, prograding foredune. Initial analyses show large accretion events on the southern prograding site. For example, during one three week period in February, portions of the site accreted over 40 cm. In contrast, during the same three week period at the northern site (less than 1 km away), response was alongshore variable with erosion and accretion of roughly 10 cm on the foredune face. Further analysis will focus on separating wind vs. wave <span class="hlt">driven</span> <span class="hlt">evolution</span> of these sites. Funded by the USACE Coastal Inlets Research Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CRMec.345..344L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CRMec.345..344L"><span><span class="hlt">Dynamic</span> and quasi-electromagnetostatic <span class="hlt">evolution</span> of a thermoelectromagnetoelastic body</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Licht, Christian; Orankitjaroen, Somsak; Sawangtong, Panumart; Weller, Thibaut</p> <p>2017-05-01</p> <p>A standard technique of <span class="hlt">evolution</span> equations in Hilbert spaces of possible states with finite energy supplies results of existence and uniqueness for the <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of a thermoelectromagnetoelastic body and for its ''quasi-electromagnetostatic approximation'' whose relevance is established through a convergence result as a parameter, accounting for the ratio of the speed of elastic wave propagation to the celerity of the light, goes to zero.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.B23B1075C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.B23B1075C"><span>Occurrence of a bimodal behavior in riparian vegetation <span class="hlt">dynamics</span> <span class="hlt">driven</span> by river flow variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Camporeale, C.; Ridolfi, L.</p> <p>2006-12-01</p> <p>The riparian zone is a fluvial ecotone which exhibits very interesting interaction between hydraulics and ecology, with several important implications in the environmental management. Even though random variability is a key characteristic of the river hydrology, which plays a crucial role in the <span class="hlt">evolution</span> of riparian vegetation, the impact of stochastic hydrologic fluctuations on the <span class="hlt">dynamics</span> of riparian vegetation ecosystems remains for most part poorly understood. Here we propose a new approach to study the distribution of phreatophyte riparian vegetation, using a stochastic process to model the random forcing exerted by river flow on the <span class="hlt">dynamics</span> of the overall biomass of vegetation. Growth and decrease of vegetation are modelled through a logistic and an exponential functions, respectively, which switch in a random way, depending on the flooding conditions. The time series of the river flow (described by the pdf and autocorrelation function), determines the corresponding time series of the water levels which in turn drives the statistical characteristics of the switching. In the logistic model, the carrying capacity is taken dependent on the water table depth through a quadratic optimum function with species-dependent parameters. A dimensional analysis shows that the fundamental factors are the autocorrelation function of the flow, the coefficient of variation, the ratio between growth and decrease rate of vegetation and the optimum water table depth. The switching <span class="hlt">dynamics</span> is shown to be described by a single stochastic differential equation <span class="hlt">driven</span> by dichotomic noise that is analytically solved herein. The main outcome is the pdf of the vegetation biomass at the steady state which allows the stability of the models and the central moments to be investigated. Bimodality of the solution and peculiar behaviors (e.g., noise-induced stability) are discussed, depending on the river geometry and the hydrological characteristics. The obtained analytical expressions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820052242&hterms=planetary+formation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dplanetary%2Bformation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820052242&hterms=planetary+formation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dplanetary%2Bformation"><span><span class="hlt">Dynamical</span> constraints on the formation and <span class="hlt">evolution</span> of planetary bodies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Harris, A. W.; Ward, W. R.</p> <p>1982-01-01</p> <p>The present investigation is concerned with a number of inferences as to the origin of planetary bodies, taking into account the present <span class="hlt">dynamical</span> state of the solar system and some of the limitations which apply to the considered conclusions. Attention is given to the <span class="hlt">dynamical</span> processes, specifically those processes which may have influenced the orbital or rotational properties of the planets and satellites. Collisional processes are explored, taking into consideration orbital spacing, planetary rotation, and stochastic effects. In connection with a discussion of the <span class="hlt">evolution</span> of rotational motion, spin state <span class="hlt">evolution</span> is investigated along with spin axis precession and resonance variation, and the Cassini states. The <span class="hlt">evolution</span> of planetary orbits is also studied. The subjects considered are related to tides, secular resonances, disk <span class="hlt">dynamics</span>, and disk-satellite interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19055679','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19055679"><span>Phylogenetic evidence for competitively <span class="hlt">driven</span> divergence: body-size <span class="hlt">evolution</span> in Caribbean treefrogs (Hylidae: Osteopilus).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moen, Daniel S; Wiens, John J</p> <p>2009-01-01</p> <p>Understanding the role of competition in explaining phenotypic diversity is a challenging problem, given that the most divergent species may no longer compete today. However, convergent <span class="hlt">evolution</span> of extreme body sizes across communities may offer evidence of past competition. For example, many treefrog assemblages around the world have convergently evolved species with very large and small body sizes. To better understand this global pattern, we studied body-size diversification within the small, endemic radiation of Caribbean treefrogs (Osteopilus). We introduce a suite of analyses designed to help reveal the signature of past competition. Diet analyses show that Osteopilus are generalist predators and that prey size is strongly associated with body size, suggesting that body-size divergence facilitates resource partitioning. Community assembly models indicate that treefrog body-size distributions in Jamaica and Hispaniola are consistent with expectations from competition. Phylogenetic analyses show that similar body-size extremes in Jamaica and Hispaniola have originated through parallel <span class="hlt">evolution</span> on each island, and the rate of body-size <span class="hlt">evolution</span> in Osteopilus is accelerated relative to mainland treefrogs. Together, these results suggest that competition may have <span class="hlt">driven</span> the rapid diversification of body sizes in Caribbean treefrogs to the extremes seen in treefrog communities around the world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..DFD.EB001V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..DFD.EB001V"><span>Nonlinear wave <span class="hlt">evolution</span> in pressure-<span class="hlt">driven</span> stratified flow of Newtonian and Herschel-Bulkley fluids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valluri, Prashant; Sahu, Kirti; Ding, Hang; Spelt, Peter; Matar, Omar; Lawrence, Chris</p> <p>2007-11-01</p> <p>Pressure-<span class="hlt">driven</span> stratified channel flow of a Newtonian fluid flowing over a Herschel-Bulkley (HB) fluid is considered. The effects of yield stress and shear-thinning rheology on the nonlinear wave <span class="hlt">evolution</span> are studied using numerical simulations; the HB rheology is regularized at low shear rates using a bi-viscosity formulation. Two different numerical methods were used to carry out the computations: a level-set method (based on that by Spelt, J. Comput. Phys. 2005) and a diffuse-interface method (based on that by Ding et al., J. Comput. Phys., in press). The simulations, which account for fluid inertia, surface tension and gravity are validated against linear theory predictions at early times. The results at later times show the spatio-temporal <span class="hlt">evolution</span> into the nonlinear regime wherein waves are strongly deformed, leading to the onset of drop entrainment. It is shown that the apparent viscosity in the region of the HB fluid directly involved in the onset of entrainment is almost constant; unyielded regions are confined to wave troughs at late stages of the nonlinear <span class="hlt">evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26453945','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26453945"><span>Biosensor-<span class="hlt">driven</span> adaptive laboratory <span class="hlt">evolution</span> of l-valine production in Corynebacterium glutamicum.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mahr, Regina; Gätgens, Cornelia; Gätgens, Jochem; Polen, Tino; Kalinowski, Jörn; Frunzke, Julia</p> <p>2015-11-01</p> <p>Adaptive laboratory <span class="hlt">evolution</span> has proven a valuable strategy for metabolic engineering. Here, we established an experimental <span class="hlt">evolution</span> approach for improving microbial metabolite production by imposing an artificial selective pressure on the fluorescent output of a biosensor using fluorescence-activated cell sorting. Cells showing the highest fluorescent output were iteratively isolated and (re-)cultivated. The L-valine producer Corynebacterium glutamicum ΔaceE was equipped with an L-valine-responsive sensor based on the transcriptional regulator Lrp of C. glutamicum. Evolved strains featured a significantly higher growth rate, increased L-valine titers (~25%) and a 3-4-fold reduction of by-product formation. Genome sequencing resulted in the identification of a loss-of-function mutation (UreD-E188*) in the gene ureD (urease accessory protein), which was shown to increase L-valine production by up to 100%. Furthermore, decreased L-alanine formation was attributed to a mutation in the global regulator GlxR. These results emphasize biosensor-<span class="hlt">driven</span> <span class="hlt">evolution</span> as a straightforward approach to improve growth and productivity of microbial production strains. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15245126','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15245126"><span>Lattice gas <span class="hlt">dynamics</span>: application to <span class="hlt">driven</span> vortices in two dimensional superconductors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gotcheva, Violeta; Wang, Albert T J; Teitel, S</p> <p>2004-06-18</p> <p>A continuous time Monte Carlo lattice gas <span class="hlt">dynamics</span> is developed to model <span class="hlt">driven</span> steady states of vortices in two dimensional superconducting networks. Dramatic differences are found when compared to a simpler Metropolis <span class="hlt">dynamics</span>. Subtle finite size effects are found at low temperature, with a moving smectic that becomes unstable to an anisotropic liquid on sufficiently large length scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=219021','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=219021"><span>Response of mountain plovers to plague-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of black-tailed prairie dog colonies</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Sylvatic plague is a major factor influencing prairie dog colony <span class="hlt">dynamics</span> in the western Great Plains. We studied the nesting response of the mountain plover (Charadrius montanus), a grassland bird that nests on prairie dog colonies, to plague-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of prairie dog colonies at three sites i...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22365732','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22365732"><span>Redshift <span class="hlt">evolution</span> of the <span class="hlt">dynamical</span> properties of massive galaxies from SDSS-III/BOSS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Beifiori, Alessandra; Saglia, Roberto P.; Bender, Ralf; Senger, Robert; Thomas, Daniel; Maraston, Claudia; Steele, Oliver; Masters, Karen L.; Pforr, Janine; Tojeiro, Rita; Johansson, Jonas; Nichol, Robert C.; Chen, Yan-Mei; Wake, David; Bolton, Adam; Brownstein, Joel R.; Leauthaud, Alexie; Schneider, Donald P.; Skibba, Ramin; Pan, Kaike; and others</p> <p>2014-07-10</p> <p>We study the redshift <span class="hlt">evolution</span> of the <span class="hlt">dynamical</span> properties of ∼180, 000 massive galaxies from SDSS-III/BOSS combined with a local early-type galaxy sample from SDSS-II in the redshift range 0.1 ≤ z ≤ 0.6. The typical stellar mass of this sample is M{sub *} ∼2 × 10{sup 11} M{sub ☉}. We analyze the <span class="hlt">evolution</span> of the galaxy parameters effective radius, stellar velocity dispersion, and the <span class="hlt">dynamical</span> to stellar mass ratio with redshift. As the effective radii of BOSS galaxies at these redshifts are not well resolved in the Sloan Digital Sky Survey (SDSS) imaging we calibrate the SDSS size measurements with Hubble Space Telescope/COSMOS photometry for a sub-sample of galaxies. We further apply a correction for progenitor bias to build a sample which consists of a coeval, passively evolving population. Systematic errors due to size correction and the calculation of <span class="hlt">dynamical</span> mass are assessed through Monte Carlo simulations. At fixed stellar or <span class="hlt">dynamical</span> mass, we find moderate <span class="hlt">evolution</span> in galaxy size and stellar velocity dispersion, in agreement with previous studies. We show that this results in a decrease of the <span class="hlt">dynamical</span> to stellar mass ratio with redshift at >2σ significance. By combining our sample with high-redshift literature data, we find that this <span class="hlt">evolution</span> of the <span class="hlt">dynamical</span> to stellar mass ratio continues beyond z ∼ 0.7 up to z > 2 as M{sub dyn}/M{sub *} ∼(1 + z){sup –0.30±0.12}, further strengthening the evidence for an increase of M{sub dyn}/M{sub *} with cosmic time. This result is in line with recent predictions from galaxy formation simulations based on minor merger <span class="hlt">driven</span> mass growth, in which the dark matter fraction within the half-light radius increases with cosmic time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160005864&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160005864&hterms=electron&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Delectron"><span>Radiation Belt Electron <span class="hlt">Dynamics</span> <span class="hlt">Driven</span> by Large-Amplitude Whistlers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.</p> <p>2013-01-01</p> <p>Acceleration of radiation belt electrons <span class="hlt">driven</span> by oblique large-amplitude whistler waves is studied. We show analytically and numerically that this is a stochastic process; the intensity of which depends on the wave power modified by Bessel functions. The type of this dependence is determined by the character of the nonlinear interaction due to coupling between action and phase. The results show that physically significant quantities have a relatively weak dependence on the wave power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160005864&hterms=bessel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbessel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160005864&hterms=bessel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbessel"><span>Radiation Belt Electron <span class="hlt">Dynamics</span> <span class="hlt">Driven</span> by Large-Amplitude Whistlers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khazanov, G. V.; Tel'nikhin, A. A.; Kronberg, T. K.</p> <p>2013-01-01</p> <p>Acceleration of radiation belt electrons <span class="hlt">driven</span> by oblique large-amplitude whistler waves is studied. We show analytically and numerically that this is a stochastic process; the intensity of which depends on the wave power modified by Bessel functions. The type of this dependence is determined by the character of the nonlinear interaction due to coupling between action and phase. The results show that physically significant quantities have a relatively weak dependence on the wave power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA619948','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA619948"><span><span class="hlt">Dynamic</span> Data <span class="hlt">Driven</span> Methods for Self-aware Aerospace Vehicles</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-04-08</p> <p>Norton worm gear actuator to impart load into the system. The actuator is rated for 5 tons (10000 lbf) and is <span class="hlt">driven</span> via a DC motor. The motor is a...Controller feedback is provided via encoder (attached to actuator worm gear), LVDT, and/or load cell. The position sensor is a MacroSensors DC750-500...the gray arrows . OFFLINE High fidelity simulations Complete dataset Measured quantities of interest qm(x) Capability quantities of interest sc(x</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109r2404J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109r2404J"><span><span class="hlt">Dynamics</span> of antiferromagnetic skyrmion <span class="hlt">driven</span> by the spin Hall effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Chendong; Song, Chengkun; Wang, Jianbo; Liu, Qingfang</p> <p>2016-10-01</p> <p>Magnetic skyrmion moved by the spin-Hall effect is promising for the application of the generation racetrack memories. However, the Magnus force causes a deflected motion of skyrmion, which limits its application. Here, we create an antiferromagnetic skyrmion by injecting a spin-polarized pulse in the nanostripe and investigate the spin Hall effect-induced motion of antiferromagnetic skyrmion by micromagnetic simulations. In contrast to ferromagnetic skyrmion, we find that the antiferromagnetic skyrmion has three evident advantages: (i) the minimum driving current density of antiferromagnetic skyrmion is about two orders smaller than the ferromagnetic skyrmion; (ii) the velocity of the antiferromagnetic skyrmion is about 57 times larger than the ferromagnetic skyrmion <span class="hlt">driven</span> by the same value of current density; (iii) antiferromagnetic skyrmion can be <span class="hlt">driven</span> by the spin Hall effect without the influence of Magnus force. In addition, antiferromagnetic skyrmion can move around the pinning sites due to its property of topological protection. Our results present the understanding of antiferromagnetic skyrmion motion <span class="hlt">driven</span> by the spin Hall effect and may also contribute to the development of antiferromagnetic skyrmion-based racetrack memories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NucFu..50e4004S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NucFu..50e4004S"><span>Large scale <span class="hlt">dynamics</span> in flux <span class="hlt">driven</span> gyrokinetic turbulence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarazin, Y.; Grandgirard, V.; Abiteboul, J.; Allfrey, S.; Garbet, X.; Ghendrih, Ph.; Latu, G.; Strugarek, A.; Dif-Pradalier, G.</p> <p>2010-05-01</p> <p>The turbulent transport governed by the toroidal ion temperature gradient <span class="hlt">driven</span> instability is analysed with the full-f global gyrokinetic code GYSELA (Grandgirard et al 2007 Plasma Phys. Control. Fusion 49 B173) when the system is <span class="hlt">driven</span> by a prescribed heat source. Weak, yet finite, collisionality governs a neoclassical ion heat flux that can compete with the turbulent <span class="hlt">driven</span> transport. In turn, the ratio of turbulent to neoclassical transport increases with the source magnitude, resulting in the degradation of confinement with additional power. The turbulent flux exhibits avalanche-like events, characterized by intermittent outbursts which propagate ballistically roughly at the diamagnetic velocity. Locally, the temperature gradient can drop well below the linear stability threshold. Large outbursts are found to correlate with streamer-like structures of the convection cells albeit their Fourier spectrum departs significantly from that of the most unstable linear modes. Last, the poloidal rotation of turbulent eddies is essentially governed by the radial electric field at moderate density gradient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21036053','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21036053"><span>Nuclear Reactions and Stellar <span class="hlt">Evolution</span>: Unified <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bauer, W.; Strother, T.</p> <p>2007-10-26</p> <p>Motivated by the success of kinetic theory in the description of observables in intermediate and high energy heavy ion collisions, we use kinetic theory to model the <span class="hlt">dynamics</span> of collapsing iron cores in type II supernova explosions. The algorithms employed to model the collapse, some preliminary results and predictions, and the future of the code are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050161943','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050161943"><span>Internal <span class="hlt">Dynamics</span> and Crustal <span class="hlt">Evolution</span> of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuber, Maria</p> <p>2005-01-01</p> <p>The objective of this work is to improve understanding of the internal structure, crustal <span class="hlt">evolution</span>, and thermal history of Mars by combining geophysical data analysis of topography, gravity and magnetics with results from analytical and computational modeling. Accomplishments thus far in this investigation include: (1) development of a new crustal thickness model that incorporates constraints from Mars meteorites, corrections for polar cap masses and other surface loads, Pratt isostasy, and core flattening; (2) determination of a refined estimate of crustal thickness of Mars from geoid/topography ratios (GTRs); (3) derivation of a preliminary estimate of the k(sub 2) gravitational Love number and a preliminary estimate of possible dissipation within Mars consistent with this value; and (4) an integrative analysis of the sequence of <span class="hlt">evolution</span> of early Mars. During the remainder of this investigation we will: (1) extend models of degree-1 mantle convection from 2-D to 3-D; (2) investigate potential causal relationships and effects of major impacts on mantle plume formation, with primary application to Mars; (3) develop exploratory models to assess the convective stability of various Martian core states as relevant to the history of dynamo action; and (4) develop models of long-wavelength relaxation of crustal thickness anomalies to potentially explain the degree-1 structure of the Martian crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24462909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24462909"><span><span class="hlt">Dynamics</span> in genome <span class="hlt">evolution</span> of Vibrio cholerae.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Banerjee, Rachana; Das, Bhabatosh; Balakrish Nair, G; Basak, Surajit</p> <p>2014-04-01</p> <p>Vibrio cholerae, the etiological agent of the acute secretary diarrheal disease cholera, is still a major public health concern in developing countries. In former centuries cholera was a permanent threat even to the highly developed populations of Europe, North America, and the northern part of Asia. Extensive studies on the cholera bug over more than a century have made significant advances in our understanding of the disease and ways of treating patients. V. cholerae has more than 200 serogroups, but only few serogroups have caused disease on a worldwide scale. Until the present, the evolutionary relationship of these pandemic causing serogroups was not clear. In the last decades, we have witnessed a shift involving genetically and phenotypically varied pandemic clones of V. cholerae in Asia and Africa. The exponential knowledge on the genome of several representatives V. cholerae strains has been used to identify and analyze the key determinants for rapid <span class="hlt">evolution</span> of cholera pathogen. Recent comparative genomic studies have identified the presence of various integrative mobile genetic elements (IMGEs) in V. cholerae genome, which can be used as a marker of differentiation of all seventh pandemic clones with very similar core genome. This review attempts to bring together some of the important researches in recent times that have contributed towards understanding the genetics, epidemiology and <span class="hlt">evolution</span> of toxigenic V. cholerae strains. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JAP...100l3521P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JAP...100l3521P"><span><span class="hlt">Dynamically</span> <span class="hlt">driven</span> phase transformations in heterogeneous materials. II. Applications including damage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plohr, JeeYeon N.; Clements, B. E.; Addessio, F. L.</p> <p>2006-12-01</p> <p>A model, developed for heterogeneous materials undergoing <span class="hlt">dynamically</span> <span class="hlt">driven</span> phase transformations in its constituents, has been extended to include the <span class="hlt">evolution</span> of damage. Damage is described by two mechanisms: interfacial debonding between the constituents and brittle failure micro-crack growth within the constituents. The analysis is applied to silicon carbide-titanium (SiC-Ti) unidirectional metal matrix composites that undergo the following phenomena: Ti has a yield stress of approximately 0.5 GPa and above a pressure of about 2 GPa undergoes a solid-solid phase transformation. The inelastic work from plastic dissipation contributes to the temperature and pressure rise in the Ti. SiC behaves elastically below a critical stress, above which it is damaged by microcrack growth. Finally, under tensile loading, the interface between Ti and SiC debonds according to an interfacial decohesion law. Each process is first examined independently in order to understand how its characteristic behavior is manifested in the stress-strain response of the composite. The complex interplay between loading states, viscoplasticity, damage, and solid-solid phase transformations is then studied at both the micromechanics and macromechanics levels.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AN....332..537B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AN....332..537B"><span><span class="hlt">Dynamic</span> <span class="hlt">evolution</span> of nearby galaxy clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biernacka, M.; Flin, P.</p> <p>2011-06-01</p> <p>A study of the <span class="hlt">evolution</span> of 377 rich ACO clusters with redshift z<0.2 is presented. The data concerning galaxies in the investigated clusters were obtained using FOCAS packages applied to Digital Sky Survey I. The 377 galaxy clusters constitute a statistically uniform sample to which visual galaxy/star reclassifications were applied. Cluster shape within 2.0 h-1 Mpc from the adopted cluster centre (the mean and the median of all galaxy coordinates, the position of the brightest and of the third brightest galaxy in the cluster) was determined through its ellipticity calculated using two methods: the covariance ellipse method (hereafter CEM) and the method based on Minkowski functionals (hereafter MFM). We investigated ellipticity dependence on the radius of circular annuli, in which ellipticity was calculated. This was realized by varying the radius from 0.5 to 2 Mpc in steps of 0.25 Mpc. By performing Monte Carlo simulations, we generated clusters to which the two ellipticity methods were applied. We found that the covariance ellipse method works better than the method based on Minkowski functionals. We also found that ellipticity distributions are different for different methods used. Using the ellipticity-redshift relation, we investigated the possibility of cluster <span class="hlt">evolution</span> in the low-redshift Universe. The correlation of cluster ellipticities with redshifts is undoubtly an indicator of structural <span class="hlt">evolution</span>. Using the t-Student statistics, we found a statistically significant correlation between ellipticity and redshift at the significance level of α = 0.95. In one of the two shape determination methods we found that ellipticity grew with redshift, while the other method gave opposite results. Monte Carlo simulations showed that only ellipticities calculated at the distance of 1.5 Mpc from cluster centre in the Minkowski functional method are robust enough to be taken into account, but for that radius we did not find any relation between e and z. Since CEM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28213985','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28213985"><span>Capillary <span class="hlt">dynamics</span> <span class="hlt">driven</span> by molecular self-layering.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Pingkeng; Nikolov, Alex; Wasan, Darsh</p> <p>2017-02-10</p> <p>Capillary <span class="hlt">dynamics</span> is a ubiquitous everyday phenomenon. It has practical applications in diverse fields, including ink-jet printing, lab-on-a-chip, biotechnology, and coating. Understanding capillary <span class="hlt">dynamics</span> requires essential knowledge on the molecular level of how fluid molecules interact with a solid substrate (the wall). Recent studies conducted with the surface force apparatus (SFA), atomic force microscope (AFM), and statistical mechanics simulation revealed that molecules/nanoparticles confined into the film/wall surfaces tend to self-layer into 2D layer/s and even 2D in-layer with increased confinement and fluid volume fraction. Here, the capillary rise <span class="hlt">dynamics</span> of simple molecular fluids in cylindrical capillary is explained by the molecular self-layering model. The proposed model considers the role of the molecular shape on self-layering and its effect on the molecularly thin film viscosity in regards to the advancing (<span class="hlt">dynamic</span>) contact angle. The model was tested to explain the capillary rise <span class="hlt">dynamics</span> of fluids of spherical, cylindrical, and disk shape molecules in borosilicate glass capillaries. The good agreement between the capillary rise data and SFA data from the literature for simple fluid self-layering shows the validity of the present model. The present model provides new insights into the design of many applications where <span class="hlt">dynamic</span> wetting is important because it reveals the significant impact of molecular self-layering close to the wall on <span class="hlt">dynamic</span> wetting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27154920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27154920"><span>Delay <span class="hlt">driven</span> spatiotemporal chaos in single species population <span class="hlt">dynamics</span> models.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jankovic, Masha; Petrovskii, Sergei; Banerjee, Malay</p> <p>2016-08-01</p> <p>Questions surrounding the prevalence of complex population <span class="hlt">dynamics</span> form one of the central themes in ecology. Limit cycles and spatiotemporal chaos are examples that have been widely recognised theoretically, although their importance and applicability to natural populations remains debatable. The ecological processes underlying such <span class="hlt">dynamics</span> are thought to be numerous, though there seems to be consent as to delayed density dependence being one of the main driving forces. Indeed, time delay is a common feature of many ecological systems and can significantly influence population <span class="hlt">dynamics</span>. In general, time delays may arise from inter- and intra-specific trophic interactions or population structure, however in the context of single species populations they are linked to more intrinsic biological phenomena such as gestation or resource regeneration. In this paper, we consider theoretically the spatiotemporal <span class="hlt">dynamics</span> of a single species population using two different mathematical formulations. Firstly, we revisit the diffusive logistic equation in which the per capita growth is a function of some specified delayed argument. We then modify the model by incorporating a spatial convolution which results in a biologically more viable integro-differential model. Using the combination of analytical and numerical techniques, we investigate the effect of time delay on pattern formation. In particular, we show that for sufficiently large values of time delay the system's <span class="hlt">dynamics</span> are indicative to spatiotemporal chaos. The chaotic <span class="hlt">dynamics</span> arising in the wake of a travelling population front can be preceded by either a plateau corresponding to <span class="hlt">dynamical</span> stabilisation of the unstable equilibrium or by periodic oscillations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA617245','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA617245"><span>The Indian Jihadist Movement: <span class="hlt">Evolution</span> and <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-07-01</p> <p>executed in Pune on August 1, 2012, and two bicycle bombs in downtown Hyderabad that killed 17 and injured over 100 people .60 It remains unclear whether...regional stability. It is a symptom of political , socioeconomic, and communal issues that India arguably would need to address even if indigenous...of Indian Muslims have been launching terrorist strikes—with and without Pakistani support—for more than two decades. The <span class="hlt">dynamics</span> of Indian</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009DDA....40.1002J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009DDA....40.1002J"><span>Tidal and <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Binary Asteroids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobson, Seth A.; Scheeres, D. J.</p> <p>2009-05-01</p> <p>We derive a realistic model for the <span class="hlt">evolution</span> of a tidally perturbed binary, using classical theory, to examine the system just after a spin-up fission event. The spin rate of an asteroid can be increased by the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect -- thermal re-radiation from an asymmetric body, which induces torques that can rotationally accelerate the body. If the asteroid is modeled as a "rubble pile", a collection of gravitationally bound gravel with no tensile strength, increasing the spin rate will lead to a fission process that would resemble that of a viscous fluidic body [Holsapple 2007]. However, high-resolution imagery of an asteroid's constituents indicates that there is a significant distribution of size scales. A specific example is the asteroid Itokawa, which appears to be two such rubble piles in contact with each other [Fujiwara 2006]. The shape of these bodies will be irregular (modeled as tri-axial ellipsoids with a gravitational potential expanded up to second order). Their motions will raise tides on the opposing body. These tides will dissipate energy, potentially providing enough energy loss for the system to settle into a stable orbit. Fissioned binary systems are always initially unstable [Scheeres 2009, 2008]. We expect tidal dissipation rates to vary widely during the initial <span class="hlt">evolution</span> of the system, due to this instability. The model applies instantaneous tidal torques to determine energy loss. Our preliminary results indicate that tidal energy dissipation could relax the system to a state of relative equilibrium on order 100,000 years, creating systems similar to those observed. Holsapple, K. A., Icarus, 187, 2007. Fujiwara, A., Science, 312, 2006. Scheeres, D., CMDA, 2009 (Accepted Jan 10, 2009). Scheeres, D., AAS, DDA meeting #39, #9.01, 2008.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3601606','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3601606"><span>Interregional neural synchrony has similar <span class="hlt">dynamics</span> during spontaneous and stimulus-<span class="hlt">driven</span> states</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ghuman, Avniel Singh; van den Honert, Rebecca N.; Martin, Alex</p> <p>2013-01-01</p> <p>Assessing the correspondence between spontaneous and stimulus-<span class="hlt">driven</span> neural activity can reveal intrinsic properties of the brain. Recent studies have demonstrated that many large-scale functional networks have a similar spatial structure during spontaneous and stimulus-<span class="hlt">driven</span> states. However, it is unknown whether the temporal <span class="hlt">dynamics</span> of network activity are also similar across these states. Here we demonstrate that, in the human brain, interhemispheric coupling of somatosensory regions is preferentially synchronized in the high beta frequency band (~20–30 Hz) in response to somatosensory stimulation and interhemispheric coupling of auditory cortices is preferentially synchronized in the alpha frequency band (~7–12 Hz) in response to auditory stimulation. Critically, these stimulus-<span class="hlt">driven</span> synchronization frequencies were also selective to these interregional interactions during spontaneous activity. This similarity between stimulus-<span class="hlt">driven</span> and spontaneous states suggests that frequency-specific oscillatory <span class="hlt">dynamics</span> are intrinsic to the interactions between the nodes of these brain networks. PMID:23512004</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27071458','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27071458"><span>Linking stress-<span class="hlt">driven</span> microstructural <span class="hlt">evolution</span> in nanocrystalline aluminium with grain boundary doping of oxygen.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Mo-Rigen; Samudrala, Saritha K; Kim, Gyuseok; Felfer, Peter J; Breen, Andrew J; Cairney, Julie M; Gianola, Daniel S</p> <p>2016-04-13</p> <p>The large fraction of material residing at grain boundaries in nanocrystalline metals and alloys is responsible for their ultrahigh strength, but also undesirable microstructural instability under thermal and mechanical loads. However, the underlying mechanism of stress-<span class="hlt">driven</span> microstructural <span class="hlt">evolution</span> is still poorly understood and precludes rational alloy design. Here we combine quantitative in situ electron microscopy with three-dimensional atom-probe tomography to directly link the mechanics and kinetics of grain boundary migration in nanocrystalline Al films with the excess of O atoms at the boundaries. Site-specific nanoindentation leads to grain growth that is retarded by impurities, and enables quantification of the critical stress for the onset of grain boundary migration. Our results show that a critical excess of impurities is required to stabilize interfaces in nanocrystalline materials against mechanical driving forces, providing new insights to guide control of deformation mechanisms and tailoring of mechanical properties apart from grain size alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4833861','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4833861"><span>Linking stress-<span class="hlt">driven</span> microstructural <span class="hlt">evolution</span> in nanocrystalline aluminium with grain boundary doping of oxygen</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>He, Mo-Rigen; Samudrala, Saritha K.; Kim, Gyuseok; Felfer, Peter J.; Breen, Andrew J.; Cairney, Julie M.; Gianola, Daniel S.</p> <p>2016-01-01</p> <p>The large fraction of material residing at grain boundaries in nanocrystalline metals and alloys is responsible for their ultrahigh strength, but also undesirable microstructural instability under thermal and mechanical loads. However, the underlying mechanism of stress-<span class="hlt">driven</span> microstructural <span class="hlt">evolution</span> is still poorly understood and precludes rational alloy design. Here we combine quantitative in situ electron microscopy with three-dimensional atom-probe tomography to directly link the mechanics and kinetics of grain boundary migration in nanocrystalline Al films with the excess of O atoms at the boundaries. Site-specific nanoindentation leads to grain growth that is retarded by impurities, and enables quantification of the critical stress for the onset of grain boundary migration. Our results show that a critical excess of impurities is required to stabilize interfaces in nanocrystalline materials against mechanical driving forces, providing new insights to guide control of deformation mechanisms and tailoring of mechanical properties apart from grain size alone. PMID:27071458</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhDT........95N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhDT........95N"><span>Energetically and kinetically <span class="hlt">driven</span> step formation and <span class="hlt">evolution</span> on silicon surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nielson, Jon-Fredrik</p> <p>2001-12-01</p> <p>Energetically and kinetically <span class="hlt">driven</span> step formation and <span class="hlt">evolution</span> on Si(001) and Si(111) surfaces has been investigated experimentally using scanning tunneling microscopy (STM), atomic force microscopy (AFM), optical microscopy, and low-energy electron microscopy (LEEM). Four systems are investigated: 1. Detailed STM measurements of boron-doped Si(001) surfaces is presented, along with large-scale AFM and LEEM observations of the well-known boron-induced 'striped' phase at elevated temperatures. Boron is shown to induce a variety of related atomic-scale structures, some of which tend to decorate surface step-edges. This, in turn, could provide an explanation for the observed boron-induced reduction in step formation energy. However, the observed boron-accumulation at step-edges does not appear to vary systematically with annealing temperature, leaving the well-known temperature dependence of the striped phase unresolved. Real-time LEEM observations of striped step formation on Si(001) during diborane (B 2H6) exposure at elevated temperatures are used to demonstrate the controlled formation of large (>5mum) surface regions with highly uniform striped step structures. 2. Large-scale step rearrangements have been investigated on Si(001) and Si(111) surfaces heated to sublimation temperatures (>900°C) using a direct current. These surfaces undergo dramatic morphological changes, which are believed to arise from a directional drift of diffusing surface atoms in the presence of an applied electric field. Such 'electromigration' phenomena include step 'bunching' and step 'wandering', as well as a predicted step 'bending' instability. Using AFM and optical microscopy, we argue that the direction of surface atom electromigration on Si(001) can be parallel, anti-parallel, or even sideways to the applied electric field, depending on the direction of the applied field with the high-symmetry <110> crystal directions. In addition, the first experimental evidence for the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12398441','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12398441"><span>Coupled <span class="hlt">dynamics</span> of translation and collapse of acoustically <span class="hlt">driven</span> microbubbles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reddy, Anil J; Szeri, Andrew J</p> <p>2002-10-01</p> <p>Pressure gradients drive the motion of microbubbles relative to liquids in which they are suspended. Examples include the hydrostatic pressure due to a gravitational field, and the pressure gradients in a sound field, useful for acoustic levitation. In this paper, the equations describing the coupled <span class="hlt">dynamics</span> of radial oscillation and translation of a microbubble are given. The formulation is based on a recently derived expression for the hydrodynamic force on a bubble of changing size in an incompressible liquid [J. Magnaudet and D. Legendre, Phys. Fluids 10, 550-556 (1998)]. The complex interaction between radial and translation <span class="hlt">dynamics</span> is best understood by examination of the added momentum associated with the liquid motion caused by the moving bubble. Translation is maximized when the bubble collapses violently. The new theory for coupled collapse and translation <span class="hlt">dynamics</span> is compared to past experiments and to previous theories for decoupled translation <span class="hlt">dynamics</span>. Special attention is paid to bubbles of relevance in biomedical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvE..86f1913A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvE..86f1913A"><span>Anharmonic <span class="hlt">dynamics</span> of intramolecular hydrogen bonds <span class="hlt">driven</span> by DNA breathing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexandrov, B. S.; Stanev, V. G.; Bishop, A. R.; Rasmussen, K. Ø.</p> <p>2012-12-01</p> <p>We study the effects of the anharmonic strand-separation <span class="hlt">dynamics</span> of double-stranded DNA on the infrared spectra of the intramolecular base-pairing hydrogen bonds. Using the extended Peyrard-Bishop-Dauxois model for the DNA breathing <span class="hlt">dynamics</span> coupled with the Lippincott-Schroeder potential for N-H⋯N and N-H⋯O hydrogen bonding, we identify a high-frequency (˜96 THz) feature in the infrared spectra. We show that this sharp peak arises as a result of the anharmonic base-pair breathing <span class="hlt">dynamics</span> of DNA. In addition, we study the effects of friction on the infrared spectra. For higher temperatures (˜300 K), where the anharmonicity of DNA <span class="hlt">dynamics</span> is pronounced, the high-frequency peak is always present irrespective of the friction strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA267409','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA267409"><span>Development of <span class="hlt">Dynamic</span>, Contex-<span class="hlt">Driven</span> Help Systems</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1993-03-01</p> <p>10 D. USER EXPERIENCE ............................................................................................................. 11...14 a. User Experience ........................................................................................ 14 b...variables, such as application mode in use, the command history of the session and user experience , can be leveraged to provide a <span class="hlt">dynamic</span>, user</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFD.G9003B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFD.G9003B"><span>Fluid-<span class="hlt">driven</span> fracturing of adhered elastica: <span class="hlt">evolution</span> of the vapour tip</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ball, Thomasina V.; Neufeld, Jerome A.</p> <p>2016-11-01</p> <p>The transient spreading of a viscous fluid beneath an elastic sheet is controlled by the <span class="hlt">dynamics</span> at the tip. The large negative pressures needed to drive the viscous fluid into the narrowing gap necessitates a vapour tip separating the fluid front and the crack tip. Adhesion of the elastic sheet imposes a curvature at the tip giving rise to an elasto-capillary length scale and the possibility of a balance between elastic deformation and the strength of adhesion. Two <span class="hlt">dynamical</span> regimes are therefore possible; viscosity dominant spreading controlled by the pressure in the vapour tip and adhesion dominant spreading controlled by interfacial adhesion. A series of constant flux experiments using clear PDMS elastic sheets allow for direct measurement of the vapour tip in the bending (thick sheet) limit. For small fluid fluxes, the experimental results can be explained by a constant interior pressure and a viscous boundary layer near the fluid front and result in an asymptotic model for the advance of adhesion and viscosity dominated fracture fronts resolving the vapour tip. Understanding the fluid-<span class="hlt">driven</span> fracturing of adhered elastica provides insight into the spreading of shallow magmatic intrusions in the Earth's crust, and the fluid-<span class="hlt">driven</span> fracturing of elastic media more generally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3116822','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3116822"><span>Functional <span class="hlt">Evolution</span> of Leptin of Ochotona curzoniae in Adaptive Thermogenesis <span class="hlt">Driven</span> by Cold Environmental Stress</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Jie; Bromage, Timothy G.; Zhao, Qian; Xu, Bao Hong; Gao, Wei Li; Tian, Hui Fang; Tang, Hui Jun; Liu, Dian Wu; Zhao, Xin Quan</p> <p>2011-01-01</p> <p>Background Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive <span class="hlt">evolution</span> of plateau pika leptin may be <span class="hlt">driven</span> by cold stress. Methodology/Principal Findings To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. Conclusions/Significance These findings support the hypothesis that cold stress has <span class="hlt">driven</span> the functional <span class="hlt">evolution</span> of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau. PMID:21698227</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26791621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26791621"><span>Meiotic recombination counteracts male-biased mutation (male-<span class="hlt">driven</span> <span class="hlt">evolution</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mawaribuchi, Shuuji; Ito, Michihiko; Ogata, Mitsuaki; Oota, Hiroki; Katsumura, Takafumi; Takamatsu, Nobuhiko; Miura, Ikuo</p> <p>2016-01-27</p> <p>Meiotic recombination is believed to produce greater genetic variation despite the fact that deoxyribonucleic acid (DNA)-replication errors are a major source of mutations. In some vertebrates, mutation rates are higher in males than in females, which developed the theory of male-<span class="hlt">driven</span> <span class="hlt">evolution</span> (male-biased mutation). However, there is little molecular evidence regarding the relationships between meiotic recombination and male-biased mutation. Here we tested the theory using the frog Rana rugosa, which has both XX/XY- and ZZ/ZW-type sex-determining systems within the species. The male-to-female mutation-rate ratio (α) was calculated from homologous sequences on the X/Y or Z/W sex chromosomes, which supported male-<span class="hlt">driven</span> <span class="hlt">evolution</span>. Surprisingly, each α value was notably higher in the XX/XY-type group than in the ZZ/ZW-type group, although α should have similar values within a species. Interestingly, meiotic recombination between homologous chromosomes did not occur except at terminal regions in males of this species. Then, by subdividing α into two new factors, a replication-based male-to-female mutation-rate ratio (β) and a meiotic recombination-based XX-to-XY/ZZ-to-ZW mutation-rate ratio (γ), we constructed a formula describing the relationship among a nucleotide-substitution rate and the two factors, β and γ. Intriguingly, the β- and γ-values were larger and smaller than 1, respectively, indicating that meiotic recombination might reduce male-biased mutations. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4795034','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4795034"><span>Meiotic recombination counteracts male-biased mutation (male-<span class="hlt">driven</span> <span class="hlt">evolution</span>)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mawaribuchi, Shuuji; Ito, Michihiko; Ogata, Mitsuaki; Oota, Hiroki; Katsumura, Takafumi; Takamatsu, Nobuhiko; Miura, Ikuo</p> <p>2016-01-01</p> <p>Meiotic recombination is believed to produce greater genetic variation despite the fact that deoxyribonucleic acid (DNA)-replication errors are a major source of mutations. In some vertebrates, mutation rates are higher in males than in females, which developed the theory of male-<span class="hlt">driven</span> <span class="hlt">evolution</span> (male-biased mutation). However, there is little molecular evidence regarding the relationships between meiotic recombination and male-biased mutation. Here we tested the theory using the frog Rana rugosa, which has both XX/XY- and ZZ/ZW-type sex-determining systems within the species. The male-to-female mutation-rate ratio (α) was calculated from homologous sequences on the X/Y or Z/W sex chromosomes, which supported male-<span class="hlt">driven</span> <span class="hlt">evolution</span>. Surprisingly, each α value was notably higher in the XX/XY-type group than in the ZZ/ZW-type group, although α should have similar values within a species. Interestingly, meiotic recombination between homologous chromosomes did not occur except at terminal regions in males of this species. Then, by subdividing α into two new factors, a replication-based male-to-female mutation-rate ratio (β) and a meiotic recombination-based XX-to-XY/ZZ-to-ZW mutation-rate ratio (γ), we constructed a formula describing the relationship among a nucleotide-substitution rate and the two factors, β and γ. Intriguingly, the β- and γ-values were larger and smaller than 1, respectively, indicating that meiotic recombination might reduce male-biased mutations. PMID:26791621</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21698227','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21698227"><span>Functional <span class="hlt">evolution</span> of leptin of Ochotona curzoniae in adaptive thermogenesis <span class="hlt">driven</span> by cold environmental stress.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Jie; Bromage, Timothy G; Zhao, Qian; Xu, Bao Hong; Gao, Wei Li; Tian, Hui Fang; Tang, Hui Jun; Liu, Dian Wu; Zhao, Xin Quan</p> <p>2011-01-01</p> <p>Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive <span class="hlt">evolution</span> of plateau pika leptin may be <span class="hlt">driven</span> by cold stress. To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. These findings support the hypothesis that cold stress has <span class="hlt">driven</span> the functional <span class="hlt">evolution</span> of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPhA...46p5001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPhA...46p5001S"><span>Time <span class="hlt">evolution</span> of the autocorrelation function in <span class="hlt">dynamical</span> replica theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakata, A.</p> <p>2013-04-01</p> <p>Asynchronous <span class="hlt">dynamics</span> given by the master equation in the Sherrington-Kirkpatrick (SK) spin-glass model is studied based on <span class="hlt">dynamical</span> replica theory (DRT) with an extension to take into account the autocorrelation function. The <span class="hlt">dynamical</span> behaviour of the system is approximately described by <span class="hlt">dynamical</span> equations of the macroscopic quantities: magnetization, energy contributed by randomness and the autocorrelation function. The <span class="hlt">dynamical</span> equations under the replica symmetry assumption are derived by introducing the subshell equipartitioning assumption and exploiting the replica method. The obtained <span class="hlt">dynamical</span> equations are compared with Monte Carlo simulations, and it is demonstrated that the proposed formula describes well the time <span class="hlt">evolution</span> of the autocorrelation function in some parameter regions. The study offers a reasonable description of the autocorrelation function in the SK spin-glass system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/127310','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/127310"><span>Gravity-<span class="hlt">driven</span> structures and rift basin <span class="hlt">evolution</span>: Rio Muni Basin, offshore equatorial West Africa</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Turner, J.P.</p> <p>1995-08-01</p> <p>Offshore Equatorial Guinea, west Africa, gravity-<span class="hlt">driven</span> nappes, more than 1 km thick and 15 km from head to toe, provide key evidence in reconstructing the late synrift: <span class="hlt">evolution</span> of this part of the South Atlantic margin basin system. Furthermore, Aptian-Cenomanian carbonate and clastic rocks in the nappes` allochthonous hanging walls are attracting interest as a new exploration play in west Africa. The nappes exhibit a range of geometries that suggest they share many of the same deformation processes as thin-skin thrust and linked extensional fault systems. Not only are these structures significant in their own right, representing a rare example of gravity tectonics in the virtual absence of major halokinesis, but their presence may record an other-wise undetectable process active during the transition from a rift basin to a passive continental margin. A review of Equatorial Guinea in its pre-Atlantic configuration, alongside neighboring basins in Brazil (the Sergipe-Alagoas basin) and Gabon, suggests that gravity gliding was sustained by a relatively steep, westward paleoslope promoted by east-ward offset of the locus of thermal uplift from the rift basin (i.e., a simple shear model of basin formation). In contrast to gravity-<span class="hlt">driven</span> structures in most postrift settings, the Equatorial Guinea nappes developed at the close of the Aptian-Albian synrift episode in response to a growing bathymetric deep caused by rapid subsidence outpacing restricted sedimentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MNRAS.451..244C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MNRAS.451..244C"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of the Cybele asteroids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carruba, V.; Nesvorný, D.; Aljbaae, S.; Huaman, M. E.</p> <p>2015-07-01</p> <p>The Cybele region, located between the 2J:-1A and 5J:-3A mean-motion resonances, is adjacent and exterior to the asteroid main belt. An increasing density of three-body resonances makes the region between the Cybele and Hilda populations <span class="hlt">dynamically</span> unstable, so that the Cybele zone could be considered the last outpost of an extended main belt. The presence of binary asteroids with large primaries and small secondaries suggested that asteroid families should be found in this region, but only relatively recently the first <span class="hlt">dynamical</span> groups were identified in this area. Among these, the Sylvia group has been proposed to be one of the oldest families in the extended main belt. In this work we identify families in the Cybele region in the context of the local <span class="hlt">dynamics</span> and non-gravitational forces such as the Yarkovsky and stochastic Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effects. We confirm the detection of the new Helga group at ≃3.65 au, which could extend the outer boundary of the Cybele region up to the 5J:-3A mean-motion resonance. We obtain age estimates for the four families, Sylvia, Huberta, Ulla, and Helga, currently detectable in the Cybele region, using Monte Carlo methods that include the effects of stochastic YORP and variability of the solar luminosity. The Sylvia family should be T = 1220 ± 40 Myr old, with a possible older secondary solution. Any collisional Cybele group formed prior to the Late Heavy Bombardment would have been most likely completely dispersed in the jumping Jupiter scenario of planetary migration.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23440686','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23440686"><span><span class="hlt">Dynamic</span> <span class="hlt">evolution</span> of interface roughness during friction and wear processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kubiak, K J; Bigerelle, M; Mathia, T G; Dubois, A; Dubar, L</p> <p>2014-01-01</p> <p><span class="hlt">Dynamic</span> <span class="hlt">evolution</span> of surface roughness and influence of initial roughness (S(a) = 0.282-6.73 µm) during friction and wear processes has been analyzed experimentally. The mirror polished and rough surfaces (28 samples in total) have been prepared by surface polishing on Ti-6Al-4V and AISI 1045 samples. Friction and wear have been tested in classical sphere/plane configuration using linear reciprocating tribometer with very small displacement from 130 to 200 µm. After an initial period of rapid degradation, <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of surface roughness converges to certain level specific to a given tribosystem. However, roughness at such <span class="hlt">dynamic</span> interface is still increasing and analysis of initial roughness influence revealed that to certain extent, a rheology effect of interface can be observed and <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of roughness will depend on initial condition and history of interface roughness <span class="hlt">evolution</span>. Multiscale analysis shows that morphology created in wear process is composed from nano, micro, and macro scale roughness. Therefore, mechanical parts working under very severe contact conditions, like rotor/blade contact, screws, clutch, etc. with poor initial surface finishing are susceptible to have much shorter lifetime than a quality finished parts. © Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26958909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26958909"><span>Koala Retroviruses: <span class="hlt">Evolution</span> and Disease <span class="hlt">Dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Wenqin; Eiden, Maribeth V</p> <p>2015-11-01</p> <p>A retroviral etiology for malignant neoplasias in koalas has long been suspected. Evidence for retroviral involvement was bolstered in 2000 by the isolation of a koala retrovirus (KoRV), now termed KoRV-A. KoRV-A is an endogenous retrovirus-a retrovirus that infects germ cells-a feature that makes it a permanent resident of the koala genome. KoRV-A lacks the genetic diversity of an exogenous retrovirus, a quality associated with the ability of a retrovirus to cause neoplasias. In 2013, a second KoRV isolate, KoRV-B, was obtained from koalas with lymphomas in the Los Angeles Zoo. Unlike KoRV-A, which is present in the genomes of all koalas in the United States, KoRV-B is restricted in its distribution and is associated with host pathology (neoplastic disease). Here, our current understanding of the <span class="hlt">evolution</span> of endogenous and exogenous KoRVs, and the relationship between them, is reviewed to build a perspective on the future impact of these viruses on koala sustainability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23841080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23841080"><span><span class="hlt">Dynamic</span> actin gene family <span class="hlt">evolution</span> in primates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Liucun; Zhang, Ying; Hu, Yijun; Wen, Tieqiao; Wang, Qiang</p> <p>2013-01-01</p> <p>Actin is one of the most highly conserved proteins and plays crucial roles in many vital cellular functions. In most eukaryotes, it is encoded by a multigene family. Although the actin gene family has been studied a lot, few investigators focus on the comparison of actin gene family in relative species. Here, the purpose of our study is to systematically investigate characteristics and evolutionary pattern of actin gene family in primates. We identified 233 actin genes in human, chimpanzee, gorilla, orangutan, gibbon, rhesus monkey, and marmoset genomes. Phylogenetic analysis showed that actin genes in the seven species could be divided into two major types of clades: orthologous group versus complex group. Codon usages and gene expression patterns of actin gene copies were highly consistent among the groups because of basic functions needed by the organisms, but much diverged within species due to functional diversification. Besides, many great potential pseudogenes were found with incomplete open reading frames due to frameshifts or early stop codons. These results implied that actin gene family in primates went through "birth and death" model of <span class="hlt">evolution</span> process. Under this model, actin genes experienced strong negative selection and increased the functional complexity by reproducing themselves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvE..86e6103R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvE..86e6103R"><span>Hopf bifurcation in the <span class="hlt">evolution</span> of networks <span class="hlt">driven</span> by spike-timing-dependent plasticity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Quansheng; Kolwankar, Kiran M.; Samal, Areejit; Jost, Jürgen</p> <p>2012-11-01</p> <p>We study the interplay of topology and <span class="hlt">dynamics</span> in a neural network connected with spike-timing-dependent plasticity (STDP) synapses. Stimulated with periodic spike trains, the STDP-<span class="hlt">driven</span> network undergoes a synaptic pruning process and evolves to a residual network. We examine the variation of topological and <span class="hlt">dynamical</span> properties of the residual network by varying two key parameters of STDP: synaptic delay and the ratio between potentiation and depression. Our extensive numerical simulations of the leaky integrate-and-fire model show that there exists two regions in the parameter space. The first corresponds to fixed-point configurations, where the distribution of peak synaptic conductances and the firing rate of neurons remain constant over time. The second corresponds to oscillating configurations, where both topological and <span class="hlt">dynamical</span> properties vary periodically, which is a result of a fixed point becoming a limit cycle via a Hopf bifurcation. This leads to interesting questions regarding the implications of these rhythms in the topology and <span class="hlt">dynamics</span> of the network for learning and cognitive processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22314820','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22314820"><span>Quantum recurrence and fractional <span class="hlt">dynamic</span> localization in ac-<span class="hlt">driven</span> perfect state transfer Hamiltonians</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Longhi, Stefano</p> <p>2014-06-15</p> <p>Quantum recurrence and <span class="hlt">dynamic</span> localization are investigated in a class of ac-<span class="hlt">driven</span> tight-binding Hamiltonians, the Krawtchouk quantum chain, which in the undriven case provides a paradigmatic Hamiltonian model that realizes perfect quantum state transfer and mirror inversion. The equivalence between the ac-<span class="hlt">driven</span> single-particle Krawtchouk Hamiltonian H{sup -hat} (t) and the non-interacting ac-<span class="hlt">driven</span> bosonic junction Hamiltonian enables to determine in a closed form the quasi energy spectrum of H{sup -hat} (t) and the conditions for exact wave packet reconstruction (<span class="hlt">dynamic</span> localization). In particular, we show that quantum recurrence, which is predicted by the general quantum recurrence theorem, is exact for the Krawtchouk quantum chain in a dense range of the driving amplitude. Exact quantum recurrence provides perfect wave packet reconstruction at a frequency which is fractional than the driving frequency, a phenomenon that can be referred to as fractional <span class="hlt">dynamic</span> localization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95o5126P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95o5126P"><span><span class="hlt">Dynamically</span> enriched topological orders in <span class="hlt">driven</span> two-dimensional systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Potter, Andrew C.; Morimoto, Takahiro</p> <p>2017-04-01</p> <p>Time-periodic driving of a quantum system can enable new <span class="hlt">dynamical</span> topological phases of matter that could not exist in thermal equilibrium. We investigate two related classes of <span class="hlt">dynamical</span> topological phenomena in 2D systems: Floquet symmetry-protected topological phases (FSPTs) and Floquet enriched topological orders (FETs). By constructing solvable lattice models for a complete set of 2D bosonic FSPT phases, we show that bosonic FSPTs can be understood as topological pumps which deposit loops of 1D SPT chains onto the boundary during each driving cycle, which protects a nontrivial edge state by <span class="hlt">dynamically</span> tuning the edge to a self-dual point poised between the 1D SPT and trivial phases of the edge. By coupling these FSPT models to <span class="hlt">dynamical</span> gauge fields, we construct solvable models of FET orders in which anyon excitations are <span class="hlt">dynamically</span> transmuted into topologically distinct anyon types during each driving period. These bosonic FSPT and gauged FSPT models are classified by group cohomology methods. In addition, we also construct examples of "beyond cohomology" FET orders, which can be viewed as topological pumps of 1D topological chains formed of emergent anyonic quasiparticles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..92f2928K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..92f2928K"><span>Forecasting critical transitions using data-<span class="hlt">driven</span> nonstationary <span class="hlt">dynamical</span> modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwasniok, Frank</p> <p>2015-12-01</p> <p>An approach to predicting critical transitions from time series is introduced. A nonstationary low-order stochastic <span class="hlt">dynamical</span> model of appropriate complexity to capture the transition mechanism under consideration is estimated from data. In the simplest case, the model is a one-dimensional effective Langevin equation, but also higher-dimensional <span class="hlt">dynamical</span> reconstructions based on time-delay embedding and local modeling are considered. Integrations with the nonstationary models are performed beyond the learning data window to predict the nature and timing of critical transitions. The technique is generic, not requiring detailed a priori knowledge about the underlying <span class="hlt">dynamics</span> of the system. The method is demonstrated to successfully predict a fold and a Hopf bifurcation well beyond the learning data window.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.118z0602B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.118z0602B"><span>Floquet <span class="hlt">Dynamics</span> of Boundary-<span class="hlt">Driven</span> Systems at Criticality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berdanier, William; Kolodrubetz, Michael; Vasseur, Romain; Moore, Joel E.</p> <p>2017-06-01</p> <p>A quantum critical system described at low energy by a conformal field theory (CFT) and subjected to a time-periodic boundary drive displays multiple <span class="hlt">dynamical</span> regimes, depending on the drive frequency. We compute the behavior of quantities including the entanglement entropy and Loschmidt echo, confirming analytic predictions from field theory by exact numerics on the transverse field Ising model and demonstrate universality by adding nonintegrable perturbations. The <span class="hlt">dynamics</span> naturally separate into three regimes: a slow-driving limit, which has an interpretation as multiple quantum quenches with amplitude corrections from CFT; a fast-driving limit, in which the system behaves as though subject to a single quantum quench; and a crossover regime displaying heating. The universal Floquet <span class="hlt">dynamics</span> in all regimes can be understood using a combination of boundary CFT and Kibble-Zurek scaling arguments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRB..122.6473P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRB..122.6473P"><span>Connecting crustal seismicity and earthquake-<span class="hlt">driven</span> stress <span class="hlt">evolution</span> in Southern California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pollitz, Fred F.; Cattania, Camilla</p> <p>2017-08-01</p> <p>Tectonic stress in the crust evolves during a seismic cycle, with slow stress accumulation over interseismic periods, episodic stress steps at the time of earthquakes, and transient stress readjustment during a postseismic period that may last months to years. Static stress transfer to surrounding faults has been well documented to alter regional seismicity rates over both short and long time scales. While static stress transfer is instantaneous and long lived, postseismic stress transfer <span class="hlt">driven</span> by viscoelastic relaxation of the ductile lower crust and mantle leads to additional, slowly varying stress perturbations. Both processes may be tested by comparing a decade-long record of regional seismicity to predicted time-dependent seismicity rates based on a stress <span class="hlt">evolution</span> model that includes viscoelastic stress transfer. Here we explore crustal stress <span class="hlt">evolution</span> arising from the seismic cycle in Southern California from 1981 to 2014 using five M≥6.5 source quakes: the M7.3 1992 Landers, M6.5 1992 Big Bear, M6.7 1994 Big Bear, M7.1 1999 Hector Mine, and M7.2 2010 El Mayor-Cucapah earthquakes. We relate the stress readjustment in the surrounding crust generated by each quake to regional seismicity using rate-and-state friction theory. Using a log likelihood approach, we quantify the potential to trigger seismicity of both static and viscoelastic stress transfer, finding that both processes have systematically shaped the spatial pattern of Southern California seismicity since 1992.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4947895','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4947895"><span>Predator-<span class="hlt">driven</span> brain size <span class="hlt">evolution</span> in natural populations of Trinidadian killifish (Rivulus hartii)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Walsh, Matthew R.; Broyles, Whitnee; Beston, Shannon M.; Munch, Stephan B.</p> <p>2016-01-01</p> <p>Vertebrates exhibit extensive variation in relative brain size. It has long been assumed that this variation is the product of ecologically <span class="hlt">driven</span> natural selection. Yet, despite more than 100 years of research, the ecological conditions that select for changes in brain size are unclear. Recent laboratory selection experiments showed that selection for larger brains is associated with increased survival in risky environments. Such results lead to the prediction that increased predation should favour increased brain size. Work on natural populations, however, foreshadows the opposite trajectory of <span class="hlt">evolution</span>; increased predation favours increased boldness, slower learning, and may thereby select for a smaller brain. We tested the influence of predator-induced mortality on brain size <span class="hlt">evolution</span> by quantifying brain size variation in a Trinidadian killifish, Rivulus hartii, from communities that differ in predation intensity. We observed strong genetic differences in male (but not female) brain size between fish communities; second generation laboratory-reared males from sites with predators exhibited smaller brains than Rivulus from sites in which they are the only fish present. Such trends oppose the results of recent laboratory selection experiments and are not explained by trade-offs with other components of fitness. Our results suggest that increased male brain size is favoured in less risky environments because of the fitness benefits associated with faster rates of learning and problem-solving behaviour. PMID:27412278</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1916770C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1916770C"><span>Active tectonics and drainage <span class="hlt">evolution</span> in the Tunisian Atlas <span class="hlt">driven</span> by interaction between crustal shortening and slab pull</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Camafort, Miquel; Booth-Rea, Guillermo; Pérez-Peña, Jose Vicente; Melki, Fetheddine; Gracia, Eulalia; Azañón, Jose Miguel; Ranero, César R.</p> <p>2017-04-01</p> <p>Active tectonics in North Africa is fundamentally <span class="hlt">driven</span> by NW-SE directed slow convergence between the Nubia and Eurasia plates, leading to a region of thrust and strike-slip faulting. In this paper we analyze the morphometric characteristics of the little-studied northern Tunisia sector. The study aimed at identifying previously unknown active tectonic structures, and to further understand the mechanisms that drive the drainage <span class="hlt">evolution</span> in this region of slow convergence. The interpretation of morphometric data was supported with a field campaign of a selection of structures. The analysis indicates that recent fluvial captures have been the main factor rejuvenating drainage catchments. The Medjerda River, which is the main catchment in northern Tunisia, has increased its drainage area during the Quaternary by capturing adjacent axial valleys to the north and south of its drainage divide. These captures are probably <span class="hlt">driven</span> by gradual uplift of adjacent axial valleys by reverse/oblique faults or associated folds like El Alia-Teboursouk and Dkhila faults. Our fieldwork found that these faults cut Holocene colluvial fans containing seismites like clastic dikes and sand volcanoes, indicating recent seismogenic faulting. The growth and stabilization of the axial Medjerda River against the natural tendency of transverse drainages might be caused by a combination of <span class="hlt">dynamic</span> topography and transpressive tectonics. The orientation of the large axial Medjerda drainage that runs from eastern Algeria towards northeastern Tunisia into the Gulf of Tunis, might be the associated to negative buoyancy caused by the underlying Nubia slab at its mouth, together with uplift of the Medjerda headwaters along the South Atlassic dextral transfer zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AN....338..464G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AN....338..464G"><span>A <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> Study of 40 2MASS Open Clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Güneş, Orhan; Karataş, Yüksel; Bonatto, Charles</p> <p>2017-05-01</p> <p>We investigate the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of 40 open clusters (OCs) by means of their astrophysical parameters derived from field-decontaminated 2MASS photometry. We find a bifurcation in the planes core radius vs. age and cluster radius vs. age, in which part of the clusters appear to expand with time probably due to the presence of stellar black holes while others seem to shrink due to <span class="hlt">dynamical</span> relaxation. Mass functions (MFs) are built for 3/4 of the sample (31 OCs), which are used to search for indications of mass segregation and external <span class="hlt">dynamical</span> processes by means of relations among astrophysical, structural and evolutionary parameters. We detect a flattening of MF slopes ocurring at the evolutionary parameters τ_{core}≤ 32 and τ_{overall}≤ 30, respectively. Within the uncertainties involved, the overall MF slopes of 14 out of 31 OCs with m_{overall} > 500 M_{⊙} are consistent with Kroupa's initial mass function, implying little or no <span class="hlt">dynamical</span> <span class="hlt">evolution</span> for these clusters. The remaining 17 OCs with MF slopes departing from that of Kroupa show mild/large scale mass segregation due to <span class="hlt">dynamical</span> <span class="hlt">evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPG12068F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPG12068F"><span>Nonlinear <span class="hlt">Dynamics</span> of Beam-<span class="hlt">driven</span> TAEs in NSTX</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Guoyong; Liu, Deyong; Wang, Feng</p> <p>2015-11-01</p> <p>Energetic particle modes and Alfvénic modes <span class="hlt">driven</span> by super-Alfvénic beam ions were routinely observed in neutral beam heated plasmas on NSTX. These modes can significantly impact beam-ion transport, thus causing beam-ion redistribution and losses. Recent simulation results of TAEs show mode radial structure consistent with the reflectometer measurements of electron density fluctuations. In this paper we report on new simulations of multiple TAEs in NSTX plasmas using the M3D-K code. The results show strong interaction between TAEs and fishbone that either enhances or reduces saturation level of individual modes depending on mode number and other parameters. As beam ion beta increases beyond a threshold, mode saturation levels are found to increases sharply. Correspondingly the locally flattening regions merge together resulting in global particle transport and substantial particle loss. These results are similar to the TAE avalanche observed in NSTX.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.465.3729S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.465.3729S"><span>Bar-<span class="hlt">driven</span> <span class="hlt">evolution</span> and quenching of spiral galaxies in cosmological simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spinoso, Daniele; Bonoli, Silvia; Dotti, Massimo; Mayer, Lucio; Madau, Piero; Bellovary, Jillian</p> <p>2017-03-01</p> <p>We analyse the outputs of the cosmological 'zoom-in' hydrodynamical simulation ErisBH to study a strong stellar bar which naturally emerges in the late <span class="hlt">evolution</span> of the simulated Milky Way-type galaxy. We focus on the analysis of the formation and <span class="hlt">evolution</span> of the bar and on its effects on the galactic structure, the gas distribution and the star formation. A large central region in the ErisBH disc becomes bar unstable after z ∼ 1.4, but a clear bar starts to grow significantly only after z ≃ 0.4, possibly triggered by the interaction with a massive satellite. At z ≃ 0.1, the bar stabilizes and reaches its maximum radial extent of l ≈ 2.2 kpc. As the bar grows, it becomes prone to buckling instability. The actual buckling event, observable at z ≃ 0.1, results in the formation of a boxy-peanut bulge clearly discernible at z = 0. During its early growth, the bar exerts a strong torque on the gas and drives gas inflows that enhance the nuclear star formation on sub-kpc scales. Later on, as the bar reaches its maximum length and strength, the gas within its extent is nearly all consumed into stars, leaving behind a gas-depleted region in the central ∼2 kpc. Observations would more likely identify a prominent, large-scale bar at the stage when the galactic central region has already been gas depleted, giving a hint at the fact that bar-<span class="hlt">driven</span> quenching may play an important role in the <span class="hlt">evolution</span> of disc-dominated galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSV...394..527Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSV...394..527Y"><span>Vibration analysis of cable-<span class="hlt">driven</span> parallel robots based on the <span class="hlt">dynamic</span> stiffness matrix method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Han; Courteille, Eric; Gouttefarde, Marc; Hervé, Pierre-Elie</p> <p>2017-04-01</p> <p>This paper focuses on the vibration analysis of Cable-<span class="hlt">Driven</span> Parallel Robots (CDPRs). An oscillating model of CDPRs able to capture the <span class="hlt">dynamic</span> behavior of the cables is derived using Lagrangian approach in conjunction with the <span class="hlt">Dynamic</span> Stiffness Matrix method. Then, an original approach to analyze the modal interaction between the local cable modes and the global CDPR modes is presented. To illustrate this approach, numerical investigations and experimental analyses are carried out on a large-dimension 6-DOF suspended CDPR <span class="hlt">driven</span> by 8 cables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPS...268..758L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPS...268..758L"><span>Real-time estimation of lead-acid battery parameters: A <span class="hlt">dynamic</span> data-<span class="hlt">driven</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yue; Shen, Zheng; Ray, Asok; Rahn, Christopher D.</p> <p>2014-12-01</p> <p>This short paper presents a recently reported <span class="hlt">dynamic</span> data-<span class="hlt">driven</span> method, Symbolic <span class="hlt">Dynamic</span> Filtering (SDF), for real-time estimation of the state-of-health (SOH) and state-of-charge (SOC) in lead-acid batteries, as an alternative to model-based analysis techniques. In particular, SOC estimation relies on a k-NN regression algorithm while SOH estimation is obtained from the divergence between extracted features. The results show that the proposed data-<span class="hlt">driven</span> method successfully distinguishes battery voltage responses under different SOC and SOH situations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28640315','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28640315"><span>Formation and field-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of nematic spheroids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fu, Fred; Abukhdeir, Nasser Mohieddin</p> <p>2017-07-19</p> <p>Unlike the canonical application of liquid crystals (LCs), LC displays, emerging technologies based on LC materials are increasingly leveraging the presence of nanoscale defects. The inherent nanoscale characteristics of LC defects present both significant opportunities as well as barriers for the application of this fascinating class of materials. Simulation-based approaches to the study of the effects of confinement and interface anchoring conditions on LC domains has resulted in significant progress over the past decade, where simulations are now able to access experimentally-relevant length scales while simultaneously capturing nanoscale defect structures. In this work, continuum simulations were performed in order to study the <span class="hlt">dynamics</span> of micron-scale nematic LC spheroids of varying shape. Nematic spheroids are one of the simplest inherently defect-containing LC structures and are relevant to polymer-dispersed LC-based "smart" window technology. Simulation results include nematic phase formation and external field-switching <span class="hlt">dynamics</span> of nematic spheroids ranging in shape from oblate to prolate. Results include both qualitative and quantitative insight into the complex coupling of nanoscale defect <span class="hlt">dynamics</span> and structure transitions to micron-scale reorientation. <span class="hlt">Dynamic</span> mechanisms are presented and related to structural transitions in LC defects present in the nematic domain. Domain-averaged metrics including order parameters and response times are determined for a range of experimentally-accessible electric field strengths. These results have both fundamental and technological relevance, in that increased understanding of LC <span class="hlt">dynamics</span> in the presence of defects is a key barrier to continued advancement in the field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890033011&hterms=pure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpure','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890033011&hterms=pure&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpure"><span>Time-dependent models of radiatively <span class="hlt">driven</span> stellar winds. I - Nonlinear <span class="hlt">evolution</span> of instabilities for a pure absorption model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Owocki, Stanley P.; Castor, John I.; Rybicki, George B.</p> <p>1988-01-01</p> <p>Numerical radiation-hydrodynamics simulations of the nonlinear <span class="hlt">evolution</span> of instabilities in radiatively <span class="hlt">driven</span> stellar winds have been performed. The results show a strong tendency for the unstable flow to form rather sharp rarefactions in which the highest speed material has very low density. The qualitative features of the model agree well with the reqirements of displaced narrow absorption components in UV lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005IJQC..102..869H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005IJQC..102..869H"><span>Nonadiabatic <span class="hlt">evolution</span> of electronic states by electron nuclear <span class="hlt">dynamics</span> theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hagelberg, Frank</p> <p></p> <p>The problem of how to determine the nonadiabatic content of any given <span class="hlt">dynamic</span> process involving molecular motion is addressed in the context of Electron Nuclear <span class="hlt">Dynamics</span> (END) theory. Specifically, it is proposed to cast the <span class="hlt">dynamic</span> END wave function into the language of static electronic configurations with time dependent complex-valued amplitudes. This is achieved by adiabatic transport of an electronic basis along the classical nuclear trajectories of the studied molecular system, as yielded by END simulation. Projecting the <span class="hlt">dynamic</span> wave function on this basis yields a natural distinction between adiabatic and nonadiabatic components of the motion considered. Tracing the <span class="hlt">evolution</span> of the leading configurations is shown to be a helpful device for clarifying the physical nature of electronic excitation processes. For illustration of these concepts, <span class="hlt">dynamic</span> configuration analysis is applied to the scattering of a proton by a lithium atom.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..MARV23003S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..MARV23003S"><span>The <span class="hlt">Evolution</span> of Bifurcation <span class="hlt">Dynamics</span> in Neurons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stemmler, Martin</p> <p>2001-03-01</p> <p>The nervous system typically encodes perception and action with short voltage pulses, called spikes, traveling from cell to cell from the sensory periphery to the muscles. There is, however, no a priori reason why the nervous system could not use standard digital logic, switching once from low to high voltage (or vice versa) to convey one bit of information. The spikes in the nervous system result from ionic conductances in the neuronal membrane that are voltage-dependent; a small shift in the voltage-dependent properties would cause a cell to behave like a digital transistor, and no longer spike. Theory suggests two principles as to why neurons spike: information compression and energy efficiency. These first principles allow one to derive biophysically plausible ``learning rules" for a non-spiking neuron model to self- organize and tune its voltage-dependent conductances to approach a <span class="hlt">dynamical</span> bifurcation point. The requirement of energy efficiency eventually forces the resulting bifurcation to become homoclinic, and thus the neuron discovers spiking. The sequence of events in the self-organization of spiking behavior is stereotypical. An examination of the evolutionary record allows one to ask whether ontogeny recapitulates phylogeny---does neuronal development echo the theoretically deduced intermediate stages of spiking behavior?</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLA..381..970Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLA..381..970Y"><span><span class="hlt">Evolution</span> properties of the community members for <span class="hlt">dynamic</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Kai; Guo, Qiang; Li, Sheng-Nan; Han, Jing-Ti; Liu, Jian-Guo</p> <p>2017-03-01</p> <p>The collective behaviors of community members for <span class="hlt">dynamic</span> social networks are significant for understanding <span class="hlt">evolution</span> features of communities. In this Letter, we empirically investigate the <span class="hlt">evolution</span> properties of the new community members for <span class="hlt">dynamic</span> networks. Firstly, we separate data sets into different slices, and analyze the statistical properties of new members as well as communities they joined in for these data sets. Then we introduce a parameter φ to describe community <span class="hlt">evolution</span> between different slices and investigate the <span class="hlt">dynamic</span> community properties of the new community members. The empirical analyses for the Facebook, APS, Enron and Wiki data sets indicate that both the number of new members and joint communities increase, the ratio declines rapidly and then becomes stable over time, and most of the new members will join in the small size communities that is s ≤ 10. Furthermore, the proportion of new members in existed communities decreases firstly and then becomes stable and relatively small for these data sets. Our work may be helpful for deeply understanding the <span class="hlt">evolution</span> properties of community members for social networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26274186','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26274186"><span>Frictional <span class="hlt">dynamics</span> of viscoelastic solids <span class="hlt">driven</span> on a rough surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Landes, François P; Rosso, Alberto; Jagla, E A</p> <p>2015-07-01</p> <p>We study the effect of viscoelastic <span class="hlt">dynamics</span> on the frictional properties of a (mean-field) spring-block system pulled on a rough surface by an external drive. When the drive moves at constant velocity V, two <span class="hlt">dynamical</span> regimes are observed: at fast driving, above a critical threshold V(c), the system slides at the drive velocity and displays a friction force with velocity weakening. Below V(c) the steady sliding becomes unstable and a stick-slip regime sets in. In the slide-hold-slide driving protocol, a peak of the friction force appears after the hold time and its amplitude increases with the hold duration. These observations are consistent with the frictional force encoded phenomenologically in the rate-and-state equations. Our model gives a microscopical basis for such macroscopic description.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..92d3009A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..92d3009A"><span>Gravity-<span class="hlt">driven</span> soap film <span class="hlt">dynamics</span> in subcritical regimes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Auliel, M. I.; Castro, F.; Sosa, R.; Artana, G.</p> <p>2015-10-01</p> <p>We undertake the analysis of soap-film <span class="hlt">dynamics</span> with the classical approach of asymptotic expansions. We focus our analysis in vertical soap film tunnels operating in subcritical regimes with elastic Mach numbers Me=O(10-1) . Considering the associated set of nondimensional numbers that characterize this flow, we show that the flow behaves as a two-dimensional (2D) divergence free flow with variable mass density. When the soap film <span class="hlt">dynamics</span> agrees with that of a 2D and almost constant mass density flow, the regions where the second invariant of the velocity gradient is non-null correspond to regions where the rate of change of film thickness is non-negligible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA627068','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA627068"><span>Design Tools for <span class="hlt">Dynamic</span>, Data-<span class="hlt">Driven</span>, Stream Mining Systems</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-01-01</p> <p>new methods for integrated modeling and optimization of real-time 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT... classification modes), we develop systematic methods for exploring complex, multidimensional design spaces associated with <span class="hlt">dynamic</span> stream mining systems, and... stages in my career as a iii PhD student, current and past members of the research group have helped me enormously. I would like to thank Dr. William</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1684e0002A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1684e0002A"><span><span class="hlt">Dynamics</span> of the <span class="hlt">driven</span> Goodwin business cycle equation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonova, A. O.; Reznik, S. N.; Todorov, M. D.</p> <p>2015-10-01</p> <p>We study <span class="hlt">dynamics</span> of the Goodwin nonlinear accelerator business cycle model with periodic forced autonomous investment Ia(t) = a(1 - cos ωt), where a and ω are the amplitude and the frequency of investment. We give examples of the parameters a and ω when the chaotic oscillations of income are possible. We find the critical values of amplitude acr (ω): if a > acr (ω) the period of the income equals to the driving period T=2π/ω.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1303...52S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1303...52S"><span><span class="hlt">Dynamical</span> Logic <span class="hlt">Driven</span> by Classified Inferences Including Abduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sawa, Koji; Gunji, Yukio-Pegio</p> <p>2010-11-01</p> <p>We propose a <span class="hlt">dynamical</span> model of formal logic which realizes a representation of logical inferences, deduction and induction. In addition, it also represents abduction which is classified by Peirce as the third inference following deduction and induction. The three types of inference are represented as transformations of a directed graph. The state of a relation between objects of the model fluctuates between the collective and the distinctive. In addition, the location of the relation in the sequence of the relation influences its state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840026391','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840026391"><span><span class="hlt">Dynamic</span> analysis of <span class="hlt">evolutive</span> conservative systems. Discussion of eigenmode crossings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morand, H. J. P.</p> <p>1984-01-01</p> <p>After an analysis of the close connection between the symmetries of a <span class="hlt">dynamical</span> system and the multiplicity of its vibrational natural frequencies, it is proved by variational arguments that for a system of invariable symmetry the eigenfrequencies associated with the eigenmodes of a given symmetry type do not cross, in general, during the <span class="hlt">evolution</span> of this system. The theory is implemented by some numerical calculations applied to the analysis of the <span class="hlt">evolution</span> of the axisymmetric hydroelastic modes of the Ariane launch vehicle during burning of the first stage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986ARA%26A..24...49Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986ARA%26A..24...49Y"><span>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of H II regions - Recent theoretical developments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yorke, Harold W.</p> <p></p> <p>Recent H II line observations of stellar systems are discussed with regard to the capabilities of current models of stellar formation, structure and <span class="hlt">dynamics</span>. Observations of emission nebulae arising from the interaction between the interstellar medium and evolving stars are summarized and time scales of stellar <span class="hlt">evolution</span> are examined. A system of basic equations that consider MHD flows, radiation transfer, ionization, recombination, thermal energy balance, boundary conditions and initial values is defined for the density and temperature range of H II regions. Current numerical models for the <span class="hlt">evolution</span> of H II regions are summarized. Planned observations of ultracompact H II regions, blisters and champagne flow are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E1723S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E1723S"><span>Nonequilibrium <span class="hlt">Dynamics</span> and the <span class="hlt">Evolution</span> of Superfluid Neutron Stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sauls, Jame</p> <p>2016-07-01</p> <p>The interior crust and the liquid core of neutron stars are predicted to be a mixture of neutron and proton superfluids and a liquid of relativistic electrons and muons. Quantized vortices in the neutron superfluid and quantized flux lines in the proton superconductor are topological defects of these hadronic condensates. I discuss the roles of nucleation, interaction and <span class="hlt">evolution</span> of topological defects under non-equilibrium conditions in the context of our current understanding and models of the rotational <span class="hlt">dynamics</span> of pulsars, as well as thermal and magnetic field <span class="hlt">evolution</span> of neutron stars. I include some speculative ideas on possibile turbulent vortex states in neutron star interiors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22419910','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22419910"><span>Coherently <span class="hlt">driven</span>, ultrafast electron-phonon <span class="hlt">dynamics</span> in transport junctions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Szekely, Joshua E.; Seideman, Tamar</p> <p>2014-07-28</p> <p>Although the vast majority of studies of transport via molecular-scale heterojunctions have been conducted in the (static) energy domain, experiments are currently beginning to apply time domain approaches to the nanoscale transport problem, combining spatial with temporal resolution. It is thus an opportune time for theory to develop models to explore both new phenomena in, and new potential applications of, time-domain, coherently <span class="hlt">driven</span> molecular electronics. In this work, we study the interaction of a molecular phonon with an electronic wavepacket transmitted via a conductance junction within a time-domain model that treats the electron and phonon on equal footing and spans the weak to strong electron-phonon coupling strengths. We explore interference between two coherent energy pathways in the electronic subspace, thus complementing previous studies of coherent phenomena in conduction junctions, where the stationary framework was used to study interference between spatial pathways. Our model provides new insights into phase decoherence and population relaxation within the electronic subspace, which have been conventionally treated by density matrix approaches that often rely on phenomenological parameters. Although the specific case of a transport junction is explored, our results are general, applying also to other instances of coupled electron-phonon systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19414472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19414472"><span>Rapid contemporary <span class="hlt">evolution</span> and clonal food web <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jones, Laura E; Becks, Lutz; Ellner, Stephen P; Hairston, Nelson G; Yoshida, Takehito; Fussmann, Gregor F</p> <p>2009-06-12</p> <p>Character <span class="hlt">evolution</span> that affects ecological community interactions often occurs contemporaneously with temporal changes in population size, potentially altering the very nature of those <span class="hlt">dynamics</span>. Such eco-evolutionary processes may be most readily explored in systems with short generations and simple genetics. Asexual and cyclically parthenogenetic organisms such as microalgae, cladocerans and rotifers, which frequently dominate freshwater plankton communities, meet these requirements. Multiple clonal lines can coexist within each species over extended periods, until either fixation occurs or a sexual phase reshuffles the genetic material. When clones differ in traits affecting interspecific interactions, within-species clonal <span class="hlt">dynamics</span> can have major effects on the population <span class="hlt">dynamics</span>. We first consider a simple predator-prey system with two prey genotypes, parametrized with data from a well-studied experimental system, and explore how the extent of differences in defence against predation within the prey population determine <span class="hlt">dynamic</span> stability versus instability of the system. We then explore how increased potential for <span class="hlt">evolution</span> affects the community <span class="hlt">dynamics</span> in a more general community model with multiple predator and multiple prey genotypes. These examples illustrate how microevolutionary 'details' that enhance or limit the potential for heritable phenotypic change can have significant effects on contemporaneous community-level <span class="hlt">dynamics</span> and the persistence and coexistence of species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...767..144F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...767..144F"><span>Nonlinear <span class="hlt">Evolution</span> of the Radiation-<span class="hlt">driven</span> Magneto-acoustic Instability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández, Rodrigo; Socrates, Aristotle</p> <p>2013-04-01</p> <p>We examine the nonlinear development of unstable magnetosonic waves <span class="hlt">driven</span> by a background radiative flux—the radiation-<span class="hlt">driven</span> magneto-acoustic instability (RMI, a.k.a. the "photon bubble" instability). The RMI may serve as a persistent source of density, radiative flux, and magnetic field fluctuations in stably stratified, optically thick media. The conditions for instability are present in a variety of astrophysical environments and do not require the radiation pressure to dominate or the magnetic field to be strong. Here, we numerically study the saturation properties of the RMI, covering three orders of magnitude in the relative strength of radiation, magnetic field, and gas energies. Two-dimensional, time-dependent radiation-magnetohydrodynamic simulations of local, stably stratified domains are conducted with Zeus-MP in the optically thick, highly conducting limit. Our results confirm the theoretical expectations of Blaes & Socrates in that the RMI operates even in gas-pressure-dominated environments that are weakly magnetized. The saturation amplitude is a monotonically increasing function of the ratio of radiation to gas pressure. Keeping this ratio constant, we find that the saturation amplitude peaks when the magnetic pressure is comparable to the radiation pressure. We discuss the implications of our results for the <span class="hlt">dynamics</span> of magnetized stellar envelopes, where the RMI should act as a source of sub-photospheric perturbations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22126903','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22126903"><span>NONLINEAR <span class="hlt">EVOLUTION</span> OF THE RADIATION-<span class="hlt">DRIVEN</span> MAGNETO-ACOUSTIC INSTABILITY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fernandez, Rodrigo; Socrates, Aristotle</p> <p>2013-04-20</p> <p>We examine the nonlinear development of unstable magnetosonic waves <span class="hlt">driven</span> by a background radiative flux-the radiation-<span class="hlt">driven</span> magneto-acoustic instability (RMI, a.k.a. the ''photon bubble'' instability). The RMI may serve as a persistent source of density, radiative flux, and magnetic field fluctuations in stably stratified, optically thick media. The conditions for instability are present in a variety of astrophysical environments and do not require the radiation pressure to dominate or the magnetic field to be strong. Here, we numerically study the saturation properties of the RMI, covering three orders of magnitude in the relative strength of radiation, magnetic field, and gas energies. Two-dimensional, time-dependent radiation-magnetohydrodynamic simulations of local, stably stratified domains are conducted with Zeus-MP in the optically thick, highly conducting limit. Our results confirm the theoretical expectations of Blaes and Socrates in that the RMI operates even in gas-pressure-dominated environments that are weakly magnetized. The saturation amplitude is a monotonically increasing function of the ratio of radiation to gas pressure. Keeping this ratio constant, we find that the saturation amplitude peaks when the magnetic pressure is comparable to the radiation pressure. We discuss the implications of our results for the <span class="hlt">dynamics</span> of magnetized stellar envelopes, where the RMI should act as a source of sub-photospheric perturbations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22413332','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22413332"><span>Induced photoemission from <span class="hlt">driven</span> nonadiabatic <span class="hlt">dynamics</span> in an avoided crossing system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arasaki, Yasuki; Mizuno, Yuta; Takatsuka, Kazuo; Scheit, Simona</p> <p>2014-12-21</p> <p>When vibrational <span class="hlt">dynamics</span> on an ionic state (large dipole moment) is coupled to that on a neutral state (small dipole moment) such as at an avoided crossing in the alkali halide system, the population transfer between the states cause oscillation of the molecular dipole, leading to dipole emission. Such <span class="hlt">dynamics</span> may be <span class="hlt">driven</span> by an external field. We study how the coupled wavepacket <span class="hlt">dynamics</span> is affected by the parameters (intensity, frequency) of the driving field with the aim of making use of the photoemission as an alternative detection scheme of femtosecond and subfemtosecond vibrational and electronic <span class="hlt">dynamics</span> or as a characteristic optical source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23587804','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23587804"><span><span class="hlt">Dynamics</span> of cluster formation in <span class="hlt">driven</span> magnetic colloids dispersed on a monolayer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jäger, Sebastian; Stark, Holger; Klapp, Sabine H L</p> <p>2013-05-15</p> <p>We report computer simulation results on the cluster formation of dipolar colloidal particles <span class="hlt">driven</span> by a rotating external field in a quasi-two-dimensional setup. We focus on the interplay between permanent dipolar and hydrodynamic interactions and its influence on the <span class="hlt">dynamic</span> behavior of the particles. This includes their individual as well as their collective motion. To investigate these characteristics, we employ Brownian <span class="hlt">dynamics</span> simulations of a finite system with and without hydrodynamic interactions. Our results indicate that hydrodynamic interactions have a profound impact on the <span class="hlt">dynamic</span> behavior of the clusters and the <span class="hlt">dynamics</span> of the clustering process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24550264','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24550264"><span><span class="hlt">Evolution</span> and selection of river networks: statics, <span class="hlt">dynamics</span>, and complexity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rinaldo, Andrea; Rigon, Riccardo; Banavar, Jayanth R; Maritan, Amos; Rodriguez-Iturbe, Ignacio</p> <p>2014-02-18</p> <p>Moving from the exact result that drainage network configurations minimizing total energy dissipation are stationary solutions of the general equation describing landscape <span class="hlt">evolution</span>, we review the static properties and the <span class="hlt">dynamic</span> origins of the scale-invariant structure of optimal river patterns. Optimal channel networks (OCNs) are feasible optimal configurations of a spanning network mimicking landscape <span class="hlt">evolution</span> and network selection through imperfect searches for <span class="hlt">dynamically</span> accessible states. OCNs are spanning loopless configurations, however, only under precise physical requirements that arise under the constraints imposed by river <span class="hlt">dynamics</span>--every spanning tree is exactly a local minimum of total energy dissipation. It is remarkable that <span class="hlt">dynamically</span> accessible configurations, the local optima, stabilize into diverse metastable forms that are nevertheless characterized by universal statistical features. Such universal features explain very well the statistics of, and the linkages among, the scaling features measured for fluvial landforms across a broad range of scales regardless of geology, exposed lithology, vegetation, or climate, and differ significantly from those of the ground state, known exactly. Results are provided on the emergence of criticality through adaptative <span class="hlt">evolution</span> and on the yet-unexplored range of applications of the OCN concept.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22410325','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22410325"><span>Numerical investigation on target implosions <span class="hlt">driven</span> by radiation ablation and shock compression in <span class="hlt">dynamic</span> hohlraums</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xiao, Delong; Sun, Shunkai; Zhao, Yingkui; Ding, Ning; Wu, Jiming; Dai, Zihuan; Yin, Li; Zhang, Yang; Xue, Chuang</p> <p>2015-05-15</p> <p>In a <span class="hlt">dynamic</span> hohlraum <span class="hlt">driven</span> inertial confinement fusion (ICF) configuration, the target may experience two different kinds of implosions. One is <span class="hlt">driven</span> by hohlraum radiation ablation, which is approximately symmetric at the equator and poles. The second is caused by the radiating shock produced in Z-pinch <span class="hlt">dynamic</span> hohlraums, only taking place at the equator. To gain a symmetrical target implosion <span class="hlt">driven</span> by radiation ablation and avoid asymmetric shock compression is a crucial issue in driving ICF using <span class="hlt">dynamic</span> hohlraums. It is known that when the target is heated by hohlraum radiation, the ablated plasma will expand outward. The pressure in the shocked converter plasma qualitatively varies linearly with the material temperature. However, the ablation pressure in the ablated plasma varies with 3.5 power of the hohlraum radiation temperature. Therefore, as the hohlraum temperature increases, the ablation pressure will eventually exceed the shock pressure, and the expansion of the ablated plasma will obviously weaken the shock propagation and decrease its velocity after propagating into the ablator plasma. Consequently, longer time duration is provided for the symmetrical target implosion <span class="hlt">driven</span> by radiation ablation. In this paper these processes are numerically investigated by changing drive currents or varying load parameters. The simulation results show that a critical hohlraum radiation temperature is needed to provide a high enough ablation pressure to decelerate the shock, thus providing long enough time duration for the symmetric fuel compression <span class="hlt">driven</span> by radiation ablation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdSpR..59..682Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdSpR..59..682Z"><span>Long-term <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of Tundra-type orbits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Ming-Jiang; Zhao, Chang-Yin; Hou, Yong-Gang; Zhu, Ting-Lei; Wang, Hong-Bo; Sun, Rong-Yu; Zhang, Wei</p> <p>2017-01-01</p> <p>Tundra-type orbits are elliptical geosynchronous orbits located at the critical inclination. The long-term <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of this type of special orbit is investigated in this paper. First, the effect of Earth's gravitational potential is examined. A simplified Hamiltonian of Tundra-type orbits subjected to Earth's gravitational potential is presented through a strict magnitude comparison of the involved terms. Based on this simplified Hamiltonian with two degrees of freedom, the equilibrium points of the orbits subjected to Earth's gravitational potential and their stabilities are discussed. This simplified Hamiltonian is then reduced to a one-degree-of-freedom system dominating the intermediate-period motion of the orbits approximately. In particular, the main characteristic parameters of the intermediate-period motion for nominal Tundra-type orbits and the corresponding specific results for three Sirius satellites in such orbits are presented. Second, the effect of lunisolar perturbations is examined. A magnitude comparison elementarily illustrates that the effect of tesseral harmonics of the Earth's gravitational potential on the long timespan <span class="hlt">evolution</span> of Tundra-type orbits is negligible compared to that of lunisolar perturbations. A simplified <span class="hlt">dynamical</span> model including lunisolar perturbations is then presented. Based on this simplified <span class="hlt">dynamical</span> model, the influences of lunar precession, the initial longitude of the ascending node, the initial argument of perigee, and the initial epoch on the long-term <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the orbits are comparatively analyzed. Finally, numerical calculations with exact perturbation models are conducted to verify the theoretical analysis and to provide more information about the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of Tundra-type orbits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28049318','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28049318"><span>Frequency analysis of the laser <span class="hlt">driven</span> nonlinear <span class="hlt">dynamics</span> of HCN.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lopez-Pina, A; Losada, J C; Benito, R M; Borondo, F</p> <p>2016-12-28</p> <p>We study the vibrational <span class="hlt">dynamics</span> of a model for the HCN molecule in the presence of a monochromatic laser field. The variation of the structural behavior of the system as a function of the laser frequency is analyzed in detail using the smaller alignment index, frequency maps, and diffusion coefficients. It is observed that the ergodicity of the system depends on the frequency of the excitation field, especially in its transitions from and into chaos. This provides a roadmap for the possibility of bond excitation and dissociation in this molecule.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJMPB..2750206V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJMPB..2750206V"><span>Stochastic <span class="hlt">Dynamics</span> of DC and AC <span class="hlt">Driven</span> Dislocation Kinks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vardanyan, A.; Kteyan, A.</p> <p>2013-02-01</p> <p><span class="hlt">Dynamics</span> of a pinned dislocation kink controlled by the acting DC and AC forces is studied analytically. The motion of the kink, described by sine-Gordon (sG) equation, is explored within the framework of McLaughlin-Scott perturbation theory. Assuming weakness of the acting AC force, the equation of motion of the dislocation kink in the pinning potential is linearized. Based on the equations derived, we study stochastic behavior of the kink, and determine the probability of its depinning. The dependencies of the depinning probability on DC and AC forces are analyzed in detail.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ApPhL..95n3505P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ApPhL..95n3505P"><span>Magnetostriction-<span class="hlt">driven</span> cantilevers for <span class="hlt">dynamic</span> atomic force microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Penedo, M.; Fernández-Martínez, I.; Costa-Krämer, J. L.; Luna, M.; Briones, F.</p> <p>2009-10-01</p> <p>An actuation mode is presented to drive the mechanical oscillation of cantilevers for <span class="hlt">dynamic</span> atomic force microscopy. The method is based on direct mechanical excitation of the cantilevers coated with amorphous Fe-B-N thin films, by means of the film magnetostriction, i.e., the dimensional change in the film when magnetized. These amorphous magnetostrictive Fe-B-N thin films exhibit soft magnetic properties, excellent corrosion resistance in liquid environments, nearly zero accumulated stress when properly deposited, and good chemical stability. We present low noise and high resolution topographic images acquired in liquid environment to demonstrate the method capability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22492608','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22492608"><span><span class="hlt">Dynamics</span> of the <span class="hlt">driven</span> Goodwin business cycle equation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Antonova, A. O.; Reznik, S. N.; Todorov, M. D.</p> <p>2015-10-28</p> <p>We study <span class="hlt">dynamics</span> of the Goodwin nonlinear accelerator business cycle model with periodic forced autonomous investment I{sub a}(t) = a(1 – cos ωt), where a and ω are the amplitude and the frequency of investment. We give examples of the parameters a and ω when the chaotic oscillations of income are possible. We find the critical values of amplitude a{sub cr} (ω): if a > a{sub cr} (ω) the period of the income equals to the driving period T=2π/ω.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15011605','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15011605"><span><span class="hlt">Dynamic</span> Data-<span class="hlt">Driven</span> Event Reconstruction for Atmospheric Releases</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mirin, A; Serban, R; Kosovic, B</p> <p>2005-03-14</p> <p>This is a collaborative LDRD Exploratory Research project involving four directorates--Energy & Environment, Engineering, NAI and Computation. The project seeks to answer the following critical questions regarding atmospheric releases--''How much material was released? When? Where? and What are the potential consequences?'' Inaccurate estimation of the source term can lead to gross errors, time delays during a crisis, and even fatalities. We are developing a capability that seamlessly integrates observational data streams with predictive models in order to provide the best possible estimates of unknown source term parameters, as well as optimal and timely situation analyses consistent with both models and data. Our approach utilizes Bayesian inference and stochastic sampling methods (Markov Chain and Sequential Monte Carlo) to reformulate the inverse problem into a solution based on efficient sampling of an ensemble of predictive simulations, guided by statistical comparisons with data. We are developing a flexible and adaptable data-<span class="hlt">driven</span> event-reconstruction capability for atmospheric releases that provides (1) quantitative probabilistic estimates of the principal source-term parameters (e.g., the time-varying release rate and location); (2) predictions of increasing fidelity as an event progresses and additional data become available; and (3) analysis tools for sensor network design and uncertainty studies. Our computational framework incorporates multiple stochastic algorithms, operates with a range and variety of atmospheric models, and runs on multiple computer platforms, from workstations to large-scale computing resources. Our final goal is a multi-resolution capability for both real-time operational response and high fidelity multi-scale applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24346733','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24346733"><span>Topological structure <span class="hlt">dynamics</span> revealing collective <span class="hlt">evolution</span> in active nematics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shi, Xia-qing; Ma, Yu-qiang</p> <p>2013-01-01</p> <p>Topological defects frequently emerge in active matter like bacterial colonies, cytoskeleton extracts on substrates, self-propelled granular or colloidal layers and so on, but their <span class="hlt">dynamical</span> properties and the relations to large-scale organization and fluctuations in these active systems are seldom touched. Here we reveal, through a simple model for active nematics using self-<span class="hlt">driven</span> hard elliptic rods, that the excitation, annihilation and transportation of topological defects differ markedly from those in non-active media. These <span class="hlt">dynamical</span> processes exhibit strong irreversibility in active nematics in the absence of detailed balance. Moreover, topological defects are the key factors in organizing large-scale <span class="hlt">dynamic</span> structures and collective flows, resulting in multi-spatial temporal effects. These findings allow us to control the self-organization of active matter through topological structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhyA..391.6655S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhyA..391.6655S"><span>Transition from the self-organized to the <span class="hlt">driven</span> <span class="hlt">dynamical</span> clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Aradhana; Jalan, Sarika</p> <p>2012-12-01</p> <p>We study the mechanism of formation of synchronized clusters in coupled maps on networks with various connection architectures. The nodes in a cluster are self-synchronized or <span class="hlt">driven</span>-synchronized, based on the coupling strength and underlying network structures. A smaller coupling strength region shows <span class="hlt">driven</span> clusters independent of the network rewiring strategies, whereas a larger coupling strength region shows the transition from the self-organized cluster to the <span class="hlt">driven</span> cluster as network connections are rewired to the bi-partite type. Lyapunov function analysis is performed to understand the <span class="hlt">dynamical</span> origin of cluster formation. The results provide insights into the relationship between the topological clusters which are based on the direct connections between the nodes, and the <span class="hlt">dynamical</span> clusters which are based on the functional behavior of these nodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JNR....16.2365M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JNR....16.2365M"><span>Entropy-<span class="hlt">driven</span> structure and <span class="hlt">dynamics</span> in carbon nanocrystallites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McNutt, N. W.; Wang, Q.; Rios, O.; Keffer, D. J.</p> <p>2014-04-01</p> <p>New carbon composite materials are being developed that contain carbon nanocrystallites in the range of 5-17 Å in radius dispersed within an amorphous carbon matrix. Evaluating the applicability of these materials for use in battery electrodes requires a molecular-level understanding of the thermodynamic, structural, and <span class="hlt">dynamic</span> properties of the nanocrystallites. Herein, molecular <span class="hlt">dynamics</span> simulations reveal the molecular-level mechanisms for such experimental observations as the increased spacing between carbon planes in nanocrystallites as a function of decreasing crystallite size. As the width of this spacing impacts Li-ion capacity, an explanation of the origin of this distance is relevant to understanding anode performance. It is thus shown that the structural configuration of these crystallites is a function of entropy. The magnitude of out-of-plane ripples, binding energy between layers, and frequency of characteristic planar modes are reported over a range of nanocrystallite sizes and temperatures. This fundamental information for layered carbon nanocrystallites may be used to explain enhanced lithium ion diffusion within the carbon composites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5958..139K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5958..139K"><span><span class="hlt">Dynamic</span> measurements of actuators <span class="hlt">driven</span> by AlN layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kacperski, Jacek; Kujawinska, Malgorzata; Leon, Sergio Camacho; Nieradko, Lukasz; Jozwik, Michal; Gorecki, Christophe</p> <p>2005-09-01</p> <p>Micro-Electro-Mechanical Systems are nowadays frequently used in many fields of industry. The number of their applications increase and their functions became more complex and demanding. Therefore precise knowledge about their static (shape, deformations, stresses) and <span class="hlt">dynamic</span> (resonance frequencies, amplitude and phase of vibration) properties is necessary. Two beam laser interferometry is one of the most popular testing methods of micromechanical elements as a non-contact, high-accurate method allowing full-field measurement. First part of the paper present microbeam actuators designed for MEMS/MOEMS applications. The proposed structures are the straight silicon microbeams formed by KOH etching of Si wafer. Aluminium nitride (AlN) thin films are promising materials for many acoustic and optic applications in MEMS field. In the proposed architecture the actuation layer is sandwiched between two metal electrodes on the top of beam. In the second part we describe the methodology of the actuator characterization. These methods applied are: stroboscopic interferometry and active interferometry (LCOS SLM is used as a reference surface in Twyman-Green interferometer). Moreover some results of FEM analysis of the sample are shown and compared with experimental results. <span class="hlt">Dynamic</span> measurements validate the design and simulations, and provide information for optimization of the actuator manufacturing process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28877494','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28877494"><span>Enhanced <span class="hlt">Dynamics</span> of Confined Cytoskeletal Filaments <span class="hlt">Driven</span> by Asymmetric Motors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ravichandran, Arvind; Vliegenthart, Gerrit A; Saggiorato, Guglielmo; Auth, Thorsten; Gompper, Gerhard</p> <p>2017-09-05</p> <p>Cytoskeletal filaments and molecular motors facilitate the micron-scale force generation necessary for the distribution of organelles and the restructuring of the cytoskeleton within eukaryotic cells. Although the mesoscopic structure and the <span class="hlt">dynamics</span> of such filaments have been studied in vitro and in vivo, their connection with filament polarity-dependent motor-mediated force generation is not well understood. Using 2D Brownian <span class="hlt">dynamics</span> simulations, we study a dense, confined mixture of rigid microtubules (MTs) and active springs that have arms that cross-link neighboring MT pairs and move unidirectionally on the attached MT. We simulate depletion interactions between MTs using an attractive potential. We show that dimeric motors, with a motile arm on only one of the two MTs, produce large polarity-sorted MT clusters, whereas tetrameric motors, with motile arms on both microtubules, produce bundles. Furthermore, dimeric motors induce, on average, higher velocities between antialigned MTs than tetrameric motors. Our results, where MTs move faster near the confining wall, are consistent with experimental observations in Drosophila oocytes where enhanced microtubule activity is found close to the confining plasma membrane. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3932260','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3932260"><span><span class="hlt">Dynamic</span> Scene Stitching <span class="hlt">Driven</span> by Visual Cognition Model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p><span class="hlt">Dynamic</span> scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, <span class="hlt">dynamic</span> scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications. PMID:24688451</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1130443','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1130443"><span>Entropy-<span class="hlt">driven</span> structure and <span class="hlt">dynamics</span> in carbon nanocrystallites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McNutt, Nicholas W; Wang, Qifei; Rios, Orlando; Keffer, David J</p> <p>2014-01-01</p> <p>New carbon composite materials are being developed that contain carbon nanocrystallites in the range of 5 17 A in radius dispersed within an amorphous carbon matrix. Evaluating the applicability of these materials for use in battery electrodes requires a molecular-level understanding of the thermodynamic, structural, and <span class="hlt">dynamic</span> properties of the nanocrystallites. Herein, molecular <span class="hlt">dynamics</span> simulations reveal the molecular-level mechanisms for such experimental observations as the increased spacing between carbon planes in nanocrystallites as a function of decreasing crystallite size. As the width of this spacing impacts Li-ion capacity, an explanation of the origin of this distance is relevant to understanding anode performance. It is thus shown that the structural configuration of these crystallites is a function of entropy. The magnitude of out-of-plane ripples, binding energy between layers, and frequency of characteristic planar modes are reported over a range of nanocrystallite sizes and temperatures. This fundamental information for layered carbon nanocrystallites may be used to explain enhanced lithium ion diffusion within the carbon composites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MSSP...79..225A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MSSP...79..225A"><span>Chaotic <span class="hlt">dynamics</span> of flexible beams <span class="hlt">driven</span> by external white noise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Awrejcewicz, J.; Krysko, A. V.; Papkova, I. V.; Zakharov, V. M.; Erofeev, N. P.; Krylova, E. Yu.; Mrozowski, J.; Krysko, V. A.</p> <p>2016-10-01</p> <p>Mathematical models of continuous structural members (beams, plates and shells) subjected to an external additive white noise are studied. The structural members are considered as systems with infinite number of degrees of freedom. We show that in mechanical structural systems external noise can not only lead to quantitative changes in the system <span class="hlt">dynamics</span> (that is obvious), but also cause the qualitative, and sometimes surprising changes in the vibration regimes. Furthermore, we show that scenarios of the transition from regular to chaotic regimes quantified by Fast Fourier Transform (FFT) can lead to erroneous conclusions, and a support of the wavelet analysis is needed. We have detected and illustrated the modifications of classical three scenarios of transition from regular vibrations to deterministic chaos. The carried out numerical experiment shows that the white noise lowers the threshold for transition into spatio-temporal chaotic <span class="hlt">dynamics</span>. A transition into chaos via the proposed modified scenarios developed in this work is sensitive to small noise and significantly reduces occurrence of periodic vibrations. Increase of noise intensity yields decrease of the duration of the laminar signal range, i.e., time between two successive turbulent bursts decreases. Scenario of transition into chaos of the studied mechanical structures essentially depends on the control parameters, and it can be different in different zones of the constructed charts (control parameter planes). Furthermore, we found an interesting phenomenon, when increase of the noise intensity yields surprisingly the vibrational characteristics with a lack of noisy effect (chaos is destroyed by noise and windows of periodicity appear).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27920382','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27920382"><span>Adaptation to fragmentation: evolutionary <span class="hlt">dynamics</span> <span class="hlt">driven</span> by human influences.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheptou, Pierre-Olivier; Hargreaves, Anna L; Bonte, Dries; Jacquemyn, Hans</p> <p>2017-01-19</p> <p>Fragmentation-the process by which habitats are transformed into smaller patches isolated from each other-has been identified as a major threat for biodiversity. Fragmentation has well-established demographic and population genetic consequences, eroding genetic diversity and hindering gene flow among patches. However, fragmentation should also select on life history, both predictably through increased isolation, demographic stochasticity and edge effects, and more idiosyncratically via altered biotic interactions. While species have adapted to natural fragmentation, adaptation to anthropogenic fragmentation has received little attention. In this review, we address how and whether organisms might adapt to anthropogenic fragmentation. Drawing on selected case studies and evolutionary ecology models, we show that anthropogenic fragmentation can generate selection on traits at both the patch and landscape scale, and affect the adaptive potential of populations. We suggest that dispersal traits are likely to experience especially strong selection, as dispersal both enables migration among patches and increases the risk of landing in the inhospitable matrix surrounding them. We highlight that suites of associated traits are likely to evolve together. Importantly, we show that adaptation will not necessarily rescue populations from the negative effects of fragmentation, and may even exacerbate them, endangering the entire metapopulation.This article is part of the themed issue 'Human influences on <span class="hlt">evolution</span>, and the ecological and societal consequences'. © 2016 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171939','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171939"><span>Autonomous <span class="hlt">Evolution</span> of <span class="hlt">Dynamic</span> Gaits with Two Quadruped Robots</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hornby, Gregory S.; Takamura, Seichi; Yamamoto, Takashi; Fujita, Masahiro</p> <p>2004-01-01</p> <p>A challenging task that must be accomplished for every legged robot is creating the walking and running behaviors needed for it to move. In this paper we describe our system for autonomously evolving <span class="hlt">dynamic</span> gaits on two of Sony's quadruped robots. Our evolutionary algorithm runs on board the robot and uses the robot's sensors to compute the quality of a gait without assistance from the experimenter. First we show the <span class="hlt">evolution</span> of a pace and trot gait on the OPEN-R prototype robot. With the fastest gait, the robot moves at over 10/min/min., which is more than forty body-lengths/min. While these first gaits are somewhat sensitive to the robot and environment in which they are evolved, we then show the <span class="hlt">evolution</span> of robust <span class="hlt">dynamic</span> gaits, one of which is used on the ERS-110, the first consumer version of AIBO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015jsrs.conf..108K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015jsrs.conf..108K"><span>Long time <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of highly elliptical satellites orbits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuznetsov, E.; Zakharova, P.</p> <p>2015-08-01</p> <p><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of objects near Molniya-type orbits is considered. Initial conditions correspond to highly elliptical satellite orbits with eccentricities 0.65 and a critical inclination 63.4°. Semi-major axis is varied near resonant value 26560 km in an interval 500 km. Variations were analyzed for positional orbital elements, an ascending node longitude and an argument of pericenter. Initial conditions determined when orbital elements variations are minimal. These regions can be used as orbits for safe stationing satellites which finish work on Molniya-type orbits. The study of <span class="hlt">dynamical</span> <span class="hlt">evolution</span> on long time intervals was performed on the basis of the results of numerical simulation. The model of disturbing forces taken into account the main perturbing factors. Time interval was up to 24 yr. Area-to-mass ratio varied from small values corresponding to satellites to big ones corresponding to space debris.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001P%26SS...49..803D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001P%26SS...49..803D"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> and collisions of asteroids with the earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dvorak, R.; Freistetter, F.</p> <p>2001-07-01</p> <p>We study the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of asteroids which are a potential danger for collisions with the Earth. The work is undertaken on basis of a simplified model of the planetary system including the perturbations from Venus to Saturn. For a whole grid of initial conditions (0.7⩽ a⩽1.45 and 0.1⩽ e⩽0.8) we integrated the equations of motion with the Lie-series integration for 0.5 Myrs for 720 fictitious objects. The analysis of the data provided the following results: (a) the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> for such objects which are initially in four different groups namely Subatens, Atens, Apollos and Amors (b) the flow between these groups and (c) the individual collision probabilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARZ17001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARZ17001D"><span>Task-Based Cohesive <span class="hlt">Evolution</span> of <span class="hlt">Dynamic</span> Brain Networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davison, Elizabeth</p> <p>2014-03-01</p> <p>Applications of graph theory to neuroscience have resulted in significant progress towards a mechanistic understanding of the brain. Functional network representation of the brain has linked efficient network structure to psychometric intelligence and altered configurations with disease. <span class="hlt">Dynamic</span> graphs provide us with tools to further study integral properties of the brain; specifically, the mathematical convention of hyperedges has allowed us to study the brain's cross-linked structure. Hyperedges capture the changes in network structure by identifying groups of brain regions with correlation patterns that change cohesively through time. We performed a hyperedge analysis on functional MRI data from 86 subjects and explored the cohesive <span class="hlt">evolution</span> properties of their functional brain networks as they performed a series of tasks. Our results establish the hypergraph as a useful measure in understanding functional brain <span class="hlt">dynamics</span> over tasks and reveal characteristic differences in the co-<span class="hlt">evolution</span> structure of task-specific networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1570K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1570K"><span>Electromagnetically <span class="hlt">Driven</span> Plasma-Field <span class="hlt">Dynamics</span> in Modified Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kochetov, Andrey; Terina, Galina</p> <p></p> <p>Under sounding of an artificial ionospheric turbulence by short probing radio pulses of ordinary polarization the two types of scattered signals were observed: a "caviton" signal (CS) and a "plasma" signal (PS), which appeared with the heating transmitter switching on and disap-peared after its switching off (G.I. Terina J. Atm. Terr. Phys, 57, 1995, 273, Izv. VUZov, Radiofizika, 39, 1998, 203). The scattered signal of PS type was revealed also after the heating switching off. It was called an "aftereffect plasma signal" (AEPS) (G.I. Terina Izv .VUZov, Radiofizika, 43, 2000, 958). This signal had large time and spatial delays and appeared mostly when corresponding PS had envelope fluctuations. The aftereffect phenomenon was expressed at time on CS by amplitude increasing at once after the heating transmitter turning off. The theoretical model of this phenomenon is proposed in and some peculiarities of the aftereffect phenomena of the scattered signals in modified ionospheric plasma are considered and discussed. For theoretical interpretation of the characteristics of CS and AEPS the numerical solution of nonlinear Shrüdinger equation (NSE) with <span class="hlt">driven</span> extension were carried out in inhomogeneous plasma layer with linear electron density profile (A.V. Kochetov, V.A. Mironov, G.I. Terina, Adv. Space Reseacrh, 29, 2002, 1369) and for the one with prescribed density depletion (and A.V. Kochetov, G.I. Terina, Adv. Space Reseacrh, 38, 2006, 2490). The simulation results obtained for linear inhomogeneous plasma layer and for plasma one with density depletion al-low us to interpret the aftereffect of CS and PS qualitatively. The field amplitude increase at relaxation stage displayed at calculations allows us to interpret of CS aftereffect. The large time delays of AEPS can be explained as a result of powerful radio waves trapping in the forming at the plasma resonance regions density depletions (E. Mjøhus, J. Geophys. Res. 103, 1998, 14711; B. Eliasson and L. Stenflo, J</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/935409','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/935409"><span>Field <span class="hlt">driven</span> ferromagnetic phase <span class="hlt">evolution</span> originating from the domain boundaries in antiferromagnetically coupled perpendicular anitsotropy films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jones, Juanita; Hauet, Thomas; Gunther, Christian; Hovorka, Ondrej; Berger, Andreas; Im, Mi-Young; Fischer, Peter; Hellwig, Olav</p> <p>2008-05-01</p> <p>Strong perpendicular anisotropy systems consisting of Co/Pt multilayer stacks that are antiferromagnetically coupled via thin Ru or NiO layers have been used as model systems to study the competition between local interlayer exchange and long-range dipolar interactions [1,2]. Magnetic Force Microscopy (MFM) studies of such systems reveal complex magnetic configurations with a mix of antiferromagnetic (AF) and ferromagnetic (FM) phases. However, MFM allows detecting surface stray fields only and can interact strongly with the magnetic structure of the sample, thus altering the original domain configuration of interest [3,4]. In the current study they combine magnetometry and state-of-the-art soft X-ray transmission microscopy (MXTM) to investigate the external field <span class="hlt">driven</span> FM phase <span class="hlt">evolution</span> originating from the domain boundaries in such antiferromagnetically coupled perpendicular anisotropy films. MXTM allows directly imaging the perpendicular component of the magnetization in an external field at sub 100 nm spatial resolution without disturbing the magnetic state of the sample [5,6]. Here they compare the domain <span class="hlt">evolution</span> for two similar [Co(4{angstrom})/Pt(7{angstrom})]x-1/{l_brace}Co(4{angstrom})/Ru(9{angstrom})/[Co(4{angstrom})/Pt(7{angstrom})]x-1{r_brace}16 samples with slightly different Co/Pt stack thickness, i.e. slightly different strength of internal dipolar fields. After demagnetization they obtain AF domains with either sharp AF domain walls for the thinner multilayer stacks or 'tiger-tail' domain walls (one dimensional FM phase) for the thicker stacks. When increasing the external field strength the sharp domain walls in the tinner stack sample transform into the one-dimensional FM phase, which then serves as nucleation site for further FM stripe domains that spread out into all directions to drive the system towards saturation. Energy calculations reveal the subtle difference between the two samples and help to understand the observed transition, when</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22356931','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22356931"><span>Two-body relaxation <span class="hlt">driven</span> <span class="hlt">evolution</span> of the young stellar disk in the galactic center</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Šubr, Ladislav; Haas, Jaroslav</p> <p>2014-05-10</p> <p>The center of our Galaxy hosts almost two hundred very young stars, a subset of which is orbiting the central supermassive black hole (SMBH) in a relatively thin disk-like structure. First analyses indicated a power-law surface density profile of the disk, Σ∝R {sup β} with β = –2. Recently, however, doubts about this profile arose. In particular, it now seems to be better described by a sort of broken power law. By means of both analytical arguments and numerical N-body modeling, we show that such a broken power-law profile is a natural consequence of the two-body relaxation of the disk. Due to the small relative velocities of the nearby stars in co-planar Keplerian orbits around the SMBH, two-body relaxation is effective enough to affect the <span class="hlt">evolution</span> of the disk on timescales comparable to its estimated age. In the inner, densest part of the disk, the profile becomes rather flat (β ≈ –1) while the outer parts keep imprints of the initial state. Our numerical models show that the observed projected surface density profile of the young stellar disk can result from two-body relaxation <span class="hlt">driven</span> <span class="hlt">evolution</span> of a disk with initial single power-law profile with –2 ≲ β ≲ –1.5. In addition, we suggest that two-body relaxation may have caused a significant radial migration of the S-stars toward the central SMBH, thus playing an important role in their formation scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22560308','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22560308"><span>Floquet–Magnus theory and generic transient <span class="hlt">dynamics</span> in periodically <span class="hlt">driven</span> many-body quantum systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kuwahara, Tomotaka; Mori, Takashi; Saito, Keiji</p> <p>2016-04-15</p> <p>This work explores a fundamental <span class="hlt">dynamical</span> structure for a wide range of many-body quantum systems under periodic driving. Generically, in the thermodynamic limit, such systems are known to heat up to infinite temperature states in the long-time limit irrespective of <span class="hlt">dynamical</span> details, which kills all the specific properties of the system. In the present study, instead of considering infinitely long-time scale, we aim to provide a general framework to understand the long but finite time behavior, namely the transient <span class="hlt">dynamics</span>. In our analysis, we focus on the Floquet–Magnus (FM) expansion that gives a formal expression of the effective Hamiltonian on the system. Although in general the full series expansion is not convergent in the thermodynamics limit, we give a clear relationship between the FM expansion and the transient <span class="hlt">dynamics</span>. More precisely, we rigorously show that a truncated version of the FM expansion accurately describes the exact <span class="hlt">dynamics</span> for a certain time-scale. Our theory reveals an experimental time-scale for which non-trivial <span class="hlt">dynamical</span> phenomena can be reliably observed. We discuss several <span class="hlt">dynamical</span> phenomena, such as the effect of small integrability breaking, efficient numerical simulation of periodically <span class="hlt">driven</span> systems, <span class="hlt">dynamical</span> localization and thermalization. Especially on thermalization, we discuss a generic scenario on the prethermalization phenomenon in periodically <span class="hlt">driven</span> systems. -- Highlights: •A general framework to describe transient <span class="hlt">dynamics</span> for periodically <span class="hlt">driven</span> systems. •The theory is applicable to generic quantum many-body systems including long-range interacting systems. •Physical meaning of the truncation of the Floquet–Magnus expansion is rigorously established. •New mechanism of the prethermalization is proposed. •Revealing an experimental time-scale for which non-trivial <span class="hlt">dynamical</span> phenomena can be reliably observed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22188529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22188529"><span>Data-<span class="hlt">driven</span> models for regional coral-reef <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Żychaluk, Kamila; Bruno, John F; Clancy, Damian; McClanahan, Tim R; Spencer, Matthew</p> <p>2012-02-01</p> <p>Coral reefs have been affected by natural and anthropogenic disturbances. Coral cover has declined on many reefs, and macroalgae have increased on some. The existence of alternative stable states with high or low coral cover has been widely debated, but not clearly established. We evaluate the evidence for alternative stable states in benthic coral-reef <span class="hlt">dynamics</span> in the Caribbean, Kenya and Great Barrier Reef (GBR), using stochastic semi-parametric models based on large numbers of time series of cover of hard corals, macroalgae and other components. Only the GBR showed a consistent short-term regional decline in coral cover. There was no evidence for regional increases in macroalgae. The equilibrium distributions of our models were close to recently observed distributions, and differed among regions. In all three regions, the equilibrium distributions were unimodal rather than bimodal, and thus did not suggest the existence of alternative stable states on a regional scale, under current conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4048087','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4048087"><span>Bioattractors: <span class="hlt">dynamical</span> systems theory and the <span class="hlt">evolution</span> of regulatory processes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jaeger, Johannes; Monk, Nick</p> <p>2014-01-01</p> <p>In this paper, we illustrate how <span class="hlt">dynamical</span> systems theory can provide a unifying conceptual framework for <span class="hlt">evolution</span> of biological regulatory systems. Our argument is that the genotype–phenotype map can be characterized by the phase portrait of the underlying regulatory process. The features of this portrait – such as attractors with associated basins and their bifurcations – define the regulatory and evolutionary potential of a system. We show how the geometric analysis of phase space connects Waddington's epigenetic landscape to recent computational approaches for the study of robustness and evolvability in network <span class="hlt">evolution</span>. We discuss how the geometry of phase space determines the probability of possible phenotypic transitions. Finally, we demonstrate how the active, self-organizing role of the environment in phenotypic <span class="hlt">evolution</span> can be understood in terms of <span class="hlt">dynamical</span> systems concepts. This approach yields mechanistic explanations that go beyond insights based on the simulation of evolving regulatory networks alone. Its predictions can now be tested by studying specific, experimentally tractable regulatory systems using the tools of modern systems biology. A systematic exploration of such systems will enable us to understand better the nature and origin of the phenotypic variability, which provides the substrate for <span class="hlt">evolution</span> by natural selection. PMID:24882812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24438212','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24438212"><span>The <span class="hlt">dynamics</span> of niche <span class="hlt">evolution</span> upon abrupt environmental change.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gallet, Romain; Latour, Yasmin; Hughes, Bradley S; Lenormand, Thomas</p> <p>2014-05-01</p> <p>Abrupt environmental changes are of particular interest to understand how species can quickly evolve at the boundary of their current niche. In particular the "sliding niche" model, wherein a niche shifts globally toward the new condition, has been used in understanding and modeling this process. Here, we investigate the <span class="hlt">dynamics</span> of relative fitness change in four evolutionary replicates of Escherichia coli populations exposed to an extreme pH shift. We analyzed these changes at generations 500, 1000, and 2000 to determine whether niche global deformations fully capture the temporal <span class="hlt">dynamics</span> of niche <span class="hlt">evolution</span>. Strikingly, this analysis reveals that fitness variations can indeed be attributed to simple and global deformation of an underlying simple niche template. Analysis from two experimental replicates displays a transient increase in niche width, consistent with recent theory considering plasticity <span class="hlt">evolution</span> in the context of an abrupt environmental change. We term this scenario the "sidestep niche model." © 2014 The Author(s). <span class="hlt">Evolution</span> © 2014 The Society for the Study of <span class="hlt">Evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24882812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24882812"><span>Bioattractors: <span class="hlt">dynamical</span> systems theory and the <span class="hlt">evolution</span> of regulatory processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaeger, Johannes; Monk, Nick</p> <p>2014-06-01</p> <p>In this paper, we illustrate how <span class="hlt">dynamical</span> systems theory can provide a unifying conceptual framework for <span class="hlt">evolution</span> of biological regulatory systems. Our argument is that the genotype-phenotype map can be characterized by the phase portrait of the underlying regulatory process. The features of this portrait--such as attractors with associated basins and their bifurcations--define the regulatory and evolutionary potential of a system. We show how the geometric analysis of phase space connects Waddington's epigenetic landscape to recent computational approaches for the study of robustness and evolvability in network <span class="hlt">evolution</span>. We discuss how the geometry of phase space determines the probability of possible phenotypic transitions. Finally, we demonstrate how the active, self-organizing role of the environment in phenotypic <span class="hlt">evolution</span> can be understood in terms of <span class="hlt">dynamical</span> systems concepts. This approach yields mechanistic explanations that go beyond insights based on the simulation of evolving regulatory networks alone. Its predictions can now be tested by studying specific, experimentally tractable regulatory systems using the tools of modern systems biology. A systematic exploration of such systems will enable us to understand better the nature and origin of the phenotypic variability, which provides the substrate for <span class="hlt">evolution</span> by natural selection. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..293..339T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..293..339T"><span>Habitable Planets: Interior <span class="hlt">Dynamics</span> and Long-Term <span class="hlt">Evolution</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tackley, Paul J.; Ammann, Michael M.; Brodholt, John P.; Dobson, David P.; Valencia, Diana</p> <p>2014-04-01</p> <p>Here, the state of our knowledge regarding the interior <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of habitable terrestrial planets including Earth and super-Earths is reviewed, and illustrated using state-of-the-art numerical models. Convection of the rocky mantle is the key process that drives the <span class="hlt">evolution</span> of the interior: it causes plate tectonics, controls heat loss from the metallic core (which generates the magnetic field) and drives long-term volatile cycling between the atmosphere/ocean and interior. Geoscientists have been studying the <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of Earth's interior since the discovery of plate tectonics in the late 1960s and on many topics our understanding is very good, yet many first-order questions remain. It is commonly thought that plate tectonics is necessary for planetary habitability because of its role in long-term volatile cycles that regulate the surface environment. Plate tectonics is the surface manifestation of convection in the 2900-km deep rocky mantle, yet exactly how plate tectonics arises is still quite uncertain; other terrestrial planets like Venus and Mars instead have a stagnant lithosphere- essentially a single plate covering the entire planet. Nevertheless, simple scalings as well as more complex models indicate that plate tectonics should be easier on larger planets (super-Earths), other things being equal. The <span class="hlt">dynamics</span> of terrestrial planets, both their surface tectonics and deep mantle <span class="hlt">dynamics</span>, change over billions of years as a planet cools. Partial melting is a key process influencing solid planet <span class="hlt">evolution</span>. Due to the very high pressure inside super-Earths' mantles the viscosity would normally be expected to be very high, as is also indicated by our density function theory (DFT) calculations. Feedback between internal heating, temperature and viscosity leads to a superadiabatic temperature profile and self-regulation of the mantle viscosity such that sluggish convection still occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009MS%26E....3a2008G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MS%26E....3a2008G"><span><span class="hlt">Evolution</span> of geometrically necessary dislocation density from computational dislocation <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guruprasad, P. J.; Benzerga, A. A.</p> <p>2009-07-01</p> <p>This paper presents a method for calculating GND densities in dislocation <span class="hlt">dynamics</span> simulations. <span class="hlt">Evolution</span> of suitably defined averages of GND density as well as maps showing the spatial nonuniform distribution of GNDs are analyzed under uniaxial loading. Focus is laid on the resolution dependence of the very notion of GND density, its dependence upon physical dimensions of plastically deformed specimens and its sensitivity to initial conditions. Acknowledgments Support from the National Science Foundation (CMMI-0748187) is gratefully acknowledged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V53A2599D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V53A2599D"><span>Lava flow <span class="hlt">dynamics</span> <span class="hlt">driven</span> by temperature-dependent viscosity variations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diniega, S.; Smrekar, S. E.; Anderson, S. W.; Stofan, E. R.</p> <p>2011-12-01</p> <p>As lava viscosity can change 1-2 orders of magnitude due to small changes in temperature, several studies have predicted the formation of low-viscosity/high-temperature "fingers" (similar to a Saffman-Taylor type instability) within an initially near-uniform flow. We examine the onset and <span class="hlt">evolution</span> of such fingers within a uniform lava sheet flow due to an influx of lava with slightly-variable temperature. We assume Hele-shaw-type geometry (depth << other dimensions), Newtonian and laminar fluid flow, a simple Nahme's exponential law relating temperature and viscosity, and radiative heat-loss through the flow's upper surface. Through the use of numerical simulation and steady-state analysis of model equations, we identify solutions that provide pahoehoe lava flows with a natural mechanism for the formation of lava channels/tubes within a sheet flow. Preliminary results indicate that flow-focusing occurs rapidly due to the thermo-viscosity relation, but zones of hotter flow commonly settle into a new steady-state and it is difficult to create perpetually-lengthening hot-fingers of lava (which seem more physically similar to developing lava tubes). This suggests that additional and/or discontinuous physical processes (such as decreasing radiative rates due to thickening of the surface crust or crystallization abruptly retarding flow within lower-temperature regions) may play important roles in the continued growth of preferred flow zones. We also derive qualitative and quantitative estimates of environmental controls on finger size, spacing, and location. This work has application to Earth and planetary volcanology studies as pahoehoe flows dominate terrestrial basaltic lavas and the eruption/emplacement mechanics that yield long lava flows on the Earth and Mars are not yet well understood.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4938066','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4938066"><span>Magnetic relaxation <span class="hlt">dynamics</span> <span class="hlt">driven</span> by the first-order character of magnetocaloric La(Fe,Mn,Si)13</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lovell, Edmund; Bratko, Milan; Caplin, A. David; Barcza, Alexander; Katter, Matthias; Ghivelder, Luis; Cohen, Lesley F.</p> <p>2016-01-01</p> <p>Here, we study the temporal <span class="hlt">evolution</span> of the magnetic field-<span class="hlt">driven</span> paramagnetic to ferromagnetic transition in the La(Fe,Mn,Si)13 material family. Three compositions are chosen that show varying strengths of the first-order character of the transition, as determined by the relative magnitude of their magnetic hysteresis and temperature separation between the zero-field transition temperature Tc and the temperature Tcrit, where the transition becomes continuous. Systematic variations in the fixed field, isothermal rate of relaxation are observed as a function of temperature and as a function of the degree of first-order character. The relaxation rate is reduced in more weakly first-order compositions and is also reduced as the temperature is increased towards Tcrit. At temperatures above Tcrit, the metastability of the transition vanishes along with its associated temporal <span class="hlt">dynamics</span>. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’. PMID:27402929</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3932906','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3932906"><span><span class="hlt">Evolution</span> and selection of river networks: Statics, <span class="hlt">dynamics</span>, and complexity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rinaldo, Andrea; Rigon, Riccardo; Banavar, Jayanth R.; Maritan, Amos; Rodriguez-Iturbe, Ignacio</p> <p>2014-01-01</p> <p>Moving from the exact result that drainage network configurations minimizing total energy dissipation are stationary solutions of the general equation describing landscape <span class="hlt">evolution</span>, we review the static properties and the <span class="hlt">dynamic</span> origins of the scale-invariant structure of optimal river patterns. Optimal channel networks (OCNs) are feasible optimal configurations of a spanning network mimicking landscape <span class="hlt">evolution</span> and network selection through imperfect searches for <span class="hlt">dynamically</span> accessible states. OCNs are spanning loopless configurations, however, only under precise physical requirements that arise under the constraints imposed by river dynamics—every spanning tree is exactly a local minimum of total energy dissipation. It is remarkable that <span class="hlt">dynamically</span> accessible configurations, the local optima, stabilize into diverse metastable forms that are nevertheless characterized by universal statistical features. Such universal features explain very well the statistics of, and the linkages among, the scaling features measured for fluvial landforms across a broad range of scales regardless of geology, exposed lithology, vegetation, or climate, and differ significantly from those of the ground state, known exactly. Results are provided on the emergence of criticality through adaptative <span class="hlt">evolution</span> and on the yet-unexplored range of applications of the OCN concept. PMID:24550264</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22357064','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22357064"><span>On the impact of radiation pressure on the <span class="hlt">dynamics</span> and inner structure of dusty wind-<span class="hlt">driven</span> shells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martínez-González, Sergio; Silich, Sergiy; Tenorio-Tagle, Guillermo</p> <p>2014-04-20</p> <p>Massive young stellar clusters are strong sources of radiation and mechanical energy. Their powerful winds and radiation pressure sweep up interstellar gas into thin expanding shells that trap the ionizing radiation produced by the central clusters affecting the <span class="hlt">dynamics</span> and the distribution of their ionized gas. Here we continue our comparison of the star cluster winds and radiation pressure effects on the <span class="hlt">dynamics</span> of shells around young massive clusters. We calculate the impact that radiation pressure has on the distribution of matter and thermal pressure within such shells, as well as on the density-weighted ionization parameter U{sub w} , and put our results on the diagnostic diagram, which allows one to discriminate between the wind-dominated and radiation-dominated regimes. We found that model-predicted values of the ionization parameter agree well with typical values found in local starburst galaxies. Radiation pressure may affect the inner structure and the <span class="hlt">dynamics</span> of wind-<span class="hlt">driven</span> shells, but only during the earliest stages of <span class="hlt">evolution</span> (before ∼3 Myr) or if a major fraction of the star cluster mechanical luminosity is dissipated or radiated away within the star cluster volume and thus the star cluster mechanical energy output is significantly smaller than star cluster synthetic models predict. However, even in these cases radiation dominates over the wind <span class="hlt">dynamical</span> pressure only if the exciting cluster is embedded into a high-density ambient medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...785..164M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...785..164M"><span>On the Impact of Radiation Pressure on the <span class="hlt">Dynamics</span> and Inner Structure of Dusty Wind-<span class="hlt">driven</span> Shells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martínez-González, Sergio; Silich, Sergiy; Tenorio-Tagle, Guillermo</p> <p>2014-04-01</p> <p>Massive young stellar clusters are strong sources of radiation and mechanical energy. Their powerful winds and radiation pressure sweep up interstellar gas into thin expanding shells that trap the ionizing radiation produced by the central clusters affecting the <span class="hlt">dynamics</span> and the distribution of their ionized gas. Here we continue our comparison of the star cluster winds and radiation pressure effects on the <span class="hlt">dynamics</span> of shells around young massive clusters. We calculate the impact that radiation pressure has on the distribution of matter and thermal pressure within such shells, as well as on the density-weighted ionization parameter Uw , and put our results on the diagnostic diagram, which allows one to discriminate between the wind-dominated and radiation-dominated regimes. We found that model-predicted values of the ionization parameter agree well with typical values found in local starburst galaxies. Radiation pressure may affect the inner structure and the <span class="hlt">dynamics</span> of wind-<span class="hlt">driven</span> shells, but only during the earliest stages of <span class="hlt">evolution</span> (before ~3 Myr) or if a major fraction of the star cluster mechanical luminosity is dissipated or radiated away within the star cluster volume and thus the star cluster mechanical energy output is significantly smaller than star cluster synthetic models predict. However, even in these cases radiation dominates over the wind <span class="hlt">dynamical</span> pressure only if the exciting cluster is embedded into a high-density ambient medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510827H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510827H"><span>Storm-<span class="hlt">driven</span> pesticide <span class="hlt">dynamics</span> in a catchment system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harrison, Rebecca; Freer, Jim; Michaelides, Katerina; Hurley, Steven; Howden, Nicholas; Bull, Ian</p> <p>2013-04-01</p> <p>Loss of pesticides from agricultural land in runoff and subsurface flow during rainfall events poses a significant concern for water quality, with adverse effects on drinking water and aquatic life. Pesticide mobilisation and transport is affected by runoff and erosion processes which leads to different flow pathways and pesticide residence times in a catchment. In the soil and sediment environment pesticides can be a significant component of surface water contamination because of their persistence in soil and sediment and that they have a tendency to desorb back into water over time. A lowland agricultural catchment upstream of a drinking-water supply reservoir in the South West of England is being used to investigate pesticide <span class="hlt">dynamics</span> at the catchment scale during individual storm events. Pesticide concentration in water and suspended sediments were determined from samples taken at incremental changes in stream flow incorporating both rising and falling river levels. The study aims to determine the relative partitioning of pesticides transported in the dissolved phase or adsorbed to sediment. Analyses of soil, sediment and water from across the catchment aids understanding of the interaction between different media and can be used to determine the importance of dissolved and sediment-bound pesticide <span class="hlt">dynamics</span> during individual storm events. Initial results imply that processes of transport and desorption are occurring in both soils and river and reservoir sediments which are likely to be an important factor for timing of pesticide movement. This suggests soil and sediment are acting as a sustained source of contamination to surface water. However; interactions between these different media are complex. Investigation of the molluscicide metaldehyde, showed this to be present in stream water at concentrations greater than 0.1 µg µl-1 nine months after application. Storm event analysis shows peak pesticide concentration in the stream to coincide with storm</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005APS..DPPQI2001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005APS..DPPQI2001B"><span>Capsule implosions <span class="hlt">driven</span> by <span class="hlt">dynamic</span> hohlraum x-rays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bailey, James</p> <p>2005-10-01</p> <p><span class="hlt">Dynamic</span> hohlraum experiments at the Z facility already implode capsules with up to 80 kJ absorbed x-ray energy. However, many challenging issues remain for ICF. The present experiments use diagnostic capsules to address two of these issues: symmetry measurement and control and building understanding of the capsule/hohlraum implosion system. A suite of x-ray spectrometers record time and space resolved spectra emitted by Ar tracer atoms in the implosion core, simultaneously from up to three different quasi-orthogonal directions. Comparing the results with simulation predictions provide severe tests of understanding. These data also can used to produce a tomographic reconstruction of the time resolved core temperature and density profiles. X-ray and neutron diagnostics are used to examine how the implosion conditions change as the capsule design changes. The capsule design changes include variations in CH wall thickness and diameter, Ge-doped CH shells, and SiO2 shells. In addition, a new campaign investigating Be capsule implosions is beginning. Be capsules may offer superior performance for <span class="hlt">dynamic</span> hohlraum research and it may be possible to investigate NIF-relevant Be implosion issues such as the fill tube effects, sensitivity to columnar growth associated with sputtered Be capsule fabrication, and the effect of Cu dopants on implosion conditions. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Dept. of Energy under contract No. DE-AC04-94AL85000. * In collaboration with G.A. Rochau, G.A. Chandler, S.A. Slutz, P.W. Lake, G. Cooper, G.S. Dunham, R.J. Leeper, R. Lemke, T.A. Mehlhorn, T.J. Nash, D.S. Nielsen, K. Peterson, C.L. Ruiz, D.B. Sinars, J. Torres, W. Varnum, Sandia; R.C. Mancini, T.J. Buris-Mog, UNR; I. Golovkin, J.J. MacFarlane, PRISM; A. Nikro, D. Steinman, J.D. Kilkenny, H. Xu, General Atomics; M. Bump, T.C. Moore, K-tech; D.G. Schroen, Schafer</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM23B2551F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM23B2551F"><span>Integrated Observations of ICME - <span class="hlt">Driven</span> Substorm - Storm <span class="hlt">Evolution</span> on 7 August 1998: Traditional and Non-Traditional Aspects.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farrugia, C. J.; Sandholt, P. E.; Torbert, R. B.</p> <p>2015-12-01</p> <p>The aim of this study is to obtain an integrated view of substorm-storm <span class="hlt">evolution</span> in relation to well-defined interplanetary (IP) conditions, and to identify traditional and non-traditional aspects of the DP1 and DP2 current systems during substorm activity. Specifically, we report a case study of substorm/storm <span class="hlt">evolution</span> <span class="hlt">driven</span> by an ICME from ground observations around the oval in relation to geoeffective IP parameters (Kan-Lee electric field, E-KL, and <span class="hlt">dynamic</span> pressure, Pdyn), geomagnetic indices (AL, SYM-H and PCN) and satellite observations (from DMSP F13 and F14, Geotail, and GOES spacecraft). A sudden enhancement of E-KL at a southward turning of the IMF led to an initial transient phase (PCN-enhancement) followed by a persistent stage of solar wind-magnetosphere-ionosphere coupling. The persistent phase terminated abruptly at a steep E-KL reduction when the ICME magnetic field turned north after a 3-hour-long interval of enhanced E-KL. The persistent phase consisted of (i) a 45-min-long substorm growth phase (DP2 current) followed by (ii) a classical substorm onset (DP1 current) in the 0100 - 0300 MLT sector, (ii) a 30-min-long expansion phase, maximizing in the same sector, and (iii) a phase lasting for 1.5 hr of 10-15 min-long DP1 events in the 2100 - 2300 and 0400 - 0600 MLT sectors. In the morning sector the expansion phase was characterized by Ps6 pulsations and omega bands. The SYM-H <span class="hlt">evolution</span> reached the level of a major storm after a 2.5-hour-long interval of E-KL ˜5 mV/m and elevated Pdyn in the substorm expansion phase. Magetosphere - Ionosphere (M - I) coupling during a localized electrojet event at 0500 MLT in the late stage of the substorm expansion is studied by ground - satellite conjunction data (Iceland - Geotail). The DP1 and DP2 components of geomagnetic activity are discussed in relation to M - I current systems and substorm current wedge morphology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3049038','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3049038"><span>The origin and <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of chemical information transfer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Steiger, Sandra; Schmitt, Thomas; Schaefer, H. Martin</p> <p>2011-01-01</p> <p>Although chemical communication is the most widespread form of communication, its <span class="hlt">evolution</span> and diversity are not well understood. By integrating studies of a wide range of terrestrial plants and animals, we show that many chemicals are emitted, which can unintentionally provide information (cues) and, therefore, act as direct precursors for the <span class="hlt">evolution</span> of intentional communication (signals). Depending on the content, design and the original function of the cue, there are predictable ways that selection can enhance the communicative function of chemicals. We review recent progress on how efficacy-based selection by receivers leads to distinct evolutionary trajectories of chemical communication. Because the original function of a cue may channel but also constrain the <span class="hlt">evolution</span> of functional communication, we show that a broad perspective on multiple selective pressures acting upon chemicals provides important insights into the origin and <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of chemical information transfer. Finally, we argue that integrating chemical ecology into communication theory may significantly enhance our understanding of the <span class="hlt">evolution</span>, the design and the content of signals in general. PMID:21177681</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AGM....16..P65M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AGM....16..P65M"><span>Viscous Models for the Long-term <span class="hlt">Evolution</span> of the Galactic Disk Based on <span class="hlt">Dynamical</span> Instabilities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meusinger, H.; Thon, R.</p> <p></p> <p>We discuss a basic family of models for the long-term <span class="hlt">evolution</span> of the Galactic disk including the following fundamental ideas: (i) Star formation is <span class="hlt">driven</span> by local <span class="hlt">dynamic</span> instabilities of the disk. Following Wang & Silk (1994), the local star formation timescale is intimately linked to the local growth rate of gravitational instabilities and is described in terms of the stability parameter Q. (ii) Radial gas flows within the disk are induced by a (hypothetical) viscosity of the interstellar medium. It is assumed that viscous gas transport and star formation are linked to the same causes and that the characteristic timescales of these both processes are therefore equivalent (Lin-Pringle condition). (iii) Secular infall of external gas, as indicated e.g. by high-velocity Hi clouds, strongly affects the long-term <span class="hlt">evolution</span> of the disk. We adopt total mass fractions for the infalling gas as high as 50% up to 95%. Infall onto the disk may induce further radial gas streaming within the disk. (iv). The abundance <span class="hlt">evolution</span> of the elements iron and oxygen is <span class="hlt">driven</span> by supernovae of type II and type Ia. The modelling of the chemical <span class="hlt">evolution</span> does not make use of the instantaneous recycling approximation. The models are compared with relevant observations concerning the solar neighbourhood and the radial profiles of the Galactic disk. Good agreement is found with most of the constraints. Moreover, the models predict a bimodal Schmidt law for the star formation rate, in qualitative agreement with what is found for nearby spiral galaxies. Applications of our results to high-z damped Lyα QSO absorbers are briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChPhB..25d4203Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChPhB..25d4203Y"><span><span class="hlt">Dynamics</span> of a three-level V-type atom <span class="hlt">driven</span> by a cavity photon and microwave field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan-Li, Xue; Shi-Deng, Zhu; Ju, Liu; Ting-Hui, Xiao; Bao-Hua, Feng; Zhi-Yuan, Li</p> <p>2016-04-01</p> <p>We discuss the <span class="hlt">dynamics</span> of a three-level V-type atom <span class="hlt">driven</span> simultaneously by a cavity photon and microwave field by examining the atomic population <span class="hlt">evolution</span>. Owing to the coupling effect of the cavity photon, periodical oscillation of the population between the two upper states and the ground state takes place, which is the well-known vacuum Rabi oscillation. Meanwhile, the population exchange between the upmost level and the middle level can occur due to the driving action of the external microwave field. The general <span class="hlt">dynamic</span> behavior is the superposition of a fast and a slow periodical oscillation under the cooperative and competitive effect of the cavity photon and the microwave field. Numerical results demonstrate that the time <span class="hlt">evolution</span> of the population is strongly dependent on the atom-cavity coupling coefficient g and Rabi frequency Ω e that reflects the intensity of the external microwave field. By modulating the two parameters g and Ω e, a large number of population transfer behaviors can be achieved. Project supported by the National Natural Science Foundation of China (Grant Nos. 11434017 and 11374357) and the National Basics Research Program of China (Grant No. 2013CB632704).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AnPhy.367...96K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AnPhy.367...96K"><span>Floquet-Magnus theory and generic transient <span class="hlt">dynamics</span> in periodically <span class="hlt">driven</span> many-body quantum systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuwahara, Tomotaka; Mori, Takashi; Saito, Keiji</p> <p>2016-04-01</p> <p>This work explores a fundamental <span class="hlt">dynamical</span> structure for a wide range of many-body quantum systems under periodic driving. Generically, in the thermodynamic limit, such systems are known to heat up to infinite temperature states in the long-time limit irrespective of <span class="hlt">dynamical</span> details, which kills all the specific properties of the system. In the present study, instead of considering infinitely long-time scale, we aim to provide a general framework to understand the long but finite time behavior, namely the transient <span class="hlt">dynamics</span>. In our analysis, we focus on the Floquet-Magnus (FM) expansion that gives a formal expression of the effective Hamiltonian on the system. Although in general the full series expansion is not convergent in the thermodynamics limit, we give a clear relationship between the FM expansion and the transient <span class="hlt">dynamics</span>. More precisely, we rigorously show that a truncated version of the FM expansion accurately describes the exact <span class="hlt">dynamics</span> for a certain time-scale. Our theory reveals an experimental time-scale for which non-trivial <span class="hlt">dynamical</span> phenomena can be reliably observed. We discuss several <span class="hlt">dynamical</span> phenomena, such as the effect of small integrability breaking, efficient numerical simulation of periodically <span class="hlt">driven</span> systems, <span class="hlt">dynamical</span> localization and thermalization. Especially on thermalization, we discuss a generic scenario on the prethermalization phenomenon in periodically <span class="hlt">driven</span> systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3324010','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3324010"><span>Supernova-<span class="hlt">driven</span> outflows and chemical <span class="hlt">evolution</span> of dwarf spheroidal galaxies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qian, Yong-Zhong; Wasserburg, G. J.</p> <p>2012-01-01</p> <p>We present a general phenomenological model for the metallicity distribution (MD) in terms of [Fe/H] for dwarf spheroidal galaxies (dSphs). These galaxies appear to have stopped accreting gas from the intergalactic medium and are fossilized systems with their stars undergoing slow internal <span class="hlt">evolution</span>. For a wide variety of infall histories of unprocessed baryonic matter to feed star formation, most of the observed MDs can be well described by our model. The key requirement is that the fraction of the gas mass lost by supernova-<span class="hlt">driven</span> outflows is close to unity. This model also predicts a relationship between the total stellar mass and the mean metallicity for dSphs in accord with properties of their dark matter halos. The model further predicts as a natural consequence that the abundance ratios [E/Fe] for elements such as O, Mg, and Si decrease for stellar populations at the higher end of the [Fe/H] range in a dSph. We show that, for infall rates far below the net rate of gas loss to star formation and outflows, the MD in our model is very sharply peaked at one [Fe/H] value, similar to what is observed in most globular clusters. This result suggests that globular clusters may be end members of the same family as dSphs. PMID:22411827</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25372142','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25372142"><span>Structure <span class="hlt">evolution</span> of graphene oxide during thermally <span class="hlt">driven</span> phase transformation: is the oxygen content really preserved?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Pengzhan; Wang, Yanlei; Liu, He; Wang, Kunlin; Wu, Dehai; Xu, Zhiping; Zhu, Hongwei</p> <p>2014-01-01</p> <p>A mild annealing procedure was recently proposed for the scalable enhancement of graphene oxide (GO) properties with the oxygen content preserved, which was demonstrated to be attributed to the thermally <span class="hlt">driven</span> phase separation. In this work, the structure <span class="hlt">evolution</span> of GO with mild annealing is closely investigated. It reveals that in addition to phase separation, the transformation of oxygen functionalities also occurs, which leads to the slight reduction of GO membranes and furthers the enhancement of GO properties. These results are further supported by the density functional theory based calculations. The results also show that the amount of chemically bonded oxygen atoms on graphene decreases gradually and we propose that the strongly physisorbed oxygen species constrained in the holes and vacancies on GO lattice might be responsible for the preserved oxygen content during the mild annealing procedure. The present experimental results and calculations indicate that both the diffusion and transformation of oxygen functional groups might play important roles in the scalable enhancement of GO properties.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22348295','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22348295"><span>Wind-<span class="hlt">driven</span> <span class="hlt">evolution</span> of white dwarf binaries to type Ia supernovae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ablimit, Iminhaji; Xu, Xiao-jie; Li, X.-D.</p> <p>2014-01-01</p> <p>In the single-degenerate scenario for the progenitors of Type Ia supernovae (SNe Ia), a white dwarf rapidly accretes hydrogen- or helium-rich material from its companion star and appears as a supersoft X-ray source. This picture has been challenged by the properties of the supersoft X-ray sources with very low mass companions and the observations of several nearby SNe Ia. It has been pointed out that the X-ray radiation or the wind from the accreting white dwarf can excite winds or strip mass from the companion star, thus significantly influencing the mass transfer processes. In this paper, we perform detailed calculations of the wind-<span class="hlt">driven</span> <span class="hlt">evolution</span> of white dwarf binaries. We present the parameter space for the possible SN Ia progenitors and for the surviving companions after the SNe. The results show that the ex-companion stars of SNe Ia have characteristics more compatible with the observations, compared with those in the traditional single-degenerate scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4221183','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4221183"><span>Structure <span class="hlt">Evolution</span> of Graphene Oxide during Thermally <span class="hlt">Driven</span> Phase Transformation: Is the Oxygen Content Really Preserved?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Pengzhan; Wang, Yanlei; Liu, He; Wang, Kunlin; Wu, Dehai; Xu, Zhiping; Zhu, Hongwei</p> <p>2014-01-01</p> <p>A mild annealing procedure was recently proposed for the scalable enhancement of graphene oxide (GO) properties with the oxygen content preserved, which was demonstrated to be attributed to the thermally <span class="hlt">driven</span> phase separation. In this work, the structure <span class="hlt">evolution</span> of GO with mild annealing is closely investigated. It reveals that in addition to phase separation, the transformation of oxygen functionalities also occurs, which leads to the slight reduction of GO membranes and furthers the enhancement of GO properties. These results are further supported by the density functional theory based calculations. The results also show that the amount of chemically bonded oxygen atoms on graphene decreases gradually and we propose that the strongly physisorbed oxygen species constrained in the holes and vacancies on GO lattice might be responsible for the preserved oxygen content during the mild annealing procedure. The present experimental results and calculations indicate that both the diffusion and transformation of oxygen functional groups might play important roles in the scalable enhancement of GO properties. PMID:25372142</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://coastaldynamics2017.dk/proceedings.html','USGSPUBS'); return false;" href="http://coastaldynamics2017.dk/proceedings.html"><span>Climate change-<span class="hlt">driven</span> cliff and beach <span class="hlt">evolution</span> at decadal to centennial time scales</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Erikson, Li; O'Neill, Andrea; Barnard, Patrick; Vitousek, Sean; Limber, Patrick</p> <p>2017-01-01</p> <p>Here we develop a computationally efficient method that evolves cross-shore profiles of sand beaches with or without cliffs along natural and urban coastal environments and across expansive geographic areas at decadal to centennial time-scales <span class="hlt">driven</span> by 21st century climate change projections. The model requires projected sea level rise rates, extrema of nearshore wave conditions, bluff recession and shoreline change rates, and cross-shore profiles representing present-day conditions. The model is applied to the ~470-km long coast of the Southern California Bight, USA, using recently available projected nearshore waves and bluff recession and shoreline change rates. The results indicate that eroded cliff material, from unarmored cliffs, contribute 11% to 26% to the total sediment budget. Historical beach nourishment rates will need to increase by more than 30% for a 0.25 m sea level rise (~2044) and by at least 75% by the year 2100 for a 1 m sea level rise, if <span class="hlt">evolution</span> of the shoreline is to keep pace with rising sea levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22411827','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22411827"><span>Supernova-<span class="hlt">driven</span> outflows and chemical <span class="hlt">evolution</span> of dwarf spheroidal galaxies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qian, Yong-Zhong; Wasserburg, G J</p> <p>2012-03-27</p> <p>We present a general phenomenological model for the metallicity distribution (MD) in terms of [Fe/H] for dwarf spheroidal galaxies (dSphs). These galaxies appear to have stopped accreting gas from the intergalactic medium and are fossilized systems with their stars undergoing slow internal <span class="hlt">evolution</span>. For a wide variety of infall histories of unprocessed baryonic matter to feed star formation, most of the observed MDs can be well described by our model. The key requirement is that the fraction of the gas mass lost by supernova-<span class="hlt">driven</span> outflows is close to unity. This model also predicts a relationship between the total stellar mass and the mean metallicity for dSphs in accord with properties of their dark matter halos. The model further predicts as a natural consequence that the abundance ratios [E/Fe] for elements such as O, Mg, and Si decrease for stellar populations at the higher end of the [Fe/H] range in a dSph. We show that, for infall rates far below the net rate of gas loss to star formation and outflows, the MD in our model is very sharply peaked at one [Fe/H] value, similar to what is observed in most globular clusters. This result suggests that globular clusters may be end members of the same family as dSphs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3587351','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3587351"><span>Temperature <span class="hlt">driven</span> <span class="hlt">evolution</span> of thermal, electrical, and optical properties of Ti–Al–N coatings</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rachbauer, Richard; Gengler, Jamie J.; Voevodin, Andrey A.; Resch, Katharina; Mayrhofer, Paul H.</p> <p>2012-01-01</p> <p>Monolithic single phase cubic (c) Ti1−xAlxN thin films are used in various industrial applications due to their high thermal stability, which beneficially effects lifetime and performance of cutting and milling tools, but also find increasing utilization in electronic and optical devices. The present study elucidates the temperature-<span class="hlt">driven</span> <span class="hlt">evolution</span> of heat conductivity, electrical resistivity and optical reflectance from room temperature up to 1400 °C and links them to structural and chemical changes in Ti1−xAlxN coatings. It is shown that various decomposition phenomena, involving recovery and spinodal decomposition (known to account for the age hardening phenomenon in c-Ti1−xAlxN), as well as the cubic to wurtzite phase transformation of spinodally formed AlN-enriched domains, effectively increase the thermal conductivity of the coatings from ∼3.8 W m−1 K−1 by a factor of three, while the electrical resistivity is reduced by one order of magnitude. A change in the coating color from metallic grey after deposition to reddish-golden after annealing to 1400 °C is related to the film structure and discussed in terms of film reflectivity. PMID:23482424</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23482424','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23482424"><span>Temperature <span class="hlt">driven</span> <span class="hlt">evolution</span> of thermal, electrical, and optical properties of Ti-Al-N coatings.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rachbauer, Richard; Gengler, Jamie J; Voevodin, Andrey A; Resch, Katharina; Mayrhofer, Paul H</p> <p>2012-03-01</p> <p>Monolithic single phase cubic (c) Ti1-x Al x N thin films are used in various industrial applications due to their high thermal stability, which beneficially effects lifetime and performance of cutting and milling tools, but also find increasing utilization in electronic and optical devices. The present study elucidates the temperature-<span class="hlt">driven</span> <span class="hlt">evolution</span> of heat conductivity, electrical resistivity and optical reflectance from room temperature up to 1400 °C and links them to structural and chemical changes in Ti1-x Al x N coatings. It is shown that various decomposition phenomena, involving recovery and spinodal decomposition (known to account for the age hardening phenomenon in c-Ti1-x Al x N), as well as the cubic to wurtzite phase transformation of spinodally formed AlN-enriched domains, effectively increase the thermal conductivity of the coatings from ∼3.8 W m(-1) K(-1) by a factor of three, while the electrical resistivity is reduced by one order of magnitude. A change in the coating color from metallic grey after deposition to reddish-golden after annealing to 1400 °C is related to the film structure and discussed in terms of film reflectivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28539520','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28539520"><span>Independent <span class="hlt">evolution</span> of baleen whale gigantism linked to Plio-Pleistocene ocean <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Slater, Graham J; Goldbogen, Jeremy A; Pyenson, Nicholas D</p> <p>2017-05-31</p> <p>Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the <span class="hlt">evolution</span> of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary <span class="hlt">dynamics</span> in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size <span class="hlt">evolution</span> during the Plio-Pleistocene. This transition, from Brownian motion-like <span class="hlt">dynamics</span> to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-<span class="hlt">driven</span> upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean <span class="hlt">dynamics</span> may have provided an ecological pathway to gigantism in multiple independent lineages. © 2017 The Author(s).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5454272','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5454272"><span>Independent <span class="hlt">evolution</span> of baleen whale gigantism linked to Plio-Pleistocene ocean <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Goldbogen, Jeremy A.</p> <p>2017-01-01</p> <p>Vertebrates have evolved to gigantic sizes repeatedly over the past 250 Myr, reaching their extreme in today's baleen whales (Mysticeti). Hypotheses for the <span class="hlt">evolution</span> of exceptionally large size in mysticetes range from niche partitioning to predator avoidance, but there has been no quantitative examination of body size evolutionary <span class="hlt">dynamics</span> in this clade and it remains unclear when, why or how gigantism evolved. By fitting phylogenetic macroevolutionary models to a dataset consisting of living and extinct species, we show that mysticetes underwent a clade-wide shift in their mode of body size <span class="hlt">evolution</span> during the Plio-Pleistocene. This transition, from Brownian motion-like <span class="hlt">dynamics</span> to a trended random walk towards larger size, is temporally linked to the onset of seasonally intensified upwelling along coastal ecosystems. High prey densities resulting from wind-<span class="hlt">driven</span> upwelling, rather than abundant resources alone, are the primary determinant of efficient foraging in extant mysticetes and Late Pliocene changes in ocean <span class="hlt">dynamics</span> may have provided an ecological pathway to gigantism in multiple independent lineages. PMID:28539520</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299187','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299187"><span>Oxidation-<span class="hlt">driven</span> surface <span class="hlt">dynamics</span> on NiAl(100)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen</p> <p>2015-01-01</p> <p>Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface <span class="hlt">dynamics</span> under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). By comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps. PMID:25548155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1261640-oxidation-driven-surface-dynamics-nial','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1261640-oxidation-driven-surface-dynamics-nial"><span>Oxidation-<span class="hlt">driven</span> surface <span class="hlt">dynamics</span> on NiAl(100)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Qin, Hailang; Chen, Xidong; Li, Liang; ...</p> <p>2014-12-29</p> <p>Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface <span class="hlt">dynamics</span> under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling upmore » of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). As a result, by comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps, we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JHyd..552..544Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JHyd..552..544Y"><span><span class="hlt">Dynamic</span> flow-<span class="hlt">driven</span> erosion - An improved approximate solution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Bofu; Guo, Dawei; Rose, Calvin W.</p> <p>2017-09-01</p> <p>Rose et al. (2007) published an approximate solution of <span class="hlt">dynamic</span> sediment concentration for steady and uniform flows, and this approximate solution shows a peak sediment concentration at the early stage of a runoff event, which can be used to describe and explain the first flush effect, a commonly observed phenomenon, especially in the urban environment. However the approximate solution does not converge to the steady state solution that is known exactly. The purpose of the note is to improve the approximate solution of Rose et al. (2007) by maintaining its functional form while forcing its steady state behaviour for sediment concentration to converge to the known steady state solution. The quality of the new approximate solution was assessed by comparing the new approximate solution with an exact solution for the single size class case, and with the numerical solution for the multiple size classes. It was found that 1) the relative error, or discrepancy, decreases as the stream power increases for all three soils considered; 2) the largest discrepancy occurs for the peak sediment concentration, and the average discrepancy in the peak concentration is less than 10% for the three soils considered; 3) for the majority of the 27 slope-flow combinations and for the three soils considered, the new approximate solution modestly underestimates the peak sediment concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1261640','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1261640"><span>Oxidation-<span class="hlt">driven</span> surface <span class="hlt">dynamics</span> on NiAl(100)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen</p> <p>2014-12-29</p> <p>Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface <span class="hlt">dynamics</span> under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). As a result, by comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps, we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PNAS..112E.103Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PNAS..112E.103Q"><span>Oxidation-<span class="hlt">driven</span> surface <span class="hlt">dynamics</span> on NiAl(100)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, Hailang; Chen, Xidong; Li, Liang; Sutter, Peter W.; Zhou, Guangwen</p> <p>2015-01-01</p> <p>Atomic steps, a defect common to all crystal surfaces, can play an important role in many physical and chemical processes. However, attempts to predict surface <span class="hlt">dynamics</span> under nonequilibrium conditions are usually frustrated by poor knowledge of the atomic processes of surface motion arising from mass transport from/to surface steps. Using low-energy electron microscopy that spatially and temporally resolves oxide film growth during the oxidation of NiAl(100) we demonstrate that surface steps are impermeable to oxide film growth. The advancement of the oxide occurs exclusively on the same terrace and requires the coordinated migration of surface steps. The resulting piling up of surface steps ahead of the oxide growth front progressively impedes the oxide growth. This process is reversed during oxide decomposition. The migration of the substrate steps is found to be a surface-step version of the well-known Hele-Shaw problem, governed by detachment (attachment) of Al atoms at step edges induced by the oxide growth (decomposition). By comparing with the oxidation of NiAl(110) that exhibits unimpeded oxide film growth over substrate steps we suggest that whenever steps are the source of atoms used for oxide growth they limit the oxidation process; when atoms are supplied from the bulk, the oxidation rate is not limited by the motion of surface steps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..MARZ18010K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..MARZ18010K"><span>Theory of the <span class="hlt">dynamics</span> of evaporation-<span class="hlt">driven</span> colloidal patterning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaplan, C. Nadir; Wu, Ning; Mandre, Shreyas; Aizenberg, Joanna; Mahadevan, L.</p> <p>2014-03-01</p> <p>In the suspensions of colloidal particles in a volatile liquid film, deposits of the solute form near the contact line due to the flow generated by evaporation. An enticingly simple and experimentally realizable model system of this mechanism is the drying of a spilled drop of coffee on the countertop. Similarly, patterns of periodic bands or continuous solid films are commonly observed on a substrate suspended vertically in a container of the colloidal solution. In order to characterize these patterns, we develop a multiphase model that couples both the liquid and solid flows, local variation of the particle concentration, the propagation <span class="hlt">dynamics</span> of the solid front, and the liquid-air interface deformation. For vertical liquid films, we further determine the nature of the filming-banding transition and the phase boundary in terms of the volume fraction of the colloids. The results of our theory are in good agreement with direct observations of these patterns. We gratefully acknowledge financial support from the Air Force Office of Scientific Research and the Kavli Institute for Bionano Science and Technology at Harvard University.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19337776','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19337776"><span>Degeneracy-<span class="hlt">driven</span> self-structuring <span class="hlt">dynamics</span> in selective repertoires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Atamas, Sergei P; Bell, Jonathan</p> <p>2009-08-01</p> <p>Numerous biological interactions, such as interactions between T cell receptors or antibodies with antigens, interactions between enzymes and substrates, or interactions between predators and prey are often not strictly specific. In such less specific, or "sloppy," systems, referred to here as degenerate systems, a given unit of a diverse resource (antigens, enzymatic substrates, prey) is at risk of being recognized and consumed by multiple consumers (lymphocytes, enzymes, predators). In this study, we model generalized degenerate consumer-resource systems of Lotka-Volterra and Verhulst types. In the degenerate systems of Lotka-Volterra, there is a continuum of types of consumer and resource based on variation of a single trait (characteristic, or preference). The consumers experience competition for a continuum of resource types. This non-local interaction system is modeled with partial differential-integral equations and shows spontaneous self-structuring of the consumer population that depends on the degree of interaction degeneracy between resource and consumer, but does not mirror the distribution of resource. We also show that the classical Verhulst (i.e. logistic) single population model can be generalized to a degenerate model, which shows qualitative behavior similar to that in the degenerate Lotka-Volterra model. These results provide better insight into the <span class="hlt">dynamics</span> of selective systems in biology, suggesting that adaptation of degenerate repertoires is not a simple "mirroring" of the environment by the "fittest" elements of population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1096331','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1096331"><span>Role of methyl groups in <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of biomolecules</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nickels, Jonathan D; Curtis, J. E.; Oneill, Hugh; Sokolov, Alexei P</p> <p>2012-01-01</p> <p>Recent studies have discovered strong differences between the <span class="hlt">dynamics</span> of nucleic acids (RNA and DNA) and proteins, especially at low hydration and low temperatures. This difference is caused primarily by <span class="hlt">dynamics</span> of methyl groups that are abundant in proteins, but are absent or very rare in RNA and DNA. In this paper, we present a hypothesis regarding the role of methyl groups as intrinsic plasticizers in proteins and their evolutionary selection to facilitate protein <span class="hlt">dynamics</span> and activity. We demonstrate the profound effect methyl groups have on protein <span class="hlt">dynamics</span> relative to nucleic acid <span class="hlt">dynamics</span>, and note the apparent correlation of methyl group content in protein classes and their need for molecular flexibility. Moreover, we note the fastest methyl groups of some enzymes appear around <span class="hlt">dynamical</span> centers such as hinges or active sites. Methyl groups are also of tremendous importance from a ydrophobicity/folding/entropy perspective. These significant roles, however, complement our hypothesis rather than preclude the recognition of methyl groups in the <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of biomolecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoJI.203.1909A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoJI.203.1909A"><span>Calculating gravitationally self-consistent sea level changes <span class="hlt">driven</span> by <span class="hlt">dynamic</span> topography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Austermann, J.; Mitrovica, J. X.</p> <p>2015-12-01</p> <p>We present a generalized formalism for computing gravitationally self-consistent sea level changes <span class="hlt">driven</span> by the combined effects of <span class="hlt">dynamic</span> topography, geoid perturbations due to mantle convection, ice mass fluctuations and sediment redistribution on a deforming Earth. Our mathematical treatment conserves mass of the surface (ice plus ocean) load and the solid Earth. Moreover, it takes precise account of shoreline migration and the associated ocean loading. The new formalism avoids a variety of approximations adopted in previous models of sea level change <span class="hlt">driven</span> by <span class="hlt">dynamic</span> topography, including the assumption that a spatially fixed isostatic amplification of `air-loaded' <span class="hlt">dynamic</span> topography accurately accounts for ocean loading effects. While our approach is valid for Earth models of arbitrary complexity, we present numerical results for a set of simple cases in which a pattern of <span class="hlt">dynamic</span> topography is imposed, the response to surface mass loading assumes that Earth structure varies only with depth and that isostatic equilibrium is maintained at all times. These calculations, involving fluid Love number theory, indicate that the largest errors in previous predictions of sea level change <span class="hlt">driven</span> by <span class="hlt">dynamic</span> topography occur in regions of shoreline migration, and thus in the vicinity of most geological markers of ancient sea level. We conclude that a gravitationally self-consistent treatment of long-term sea level change is necessary in any effort to use such geological markers to estimate ancient ice volumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8744E..0JB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8744E..0JB"><span><span class="hlt">Dynamic</span> Data <span class="hlt">Driven</span> Applications Systems (DDDAS) modeling for automatic target recognition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blasch, Erik; Seetharaman, Guna; Darema, Frederica</p> <p>2013-05-01</p> <p>The <span class="hlt">Dynamic</span> Data <span class="hlt">Driven</span> Applications System (DDDAS) concept uses applications modeling, mathematical algorithms, and measurement systems to work with <span class="hlt">dynamic</span> systems. A <span class="hlt">dynamic</span> systems such as Automatic Target Recognition (ATR) is subject to sensor, target, and the environment variations over space and time. We use the DDDAS concept to develop an ATR methodology for multiscale-multimodal analysis that seeks to integrated sensing, processing, and exploitation. In the analysis, we use computer vision techniques to explore the capabilities and analogies that DDDAS has with information fusion. The key attribute of coordination is the use of sensor management as a data <span class="hlt">driven</span> techniques to improve performance. In addition, DDDAS supports the need for modeling from which uncertainty and variations are used within the <span class="hlt">dynamic</span> models for advanced performance. As an example, we use a Wide-Area Motion Imagery (WAMI) application to draw parallels and contrasts between ATR and DDDAS systems that warrants an integrated perspective. This elementary work is aimed at triggering a sequence of deeper insightful research towards exploiting sparsely sampled piecewise dense WAMI measurements - an application where the challenges of big-data with regards to mathematical fusion relationships and high-performance computations remain significant and will persist. <span class="hlt">Dynamic</span> data-<span class="hlt">driven</span> adaptive computations are required to effectively handle the challenges with exponentially increasing data volume for advanced information fusion systems solutions such as simultaneous target tracking and ATR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3913366','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3913366"><span>Analysis of <span class="hlt">Dynamic</span> Behavior of Multiple-Stage Planetary Gear Train Used in Wind <span class="hlt">Driven</span> Generator</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Jungang; Wang, Yong; Huo, Zhipu</p> <p>2014-01-01</p> <p>A <span class="hlt">dynamic</span> model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind <span class="hlt">driven</span> generator to analyze the influence of revolution speed and mesh error on <span class="hlt">dynamic</span> load sharing characteristic based on the lumped parameter theory. <span class="hlt">Dynamic</span> equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind <span class="hlt">driven</span> generator. PMID:24511295</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24511295','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24511295"><span>Analysis of <span class="hlt">dynamic</span> behavior of multiple-stage planetary gear train used in wind <span class="hlt">driven</span> generator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jungang; Wang, Yong; Huo, Zhipu</p> <p>2014-01-01</p> <p>A <span class="hlt">dynamic</span> model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind <span class="hlt">driven</span> generator to analyze the influence of revolution speed and mesh error on <span class="hlt">dynamic</span> load sharing characteristic based on the lumped parameter theory. <span class="hlt">Dynamic</span> equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind <span class="hlt">driven</span> generator.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27115521','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27115521"><span><span class="hlt">Driven</span> colloidal fluids: construction of <span class="hlt">dynamical</span> density functional theories from exactly solvable limits.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scacchi, Alberto; Krüger, Matthias; Brader, Joseph M</p> <p>2016-06-22</p> <p>The classical <span class="hlt">dynamical</span> density functional theory (DDFT) provides an approximate extension of equilibrium DFT to treat nonequilibrium systems subject to Brownian <span class="hlt">dynamics</span>. However, the method fails when applied to <span class="hlt">driven</span> systems, such as sheared colloidal dispersions. The breakdown of DDFT can be traced back to an inadequate treatment of the flow-induced distortion of the pair correlation functions. By considering the distortion of the pair correlations to second order in the flow-rate we show how to systematically correct the DDFT for <span class="hlt">driven</span> systems. As an application of our approach we consider Poiseuille flow. The theory predicts that the particles will accumulate in spatial regions where the local shear rate is small, an effect known as shear-induced migration. We compare these predictions to Brownian <span class="hlt">dynamics</span> simulations with generally good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCM...28x4023S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCM...28x4023S"><span><span class="hlt">Driven</span> colloidal fluids: construction of <span class="hlt">dynamical</span> density functional theories from exactly solvable limits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Scacchi, Alberto; Krüger, Matthias; Brader, Joseph M.</p> <p>2016-06-01</p> <p>The classical <span class="hlt">dynamical</span> density functional theory (DDFT) provides an approximate extension of equilibrium DFT to treat nonequilibrium systems subject to Brownian <span class="hlt">dynamics</span>. However, the method fails when applied to <span class="hlt">driven</span> systems, such as sheared colloidal dispersions. The breakdown of DDFT can be traced back to an inadequate treatment of the flow-induced distortion of the pair correlation functions. By considering the distortion of the pair correlations to second order in the flow-rate we show how to systematically correct the DDFT for <span class="hlt">driven</span> systems. As an application of our approach we consider Poiseuille flow. The theory predicts that the particles will accumulate in spatial regions where the local shear rate is small, an effect known as shear-induced migration. We compare these predictions to Brownian <span class="hlt">dynamics</span> simulations with generally good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B41K0211K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B41K0211K"><span><span class="hlt">Dynamic</span> Pulse-<span class="hlt">Driven</span> Flowering Phenology in a Semiarid Shrubland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krell, N.; Papuga, S. A.; Kipnis, E. L.; Nelson, K.</p> <p>2014-12-01</p> <p>Elevated springtime temperature has been convincingly linked to an increasingly earlier onset of phenological activity. Studies highlighting this phenomenon have generally been conducted in ecosystems where energy is the primary limiting factor. Importantly, phenological studies in semiarid ecosystems where water is the major limiting factor are rare. In semiarid ecosystems, the timing of phenological activity is also highly sensitive to discrete moisture pulses from infrequent precipitation events. The objective of this study is to identify the triggers of flowering phenology in a semiarid creosotebush-dominated ecosystem. Creosotebush (Larrea tridentata) is a repeat-flowering evergreen shrub that is the dominant species in three of the North American deserts. We present results from six years of daily meteorological and phenological data collected within the Santa Rita Experimental Range in southern Arizona. Our site is equipped with an eddy covariance tower providing estimates of water and carbon fluxes and associated meteorological variables including precipitation and soil moisture at multiple depths. Additionally, three digital cameras distributed within the footprint of the eddy provide daily images of phenological activity. Our results highlight substantial interannual variability in flowering phenology, both in spring and summer flowering. We show that spring flowering activity tends to be associated with energy triggers (e.g. temperature, growing degree days), whereas summer flowering activity tends to be associated with moisture triggers (e.g. large precipitation events, deep soil moisture). Our study suggests that changes in frequency and duration of precipitation events will impact timing of phenological activity resulting in important consequences for vegetation <span class="hlt">dynamics</span> and pollinator behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090041267','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090041267"><span>Dual-Beam Atom Laser <span class="hlt">Driven</span> by Spinor <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, Robert; Lundblad, Nathan; Maleki, Lute; Aveline, David</p> <p>2007-01-01</p> <p>An atom laser now undergoing development simultaneously generates two pulsed beams of correlated Rb-87 atoms. (An atom laser is a source of atoms in beams characterized by coherent matter waves, analogous to a conventional laser, which is a source of coherent light waves.) The pumping mechanism of this atom laser is based on spinor <span class="hlt">dynamics</span> in a Bose-Einstein condensate. By virtue of the angular-momentum conserving collisions that generate the two beams, the number of atoms in one beam is correlated with the number of atoms in the other beam. Such correlations are intimately linked to entanglement and squeezing in atomic ensembles, and atom lasers like this one could be used in exploring related aspects of Bose-Einstein condensates, and as components of future sensors relying on atom interferometry. In this atom-laser apparatus, a Bose-Einstein condensate of about 2 x 10(exp 6) Rb-87 atoms at a temperature of about 120 micro-K is first formed through all-optical means in a relatively weak singlebeam running-wave dipole trap that has been formed by focusing of a CO2-laser beam. By a technique that is established in the art, the trap is loaded from an ultrahigh-vacuum magnetooptical trap that is, itself, loaded via a cold atomic beam from an upstream two-dimensional magneto-optical trap that resides in a rubidium-vapor cell that is differentially pumped from an adjoining vacuum chamber, wherein are performed scientific observations of the beams ultimately generated by the atom laser.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22253857','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22253857"><span>Cascaded spin motive force <span class="hlt">driven</span> by the <span class="hlt">dynamics</span> of the skyrmion lattice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ohe, Jun-ichiro; Shimada, Yuhki</p> <p>2013-12-09</p> <p>We numerically investigate the spin motive force (SMF) <span class="hlt">driven</span> by the <span class="hlt">dynamics</span> of a Skyrmion lattice. The rotating mode of the Skyrmion core excited by the AC magnetic field induces the large spin-dependent electric field near the core. Due to the collective <span class="hlt">dynamics</span> of Skyrmion lattice, the measurable voltage is enhanced by the cascade effect of the SMF. The amplitude of the AC voltage is estimated to 30 μV in a macroscopic sample, where 100 Skyrmions exist between two probes. We also investigate the SMF due to the <span class="hlt">dynamics</span> of the helical magnetic state, where the enhancement of the SMF does not occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017InPhT..81..195H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017InPhT..81..195H"><span><span class="hlt">Dynamic</span> modeling of optically pumped electrically <span class="hlt">driven</span> terahertz quantum cascade lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamadou, A.; Thobel, J.-L.; Lamari, S.</p> <p>2017-03-01</p> <p>Based on our four-level rate equations model, we analyze through numerical simulations the <span class="hlt">dynamics</span> of the electron density, population inversion and terahertz intensity present within the cavity of a mid-infrared optically pumped electrically <span class="hlt">driven</span> THz quantum cascade laser. We find in particular that the mid-infrared pump intensity influences significantly the <span class="hlt">dynamical</span> behavior of the present device. Moreover, compared to its homologue, the conventional electrically injected THz quantum cascade laser, this system presents much faster <span class="hlt">dynamics</span>. In addition, within the premises of our model, we derive in the most general case the equation that allows for the determination of the turn-on delay time tth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tecto..36..929B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tecto..36..929B"><span><span class="hlt">Dynamic</span> topography and eustasy controlled the paleogeographic <span class="hlt">evolution</span> of northern Africa since the mid-Cretaceous</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barnett-Moore, N.; Hassan, R.; Müller, R. D.; Williams, S. E.; Flament, N.</p> <p>2017-05-01</p> <p>Northern Africa underwent widespread inundation during the Late Cretaceous. Changes in eustasy do not explain the absence of this inundation across the remainder of Africa, and the timing and location of documented tectonic deformation do not explain the large-scale paleogeographic <span class="hlt">evolution</span>. We investigate the combined effects of vertical surface displacements predicted by a series of mantle flow models and eustasy on northern African paleoenvironmental change. We compare changes in base level computed as the difference between eustasy and long-wavelength <span class="hlt">dynamic</span> topography arising from sources of buoyancy deeper than 350 km to the <span class="hlt">evolution</span> of paleoshorelines derived from two interpolated global data sets since the mid-Cretaceous. We also compare the predicted mantle temperature field of these mantle flow models at present-day to several seismic tomography models. This approach reveals that <span class="hlt">dynamic</span> subsidence, related to Africa's northward motion away from the buoyant regions overlying the African large low shear velocity province, amplified sea level rise, resulting in maximum inundation of northern Africa during the Cenomanian and Turonian. By the Cenozoic, decreased magnitudes of <span class="hlt">dynamic</span> subsidence, reflecting the reduced drawdown effects of slab material beneath northern Africa associated with the impact of the Africa-Eurasia collision, combined with a comparatively pronounced progressive sea level fall resulted in ongoing region-wide regression along coastal regions. The temporal match between our preferred model and the paleoshoreline data sets suggests that the paleogeographic <span class="hlt">evolution</span> of this region since the Late Cretaceous has mainly been influenced by the interplay between eustasy and long-wavelength <span class="hlt">dynamic</span> topography arising from large-scale, subduction-<span class="hlt">driven</span>, lower mantle convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatCo...815417F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatCo...815417F"><span>Energy landscape-<span class="hlt">driven</span> non-equilibrium <span class="hlt">evolution</span> of inherent structure in disordered material</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fan, Yue; Iwashita, Takuya; Egami, Takeshi</p> <p>2017-05-01</p> <p>Complex states in glasses can be neatly expressed by the potential energy landscape (PEL). However, because PEL is highly multi-dimensional it is difficult to describe how the system moves around in PEL. Here we demonstrate that it is possible to predict the <span class="hlt">evolution</span> of macroscopic state in a metallic glass, such as ageing and rejuvenation, through a set of simple equations describing excitations in the PEL. The key to this simplification is the realization that the step of activation from the initial state to the saddle point in PEL and the following step of relaxation to the final state are essentially decoupled. The model shows that the interplay between activation and relaxation in PEL is the key driving force that simultaneously explains both the equilibrium of supercooled liquid and the thermal hysteresis observed in experiments. It further predicts anomalous peaks in truncated thermal scanning, validated by independent molecular <span class="hlt">dynamics</span> simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1360078-energy-landscape-driven-non-equilibrium-evolution-inherent-structure-disordered-material','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1360078-energy-landscape-driven-non-equilibrium-evolution-inherent-structure-disordered-material"><span>Energy landscape-<span class="hlt">driven</span> non-equilibrium <span class="hlt">evolution</span> of inherent structure in disordered material</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Fan, Yue; Iwashita, Takuya; Egami, Takeshi</p> <p>2017-05-19</p> <p>Complex states in glasses can be neatly expressed by the potential energy landscape (PEL). But, because PEL is highly multi-dimensional it is difficult to describe how the system moves around in PEL. We demonstrate that it is possible to predict the <span class="hlt">evolution</span> of macroscopic state in a metallic glass, such as ageing and rejuvenation, through a set of simple equations describing excitations in the PEL. The key to this simplification is the realization that the step of activation from the initial state to the saddle point in PEL and the following step of relaxation to the final state are essentiallymore » decoupled. Furthermore, the model shows that the interplay between activation and relaxation in PEL is the key driving force that simultaneously explains both the equilibrium of supercooled liquid and the thermal hysteresis observed in experiments. It further predicts anomalous peaks in truncated thermal scanning, validated by independent molecular <span class="hlt">dynamics</span> simulation.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhPl...24a3117L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhPl...24a3117L"><span>Study of plasma pressure <span class="hlt">evolution</span> <span class="hlt">driven</span> by strong picosecond laser pulse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, M.; Wang, J. X.; Xu, Y. X.; Zhu, W. J.</p> <p>2017-01-01</p> <p>Through one dimensional relativistic particle-in-cell simulation of strong laser interaction with the solid-density plasma, the <span class="hlt">evolution</span> of the plasma impact pressure behind a thin foil has been investigated in details. An energy-compression mechanism has been proposed to help optimizing the laser and plasma parameters. It has been found that by using a picosecond laser with intensity 1015 W cm-2, an impact pressure as high as several hundreds of GPa order of magnitude can be obtained. The numerical analysis demonstrates that the peak pressure is mainly resulted from the ion contribution. These results are of potential application to the laser loading upon solids in order to study the material properties under extra-high <span class="hlt">dynamic</span> pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JSMTE..10..018P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JSMTE..10..018P"><span>Network <span class="hlt">evolution</span> induced by the <span class="hlt">dynamical</span> rules of two populations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Platini, Thierry; Zia, R. K. P.</p> <p>2010-10-01</p> <p>We study the <span class="hlt">dynamical</span> properties of a finite <span class="hlt">dynamical</span> network composed of two interacting populations, namely extrovert (a) and introvert (b). In our model, each group is characterized by its size (Na and Nb) and preferred degree (κa and \\kappa_b\\ll \\kappa_a ). The network <span class="hlt">dynamics</span> is governed by the competing microscopic rules of each population that consist of the creation and destruction of links. Starting from an unconnected network, we give a detailed analysis of the mean field approach which is compared to Monte Carlo simulation data. The time <span class="hlt">evolution</span> of the restricted degrees langkbbrang and langkabrang presents three time regimes and a non-monotonic behavior well captured by our theory. Surprisingly, when the population sizes are equal Na = Nb, the ratio of the restricted degree θ0 = langkabrang/langkbbrang appears to be an integer in the asymptotic limits of the three time regimes. For early times (defined by t < t1 = κb) the total number of links presents a linear <span class="hlt">evolution</span>, where the two populations are indistinguishable and where θ0 = 1. Interestingly, in the intermediate time regime (defined for t_1\\lt t\\lt t_2\\propto \\kappa_a and for which θ0 = 5), the system reaches a transient stationary state, where the number of contacts among introverts remains constant while the number of connections increases linearly in the extrovert population. Finally, due to the competing <span class="hlt">dynamics</span>, the network presents a frustrated stationary state characterized by a ratio θ0 = 3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12803890','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12803890"><span><span class="hlt">Evolution</span> as a critical component of plankton <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fussmann, Gregor F; Ellner, Stephen P; Hairston, Nelson G</p> <p>2003-05-22</p> <p>Microevolution is typically ignored as a factor directly affecting ongoing population <span class="hlt">dynamics</span>. We show here that density-dependent natural selection has a direct and measurable effect on a planktonic predator-prey interaction. We kept populations of Brachionus calyciflorus, a monogonont rotifer that exhibits cyclical parthenogenesis, in continuous flow-through cultures (chemostats) for more than 900 days. Initially, females frequently produced male offspring, especially at high population densities. We observed rapid <span class="hlt">evolution</span>, however, towards low propensity to reproduce sexually, and by 750 days, reproduction had become entirely asexual. There was strong selection favouring asexual reproduction because, under the turbulent chemostat regime, males were unable to mate with females, produced no offspring, and so had zero fitness. In replicated chemostat experiments we found that this evolutionary process directly influenced the population <span class="hlt">dynamics</span>. We observed very specific but reproducible plankton <span class="hlt">dynamics</span> which are explained well by a mathematical model that explicitly includes <span class="hlt">evolution</span>. This model accounts for both asexual and sexual reproduction and treats the propensity to reproduce sexually as a quantitative trait under selection. We suggest that a similar amalgam of ecological and evolutionary mechanisms may drive the <span class="hlt">dynamics</span> of rapidly reproducing organisms in the wild.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1794f0001C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1794f0001C"><span>Research on influence factor about the <span class="hlt">dynamic</span> characteristic of armored vehicle hydraulic-<span class="hlt">driven</span> fan system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chao, Zhiqiang; Mao, Feiyue; Liu, Xiangbo; Li, Huaying; Han, Shousong</p> <p>2017-01-01</p> <p>In view of the large power of armored vehicle cooling system, the demand for high fan speed control and energy saving, this paper expounds the basic composition and principle of hydraulic-<span class="hlt">driven</span> fan system and establishes the mathematical model of the system. Through the simulation analysis of different parameters, such as displacement of motor and working volume of fan system, the influences of performance parameters on the <span class="hlt">dynamic</span> characteristic of hydraulic-<span class="hlt">driven</span> fan system are obtained, which can provide theoretical guidance for system optimization design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3566791','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3566791"><span>Movement Patterns, Social <span class="hlt">Dynamics</span>, and the <span class="hlt">Evolution</span> of Cooperation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smaldino, Paul E.; Schank, Jeffrey C.</p> <p>2012-01-01</p> <p>The structure of social interactions influences many aspects of social life, including the spread of information and behavior, and the <span class="hlt">evolution</span> of social phenotypes. After dispersal, organisms move around throughout their lives, and the patterns of their movement influence their social encounters over the course of their lifespan. Though both space and mobility are known to influence social <span class="hlt">evolution</span>, there is little analysis of the influence of specific movement patterns on evolutionary <span class="hlt">dynamics</span>. We explored the effects of random movement strategies on the <span class="hlt">evolution</span> of cooperation using an agent-based prisoner’s dilemma model with mobile agents. This is the first systematic analysis of a model in which cooperators and defectors can use different random movement strategies, which we chose to fall on a spectrum between highly exploratory and highly restricted in their search tendencies. Because limited dispersal and restrictions to local neighborhood size are known to influence the ability of cooperators to effectively assort, we also assessed the robustness of our findings with respect to dispersal and local capacity constraints. We show that differences in patterns of movement can dramatically influence the likelihood of cooperator success, and that the effects of different movement patterns are sensitive to environmental assumptions about offspring dispersal and local space constraints. Since local interactions implicitly generate <span class="hlt">dynamic</span> social interaction networks, we also measured the average number of unique and total interactions over a lifetime and considered how these emergent network <span class="hlt">dynamics</span> helped explain the results. This work extends what is known about mobility and the <span class="hlt">evolution</span> of cooperation, and also has general implications for social models with randomly moving agents. PMID:22838026</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22838026','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22838026"><span>Movement patterns, social <span class="hlt">dynamics</span>, and the <span class="hlt">evolution</span> of cooperation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smaldino, Paul E; Schank, Jeffrey C</p> <p>2012-08-01</p> <p>The structure of social interactions influences many aspects of social life, including the spread of information and behavior, and the <span class="hlt">evolution</span> of social phenotypes. After dispersal, organisms move around throughout their lives, and the patterns of their movement influence their social encounters over the course of their lifespan. Though both space and mobility are known to influence social <span class="hlt">evolution</span>, there is little analysis of the influence of specific movement patterns on evolutionary <span class="hlt">dynamics</span>. We explored the effects of random movement strategies on the <span class="hlt">evolution</span> of cooperation using an agent-based prisoner's dilemma model with mobile agents. This is the first systematic analysis of a model in which cooperators and defectors can use different random movement strategies, which we chose to fall on a spectrum between highly exploratory and highly restricted in their search tendencies. Because limited dispersal and restrictions to local neighborhood size are known to influence the ability of cooperators to effectively assort, we also assessed the robustness of our findings with respect to dispersal and local capacity constraints. We show that differences in patterns of movement can dramatically influence the likelihood of cooperator success, and that the effects of different movement patterns are sensitive to environmental assumptions about offspring dispersal and local space constraints. Since local interactions implicitly generate <span class="hlt">dynamic</span> social interaction networks, we also measured the average number of unique and total interactions over a lifetime and considered how these emergent network <span class="hlt">dynamics</span> helped explain the results. This work extends what is known about mobility and the <span class="hlt">evolution</span> of cooperation, and also has general implications for social models with randomly moving agents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28298004','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28298004"><span><span class="hlt">Driven</span> optical matter: <span class="hlt">Dynamics</span> of electrodynamically coupled nanoparticles in an optical ring vortex.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Figliozzi, Patrick; Sule, Nishant; Yan, Zijie; Bao, Ying; Burov, Stanislav; Gray, Stephen K; Rice, Stuart A; Vaikuntanathan, Suriyanarayanan; Scherer, Norbert F</p> <p>2017-02-01</p> <p>To date investigations of the <span class="hlt">dynamics</span> of <span class="hlt">driven</span> colloidal systems have focused on hydrodynamic interactions and often employ optical (laser) tweezers for manipulation. However, the optical fields that provide confinement and drive also result in electrodynamic interactions that are generally neglected. We address this issue with a detailed study of interparticle <span class="hlt">dynamics</span> in an optical ring vortex trap using 150-nm diameter Ag nanoparticles. We term the resultant electrodynamically interacting nanoparticles a <span class="hlt">driven</span> optical matter system. We also show that a superior trap is created by using a Au nanoplate mirror in a retroreflection geometry, which increases the electric field intensity, the optical drive force, and spatial confinement. Using nanoparticles versus micron sized colloids significantly reduces the surface hydrodynamic friction allowing us to access small values of optical topological charge and drive force. We quantify a further 50% reduction of hydrodynamic friction when the nanoparticles are <span class="hlt">driven</span> over the Au nanoplate mirrors versus over a mildly electrostatically repulsive glass surface. Further, we demonstrate through experiments and electrodynamics-Langevin <span class="hlt">dynamics</span> simulations that the optical drive force and the interparticle interactions are not constant around the ring for linearly polarized light, resulting in a strong position-dependent variation in the nanoparticle velocity. The nonuniformity in the optical drive force is also manifest as an increase in fluctuations of interparticle separation, or effective temperature, as the optical driving force is increased. Finally, we resolve an open issue in the literature on periodic modulation of interparticle separation with comparative measurements of <span class="hlt">driven</span> 300-nm-diameter polystyrene beads that also clearly reveal the significance of electrodynamic forces and interactions in optically <span class="hlt">driven</span> colloidal systems. Therefore, the modulations in the optical forces and electrodynamic interactions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95b2604F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95b2604F"><span><span class="hlt">Driven</span> optical matter: <span class="hlt">Dynamics</span> of electrodynamically coupled nanoparticles in an optical ring vortex</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Figliozzi, Patrick; Sule, Nishant; Yan, Zijie; Bao, Ying; Burov, Stanislav; Gray, Stephen K.; Rice, Stuart A.; Vaikuntanathan, Suriyanarayanan; Scherer, Norbert F.</p> <p>2017-02-01</p> <p>To date investigations of the <span class="hlt">dynamics</span> of <span class="hlt">driven</span> colloidal systems have focused on hydrodynamic interactions and often employ optical (laser) tweezers for manipulation. However, the optical fields that provide confinement and drive also result in electrodynamic interactions that are generally neglected. We address this issue with a detailed study of interparticle <span class="hlt">dynamics</span> in an optical ring vortex trap using 150-nm diameter Ag nanoparticles. We term the resultant electrodynamically interacting nanoparticles a <span class="hlt">driven</span> optical matter system. We also show that a superior trap is created by using a Au nanoplate mirror in a retroreflection geometry, which increases the electric field intensity, the optical drive force, and spatial confinement. Using nanoparticles versus micron sized colloids significantly reduces the surface hydrodynamic friction allowing us to access small values of optical topological charge and drive force. We quantify a further 50% reduction of hydrodynamic friction when the nanoparticles are <span class="hlt">driven</span> over the Au nanoplate mirrors versus over a mildly electrostatically repulsive glass surface. Further, we demonstrate through experiments and electrodynamics-Langevin <span class="hlt">dynamics</span> simulations that the optical drive force and the interparticle interactions are not constant around the ring for linearly polarized light, resulting in a strong position-dependent variation in the nanoparticle velocity. The nonuniformity in the optical drive force is also manifest as an increase in fluctuations of interparticle separation, or effective temperature, as the optical driving force is increased. Finally, we resolve an open issue in the literature on periodic modulation of interparticle separation with comparative measurements of <span class="hlt">driven</span> 300-nm-diameter polystyrene beads that also clearly reveal the significance of electrodynamic forces and interactions in optically <span class="hlt">driven</span> colloidal systems. Therefore, the modulations in the optical forces and electrodynamic interactions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14995348','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14995348"><span>Competition-<span class="hlt">driven</span> network <span class="hlt">dynamics</span>: emergence of a scale-free leadership structure and collective efficiency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anghel, M; Toroczkai, Zoltán; Bassler, Kevin E; Korniss, G</p> <p>2004-02-06</p> <p>Using the minority game as a model for competition <span class="hlt">dynamics</span>, we investigate the effects of interagent communications across a network on the global <span class="hlt">evolution</span> of the game. Agent communication across this network leads to the formation of an influence network, which is <span class="hlt">dynamically</span> coupled to the <span class="hlt">evolution</span> of the game, and it is responsible for the information flow driving the agents' actions. We show that the influence network spontaneously develops hubs with a broad distribution of in-degrees, defining a scale-free robust leadership structure. Furthermore, in realistic parameter ranges, facilitated by information exchange on the network, agents can generate a high degree of cooperation making the collective almost maximally efficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvL..92e8701A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvL..92e8701A"><span>Competition-<span class="hlt">Driven</span> Network <span class="hlt">Dynamics</span>: Emergence of a Scale-Free Leadership Structure and Collective Efficiency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anghel, M.; Toroczkai, Zoltán; Bassler, Kevin E.; Korniss, G.</p> <p>2004-02-01</p> <p>Using the minority game as a model for competition <span class="hlt">dynamics</span>, we investigate the effects of interagent communications across a network on the global <span class="hlt">evolution</span> of the game. Agent communication across this network leads to the formation of an influence network, which is <span class="hlt">dynamically</span> coupled to the <span class="hlt">evolution</span> of the game, and it is responsible for the information flow driving the agents' actions. We show that the influence network spontaneously develops hubs with a broad distribution of in-degrees, defining a scale-free robust leadership structure. Furthermore, in realistic parameter ranges, facilitated by information exchange on the network, agents can generate a high degree of cooperation making the collective almost maximally efficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AAS...22910302B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AAS...22910302B"><span>Exploring Quenching, Morphological Transformation and AGN-<span class="hlt">Driven</span> Winds with Simulations of Galaxy <span class="hlt">Evolution</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brennan, Ryan; CANDELS</p> <p>2017-01-01</p> <p>We present an examination of the spheroid growth and star formation quenching experienced by galaxies since z~3 by studying the <span class="hlt">evolution</span> with redshift of the quiescent and spheroid-dominated fractions of galaxies from the CANDELS and GAMA surveys. We compare these fractions with predictions from a semi-analytic model which includes prescriptions for bulge growth and AGN feedback due to mergers and disk instabilities. We then subdivide our population into the four quadrants of the specific star-formation rate (sSFR)-Sersic index plane. We find that the fraction of star forming disks declines steadily while the fraction of quiescent spheroids increases with cosmic time. The fraction of star-forming spheroids and quiescent disks are both non-negligible and remain nearly constant. Our model is qualitatively successful at reproducing these fractions, suggesting a plausible explanation for the observed correlations between star formation activity and galaxy structure.Next, we study the correlation of galaxy structural properties with their location relative to the star-formation rate-stellar mass correlation, or the star forming main sequence. We find that as we move from observed galaxies above the main sequence to those below it, we see a nearly monotonic trend towards higher median Sersic index, smaller radius, lower SFR density and higher stellar mass density. Our model again qualitatively reproduces these trends, supporting a picture in which bulges and black holes co-evolve and AGN feedback plays a critical role in galaxy quenching.Finally, we examine AGN-<span class="hlt">driven</span> winds in a suite of cosmological zoom simulations including a novel mechanical and radiation-<span class="hlt">driven</span> AGN feedback prescription and compare the gas cycle with a matched suite of zoom simulations that include only feedback from supernovae and young stars. We find that while stellar feedback can drive mass out of galaxies, it is unlikely to be able to keep the gas from re-accreting, whereas in our AGN runs it</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.U53C..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.U53C..04M"><span>Late Cenozoic Temporal <span class="hlt">Evolution</span> of North American <span class="hlt">Dynamic</span> Topography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moucha, R.; Forte, A. M.; Rowley, D. B.; Mitrovica, J. X.; Simmons, N. A.; Grand, S. P.</p> <p>2008-12-01</p> <p>The Farallon plate was completely overridden by the North American plate by mid-Cenozoic. Although the Farallon plate ceased to exist on the surface, it continues to have a significant tectonic impact on North America. At the present time, the subducted Farallon plate drives a large-scale thermal convective cell below the southern half of North America, where downward flow in the east is <span class="hlt">driven</span> by the dense Farallon slab and upward flow in the west is a combination of local, buoyancy-<span class="hlt">driven</span> hot upwelling and large-scale return flow. Herein, we will explore the geodynamic implications of this convective flow throughout the late Cenozoic by carrying out backward mantle flow simulations starting with present-day heterogeneity derived from a high resolution joint seismic-geodynamic tomography model (Simmons et al., 2007) that yields excellent fits to present day surface observables (e.g. <span class="hlt">dynamic</span> topography and the geoid). Our proposed temporal model of late Cenozoic North American mantle <span class="hlt">dynamics</span> brings together the uplift of the Colorado Plateau in the southwestern US and offers an explanation for present-day seismicity at the New Madrid seismic zone. Furthermore, we consider the impact of this model on inferences of eustatic sea level change from measurements at the New Jersey passive margin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT........98J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT........98J"><span><span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of small bodies in the Solar System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobson, Seth A.</p> <p>2012-05-01</p> <p>This thesis explores the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of small bodies in the Solar System. It focuses on the asteroid population but parts of the theory can be applied to other systems such as comets or Kuiper Belt objects. Small is a relative term that refers to bodies whose <span class="hlt">dynamics</span> can be significantly perturbed by non-gravitational forces and tidal torques on timescales less than their lifetimes (for instance the collisional timescale in the Main Belt asteroid population or the sun impact timescale for the near-Earth asteroid population). Non-gravitational torques such as the YORP effect can result in the active endogenous <span class="hlt">evolution</span> of asteroid systems; something that was not considered more than twenty years ago. This thesis is divided into three independent studies. The first explores the <span class="hlt">dynamics</span> of a binary systems immediately after formation from rotational fission. The rotational fission hypothesis states that a rotationally torqued asteroid will fission when the centrifugal accelerations across the body exceed gravitational attraction. Asteroids must have very little or no tensile strength for this to occur, and are often referred to as "rubble piles.'' A more complete description of the hypothesis and the ensuing <span class="hlt">dynamics</span> is provided there. From that study a framework of asteroid <span class="hlt">evolution</span> is assembled. It is determined that mass ratio is the most important factor for determining the outcome of a rotational fission event. Each observed binary morphology is tied to this evolutionary schema and the relevant timescales are assessed. In the second study, the role of non-gravitational and tidal torques in binary asteroid systems is explored. Understanding the competition between tides and the YORP effect provides insight into the relative abundances of the different binary morphologies and the effect of planetary flybys. The interplay between tides and the BYORP effect creates dramatic evolutionary pathways that lead to interesting end states including stranded</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988ApJ...335..914O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988ApJ...335..914O"><span>Time-dependent models of radiatively <span class="hlt">driven</span> stellar winds. I - Nonlinear <span class="hlt">evolution</span> of instabilities for a pure absorption model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Owocki, Stanley P.; Castor, John I.; Rybicki, George B.</p> <p>1988-12-01</p> <p>The authors describe results of numerical radiation-hydrodynamics simulations of the nonlinear <span class="hlt">evolution</span> of instabilities in radiatively <span class="hlt">driven</span> stellar winds. The wind is idealized as a spherically symmetric, isothermal flow <span class="hlt">driven</span> by pure absorption of stellar radiation in a fixed ensemble of spectral lines. The simulations indicate that there is a strong tendency for the unstable flow to form rather sharp rarefactions in which the highest speed material has very low density. The growth of wave perturbations thus remains nearly exponential well beyond the linear regime, until the waves are kinematically steepened into strong shocks. The strongest shocks here are reverse shocks that arise to decelerate high-speed, rarefied flow as it impacts slower material that has been compressed into dense shells. The subsequent wind <span class="hlt">evolution</span> shows a slow decay of the shocks and the gradual thermal decompression and interaction of the dense shells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARJ47008A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARJ47008A"><span>In silico <span class="hlt">evolution</span> of oscillatory <span class="hlt">dynamics</span> in biochemical networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ali, Md Zulfikar; Wingreen, Ned S.; Mukhopadhyay, Ranjan</p> <p>2015-03-01</p> <p>We are studying in silico <span class="hlt">evolution</span> of complex, oscillatory network <span class="hlt">dynamics</span> within the framework of a minimal mutational model of protein-protein interactions. In our model we consider two different types of proteins, kinase (activator) and phosphatase(inhibitor). In our model. each protein can either be phosphorylated(active) or unphospphorylated (inactive), represented by binary strings. Active proteins can modify their target based on the Michaelis-Menten kinetics of chemical equation. Reaction rate constants are directly related to sequence dependent protein-protein interaction energies. This model can be stuided for non-trivial behavior e.g. oscillations, chaos, multiple stable states. We focus here on biochemical oscillators; some questions we will address within our framework include how the oscillatory <span class="hlt">dynamics</span> depends on number of protein species, connectivity of the network, whether <span class="hlt">evolution</span> can readily converge on a stable oscillator if we start with random intitial parameters, neutral <span class="hlt">evolution</span> with additional protein components and general questions of robustness and evolavability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22092344','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22092344"><span><span class="hlt">DYNAMICAL</span> <span class="hlt">EVOLUTION</span> OF VISCOUS DISKS AROUND Be STARS. I. PHOTOMETRY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Haubois, X.; Carciofi, A. C.; Rivinius, Th.; Okazaki, A. T.; Bjorkman, J. E.</p> <p>2012-09-10</p> <p>Be stars possess gaseous circumstellar disks that modify in many ways the spectrum of the central B star. Furthermore, they exhibit variability at several timescales and for a large number of observables. Putting the pieces together of this <span class="hlt">dynamical</span> behavior is not an easy task and requires a detailed understanding of the physical processes that control the temporal <span class="hlt">evolution</span> of the observables. There is an increasing body of evidence that suggests that Be disks are well described by standard {alpha}-disk theory. This paper is the first of a series that aims at studying the possibility of inferring several disk and stellar parameters through the follow-up of various observables. Here we study the temporal <span class="hlt">evolution</span> of the disk density for different <span class="hlt">dynamical</span> scenarios, including the disk build-up as a result of a long and steady mass injection from the star, the disk dissipation that occurs after mass injection is turned off, as well as scenarios in which active periods are followed by periods of quiescence. For those scenarios, we investigate the temporal <span class="hlt">evolution</span> of continuum photometric observables using a three-dimensional non-LTE radiative transfer code. We show that light curves for different wavelengths are specific of a mass loss history, inclination angle, and {alpha} viscosity parameter. The diagnostic potential of those light curves is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMMM..409..155S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMMM..409..155S"><span>Asymmetric <span class="hlt">driven</span> <span class="hlt">dynamics</span> of Dzyaloshinskii domain walls in ultrathin ferromagnetic strips with perpendicular magnetic anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez-Tejerina, L.; Alejos, Ó.; Martínez, E.; Muñoz, J. M.</p> <p>2016-07-01</p> <p>The <span class="hlt">dynamics</span> of domain walls in ultrathin ferromagnetic strips with perpendicular magnetic anisotropy is studied from both numerical and analytical micromagnetics. The influence of a moderate interfacial Dzyaloshinskii-Moriya interaction associated to a bi-layer strip arrangement has been considered, giving rise to the formation of Dzyaloshinskii domain walls. Such walls possess under equilibrium conditions an inner magnetization structure defined by a certain orientation angle that make them to be considered as intermediate configurations between Bloch and Néel walls. Two different <span class="hlt">dynamics</span> are considered, a field-<span class="hlt">driven</span> and a current-<span class="hlt">driven</span> <span class="hlt">dynamics</span>, in particular, the one promoted by the spin torque due to the spin-Hall effect. Results show an inherent asymmetry associated with the rotation of the domain wall magnetization orientation before reaching the stationary regime, characterized by a constant terminal speed. For a certain initial DW magnetization orientation at rest, the rotation determines whether the reorientation of the DW magnetization prior to reach stationary motion is smooth or abrupt. This asymmetry affects the DW motion, which can even reverse for a short period of time. Additionally, it is found that the terminal speed in the case of the current-<span class="hlt">driven</span> <span class="hlt">dynamics</span> may depend on either the initial DW magnetization orientation at rest or the sign of the longitudinally injected current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94f4302Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94f4302Y"><span>Scaling in <span class="hlt">driven</span> <span class="hlt">dynamics</span> starting in the vicinity of a quantum critical point</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yin, Shuai; Lo, Chung-Yu; Chen, Pochung</p> <p>2016-08-01</p> <p><span class="hlt">Driven</span> <span class="hlt">dynamics</span> across a quantum critical point is usually described by the Kibble-Zurek scaling. Although the original Kibble-Zurek scaling requires an adiabatic initial state, it has been shown that scaling behaviors exist even when the <span class="hlt">driven</span> <span class="hlt">dynamics</span> is triggered from a thermal equilibrium state exactly at the critical point, in spite of the breakdown of the initial adiabaticity. In this paper, we show that the existence of the scaling behavior can be generalized to the case of the initial state being a thermal equilibrium state near the critical point. We propose a scaling theory in which the initial parameters are included as additional scaling variables due to the breakdown of the initial adiabaticity. In particular, we demonstrate that for the <span class="hlt">driven</span> critical <span class="hlt">dynamics</span> in a closed system, the nontrivial thermal effects are closely related to the initial distance to the critical point. We numerically confirm the scaling theory by simulating the real-time <span class="hlt">dynamics</span> of the one-dimensional quantum Ising model at both zero and finite temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95d2902Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95d2902Y"><span><span class="hlt">Dynamic</span> phases, clustering, and chain formation for <span class="hlt">driven</span> disk systems in the presence of quenched disorder</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Y.; McDermott, D.; Reichhardt, C. J. Olson; Reichhardt, C.</p> <p>2017-04-01</p> <p>We numerically examine the <span class="hlt">dynamic</span> phases and pattern formation of two-dimensional monodisperse repulsive disks <span class="hlt">driven</span> over random quenched disorder. We show that there is a series of distinct <span class="hlt">dynamic</span> regimes as a function of increasing drive, including a clogged or pile-up phase near depinning, a homogeneous disordered flow state, and a <span class="hlt">dynamically</span> phase separated regime consisting of high-density crystalline regions surrounded by a low density of disordered disks. At the highest drives the disks arrange into one-dimensional moving chains. The phase separated regime has parallels with the phase separation observed in active matter systems, but arises from a distinct mechanism consisting of the combination of nonequilibrium fluctuations with density-dependent mobility. We discuss the pronounced differences between this system and previous studies of <span class="hlt">driven</span> particles with longer-range repulsive interactions moving over random substrates, such as superconducting vortices or electron crystals, where <span class="hlt">dynamical</span> phase separation and distinct one-dimensional moving chains are not observed. Our results should be generic to a broad class of systems in which the particle-particle interactions are short ranged, such as sterically interacting colloids or Yukawa particles with strong screening <span class="hlt">driven</span> over random pinning arrays, superconducting vortices in the limit of small penetration depths, or quasi-two-dimensional granular matter flowing over rough landscapes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23004812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23004812"><span>Electromagnetic oscillations in a <span class="hlt">driven</span> nonlinear resonator: a description of complex nonlinear <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Petrov, E Yu; Kudrin, A V</p> <p>2012-05-01</p> <p>Many intriguing properties of <span class="hlt">driven</span> nonlinear resonators, including the appearance of chaos, are very important for understanding the universal features of nonlinear <span class="hlt">dynamical</span> systems and can have great practical significance. We consider a cylindrical cavity resonator <span class="hlt">driven</span> by an alternating voltage and filled with a nonlinear nondispersive medium. It is assumed that the medium lacks a center of inversion and the dependence of the electric displacement on the electric field can be approximated by an exponential function. We show that the Maxwell equations are integrated exactly in this case and the field components in the cavity are represented in terms of implicit functions of special form. The <span class="hlt">driven</span> electromagnetic oscillations in the cavity are found to display very interesting temporal behavior and their Fourier spectra contain singular continuous components. This is a demonstration of the existence of a singular continuous (fractal) spectrum in an exactly integrable system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016diga.confE..45J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016diga.confE..45J"><span>The Chemo-<span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> Of The Milky Way Disc</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Just, Andreas</p> <p>2016-09-01</p> <p>The kinematic properties of the stellar subpopulations in the Milky Way disc are linked to their radial and vertical scale lengths. On the other hand, element abundances and abundance ratios are a signature of the <span class="hlt">evolution</span> history of the stellar components. Large spectroscopic surveys like SEGUE, RAVE, APOGEE and Gaia-ESO, combined with proper motions and distances (ultimately from the Gaia mission starting with the TEGAS data release in Sept. 2016) are linking the kinematic and chemical properties and provide powerful tests of any Milky Way model. Our self-consistent local disc model (the JJ-model) with the star formation history (SFR), the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> (AVR) and stellar <span class="hlt">evolution</span> as ingredients reproduces the local kinematics of main sequence stars, SDSS star counts towards the North Galactic Pole, and the metallicity distribution of G dwarfs very well. From local star counts the IMF is determined and we derive the age-metallicity relation (AMR) and the gas infall rate using the alpha-element and iron distributions. Radially extended data from APOGEE and other surveys allow an insight in the inside-out growth of the Milky Way thin disc. Correlations of radial gradients in density, kinematics, abundances, and age are crucial to constrain the <span class="hlt">evolution</span> scenario of the Milky Way disc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJWC.10104004D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJWC.10104004D"><span>Star-planet interactions and <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of exoplanetary systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damiani, Cilia</p> <p>2015-09-01</p> <p>The <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of planetary systems, after the evaporation of the accretion disk, is the result of the competition between tidal dissipation and the net angular momentum loss of the system. The description of the diversity of orbital configurations, and correlations between parameters of the observed system (e.g. in the case of hot jupiters), is still limited by our understanding of the transport of angular momentum within the stars, and its effective loss by magnetic braking. After discussing the challenges of modelling tidal <span class="hlt">evolution</span> for exoplanets, I will review recent results showing the importance of tidal interactions to test models of planetary formation. This kind of studies rely on the determination of stellar radii, masses and ages. Major advances will thus be obtained with the results of the PLATO 2.0 mission, selected as the next M-class mission of ESA's Cosmic Vision plan, that will allow the complete characterisation of host stars using asteroseismology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20083505','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20083505"><span>Star clusters as laboratories for stellar and <span class="hlt">dynamical</span> <span class="hlt">evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalirai, Jason S; Richer, Harvey B</p> <p>2010-02-28</p> <p>Open and globular star clusters have served as benchmarks for the study of stellar <span class="hlt">evolution</span> owing to their supposed nature as simple stellar populations of the same age and metallicity. After a brief review of some of the pioneering work that established the importance of imaging stars in these systems, we focus on several recent studies that have challenged our fundamental picture of star clusters. These new studies indicate that star clusters can very well harbour multiple stellar populations, possibly formed through self-enrichment processes from the first-generation stars that evolved through post-main-sequence evolutionary phases. Correctly interpreting stellar <span class="hlt">evolution</span> in such systems is tied to our understanding of both chemical-enrichment mechanisms, including stellar mass loss along the giant branches, and the <span class="hlt">dynamical</span> state of the cluster. We illustrate recent imaging, spectroscopic and theoretical studies that have begun to shed new light on the evolutionary processes that occur within star clusters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013949','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013949"><span>Analysis of planetary <span class="hlt">evolution</span> with emphasis on differentiation and <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kaula, William M.; Newman, William I.</p> <p>1987-01-01</p> <p>In order to address the early stages of nebula <span class="hlt">evolution</span>, a three-dimensional collapse code which includes not only hydrodynamics and radiative transfer, but also the effects of ionization and, possibly, magnetic fields is being addressed. As part of the examination of solar system <span class="hlt">evolution</span>, an N-body code was developed which describes the latter stages of planet formation from the accretion of planetesimals. To test the code for accuracy and run-time efficiency, and to develop a stronger theoretical foundation, problems were studied in orbital <span class="hlt">dynamics</span>. A regional analysis of the correlation in the gravity and topography fields of Venus was performed in order to determine the small and intermediate scale subsurface structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950034794&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Devolution%2Btheory','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950034794&hterms=evolution+theory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Devolution%2Btheory"><span>The <span class="hlt">dynamical</span> and radiative <span class="hlt">evolution</span> of clumpy supernova ejecta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, M. C.; Jones, T. W.; Rudnick, L.; Tregillis, I. L.; Kang, Hyesung</p> <p>1994-01-01</p> <p>Numerical simulations describing the <span class="hlt">dynamical</span> and radiative <span class="hlt">evolution</span> of clumpy supernova ejecta are compared with observations of optical and radio emission knots in supernova remnant (SNR) Cassiopeia A. Three major phases are identified in the <span class="hlt">evolution</span> of clumpy ejecta: a bow-shock phase, an instability phase, and a dispersal phase. The phenomenological and radiative signatures of each phase are discussed and compared with multi-epoch measurements of small-scale features in Cas A. Good correspondence is found between theory and observations. Both support the premise that compact radio emission features are controlled more by magnetic field amplification triggered in the instability phase than by in situ acceleration of new relativistic particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28035001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28035001"><span>Structural and Molecular Evidence Suggesting Coronavirus-<span class="hlt">driven</span> <span class="hlt">Evolution</span> of Mouse Receptor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peng, Guiqing; Yang, Yang; Pasquarella, Joseph R; Xu, Liqing; Qian, Zhaohui; Holmes, Kathryn V; Li, Fang</p> <p>2017-02-10</p> <p>Hosts and pathogens are locked in an evolutionary arms race. To infect mice, mouse hepatitis coronavirus (MHV) has evolved to recognize mouse CEACAM1a (mCEACAM1a) as its receptor. To elude MHV infections, mice may have evolved a variant allele from the Ceacam1a gene, called Ceacam1b, producing mCEACAM1b, which is a much poorer MHV receptor than mCEACAM1a. Previous studies showed that sequence differences between mCEACAM1a and mCEACAM1b in a critical MHV-binding CC' loop partially account for the low receptor activity of mCEACAM1b, but detailed structural and molecular mechanisms for the differential MHV receptor activities of mCEACAM1a and mCEACAM1b remained elusive. Here we have determined the crystal structure of mCEACAM1b and identified the structural differences and additional residue differences between mCEACAM1a and mCEACAM1b that affect MHV binding and entry. These differences include conformational alterations of the CC' loop as well as residue variations in other MHV-binding regions, including β-strands C' and C'' and loop C'C''. Using pseudovirus entry and protein-protein binding assays, we show that substituting the structural and residue features from mCEACAM1b into mCEACAM1a reduced the viral receptor activity of mCEACAM1a, whereas substituting the reverse changes from mCEACAM1a into mCEACAM1b increased the viral receptor activity of mCEACAM1b. These results elucidate the detailed molecular mechanism for how mice may have kept pace in the evolutionary arms race with MHV by undergoing structural and residue changes in the MHV receptor, providing insight into this possible example of pathogen-<span class="hlt">driven</span> <span class="hlt">evolution</span> of a host receptor protein.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.443L..79V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.443L..79V"><span>Kinematical fingerprints of star cluster early <span class="hlt">dynamical</span> <span class="hlt">evolution</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vesperini, Enrico; Varri, Anna Lisa; McMillan, Stephen L. W.; Zepf, Stephen E.</p> <p>2014-09-01</p> <p>We study the effects of the external tidal field on the violent relaxation phase of star clusters <span class="hlt">dynamical</span> <span class="hlt">evolution</span>, with particular attention to the kinematical properties of the equilibrium configurations emerging at the end of this phase. We show that star clusters undergoing the process of violent relaxation in the tidal field of their host galaxy can acquire significant internal differential rotation and are characterized by a distinctive radial variation of the velocity anisotropy. These kinematical properties are the result of the symmetry breaking introduced by the external tidal field in the collapse phase and of the action of the Coriolis force on the orbit of the stars. The resulting equilibrium configurations are characterized by differential rotation, with a peak located between one and two half-mass radii. As for the anisotropy, similar to clusters evolving in isolation, the systems explored in this Letter are characterized by an inner isotropic core, followed by a region of increasing radial anisotropy. However, for systems evolving in an external tidal field, the degree of radial anisotropy reaches a maximum in the cluster intermediate regions and then progressively decreases, with the cluster outermost regions being characterized by isotropy or a mild tangential anisotropy. Young or old but less-relaxed <span class="hlt">dynamically</span> young star clusters may keep memory of these kinematical fingerprints of their early <span class="hlt">dynamical</span> <span class="hlt">evolution</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ebi..conf..2.8H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ebi..conf..2.8H"><span><span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> and Migration of Circumbinary Planets and Their Habitability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haghighipour, N.; Kley, W.; Kaltenegger, L.</p> <p>2014-03-01</p> <p>The recent success of the Kepler space telescope in detecting several circumbinary planets has raised many questions on the formation, <span class="hlt">evolution</span>, and habitability of these objects. The detection of multiple transists in these systems points to the co-planarity of the orbital planes of the binary and planet(s), giving strong support to the idea that these planets formed in circumbinary protoplanetary disks. The proximity of some of these planets to the boundary of orbital instability around the binary suggests an evolutionary scenario in which planets form at larger distances and migrate to their present orbits. How such planets form, and how the binarity of the system affects their formation and subsequent migration are among fundamental questions that require deep understanding of the growth and <span class="hlt">evolution</span> of solid objects in circumbinary environments, and their <span class="hlt">dynamical</span> <span class="hlt">evolution</span>. Given that several of the currently known circumbinary planets are in the habitable zone, the habitability of planet-hosting binary systems has also become an important topic of research. We have carried out extensive analysis of the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of planets in a circumbinary disk, and their habitability. The results of our hydrodynamical simulations indicate that planets migrate inward and settle near the inner edge of the circumbinary disk (the stability limit), in good agreement with the results of the observations. Our model of habitability takes into account, self-consistently, the contribution of each star to the total flux received at the top of the planet's atmosphere, producing accurate maps of the HZ of the system. We present the results of our studies and discuss their applications to the formation and habitability of the currently known Kepler circumbinary planets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007NJPh....9..108D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007NJPh....9..108D"><span>2D pattern <span class="hlt">evolution</span> constrained by complex network <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>da Rocha, L. E. C.; Costa, L. da F.</p> <p>2007-03-01</p> <p>Complex networks have established themselves in recent years as being particularly suitable and flexible for representing and modelling several complex natural and artificial systems. In the same time in which the structural intricacies of such networks are being revealed and understood, efforts have also been directed at investigating how such connectivity properties define and constrain the <span class="hlt">dynamics</span> of systems unfolding on such structures. However, less attention has been focused on hybrid systems, i.e. involving more than one type of network and/or <span class="hlt">dynamics</span>. Several real systems present such an organization, e.g. the <span class="hlt">dynamics</span> of a disease coexisting with the <span class="hlt">dynamics</span> of the immune system. The current paper investigates a specific system involving diffusive (linear and nonlinear) <span class="hlt">dynamics</span> taking place in a regular network while interacting with a complex network of defensive agents following Erdös Rényi (ER) and Barabási Albert (BA) graph models with moveable nodes. More specifically, the complex network is expected to control, and if possible, to extinguish the diffusion of some given unwanted process (e.g. fire, oil spilling, pest dissemination, and virus or bacteria reproduction during an infection). Two types of pattern <span class="hlt">evolution</span> are considered: Fick and Gray Scott. The nodes of the defensive network then interact with the diffusing patterns and communicate between themselves in order to control the diffusion. The main findings include the identification of higher efficiency for the BA control networks and the presence of relapses in the case of the ER model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhRvE..82f6204G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhRvE..82f6204G"><span>Noisy scattering <span class="hlt">dynamics</span> in the randomly <span class="hlt">driven</span> Hénon-Heiles oscillator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gan, Chunbiao; Yang, Shixi; Lei, Hua</p> <p>2010-12-01</p> <p>Noisy scattering <span class="hlt">dynamics</span> in the randomly <span class="hlt">driven</span> Hénon-Heiles oscillator is investigated when the energy is above the threshold to permit particles to escape from the scattering region. First, some basic simulation procedures are briefly introduced and the fractal exit basins appear to be robust when the bounded noisy excitation is imposed on the oscillator. Second, several key fractal characteristics of the sample basin boundaries, such as the delay-time function and the uncertainty dimension, are estimated from which this oscillator is found to be structurally unstable against the bounded noisy excitation. Moreover, the stable and unstable manifolds of some sample chaotic invariant sets are estimated and illustrated in a special two-dimensional Poincaré section. Lastly, several previous methods are developed to identify three arbitrarily chosen noisy scattering time series of the randomly <span class="hlt">driven</span> Hénon-Heiles oscillator, from which the quasiperiodic-dominant and the chaotic-dominant <span class="hlt">dynamical</span> behaviors are distinguished.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JSP...144..813L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JSP...144..813L"><span>Asymptotic <span class="hlt">Dynamics</span> of Self-<span class="hlt">driven</span> Vehicles in a Closed Boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Chi-Lun; Huang, Chia-Ling</p> <p>2011-08-01</p> <p>We study the asymptotic <span class="hlt">dynamics</span> of self-<span class="hlt">driven</span> vehicles in a loop using a car-following model with the consideration of volume exclusions. In particular, we derive the <span class="hlt">dynamical</span> steady states for the single-cluster case and obtain the corresponding fundamental diagrams, exhibiting two branches representative of entering and leaving the jam, respectively. By simulations we find that the speed average over all vehicles eventually reaches the same value, regardless of final clustering states. The autocorrelation functions for overall speed average and single-vehicle speed are studied, each revealing a unique time scale. We also discuss the role of noises in vehicular accelerations. Based on our observations we give trial definitions about the degree of chaoticity for general self-<span class="hlt">driven</span> many-body systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NJPh...18a2001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NJPh...18a2001D"><span>Shortcuts to adiabaticity: suppression of pair production in <span class="hlt">driven</span> Dirac <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deffner, Sebastian</p> <p>2016-01-01</p> <p>Achieving effectively adiabatic <span class="hlt">dynamics</span> in finite time is a ubiquitous goal in virtually all areas of modern physics. So-called shortcuts to adiabaticity refer to a set of methods and techniques that allow us to produce in a short time the same final state that would result from an adiabatic, infinitely slow process. In this paper we generalize one of these methods—the fast-forward technique—to <span class="hlt">driven</span> Dirac <span class="hlt">dynamics</span>. As our main result we find that shortcuts to adiabaticity for the (1+1)-dimensional Dirac equation are facilitated by a combination of both scalar and pseudoscalar potentials. Our findings are illustrated for two analytically solvable examples, namely charged particles <span class="hlt">driven</span> in spatially homogeneous and linear vector fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1238987-shortcuts-adiabaticity-suppression-pair-production-driven-dirac-dynamics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1238987-shortcuts-adiabaticity-suppression-pair-production-driven-dirac-dynamics"><span>Shortcuts to adiabaticity. Suppression of pair production in <span class="hlt">driven</span> Dirac <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Deffner, Sebastian</p> <p>2015-12-21</p> <p>By achieving effectively adiabatic <span class="hlt">dynamics</span> in finite time, we have found that it is our ubiquitous goal in virtually all areas of modern physics. So-called shortcuts to adiabaticity refer to a set of methods and techniques that allow us to produce in a short time the same final state that would result from an adiabatic, infinitely slow process. In this paper we generalize one of these methods—the fast-forward technique—to <span class="hlt">driven</span> Dirac <span class="hlt">dynamics</span>. We find that our main result shortcuts to adiabaticity for the (1+1)-dimensional Dirac equation are facilitated by a combination of both scalar and pseudoscalar potentials. Our findings aremore » illustrated for two analytically solvable examples, namely charged particles <span class="hlt">driven</span> in spatially homogeneous and linear vector fields.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24055617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24055617"><span>On learning <span class="hlt">dynamics</span> underlying the <span class="hlt">evolution</span> of learning rules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dridi, Slimane; Lehmann, Laurent</p> <p>2014-02-01</p> <p>In order to understand the development of non-genetically encoded actions during an animal's lifespan, it is necessary to analyze the <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of learning rules producing behavior. Owing to the intrinsic stochastic and frequency-dependent nature of learning <span class="hlt">dynamics</span>, these rules are often studied in evolutionary biology via agent-based computer simulations. In this paper, we show that stochastic approximation theory can help to qualitatively understand learning <span class="hlt">dynamics</span> and formulate analytical models for the <span class="hlt">evolution</span> of learning rules. We consider a population of individuals repeatedly interacting during their lifespan, and where the stage game faced by the individuals fluctuates according to an environmental stochastic process. Individuals adjust their behavioral actions according to learning rules belonging to the class of experience-weighted attraction learning mechanisms, which includes standard reinforcement and Bayesian learning as special cases. We use stochastic approximation theory in order to derive differential equations governing action play probabilities, which turn out to have qualitative features of mutator-selection equations. We then perform agent-based simulations to find the conditions where the deterministic approximation is closest to the original stochastic learning process for standard 2-action 2-player fluctuating games, where interaction between learning rules and preference reversal may occur. Finally, we analyze a simplified model for the <span class="hlt">evolution</span> of learning in a producer-scrounger game, which shows that the exploration rate can interact in a non-intuitive way with other features of co-evolving learning rules. Overall, our analyses illustrate the usefulness of applying stochastic approximation theory in the study of animal learning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24146882','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24146882"><span><span class="hlt">Dynamics</span> of green Sahara periods and their role in hominin <span class="hlt">evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Larrasoaña, Juan C; Roberts, Andrew P; Rohling, Eelco J</p> <p>2013-01-01</p> <p>Astronomically forced insolation changes have <span class="hlt">driven</span> monsoon <span class="hlt">dynamics</span> and recurrent humid episodes in North Africa, resulting in green Sahara Periods (GSPs) with savannah expansion throughout most of the desert. Despite their potential for expanding the area of prime hominin habitats and favouring out-of-Africa dispersals, GSPs have not been incorporated into the narrative of hominin <span class="hlt">evolution</span> due to poor knowledge of their timing, <span class="hlt">dynamics</span> and landscape composition at evolutionary timescales. We present a compilation of continental and marine paleoenvironmental records from within and around North Africa, which enables identification of over 230 GSPs within the last 8 million years. By combining the main climatological determinants of woody cover in tropical Africa with paleoenvironmental and paleoclimatic data for representative (Holocene and Eemian) GSPs, we estimate precipitation regimes and habitat distributions during GSPs. Their chronology is consistent with the ages of Saharan archeological and fossil hominin sites. Each GSP took 2-3 kyr to develop, peaked over 4-8 kyr, biogeographically connected the African tropics to African and Eurasian mid latitudes, and ended within 2-3 kyr, which resulted in rapid habitat fragmentation. We argue that the well-dated succession of GSPs presented here may have played an important role in migration and <span class="hlt">evolution</span> of hominins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3797788','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3797788"><span><span class="hlt">Dynamics</span> of Green Sahara Periods and Their Role in Hominin <span class="hlt">Evolution</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Larrasoaña, Juan C.; Roberts, Andrew P.; Rohling, Eelco J.</p> <p>2013-01-01</p> <p>Astronomically forced insolation changes have <span class="hlt">driven</span> monsoon <span class="hlt">dynamics</span> and recurrent humid episodes in North Africa, resulting in green Sahara Periods (GSPs) with savannah expansion throughout most of the desert. Despite their potential for expanding the area of prime hominin habitats and favouring out-of-Africa dispersals, GSPs have not been incorporated into the narrative of hominin <span class="hlt">evolution</span> due to poor knowledge of their timing, <span class="hlt">dynamics</span> and landscape composition at evolutionary timescales. We present a compilation of continental and marine paleoenvironmental records from within and around North Africa, which enables identification of over 230 GSPs within the last 8 million years. By combining the main climatological determinants of woody cover in tropical Africa with paleoenvironmental and paleoclimatic data for representative (Holocene and Eemian) GSPs, we estimate precipitation regimes and habitat distributions during GSPs. Their chronology is consistent with the ages of Saharan archeological and fossil hominin sites. Each GSP took 2–3 kyr to develop, peaked over 4–8 kyr, biogeographically connected the African tropics to African and Eurasian mid latitudes, and ended within 2–3 kyr, which resulted in rapid habitat fragmentation. We argue that the well-dated succession of GSPs presented here may have played an important role in migration and <span class="hlt">evolution</span> of hominins. PMID:24146882</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010PhRvL.105z8101W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010PhRvL.105z8101W"><span><span class="hlt">Dynamical</span> Phase Transition in a Model for <span class="hlt">Evolution</span> with Migration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Waclaw, Bartłomiej; Allen, Rosalind J.; Evans, Martin R.</p> <p>2010-12-01</p> <p>We study a simple quasispecies model for <span class="hlt">evolution</span> in two different habitats, with different fitness landscapes, coupled through one-way migration. Our key finding is a <span class="hlt">dynamical</span> phase transition at a critical value of the migration rate, at which the time to reach the steady state diverges. The genetic composition of the population is qualitatively different above and below the transition. Using results from localization theory, we show that the critical migration rate may be very small—demonstrating that evolutionary outcomes can be very sensitive to even a small amount of migration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMMM..424..238D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMMM..424..238D"><span>Nonstationary current-<span class="hlt">driven</span> <span class="hlt">dynamics</span> of vortex domain walls in films with in-plane anisotropy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubovik, M. N.; Filippov, B. N.; Korzunin, L. G.</p> <p>2017-02-01</p> <p>Micromagnetic simulation of a current-<span class="hlt">driven</span> vortex domain wall motion in a film with in-plane anisotropy was carried out. The current density values j >jc were considered corresponding to the nonstationary motion, with the domain wall structure <span class="hlt">dynamic</span> transformation occurred. A nonlinear dependence of the jc value on the film thickness was obtained. The nonstationary motion regime existence restricted the possibility to increase the domain wall velocity by increasing j and decreasing the damping parameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/902319','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/902319"><span>High Brightness, Laser-<span class="hlt">Driven</span> X-ray Source for Nanoscale Metrology and Femtosecond <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Siders, C W; Crane, J K; Semenov, V; Betts, S; Kozioziemski, B; Wharton, K; Wilks, S; Barbee, T; Stuart, B; Kim, D E; An, J; Barty, C</p> <p>2007-02-26</p> <p>This project developed and demonstrated a new, bright, ultrafast x-ray source based upon laser-<span class="hlt">driven</span> K-alpha generation, which can produce an x-ray flux 10 to 100 times greater than current microfocus x-ray tubes. The short-pulse (sub-picosecond) duration of this x-ray source also makes it ideal for observing time-resolved <span class="hlt">dynamics</span> of atomic motion in solids and thin films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DPPCO5006L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPCO5006L"><span>Structure and <span class="hlt">dynamics</span> of plasma interfaces in laser-<span class="hlt">driven</span> hohlraums</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, C. K.; Sio, H.; Frenje, J. A.; Séguin, F. H.; Birkel, A.; Petrasso, R. D.; Wilks, S. C.; Amendt, P. A.; Remington, B. A.; Masson-Laborde, P.-E.; Laffite, S.; Tassin, V.; Betti, R.; Sanster, T. C.; Fitzsimmons, P.; Farrell, M.</p> <p>2016-10-01</p> <p>Understanding the structure and <span class="hlt">dynamics</span> of plasma interfaces in laser-<span class="hlt">driven</span> hohlraums is important because of their potential effects on capsule implosion <span class="hlt">dynamics</span>. To that end, a series of experiments was performed to explore critical aspects of the hohlraum environment, with particular emphasis on the role of self-generated spontaneous electric and magnetic fields at plasma interfaces, including the interface between fill-gas and Au-blowoff. The charged fusion products (3-MeV DD protons and 14.7-MeV D3He protons generated in shock-<span class="hlt">driven</span>, D3He filled backlighter capsule) pass through the subject hohlraum and form images on CR-39 nuclear track detectors, providing critical information. Important physics topics, including ion diffusive mix and Rayleigh-Taylor instabilities, will be studied to illuminate ion kinetic <span class="hlt">dynamics</span> and hydrodynamic instability at plasma interfaces in laser-<span class="hlt">driven</span> hohlraums. This work was supported in part by LLE, the U.S. DoE (NNSA, NLUF) and LLNL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/12721','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/12721"><span>The Prospects for High-Yield ICF with a Z-Pinch <span class="hlt">Driven</span> <span class="hlt">Dynamic</span> Hohlraum</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>CHANDLER, GORDON A.; CHRIEN, R.; COOPER, GARY WAYNE; DERZON, MARK S.; DOUGLAS, MELISSA R.; HEBRON, DAVID E.; LASH, JOEL S.; LEEPER, RAMON J.; MATZEN, M. KEITH; MEHLHORN, THOMAS A.; NASH, THOMAS J.; OLSON, RICHARD E.; PETERSON, D.L.; RUIZ, CARLOS L.; SANFORD, THOMAS W. L.; SLUTZ, STEPHEN A.</p> <p>1999-09-07</p> <p>Recent success with the Sandia Z machine has renewed interest in utilizing fast z-pinenes for ICF. One promising concept places the ICF capsule internal to the imploding z-pinch. At machine parameters relevant to achieving high yield, the imploding z-pinch mass has sufficient opacity to trap radiation giving rise to a <span class="hlt">dynamic</span> hohlraum. The concept utilizes a 12 MJ, 54 MA z-pinch driver producing a capsule drive temperature exceeding 300 eV to realize a 550 MJ thermonuclear yield. They present the current high-yield design and its development that supports high-yield ICF with a z-pinch <span class="hlt">driven</span> <span class="hlt">dynamic</span> hohlraum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARB43011P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARB43011P"><span><span class="hlt">Dynamic</span> structural network <span class="hlt">evolution</span> in compressed granular systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Papadopoulos, Lia; Puckett, James; Daniels, Karen; Bassett, Danielle</p> <p></p> <p>The heterogeneous <span class="hlt">dynamic</span> behavior of granular packings under shear or compression is not well-understood. In this study, we use novel techniques from network science to investigate the structural <span class="hlt">evolution</span> that occurs in compressed granular systems. Specifically, we treat particles as network nodes, and pressure-dependent forces between particles as layer-specific network edges. Then, we use a generalization of community detection methods to multilayer networks, and develop quantitative measures that characterize changes in the architecture of the force network as a function of pressure. We observe that branchlike domains reminiscent of force chains evolve differentially as pressure is applied: topological characteristics of these domains at rest predict their coalescence or dispersion under pressure. Our methods allow us to study the <span class="hlt">dynamics</span> of mesoscale structure in granular systems, and provide a direct way to compare data from systems under different external conditions or with different physical makeup.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28551106','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28551106"><span><span class="hlt">Evolution</span> in Mind: Evolutionary <span class="hlt">Dynamics</span>, Cognitive Processes, and Bayesian Inference.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suchow, Jordan W; Bourgin, David D; Griffiths, Thomas L</p> <p>2017-07-01</p> <p>Evolutionary theory describes the <span class="hlt">dynamics</span> of population change in settings affected by reproduction, selection, mutation, and drift. In the context of human cognition, evolutionary theory is most often invoked to explain the origins of capacities such as language, metacognition, and spatial reasoning, framing them as functional adaptations to an ancestral environment. However, evolutionary theory is useful for understanding the mind in a second way: as a mathematical framework for describing evolving populations of thoughts, ideas, and memories within a single mind. In fact, deep correspondences exist between the mathematics of <span class="hlt">evolution</span> and of learning, with perhaps the deepest being an equivalence between certain evolutionary <span class="hlt">dynamics</span> and Bayesian inference. This equivalence permits reinterpretation of evolutionary processes as algorithms for Bayesian inference and has relevance for understanding diverse cognitive capacities, including memory and creativity. Copyright © 2017 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21247148','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21247148"><span>Formation and <span class="hlt">evolution</span> <span class="hlt">dynamics</span> of bipolarons in conjugated polymers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Di, B; Meng, Y; Wang, Y D; Liu, X J; An, Z</p> <p>2011-02-10</p> <p>Combining the one-dimensional tight-binding Su-Schrieffer-Heeger (SSH) model and the extended Hubbard model (EHM), we analyze the scattering and combination in conjugated polymers of two polarons with the same charges and parallel or antiparallel spins using a nonadiabatic <span class="hlt">evolution</span> method. Results show that collisions between the two same charge polarons with parallel spin are essentially elastic due to strong Pauli repulsion, whereas the two same charge polarons with antiparallel spins can combine into a singlet bipolaronic state. The <span class="hlt">dynamics</span> of bipolarons on two coupled polymer chains and at the interface of a polymer/polymer heterojunction are discussed in detail. This knowledge will serve to understand the <span class="hlt">dynamics</span> of the system when many polarons are created in the system, e.g., by electroluminescence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.tmp...85A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.tmp...85A"><span>On the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the Orion Trapezium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Allen, Christine.; Costero, Rafael; Ruelas-Mayorga, Alex; Sánchez, L. J.</p> <p>2017-01-01</p> <p>We discuss recent observational data on the transverse and radial velocities, as well as on the masses of the main components of the Orion Trapezium. Based on the most reliable values of these quantities we study the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of ensembles of multiple systems mimicking the Orion Trapezium. To this end we conduct numerical N -body integrations using the observed masses, planar positions and velocities, radial velocities, and random line-of-sight (z) positions for all components. We include perturbations in these quantities compatible with the observational errors. We find the <span class="hlt">dynamical</span> lifetimes of such systems to be quite short, of the order of 10 to 50 thousand years. The end result of the simulations is usually a tight binary, or sometimes a hierarchical triple. The properties of the evolved systems are studied at different values of the crossing times. The frequency distributions of the major semiaxes and eccentricities of the resulting binaries are discussed and compared with observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT........88M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT........88M"><span>The <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Stellar-Mass Black Holes in Dense Star Clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morscher, Maggie</p> <p></p> <p> Solar masses. Birth kicks from supernova explosions may eject some black holes from their birth clusters, but most should be retained initially. Using our Monte Carlo code, we have investigated the long-term <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of globular clusters containing large numbers of stellar black holes. Our study is the first to explore in detail the <span class="hlt">dynamics</span> of BHs in clusters through a large number of realistic simulations covering a wide range of initial conditions (cluster masses from 105 -- 106 Solar masses, as well as variation in other key parameters, such as the virial radius, central concentration, and metallicity), that also includes all the required physics. In almost all of our models we find that significant numbers of black holes (up to about a 1000) are retained all the way to the present. This is in contrast to previous theoretical expectations that most black holes should be ejected <span class="hlt">dynamically</span> within a few Gyr. The main reason for this difference is that core collapse <span class="hlt">driven</span> by black holes (through the Spitzer "mass segregation instability'') is easily reverted through three-body processes, and involves only a small number of the most massive black holes, while lower-mass black holes remain well-mixed with ordinary stars far from the central cusp. Thus the rapid segregation of stellar black holes does not lead to a long-term physical separation of most black holes into a <span class="hlt">dynamically</span> decoupled inner core, as often assumed previously; this is one of the most important results of this dissertation. Combined with the recent detections of several black hole X-ray binary candidates in Galactic globular clusters, our results suggest that stellar black holes could still be present in large numbers in many globular clusters today, and that they may play a significant role in shaping the long-term <span class="hlt">dynamical</span> <span class="hlt">evolution</span> and the present-day <span class="hlt">dynamical</span> structure of many clusters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1391852','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1391852"><span>Complex collective <span class="hlt">dynamics</span> of active torque-<span class="hlt">driven</span> colloids at interfaces.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Snezhko, Alexey</p> <p>2016-02-01</p> <p>Modern self-assembly techniques aiming to produce complex structural order or functional diversity often rely on non-equilibrium conditions in the system. Light, electric, or magnetic fields are predominantly used to modify interaction profiles of colloidal particles during self-assembly or induce complex out-of-equilibrium <span class="hlt">dynamic</span> ordering. The energy injection rate, properties of the environment are important control parameters that influence the outcome of active (<span class="hlt">dynamic</span>) self-assembly. The current review is focused on a case of collective <span class="hlt">dynamics</span> and self-assembly of particles with externally <span class="hlt">driven</span> torques coupled to a liquid or solid interface. The complexity of interactions in such systems is further enriched by strong hydrodynamic coupling between particles. Unconventionally ordered <span class="hlt">dynamic</span> self-assembled patterns, spontaneous symmetry breaking phenomena, self-propulsion, and collective transport have been reported in torque-<span class="hlt">driven</span> colloids. Some of the features of the complex collective behavior and <span class="hlt">dynamic</span> pattern formation in those active systems have been successfully captured in simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4793220','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4793220"><span>In situ Transmission Electron Microscopy observation of Ag nanocrystal <span class="hlt">evolution</span> by surfactant free electron-<span class="hlt">driven</span> synthesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Longo, Elson; Avansi, Waldir; Bettini, Jefferson; Andrés, Juan; Gracia, Lourdes</p> <p>2016-01-01</p> <p>The study of the interaction of electron irradiation with matter and the response of the material to the passage of electrons is a very challenging problem. However, the growth mechanism observed during nanostructural <span class="hlt">evolution</span> appears to be a broad and promising scientific field in nanotechnology. We report the in situ TEM study of nanostructural <span class="hlt">evolution</span> of electron-<span class="hlt">driven</span> silver (Ag) nanocrystals through an additive-free synthetic procedure. Observations revealed the direct effect of the electron beam on the morphological <span class="hlt">evolution</span> of Ag nanocrystals through different mechanisms, such as mass transport, site-selective coalescence, and an appropriate structural configuration after coalescence leading to a more stable configuration. A fundamental understanding of the growth and formation mechanisms of Ag nanocrystals, which interact with the electron beam, is essential to improve the nanocrystal shape-control mechanisms as well as the future design and study of nanomaterials. PMID:26979671</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.S43C2285W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.S43C2285W"><span>A Fault <span class="hlt">Evolution</span> Model Including the Rupture <span class="hlt">Dynamic</span> Simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Y.; Chen, X.</p> <p>2011-12-01</p> <p>We perform a preliminary numerical simulation of seismicity and stress <span class="hlt">evolution</span> along a strike-slip fault in a 3D elastic half space. Following work of Ben-Zion (1996), the fault geometry is devised as a vertical plane which is about 70 km long and 17 km wide, comparable to the size of San Andreas Fault around Parkfield. The loading mechanism is described by "backslip" method. The fault failure is governed by a static/kinetic friction law, and induced stress transfer is calculated with Okada's static solution. In order to track the rupture propagation in detail, we allow induced stress to propagate through the medium at the shear wave velocity by introducing a distance-dependent time delay to responses to stress changes. Current simulation indicates small to moderate earthquakes following the Gutenberg-Richter law and quasi-periodical characteristic large earthquakes, which are consistent with previous work by others. Next we will consider introducing a more realistic friction law, namely, the laboratory-derived rate- and state- dependent law, which can simulate more realistic and complicated sliding behavior such as the stable and unstable slip, the aseismic sliding and the slip nucleation process. In addition, the long duration of aftershocks is expected to be reproduced due to this time-dependent friction law, which is not available in current seismicity simulation. The other difference from previous work is that we are trying to include the <span class="hlt">dynamic</span> ruptures in this study. Most previous study on seismicity simulation is based on the static solution when dealing with failure induced stress changes. However, studies of numerical simulation of rupture <span class="hlt">dynamics</span> have revealed lots of important details which are missing in the quasi-static/quasi- <span class="hlt">dynamic</span> simulation. For example, <span class="hlt">dynamic</span> simulations indicate that the slip on the ground surface becomes larger if the <span class="hlt">dynamic</span> rupture process reaches the free surface. The concentration of stress on the propagating crack</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhA...50j5002Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhA...50j5002Y"><span>Molecular <span class="hlt">dynamics</span> on nonequilibrium motion of a colloidal particle <span class="hlt">driven</span> by an external torque</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yoo, Donghwan; Jung, Youngkyun; Kwon, Chulan</p> <p>2017-03-01</p> <p>We investigate the motion of a colloidal particle <span class="hlt">driven</span> out of equilibrium by an external torque. We use molecular <span class="hlt">dynamics</span> simulation as an alternative to the Langevin <span class="hlt">dynamics</span>. We prepare a heat bath composed of thousands of particles interacting with each other through the Lennard–Jones potential and impose the Langevin thermostat to maintain the heat bath in equilibrium. We consider a single colloidal particle interacting with with the particles of the heat bath also by the Lennard–Jones potential, without applying any types of dissipative or fluctuating forces used in Langevin <span class="hlt">dynamics</span>. We set up simulation protocol fit for the overdamped limit as in real experiments, by increasing the size and mass of the colloidal particle. We study nonequilibrium fluctuations for work and heat produced incessantly in time and compare the results with those obtained from the previous studies via the overdamped Langevin <span class="hlt">dynamics</span>. We confirm the Gallavotti–Cohen symmetry and the fluctuation theorem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NJPh...19a3010J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NJPh...19a3010J"><span><span class="hlt">Dynamic</span> mode locking in a <span class="hlt">driven</span> colloidal system: experiments and theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Juniper, Michael P. N.; Zimmermann, Urs; Straube, Arthur V.; Besseling, Rut; Aarts, Dirk G. A. L.; Löwen, Hartmut; Dullens, Roel P. A.</p> <p>2017-01-01</p> <p>In this article we examine the <span class="hlt">dynamics</span> of a colloidal particle <span class="hlt">driven</span> by a modulated force over a sinusoidal optical potential energy landscape. Coupling between the competing frequencies of the modulated drive and that of particle motion over the periodic landscape leads to synchronisation of particle motion into discrete modes. This synchronisation manifests as steps in the average particle velocity, with mode locked steps covering a range of average driving velocities. The amplitude and frequency dependence of the steps are considered, and compared to results from analytic theory, Langevin <span class="hlt">dynamics</span> simulations, and <span class="hlt">dynamic</span> density functional theory. Furthermore, the critical driving velocity is studied, and simulation used to extend the range of conditions accessible in experiments alone. Finally, state diagrams from experiment, simulation, and theory are used to show the extent of the <span class="hlt">dynamically</span> locked modes in two dimensions, as a function of both the amplitude and frequency of the modulated drive.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21544684','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21544684"><span>Interface <span class="hlt">dynamics</span> of a two-component Bose-Einstein condensate <span class="hlt">driven</span> by an external force</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kobyakov, D.; Bychkov, V.; Lundh, E.; Bezett, A.; Marklund, M.; Akkerman, V.</p> <p>2011-04-15</p> <p>The <span class="hlt">dynamics</span> of an interface in a two-component Bose-Einstein condensate <span class="hlt">driven</span> by a spatially uniform time-dependent force is studied. Starting from the Gross-Pitaevskii Lagrangian, the dispersion relation for linear waves and instabilities at the interface is derived by means of a variational approach. A number of diverse <span class="hlt">dynamical</span> effects for different types of driving force is demonstrated, which includes the Rayleigh-Taylor instability for a constant force, the Richtmyer-Meshkov instability for a pulse force, <span class="hlt">dynamic</span> stabilization of the Rayleigh-Taylor instability and onset of the parametric instability for an oscillating force. Gaussian Markovian and non-Markovian stochastic forces are also considered. It is found that the Markovian stochastic force does not produce any average effect on the <span class="hlt">dynamics</span> of the interface, while the non-Markovian force leads to exponential perturbation growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998APS..MAR.E3701R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998APS..MAR.E3701R"><span>Nonequilibriun <span class="hlt">Dynamic</span> Phases of <span class="hlt">Driven</span> Vortex Lattices in Superconductors with Periodic Pinning Arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reichhardt, C.; Olson, C. J.; Nori, F.</p> <p>1998-03-01</p> <p>We present results from extensive simulations of <span class="hlt">driven</span> vortex lattices interacting with periodic pinning arrays. Changing an applied driving force produces an exceptionally rich variety of distinct <span class="hlt">dynamic</span> phases which include over a dozen well defined plastic flow phases. Transitions between different <span class="hlt">dynamical</span> phases are marked by sharp jumps in the V(I) curves that coincide with distinct changes in the vortex trajectories and vortex lattice order. A series of <span class="hlt">dynamical</span> phase diagrams are presented which outline the onset of the different <span class="hlt">dynamical</span> phases (C. Reichhardt, C.J. Olson, and F. Nori, Phys. Rev. Lett. 78), 2648 (1997); and to be published. Videos are avaliable at http://www-personal.engin.umich.edu/ñori/. Using force balance arguments, several of the phase boundaries can be derived analyticaly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLA..380.3665J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLA..380.3665J"><span>Quantum system <span class="hlt">driven</span> by incoherent a.c fields: Multi-crossing Landau Zener <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jipdi, M. N.; Fai, L. C.; Tchoffo, M.</p> <p>2016-10-01</p> <p>The paper investigates the multi-crossing <span class="hlt">dynamics</span> of a Landau-Zener (LZ) system <span class="hlt">driven</span> by two sinusoidal a.c fields applying the <span class="hlt">Dynamic</span> Matrix approach (DMA). The system is shown to follow one-crossing and multi-crossing <span class="hlt">dynamics</span> for low and high frequency regime respectively. It is shown that in low frequency regime, the resonance phenomenon occurs and leads to the decoupling of basis states; the effective gap vanishes and then the complete blockage of the system. For high frequency, the system achieves multi-crossing <span class="hlt">dynamics</span> with two fictitious crossings; the system models a Landau-Zener-Stückelberg (LZS) interferometer with critical parameters that tailor probabilities. The system is then shown to depend only on the phase that permits the easiest control with possible application in implementing logic gates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HEAD...1410303K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HEAD...1410303K"><span>MYStIX: <span class="hlt">Dynamical</span> <span class="hlt">evolution</span> of young clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhn, Michael A.</p> <p>2014-08-01</p> <p>The spatial structure of young stellar clusters in Galactic star-forming regions provides insight into these clusters’ <span class="hlt">dynamical</span> <span class="hlt">evolution</span>---a topic with implications for open questions in star-formation and cluster survival. The Massive Young Star-Forming Complex Study in Infrared and X-ray (MYStIX) provides a sample of >30,000 young stars in star-forming regions (d<3.6 kpc) that contain at least one O-type star. We use the finite mixture model analysis to identify subclusters of stars and determine their properties: including subcluster radii, intrinsic numbers of stars, central density, ellipticity, obscuration, and age. In 17 MYStIX regions we find 142 subclusters, with a diverse radii and densities and age spreads of up to ~1 Myr in a region. There is a strong negative correlation between subcluster radius and density, which indicates that embedded subclusters expand but also gain stars as they age. Subcluster expansion is also shown by a positive radius--age correlation, which indicates that subclusters are expanding at <1 km/s. The subcluster ellipticity distribution and number--density relation show signs of a hierarchical merger scenario, whereby young stellar clusters are built up through mergers of smaller clumps, causing <span class="hlt">evolution</span> from a clumpy spatial distribution of stars (seen in some regions) to a simpler distribution of stars (seen in other regions). Many of the simple young stellar clusters show signs of <span class="hlt">dynamically</span> relaxation, even though they are not old enough for this to have occurred through two-body interactions. However, this apparent contradiction might be explained if small subcluster, which have shorter <span class="hlt">dynamical</span> relaxation times, can produce <span class="hlt">dynamically</span> relaxed clusters through hierarchical mergers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MNRAS.460.1445P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MNRAS.460.1445P"><span><span class="hlt">Evolution</span> and <span class="hlt">dynamics</span> of a matter creation model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, S.; de Haro, J.; Paliathanasis, A.; Slagter, R. J.</p> <p>2016-08-01</p> <p>In a flat Friedmann-Lemaître-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the expanding universe, we have considered a general creation rate and analysed this rate in the framework of <span class="hlt">dynamical</span> analysis. The <span class="hlt">dynamical</span> analysis hints the presence of a non-singular universe (without the big bang singularity) with two successive accelerated phases, one at the very early phase of the universe (i.e. inflation), and the other one describes the current accelerating universe, where this early, late accelerated phases are associated with an unstable fixed point (i.e. repeller) and a stable fixed point (attractor), respectively. We have described this phenomena by analytic solutions of the Hubble function and the scale factor of the FLRW universe. Using Jacobi last multiplier method, we have found a Lagrangian for this matter creation rate describing this scenario of the universe. To match with our early physics results, we introduce an equivalent <span class="hlt">dynamics</span> <span class="hlt">driven</span> by a single scalar field, discuss the associated observable parameters and compare them with the latest Planck data sets. Finally, introducing the teleparallel modified gravity, we have established an equivalent gravitational theory in the framework of matter creation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010NJPh...12g5029T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010NJPh...12g5029T"><span>Schumpeterian economic <span class="hlt">dynamics</span> as a quantifiable model of <span class="hlt">evolution</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thurner, Stefan; Klimek, Peter; Hanel, Rudolf</p> <p>2010-07-01</p> <p>We propose a simple quantitative model of Schumpeterian economic <span class="hlt">dynamics</span>. New goods and services are endogenously produced through combinations of existing goods. As soon as new goods enter the market, they may compete against already existing goods. In other words, new products can have destructive effects on existing goods. As a result of this competition mechanism, existing goods may be <span class="hlt">driven</span> out from the market—often causing cascades of secondary defects (Schumpeterian gales of destruction). The model leads to generic <span class="hlt">dynamics</span> characterized by phases of relative economic stability followed by phases of massive restructuring of markets—which could be interpreted as Schumpeterian business 'cycles'. Model time series of product diversity and productivity reproduce several stylized facts of economics time series on long timescales, such as GDP or business failures, including non-Gaussian fat tailed distributions and volatility clustering. The model is phrased in an open, non-equilibrium setup which can be understood as a self-organized critical system. Its diversity <span class="hlt">dynamics</span> can be understood by the time-varying topology of the active production networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27369498','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27369498"><span>Quantum <span class="hlt">dynamics</span> of incoherently <span class="hlt">driven</span> V-type systems: Analytic solutions beyond the secular approximation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dodin, Amro; Tscherbul, Timur V; Brumer, Paul</p> <p>2016-06-28</p> <p>Closed-form analytic solutions to non-secular Bloch-Redfield master equations for quantum <span class="hlt">dynamics</span> of a V-type system <span class="hlt">driven</span> by weak coupling to a thermal bath, relevant to light harvesting processes, are obtained and discussed. We focus on noise-induced Fano coherences among the excited states induced by incoherent driving of the V-system initially in the ground state. For suddenly turned-on incoherent driving, the time <span class="hlt">evolution</span> of the coherences is determined by the damping parameter ζ=12(γ1+γ2)/Δp, where γi are the radiative decay rates of the excited levels i = 1, 2, and Δp=Δ(2)+(1-p(2))γ1γ2 depends on the excited-state level splitting Δ > 0 and the angle between the transition dipole moments in the energy basis. The coherences oscillate as a function of time in the underdamped limit (ζ ≫ 1), approach a long-lived quasi-steady state in the overdamped limit (ζ ≪ 1), and display an intermediate behavior at critical damping (ζ = 1). The sudden incoherent turn-on is shown to generate a mixture of excited eigenstates |e1〉 and |e2〉 and their in-phase coherent superposition |ϕ+〉=1r1+r2(r1|e1〉+r2|e2〉), which is remarkably long-lived in the overdamped limit (where r1 and r2 are the incoherent pumping rates). Formation of this coherent superposition enhances the decay rate from the excited states to the ground state. In the strongly asymmetric V-system where the coupling strengths between the ground state and the excited states differ significantly, additional asymptotic quasistationary coherences are identified, which arise due to slow equilibration of one of the excited states. Finally, we demonstrate that noise-induced Fano coherences are maximized with respect to populations when r1 = r2 and the transition dipole moments are fully aligned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144x4108D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144x4108D"><span>Quantum <span class="hlt">dynamics</span> of incoherently <span class="hlt">driven</span> V-type systems: Analytic solutions beyond the secular approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dodin, Amro; Tscherbul, Timur V.; Brumer, Paul</p> <p>2016-06-01</p> <p>Closed-form analytic solutions to non-secular Bloch-Redfield master equations for quantum <span class="hlt">dynamics</span> of a V-type system <span class="hlt">driven</span> by weak coupling to a thermal bath, relevant to light harvesting processes, are obtained and discussed. We focus on noise-induced Fano coherences among the excited states induced by incoherent driving of the V-system initially in the ground state. For suddenly turned-on incoherent driving, the time <span class="hlt">evolution</span> of the coherences is determined by the damping parameter ζ = /1 2 ( γ 1 + γ 2) / Δ p , where γi are the radiative decay rates of the excited levels i = 1, 2, and Δ p = √{ Δ 2 + ( 1 - p 2) γ 1 γ 2 } depends on the excited-state level splitting Δ > 0 and the angle between the transition dipole moments in the energy basis. The coherences oscillate as a function of time in the underdamped limit (ζ ≫ 1), approach a long-lived quasi-steady state in the overdamped limit (ζ ≪ 1), and display an intermediate behavior at critical damping (ζ = 1). The sudden incoherent turn-on is shown to generate a mixture of excited eigenstates |e1> and |e2> and their in-phase coherent superposition | ϕ + > = /1 √{ r 1 + r 2 } ( √{ r 1 } | e 1 > + √{ r 2 } | e 2 >) , which is remarkably long-lived in the overdamped limit (where r1 and r2 are the incoherent pumping rates). Formation of this coherent superposition enhances the decay rate from the excited states to the ground state. In the strongly asymmetric V-system where the coupling strengths between the ground state and the excited states differ significantly, additional asymptotic quasistationary coherences are identified, which arise due to slow equilibration of one of the excited states. Finally, we demonstrate that noise-induced Fano coherences are maximized with respect to populations when r1 = r2 and the transition dipole moments are fully aligned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJD...70..217S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJD...70..217S"><span>Molecular <span class="hlt">dynamics</span> for irradiation <span class="hlt">driven</span> chemistry: application to the FEBID process*</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sushko, Gennady B.; Solov'yov, Ilia A.; Solov'yov, Andrey V.</p> <p>2016-10-01</p> <p>A new molecular <span class="hlt">dynamics</span> (MD) approach for computer simulations of irradiation <span class="hlt">driven</span> chemical transformations of complex molecular systems is suggested. The approach is based on the fact that irradiation induced quantum transformations can often be treated as random, fast and local processes involving small molecules or molecular fragments. We advocate that the quantum transformations, such as molecular bond breaks, creation and annihilation of dangling bonds, electronic charge redistributions, changes in molecular topologies, etc., could be incorporated locally into the molecular force fields that describe the classical MD of complex molecular systems under irradiation. The proposed irradiation <span class="hlt">driven</span> molecular <span class="hlt">dynamics</span> (IDMD) methodology is designed for the molecular level description of the irradiation <span class="hlt">driven</span> chemistry. The IDMD approach is implemented into the MBN Explorer software package capable to operate with a large library of classical potentials, many-body force fields and their combinations. IDMD opens a broad range of possibilities for modelling of irradiation <span class="hlt">driven</span> modifications and chemistry of complex molecular systems ranging from radiotherapy cancer treatments to the modern technologies such as focused electron beam deposition (FEBID). As an example, the new methodology is applied for studying the irradiation <span class="hlt">driven</span> chemistry caused by FEBID of tungsten hexacarbonyl W(CO)6 precursor molecules on a hydroxylated SiO2 surface. It is demonstrated that knowing the interaction parameters for the fragments of the molecular system arising in the course of irradiation one can reproduce reasonably well experimental observations and make predictions about the morphology and molecular composition of nanostructures that emerge on the surface during the FEBID process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741639','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741639"><span>Noise-resilient quantum <span class="hlt">evolution</span> steered by <span class="hlt">dynamical</span> decoupling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Gang-Qin; Po, Hoi Chun; Du, Jiangfeng; Liu, Ren-Bao; Pan, Xin-Yu</p> <p>2013-01-01</p> <p>Realistic quantum computing is subject to noise. Therefore, an important frontier in quantum computing is to implement noise-resilient quantum control over qubits. At the same time, <span class="hlt">dynamical</span> decoupling can protect the coherence of qubits. Here we demonstrate non-trivial quantum <span class="hlt">evolution</span> steered by <span class="hlt">dynamical</span> decoupling control, which simultaneously suppresses noise effects. We design and implement a self-protected controlled-NOT gate on the electron spin of a nitrogen-vacancy centre and a nearby carbon-13 nuclear spin in diamond at room temperature, by employing an engineered <span class="hlt">dynamical</span> decoupling control on the electron spin. Final state fidelity of 0.91(1) is observed in preparation of a Bell state using the gate. At the same time, the qubit coherence time is elongated at least 30 fold. The design scheme does not require the <span class="hlt">dynamical</span> decoupling control to commute with the qubit interaction and therefore works for general qubit systems. This work marks a step towards implementing realistic quantum computing systems. PMID:23912335</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011utcs.book...49B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011utcs.book...49B"><span>Random <span class="hlt">Evolution</span> of Idiotypic Networks: <span class="hlt">Dynamics</span> and Architecture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brede, Markus; Behn, Ulrich</p> <p></p> <p>The paper deals with modelling a subsystem of the immune system, the so-called idiotypic network (INW). INWs, conceived by N.K. Jerne in 1974, are functional networks of interacting antibodies and B cells. In principle, Jernes' framework provides solutions to many issues in immunology, such as immunological memory, mechanisms for antigen recognition and self/non-self discrimination. Explaining the interconnection between the elementary components, local <span class="hlt">dynamics</span>, network formation and architecture, and possible modes of global system function appears to be an ideal playground of statistical mechanics. We present a simple cellular automaton model, based on a graph representation of the system. From a simplified description of idiotypic interactions, rules for the random <span class="hlt">evolution</span> of networks of occupied and empty sites on these graphs are derived. In certain biologically relevant parameter ranges the resultant <span class="hlt">dynamics</span> leads to stationary states. A stationary state is found to correspond to a specific pattern of network organization. It turns out that even these very simple rules give rise to a multitude of different kinds of patterns. We characterize these networks by classifying `static' and `<span class="hlt">dynamic</span>' network-patterns. A type of `<span class="hlt">dynamic</span>' network is found to display many features of real INWs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhyD..267...81P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyD..267...81P"><span>Adaptive network <span class="hlt">dynamics</span> and <span class="hlt">evolution</span> of leadership in collective migration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pais, Darren; Leonard, Naomi E.</p> <p>2014-01-01</p> <p>The <span class="hlt">evolution</span> of leadership in migratory populations depends not only on costs and benefits of leadership investments but also on the opportunities for individuals to rely on cues from others through social interactions. We derive an analytically tractable adaptive <span class="hlt">dynamic</span> network model of collective migration with fast timescale migration <span class="hlt">dynamics</span> and slow timescale adaptive <span class="hlt">dynamics</span> of individual leadership investment and social interaction. For large populations, our analysis of bifurcations with respect to investment cost explains the observed hysteretic effect associated with recovery of migration in fragmented environments. Further, we show a minimum connectivity threshold above which there is evolutionary branching into leader and follower populations. For small populations, we show how the topology of the underlying social interaction network influences the emergence and location of leaders in the adaptive system. Our model and analysis can be extended to study the <span class="hlt">dynamics</span> of collective tracking or collective learning more generally. Thus, this work may inform the design of robotic networks where agents use decentralized strategies that balance direct environmental measurements with agent interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001EPJE....5..207R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001EPJE....5..207R"><span>Hydrodynamic-flow-<span class="hlt">driven</span> phase <span class="hlt">evolution</span> in a polymer blend film modified by diblock copolymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rysz, J.; Ermer, H.; Budkowski, A.; Bernasik, A.; Lekki, J.; Juengst, G.; Brenn, R.; Kowalski, K.; Camra, J.; Lekka, M.; Jedliński, J.</p> <p></p> <p>We have studied surface-directed phase separation in thin films of deuterated polystyrene and poly(bromostyrene) (with 22.7% of monomers brominated) using ^{{3}}He nuclear reaction analysis, <span class="hlt">dynamic</span> secondary ion mass spectroscopy and atomic force microscopy combined with preferential dissolution. The crossover from competing to neutral surfaces of the critical blend film (cast onto Au) was commenced: polyisoprene-polystyrene diblock copolymers were added and segregated to both surfaces reducing in a tuneable manner the effective interactions. Two main stages of phase <span class="hlt">evolution</span> are characterised by i) the growth of two surface layers and by ii) the transition from the four-layer to the final bilayer morphology. For increasing copolymer content the kinetics of the first stage is hardly affected but the amplitude of composition oscillations is reduced indicating more fragmented inner layers. As a result, a faster mass flow to the surfaces and an earlier completion of the second stage were observed. The hydrodynamic flow mechanism, driving both stages, is evidenced by nearly linear growth of the surface layer and by mass flow channels extending from the surface layer into the bulk. The final bilayer structure, formed even for the surfaces covered by strongly overlapped copolymers, is indicative of long-range (antisymmetric) surface forces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DMP.Q1105M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DMP.Q1105M"><span>Control <span class="hlt">dynamics</span> of interaction quenched ultracold bosons in periodically <span class="hlt">driven</span> lattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mistakidis, Simeon; Schmelcher, Peter; Group of Fundamental Processes in Quantum Physics Team</p> <p>2016-05-01</p> <p>The out-of-equilibrium <span class="hlt">dynamics</span> of ultracold bosons following an interaction quench upon a periodically <span class="hlt">driven</span> optical lattice is investigated. It is shown that an interaction quench triggers the inter-well tunneling <span class="hlt">dynamics</span>, while for the intra-well <span class="hlt">dynamics</span> breathing and cradle-like processes can be generated. In particular, the occurrence of a resonance between the cradle and tunneling modes is revealed. On the other hand, the employed periodic driving enforces the bosons in the mirror wells to oscillate out-of-phase and to exhibit a dipole mode, while in the central well the cloud experiences a breathing mode. The <span class="hlt">dynamical</span> behaviour of the system is investigated with respect to the driving frequency revealing a resonant behaviour of the intra-well <span class="hlt">dynamics</span>. To drive the system in a highly non-equilibrium state an interaction quench upon the driving is performed giving rise to admixtures of excitations in the outer wells, an enhanced breathing in the center and an amplification of the tunneling <span class="hlt">dynamics</span>. As a result of the quench the system experiences multiple resonances between the inter- and intra-well <span class="hlt">dynamics</span> at different quench amplitudes. Deutsche Forschungsgemeinschaft, SFB 925 ``Light induced <span class="hlt">dynamics</span> and control of correlated quantum systems''.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10415491','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10415491"><span><span class="hlt">Dynamic</span> <span class="hlt">evolution</span> of genomes and the concept of genome space.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bellgard, M I; Itoh, T; Watanabe, H; Imanishi, T; Gojobori, T</p> <p>1999-05-18</p> <p>A new era in the elucidation of genome <span class="hlt">evolution</span> has been heralded with the availability of numerous genome sequences. With these data, it has been possible to study evolutionary processes at a greater level of detail in order to characterize features such as gene shuffling, genome rearrangements, base bias composition, and horizontal gene transfer. In this paper, we discuss the evolutionary implications of significant rearrangements within genomes as well as characteristic genomic regions that have been conserved across genomes. This is based on our analysis of orthologous and paralogous genes. We argue that genome plasticity has most likely contributed substantially to the <span class="hlt">dynamic</span> <span class="hlt">evolution</span> of genomes. We also describe the characteristic mosaic features of an archaea genome that is comprised of both bacterial and eukaryal elements. Here we investigate base compositional differences as well as the similarity of this species' genes to either bacteria or eukarya. We conclude that these features can be largely explained by the mechanism of horizontal gene transfer. Finally, we introduce the concept of genome space which is defined as the entire set of genomes of all living organisms. We explain its usefulness to describe as well as to gain deeper insight into the general features of the <span class="hlt">dynamic</span> genomic evolutionary process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..DFDG17007H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DFDG17007H"><span>Vortex <span class="hlt">evolution</span> and <span class="hlt">dynamics</span> during turbulence-flame interaction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haffner, Eileen; Peter Hamlington Collaboration, Dr.; Alexei Poludnenko Collaboration, Dr.; Elaine Oran Collaboration, Dr.; Melissa A. Green Collaboration, Dr.</p> <p>2016-11-01</p> <p>Individual vortex structures are tracked in <span class="hlt">dynamic</span> three-dimensional vortex-flame interactions using results from a previously-published implicit LES of premixed hydrogen and air combustion. The <span class="hlt">evolution</span> of the vortices are visualized using isosurfaces of the Q criterion coupled with isosurfaces of the fuel mass fraction throughout the flame brush. Structures with high magnitude vorticity are observed to persist through the flame brush, whereas weaker vortices lose vorticity magnitude due to fluid stretching effects and volume expansion when interacting with the flame brush. The flame itself can also create new vortex structures both within and outside of the flame brush, which has been shown in previous two-dimensional simulations and experiments. The individual terms of the vorticity <span class="hlt">evolution</span> equation were calculated to further explore the <span class="hlt">dynamics</span> of the vorticity within the flame brush, such as: stretch due to compressibility effects, tilt due to changes in the velocity gradients, and vorticity generation and destruction due to baroclinic torque (misalignment of the pressure and density gradients). The baroclinic torque is the potential generator for new structures that appear within the flame brush. Using these calculations we can obtain a better idea of the physical phenomenon that is occurring within and after the flame brush.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18702601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18702601"><span>Multiple infections, immune <span class="hlt">dynamics</span>, and the <span class="hlt">evolution</span> of virulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Alizon, Samuel; van Baalen, Minus</p> <p>2008-10-01</p> <p>Understanding the effect of multiple infections is essential for the prediction (and eventual control) of virulence <span class="hlt">evolution</span>. Some theoretical studies have considered the possibility that several strains coexist in the same host (coinfection), but few have taken their within-host <span class="hlt">dynamics</span> explicitly into account. Here, we develop a nested approach based on a simple model for the interaction of parasite strains with their host's immune system. We study virulence <span class="hlt">evolution</span> by linking the within-host <span class="hlt">dynamics</span> to an epidemiological framework that incorporates multiple infections. Our model suggests that antigenically similar parasite strains cannot coexist in the long term inside a host. We also find that the optimal level of virulence increases with the efficiency of multiple infections. Finally, we notice that coinfections create heterogeneity in the host population (with susceptible hosts and infected hosts), which can lead to evolutionary branching in the parasite population and the emergence of a hypervirulent parasite strategy. We interpret this result as a parasite specialization to the infectious state of the hosts. Our study has experimental and theoretical implications in a virulence management perspective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12786401','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12786401"><span><span class="hlt">Dynamics</span> of the <span class="hlt">evolution</span> of learning algorithms by selection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neirotti, Juan Pablo; Caticha, Nestor</p> <p>2003-04-01</p> <p>We study the <span class="hlt">evolution</span> of artificial learning systems by means of selection. Genetic programming is used to generate populations of programs that implement algorithms used by neural network classifiers to learn a rule in a supervised learning scenario. In contrast to concentrating on final results, which would be the natural aim while designing good learning algorithms, we study the <span class="hlt">evolution</span> process. Phenotypic and genotypic entropies, which describe the distribution of fitness and of symbols, respectively, are used to monitor the <span class="hlt">dynamics</span>. We identify significant functional structures responsible for the improvements in the learning process. In particular, some combinations of variables and operators are useful in assessing performance in rule extraction and can thus implement annealing of the learning schedule. We also find combinations that can signal surprise, measured on a single example, by the difference between predicted and correct classification. When such favorable structures appear, they are disseminated on very short time scales throughout the population. Due to such abruptness they can be thought of as <span class="hlt">dynamical</span> transitions. But foremost, we find a strict temporal order of such discoveries. Structures that measure performance are never useful before those for measuring surprise. Invasions of the population by such structures in the reverse order were never observed. Asymptotically, the generalization ability approaches Bayesian results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhRvE..67d1912N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhRvE..67d1912N"><span><span class="hlt">Dynamics</span> of the <span class="hlt">evolution</span> of learning algorithms by selection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neirotti, Juan Pablo; Caticha, Nestor</p> <p>2003-04-01</p> <p>We study the <span class="hlt">evolution</span> of artificial learning systems by means of selection. Genetic programming is used to generate populations of programs that implement algorithms used by neural network classifiers to learn a rule in a supervised learning scenario. In contrast to concentrating on final results, which would be the natural aim while designing good learning algorithms, we study the <span class="hlt">evolution</span> process. Phenotypic and genotypic entropies, which describe the distribution of fitness and of symbols, respectively, are used to monitor the <span class="hlt">dynamics</span>. We identify significant functional structures responsible for the improvements in the learning process. In particular, some combinations of variables and operators are useful in assessing performance in rule extraction and can thus implement annealing of the learning schedule. We also find combinations that can signal surprise, measured on a single example, by the difference between predicted and correct classification. When such favorable structures appear, they are disseminated on very short time scales throughout the population. Due to such abruptness they can be thought of as <span class="hlt">dynamical</span> transitions. But foremost, we find a strict temporal order of such discoveries. Structures that measure performance are never useful before those for measuring surprise. Invasions of the population by such structures in the reverse order were never observed. Asymptotically, the generalization ability approaches Bayesian results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......424C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......424C"><span>Radiation Recoil Effects on the <span class="hlt">Dynamical</span> <span class="hlt">Evolution</span> of Asteroids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cotto-Figueroa, Desiree</p> <p></p> <p>The Yarkovsky effect is a radiation recoil force that results in a semimajor axis drift in the orbit that can cause Main Belt asteroids to be delivered to powerful resonances from which they could be transported to Earth-crossing orbits. This force depends on the spin state of the object, which is modified by the YORP effect, a variation of the Yarkovsky effect that results in a torque that changes the spin rate and the obliquity. Extensive analyses of the basic behavior of the YORP effect have been previously conducted in the context of the classical spin state <span class="hlt">evolution</span> of rigid bodies (YORP cycle). However, the YORP effect has an extreme sensitivity to the topography of the asteroids and a minor change in the shape of an aggregate asteroid can stochastically change the YORP torques. Here we present the results of the first simulations that self-consistently model the YORP effect on the spin states of <span class="hlt">dynamically</span> evolving aggregates. For these simulations we have developed several algorithms and combined them with two codes, TACO and pkdgrav. TACO is a thermophysical asteroid code that models the surface of an asteroid using a triangular facet representation and which can compute the YORP torques. The code pkdgrav is a cosmological N-body tree code modified to simulate the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of asteroids represented as aggregates of spheres using gravity and collisions. The continuous changes in the shape of an aggregate result in a different <span class="hlt">evolution</span> of the YORP torques and therefore aggregates do not evolve through the YORP cycle as a rigid body would. Instead of having a spin <span class="hlt">evolution</span> ruled by long periods of rotational acceleration and deceleration as predicted by the classical YORP cycle, the YORP effect is self-limiting and stochastic on aggregate asteroids. We provide a statistical description of the spin state <span class="hlt">evolution</span> which lays out the foundation for new simulations of a coupled Yarkovsky/YORP <span class="hlt">evolution</span>. Both self-limiting YORP and to a lesser</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27862515','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27862515"><span>Co-evolutionary <span class="hlt">dynamics</span> between a defensive microbe and a pathogen <span class="hlt">driven</span> by fluctuating selection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ford, Suzanne A; Williams, David; Paterson, Steve; King, Kayla C</p> <p>2017-04-01</p> <p>Microbes that protect their hosts from pathogenic infection are widespread components of the microbiota of both plants and animals. It has been found that interactions between 'defensive' microbes and pathogens can be genotype-specific and even underlie the variation in host resistance to pathogenic infection. These observations suggest a <span class="hlt">dynamic</span> co-evolutionary association between pathogens and defensive microbes, but direct evidence of co-<span class="hlt">evolution</span> is lacking. We tested the hypothesis that defensive microbes and pathogens could co-evolve within host populations by co-passaging a microbe with host-defensive properties (Enterococcus faecalis) and a pathogen (Staphylococcus aureus) within Caenorhabditis elegans nematodes. Using both phenotypic and genomic analyses across evolutionary time, we found patterns of pathogen local adaptation and defensive microbe-pathogen co-<span class="hlt">evolution</span> via fluctuating selection <span class="hlt">dynamics</span>. Moreover, co-<span class="hlt">evolution</span> with defensive microbes resulted in more rapid and divergent pathogen <span class="hlt">evolution</span> compared to pathogens evolved independently in host populations. Taken together, our results indicate the potential for defensive microbes and pathogens to co-evolve, driving interaction specificity and pathogen evolutionary divergence in the absence of host <span class="hlt">evolution</span>. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26382540','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26382540"><span><span class="hlt">Dynamic</span> reconstruction of heterogeneous materials and microstructure <span class="hlt">evolution</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Shaohua; Li, Hechao; Jiao, Yang</p> <p>2015-08-01</p> <p>Reconstructing heterogeneous materials from limited structural information has been a topic that attracts extensive research efforts and still poses many challenges. The Yeong-Torquato procedure is one of the most popular reconstruction techniques, in which the material reconstruction problem based on a set of spatial correlation functions is formulated as a constrained energy minimization (optimization) problem and solved using simulated annealing [Yeong and Torquato, Phys. Rev. E 57, 495 (1998)]. The standard two-point correlation function S2 has been widely used in reconstructions, but can also lead to large structural degeneracy for certain nearly percolating systems. To improve reconstruction accuracy and reduce structural degeneracy, one can successively incorporate additional morphological information (e.g., nonconventional or higher-order correlation functions), which amounts to reshaping the energy landscape to create a deep (local) energy minimum. In this paper, we present a <span class="hlt">dynamic</span> reconstruction procedure that allows one to use a series of auxiliary S2 to achieve the same level of accuracy as those incorporating additional nonconventional correlation functions. In particular, instead of randomly sampling the microstructure space as in the simulated annealing scheme, our procedure utilizes a series of auxiliary microstructures that mimic a physical structural <span class="hlt">evolution</span> process (e.g., grain growth). This amounts to constructing a series auxiliary energy landscapes that bias the convergence of the reconstruction to a favored (local) energy minimum. Moreover, our <span class="hlt">dynamic</span> procedure can be naturally applied to reconstruct an actual microstructure <span class="hlt">evolution</span> process. In contrast to commonly used <span class="hlt">evolution</span> reconstruction approaches that separately generate individual static configurations, our procedure continuously evolves a single microstructure according to a time-dependent correlation function. The utility of our procedure is illustrated by successfully</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMEP53E1026H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMEP53E1026H"><span>Sediment Transport <span class="hlt">Dynamics</span> and Bedform <span class="hlt">Evolution</span> During Unsteady Flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hu, H.; Parsons, D. R.; Ockelford, A.; Hardy, R. J.; Ashworth, P. J.; Best, J.</p> <p>2016-12-01</p> <p>Dunes are ubiquitous features in sand bed rivers and estuaries, and their formation, growth and kinematics play a dominant role in boundary flow structure, flow resistance and sediment transport processes. However, bedform <span class="hlt">evolution</span> and <span class="hlt">dynamics</span> during the rising/falling limb of a flood wave remain poorly understood. Herein, we report on a series of flume experiments, undertaken at the University of Hull's Total Environment Simulator flume/wave tank facility, with imposed flow variations and different hydrographs: i) a sudden (shock) change, ii) a fast flood wave and iii) a slow flood wave. Our analysis shows that, because of changes of sediment transport mechanisms with discharge, the sediment flux rather than bedform migration rate is a more appropriate parameter to relate to transport stage. This is particularly the case during bedload transport dominated periods at lower flow discharge, where a strong power law relationship was detected. In terms of varying processes across the hydrograph limbs, bedform <span class="hlt">evolution</span> during the rising limb is dominated not only by bedform amalgamation but also by the washing out of smaller-scale bedforms. Furthermore, bedform growth is independent of the rising rate of the hydrograph limb, while <span class="hlt">evolution</span> of bedform decay is affected by the rate of discharge decrease. This results in an anticlockwise hysteresis between transport stage and total flux was found in fast wave experiment, indicating a significant role of the change in sediment transport mechanisms on bedform <span class="hlt">evolution</span>. Moreover, analysis on the variation of deformation fraction (F, ratio of the deformation flux to the total bed material flux) suggests that net degradation of the bed enhances bedform deformation and leads to a higher F ( 0.65). This work extends our knowledge on how dunes generate and develop under variable flows and has begun to explore how variations in transport stage can be coupled with the variation in sediment transport mechanisms, and/or sediment</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016LPICo1962.4059K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016LPICo1962.4059K"><span>Neutrino Transport in Black Hole-Neutron Star Binaries: <span class="hlt">Dynamical</span> Mass Ejection and Neutrino-<span class="hlt">Driven</span> Wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kyutoku, K.; Kiuchi, K.; Sekiguchi, Y.; Shibata, M.; Taniguchi, K.</p> <p>2016-10-01</p> <p>We present our recent results of numerical-relativity simulations of black hole-neutron star binary mergers incorporating approximate neutrino transport. We in particular discuss <span class="hlt">dynamical</span> mass ejection and neutrino-<span class="hlt">driven</span> wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DDA....4540001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DDA....4540001M"><span>A few points on the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of the young solar system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malhotra, Renu</p> <p>2014-05-01</p> <p>The phenomenon of planetesimal-<span class="hlt">driven</span> giant planet migration in the early history of our planetary system has become increasingly recognized as a key process for understanding the overall solar system architecture and its <span class="hlt">dynamical</span> <span class="hlt">evolution</span>. The <span class="hlt">dynamical</span> structure of the Kuiper belt indicates that such migration caused Neptune's orbit to expand outward from its birth orbit by about 10 AU. It follows from energy and angular momentum conservation that a few tens of earth-masses of leftover planetesimals were ejected from the early solar system, and that Jupiter migrated inward by a few tenths of an AU. The orbital distribution of asteroids near resonances provides independent estimates of Jupiter's and Saturn's migration. An initially slow migration of the giant planets may have been accelerated during a brief but dramatic orbital instability due to planet-planet resonant encounters. While there is compelling evidence in the outer solar system for the above scenario, there is also tension with the observed properties of the inner solar system: the migration of the giant planets, with or without resonant encounters, would have caused severe, potentially destabilizing, perturbations on the inner planets’ orbits. I will describe these considerations and some ideas for resolving this crisis in our understanding of the <span class="hlt">dynamical</span> history of the solar system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27812210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27812210"><span>Collective <span class="hlt">Dynamics</span> of Belief <span class="hlt">Evolution</span> under Cognitive Coherence and Social Conformity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rodriguez, Nathaniel; Bollen, Johan; Ahn, Yong-Yeol</p> <p>2016-01-01</p> <p>Human history has been marked by social instability and conflict, often <span class="hlt">driven</span> by the irreconcilability of opposing sets of beliefs, ideologies, and religious dogmas. The <span class="hlt">dynamics</span> of belief systems has been studied mainly from two distinct perspectives, namely how cognitive biases lead to individual belief rigidity and how social influence leads to social conformity. Here we propose a unifying framework that connects cognitive and social forces together in order to study the <span class="hlt">dynamics</span> of societal belief <span class="hlt">evolution</span>. Each individual is endowed with a network of interacting beliefs that evolves through interaction with other individuals in a social network. The adoption of beliefs is affected by both internal coherence and social conformity. Our framework may offer explanations for how social transitions can arise in otherwise homogeneous populations, how small numbers of zealots with highly coherent beliefs can overturn societal consensus, and how belief rigidity protects fringe groups and cults against invasion from mainstream beliefs, allowing them to persist and even thrive in larger societies. Our results suggest that strong consensus may be insufficient to guarantee social stability, that the cognitive coherence of belief-systems is vital in determining their ability to spread, and that coherent belief-systems may pose a serious problem for resolving social polarization, due to their ability to prevent consensus even under high levels of social exposure. We argue that the inclusion of cognitive factors into a social model could provide a more complete picture of collective human <span class="hlt">dynamics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5094740','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5094740"><span>Collective <span class="hlt">Dynamics</span> of Belief <span class="hlt">Evolution</span> under Cognitive Coherence and Social Conformity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rodriguez, Nathaniel; Bollen, Johan</p> <p>2016-01-01</p> <p>Human history has been marked by social instability and conflict, often <span class="hlt">driven</span> by the irreconcilability of opposing sets of beliefs, ideologies, and religious dogmas. The <span class="hlt">dynamics</span> of belief systems has been studied mainly from two distinct perspectives, namely how cognitive biases lead to individual belief rigidity and how social influence leads to social conformity. Here we propose a unifying framework that connects cognitive and social forces together in order to study the <span class="hlt">dynamics</span> of societal belief <span class="hlt">evolution</span>. Each individual is endowed with a network of interacting beliefs that evolves through interaction with other individuals in a social network. The adoption of beliefs is affected by both internal coherence and social conformity. Our framework may offer explanations for how social transitions can arise in otherwise homogeneous populations, how small numbers of zealots with highly coherent beliefs can overturn societal consensus, and how belief rigidity protects fringe groups and cults against invasion from mainstream beliefs, allowing them to persist and even thrive in larger societies. Our results suggest that strong consensus may be insufficient to guarantee social stability, that the cognitive coherence of belief-systems is vital in determining their ability to spread, and that coherent belief-systems may pose a serious problem for resolving social polarization, due to their ability to prevent consensus even under high levels of social exposure. We argue that the inclusion of cognitive factors into a social model could provide a more complete picture of collective human <span class="hlt">dynamics</span>. PMID:27812210</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvE..95b0101R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvE..95b0101R"><span>Interplay of interfacial noise and curvature-<span class="hlt">driven</span> <span class="hlt">dynamics</span> in two dimensions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roy, Parna; Sen, Parongama</p> <p>2017-02-01</p> <p>We explore the effect of interplay of interfacial noise and curvature-<span class="hlt">driven</span> <span class="hlt">dynamics</span> in a binary spin system. An appropriate model is the generalized two-dimensional voter model proposed earlier [M. J. de Oliveira, J. F. F. Mendes, and M. A. Santos, J. Phys. A: Math. Gen. 26, 2317 (1993), 10.1088/0305-4470/26/10/006], where the flipping probability of a spin depends on the state of its neighbors and is given in terms of two parameters, x and y . x =0.5 andy =1 correspond to the conventional voter model which is purely interfacial noise <span class="hlt">driven</span>, while x =1 and y =1 correspond to the Ising model, where coarsening is fully curvature <span class="hlt">driven</span>. The coarsening phenomena for 0.5 <x <1 keeping y =1 is studied in detail. The <span class="hlt">dynamical</span> behavior of the relevant quantities show characteristic differences from both x =0.5 and 1. The most remarkable result is the existence of two time scales for x ≥xc where xc≈0.7 . On the other hand, we have studied the exit probability which shows Ising-like behavior with a universal exponent for any value of x >0.5 ; the effect of x appears in altering the value of the parameter occurring in the scaling function only.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28903894','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28903894"><span>Prototype Development: Context-<span class="hlt">Driven</span> <span class="hlt">Dynamic</span> XML Ophthalmologic Data Capture Application.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peissig, Peggy; Schwei, Kelsey M; Kadolph, Christopher; Finamore, Joseph; Cancel, Efrain; McCarty, Catherine A; Okorie, Asha; Thomas, Kate L; Allen Pacheco, Jennifer; Pathak, Jyotishman; Ellis, Stephen B; Denny, Joshua C; Rasmussen, Luke V; Tromp, Gerard; Williams, Marc S; Vrabec, Tamara R; Brilliant, Murray H</p> <p>2017-09-13</p> <p>The capture and integration of structured ophthalmologic data into electronic health records (EHRs) has historically been a challenge. However, the importance of this activity for patient care and research is critical. The purpose of this study was to develop a prototype of a context-<span class="hlt">driven</span> <span class="hlt">dynamic</span> extensible markup language (XML) ophthalmologic data capture application for research and clinical care that could be easily integrated into an EHR system. Stakeholders in the medical, research, and informatics fields were interviewed and surveyed to determine data and system requirements for ophthalmologic data capture. On the basis of these requirements, an ophthalmology data capture application was developed to collect and store discrete data elements with important graphical information. The context-<span class="hlt">driven</span> data entry application supports several features, including ink-over drawing capability for documenting eye abnormalities, context-based Web controls that guide data entry based on preestablished dependencies, and an adaptable database or XML schema that stores Web form specifications and allows for immediate changes in form layout or content. The application utilizes Web services to enable data integration with a variety of EHRs for retrieval and storage of patient data. This paper describes the development process used to create a context-<span class="hlt">driven</span> <span class="hlt">dynamic</span> XML data capture application for optometry and ophthalmology. The list of ophthalmologic data elements identified as important for care and research can be used as a baseline list for future ophthalmologic data collection activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003APS..NWS.D1025K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003APS..NWS.D1025K"><span>Thermally <span class="hlt">Driven</span> and Cytoskeletal-Assisted <span class="hlt">Dynamics</span> of the Mitochondrial Reticulum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knowles, Michelle K.; Marcus, Andrew H.</p> <p>2003-05-01</p> <p>We report Fourier imaging correlation spectroscopy (FICS) and digital video fluorescence microscopy (DVFM) measurements of the <span class="hlt">dynamics</span> of the mitochondrial reticulum in living osteosarcoma cells. Mitochondrial <span class="hlt">dynamics</span> are strongly influenced by interactions with cytoskeletal filaments and their associated motor proteins, which lead to complex multi-exponential relaxations that occur over a wide range of spatial and temporal scales. The cytoskeleton consists of an interconnected polymer network whose primary components are microfilaments (actin) and microtubules (tubulin). These filaments work with motor proteins to translate organelles through the cell. We studied the <span class="hlt">dynamics</span> of osteosarcoma cells labeled with red fluorescent protein in the mitochondrial matrix space using DVFM and FICS. Cells were then treated with cytoskeletal destabilizing drugs. Analysis of microscopy data allows for us to determine whether <span class="hlt">dynamic</span> processes are diffusive or <span class="hlt">driven</span> (by the cytoskeleton or collective <span class="hlt">dynamics</span>). In FICS experiments, the control cells exhibit a unique pattern of <span class="hlt">dynamics</span> that are then simplified when the cytoskeleton is depolymerized. Upon depolymerization, the <span class="hlt">dynamics</span> of the organelle appear primarily diffusive.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMGC23F1292P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMGC23F1292P"><span><span class="hlt">Dynamic</span> simulation of storm-<span class="hlt">driven</span> barrier island morphology under future sea level rise</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Passeri, D. L.; Long, J.; Plant, N. G.; Bilskie, M. V.; Hagen, S. C.</p> <p>2016-12-01</p> <p>The impacts of short-term processes such as tropical and extratropical storms have the potential to alter barrier island morphology. On the event scale, the effects of storm-<span class="hlt">driven</span> morphology may result in damage or loss of property, infrastructure and habitat. On the decadal scale, the combination of storms and sea level rise (SLR) will evolve barrier islands. The effects of SLR on hydrodynamics and coastal morphology are <span class="hlt">dynamic</span> and inter-related; nonlinearities in SLR can cause larger peak surges, lengthier inundation times and additional inundated land, which may result in increased erosion, overwash or breaching along barrier islands. This study uses a two-dimensional morphodynamic model (XBeach) to examine the response of Dauphin Island, AL to storm surge under future SLR. The model is forced with water levels and waves provided by a large-domain hydrodynamic model. A historic validation of hurricanes Ivan and Katrina indicates the model is capable of predicting morphologic response with high skill (0.5). The validated model is used to simulate storm surge <span class="hlt">driven</span> by Ivan and Katrina under four future SLR scenarios, ranging from 20 cm to 2 m. Each SLR scenario is implemented using a static or "bathtub" approach (in which water levels are increased linearly by the amount of SLR) versus a <span class="hlt">dynamic</span> approach (in which SLR is applied at the open ocean boundary of the hydrodynamic model and allowed to propagate through the domain as guided by the governing equations). Results illustrate that higher amounts of SLR result in additional shoreline change, dune erosion, overwash and breaching. Compared to the <span class="hlt">dynamic</span> approach, the static approach over-predicts inundation, dune erosion, overwash and breaching of the island. Overall, results provide a better understanding of the effects of SLR on storm-<span class="hlt">driven</span> barrier island morphology and support a paradigm shift away from the "bathtub" approach, towards considering the integrated, <span class="hlt">dynamic</span> effects of SLR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT........86J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT........86J"><span>Binaries and the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of globular clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Jun</p> <p></p> <p>Binaries are thought to be the primary heating source in globular clusters, since they can heat the environment of globular clusters by converting their binding energy to the kinetic energy of the incoming stars through the <span class="hlt">dynamical</span> interactions. Even a small primordial binary fraction is sufficient to postpone globular clusters from the core collapse for many relaxation times. So the binary fraction is an essential parameter which can dramatically affect the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of globular clusters. In this thesis work, I determined the binary fractions for a sample of 35 Galactic globular clusters with their color-magnitude diagrams (CMDs), which covers a wide range of the <span class="hlt">dynamical</span> ages and metallicity. Those CMDs were constructed with the PSF photometry by Dolphot (V1.2) from their HST ACS archival data. Three different methods were used to estimate the binary fractions within the core, the half-mass radius, and the whole field of view regions. The binary fractions along the cluster radial bins were also analyzed. From the results, I found that the mean binary fractions within the core and the half-mass radii are 7.0% and 5.6%, respectively. The binary fractions within the core and the half-mass radii correlate with the cluster ages, with decreasing binary fractions against time, but not with their <span class="hlt">dynamical</span> times and metallicity. The binary fractions within the half-mass radius also correlate with the cluster absolute V magnitudes, with fainter clusters having higher binary fractions. The radial distribution of the binary fractions show a significant correlation with the cluster radii, with decreasing values outwards. This is consistent with the mass segregation effect predicted by the simulations of the <span class="hlt">dynamical</span> <span class="hlt">evolution</span> of globular clusters. I also compiled a catalog containing 6,004 high mass-ratio binary candidates selected from 23 Galactic globular clusters in our sample through their CMDs, which can be used to search the main</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4891819','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4891819"><span>Long-Range Coulomb Effect in Intense Laser-<span class="hlt">Driven</span> Photoelectron <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Quan, Wei; Hao, XiaoLei; Chen, YongJu; Yu, ShaoGang; Xu, SongPo; Wang, YanLan; Sun, RenPing; Lai, XuanYang; Wu, ChengYin; Gong, QiHuang; He, XianTu; Liu, XiaoJun; Chen, Jing</p> <p>2016-01-01</p> <p>In strong field atomic physics community, long-range Coulomb interaction has for a long time been overlooked and its significant role in intense laser-<span class="hlt">driven</span> photoelectron <span class="hlt">dynamics</span> eluded experimental observations. Here we report an experimental investigation of the effect of long-range Coulomb potential on the <span class="hlt">dynamics</span> of near-zero-momentum photoelectrons produced in photo-ionization process of noble gas atoms in intense midinfrared laser pulses. By exploring the dependence of photoelectron distributions near zero momentum on laser intensity and wavelength, we unambiguously demonstrate that the long-range tail of the Coulomb potential (i.e., up to several hundreds atomic units) plays an important role in determining the photoelectron <span class="hlt">dynamics</span> after the pulse ends. PMID:27256904</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011seen.book...85N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011seen.book...85N"><span>Coordination, Organisation and Model-<span class="hlt">driven</span> Approaches for <span class="hlt">Dynamic</span>, Flexible, Robust Software and Services Engineering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nieves, Juan Carlos; Padget, Julian; Vasconcelos, Wamberto; Staikopoulos, Athanasios; Cliffe, Owen; Dignum, Frank; Vázquez-Salceda, Javier; Clarke, Siobhán; Reed, Chris</p> <p></p> <p>Enterprise systems are increasingly composed of (and even functioning as) components in a <span class="hlt">dynamic</span>, digital ecosystem. On the one hand, this new situation requires flexible, spontaneous and opportunistic collaboration activities to be identified and established among (electronic) business parties. On the other, it demands engineering methods that are able to integrate new functionalities and behaviours into running systems composed by active, distributed, interdependent processes. Here we present a multi-level architecture that combines organisational and coordination theories with model <span class="hlt">driven</span>