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Sample records for vi dynamical interaction

  1. Interaction of aerobic soil bacteria with plutonium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Panak, P.J. [Lawrence Berkeley National Lab., Berkeley, CA (United States). Chemical Sciences Div.; Nitsche, H. [Lawrence Berkeley National Lab., Berkeley, CA (United States). Chemical Sciences Div.; California Univ., Berkeley, CA (United States). Dept. of Chemistry

    2001-07-01

    We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The biosorption studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The relative sorption efficiency toward Pu(VI) related to the amount of biomass used decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decrease of the number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH dependency of the biosorption and extraction studies with 0.01 M EDTA solution have shown that the biosorption of plutonium is a reversible process and the plutonium is bound by surface complexation. Optical absorption spectroscopy showed that one third of the initially present Pu(VI) was reduced to Pu(V) after 24 hours. Kinetic studies and solvent extraction to separate different oxidation states of Pu after contact with the biomass provided further information on the yield and the kinetics of the bacteria-mediated reduction. Long-term studies showed that also 16% of Pu(IV) was formed after one month. The slow kinetics of this process indicate that under our experimental conditions the Pu(IV) was not a produced by microbial reduction but seemed to be rather the result of the disproportionation of the formed Pu(V) or autoreduction of Pu(VI). (orig.)

  2. Spectroscopic studies on the interaction of chromium (VI) and chromium (III) with keyhole limpet hemocyanin.

    Science.gov (United States)

    Fan, Yulan; Zeng, Guidi; Liu, Jingyi; Chen, Huifang; Xue, Jun; Wu, Yongquan; Li, Xun

    2017-03-01

    The interactions of keyhole limpet hemocyanin (KLH) with chromium nitrate, potassium dichromate, and chromate were investigated using fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy under simulated physiological conditions. The experimental results showed that the different forms of chromium could quench the intrinsic fluorescence of KLH following a static quenching mechanism rather than by dynamic collision, which indicated that a Cr-KLH complex was formed. The Stern-Volmer quenching constants for the interaction indicated that the binding reaction of KLH with Cr(VI) was stronger the binding of KLH with Cr(III). The thermodynamic values for binding of Cr(VI) to KLH are ΔH > 0 and ΔS > 0. By contrast, the values for the interaction of Cr(III) with KLH are ΔH chromium. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Interaction of monosaccharides and related compounds with oxocations of Mo(VI), W(VI) and U(VI) studied by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Geraldes, C.F.G.C.; Castro, M.M.C.A.; Saraiva, M.E.; Aureliano, M.; Dias, B.A.

    1988-05-01

    Proton, /sup 13/C and /sup 31/P nuclear magnetic resonance spectroscopy has been used to study the complexation of Mo(VI), W(VI) and U(VI) oxocations with various aldoses, cyclic polyols and ribose-5-phosphate in aqueous solution. The aldoses D-mannose, D-lyxose and D-ribose form tridentate complexes with Mo(VI) and W(VI) at pH similarly ordered 5, via the 1,2,3-hydroxyl groups, which are cis to each other in these sugars. Other aldoses, like D-arabinose, D-glucose, D-xylose and D-galactose form weaker bidentate complexes with those ions because they can only use the 1 and 3-cis hydroxyl groups in metal binding. These bidentate interactions also take place in the binding of U(VI) to D-mannose and D-ribose, at pH similarly ordered 10. However, sugars having 1,3,5-hydroxyl groups in the cis position do not form stable chelates with these oxocations, possibly due to steric crowding. In the case of ribose-5-phosphate, the phosphate group is the exclusive binding site for the three oxocations, except for U(VI) at very basic pH (pH > 10), where the hydroxyl groups also interact with UO/sub 2//sup 2 +/.

  4. Interaction of aerobic soil bacteria with plutonium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Panak, Petra J.; Nitsche, Heino

    2000-08-22

    We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The accumulation studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The sorption efficiency toward Pu(VI) decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decreased total surface area and number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH dependency of the biosorption and extraction studies with 0.01 M EDTA solution have shown that the biosorption of plutonium is a reversible process and the plutonium is bound by surface complexation. Optical absorption spectroscopy showed that one third of the initially present Pu(VI) was reduced to Pu(V) after 24 hours. Kinetic studies and solvent extraction to separate different oxidation states of Pu after contact with the biomass provided further information on the yield and the kinetics of the bacteria-mediated reduction. Long-term studies showed that also 16% of Pu(IV) was formed after one month. The comparison of the amount of Pu(IV) formed during that time period with literature data of the Pu(V) disproportionation, indicated that the Pu(IV) seemed to be rather the result of the disproportionation of the formed Pu(V) than of a further microbial reduction.

  5. Study on the interaction of U(VI) species with natural organic matters in KURT groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Euo Chang; Baik, Min Hoon; Cho, Hye Ryun; Kim, Hee Kyung; Cha, Wansik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    The interaction of U(VI) (hexavalent uranium) species with natural organic matter (NOM) in KURT (KAERI Underground Research Tunnel) groundwater is investigated using a laser spectroscopic technique. The luminescence spectra of the NOM are observed in the ultraviolet and blue wavelength regions by irradiating a laser beam at 266 nm in groundwater. The luminescence spectra of U(VI) species in groundwater containing uranium concentrations of 0.034-0.788 mg·L-1 are measured in the green-colored wavelength region. The luminescence characteristics (peak wavelengths and lifetime) of U(VI) in the groundwater agree well with those of Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) in a standard solution prepared in a laboratory. The luminescence intensities of U(VI) in the groundwater are weaker than those of Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) in the standard solution at the same uranium concentrations. The luminescence intensities of Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) in the standard solution mixed with the groundwater are also weaker than those of Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) in the standard solution at the same uranium concentrations. These results can be ascribed to calcium-U(VI)-carbonate species interacting with NOM and forming non-radiative U(VI) complexes in groundwater.

  6. The type VI secretion system impacts bacterial invasion and population dynamics in a model intestinal microbiota

    Science.gov (United States)

    Logan, Savannah L.; Shields, Drew S.; Hammer, Brian K.; Xavier, Joao B.; Parthasarathy, Raghuveer

    Animal gastrointestinal tracts are home to a diverse community of microbes. The mechanisms by which microbial species interact and compete in this dense, physically dynamic space are poorly understood, limiting our understanding of how natural communities are assembled and how different communities could be engineered. Here, we focus on a physical mechanism for competition: the type VI secretion system (T6SS). The T6SS is a syringe-like organelle used by certain bacteria to translocate effector proteins across the cell membranes of target bacterial cells, killing them. Here, we use T6SS+ and T6SS- strains of V. cholerae, the pathogen that causes cholera in humans, and light sheet fluorescence microscopy for in vivo imaging to show that the T6SS provides an advantage to strains colonizing the larval zebrafish gut. Furthermore, we show that T6SS+ bacteria can invade and alter an existing population of a different species in the zebrafish gut, reducing its abundance and changing the form of its population dynamics. This work both demonstrates a mechanism for altering the gut microbiota with an invasive species and explores the processes controlling the stability and dynamics of the gut ecosystem. Research Corporation, Gordon and Betty Moore Foundation, and the Simons Foundation.

  7. Visualization of the Serratia Type VI Secretion System Reveals Unprovoked Attacks and Dynamic Assembly.

    Science.gov (United States)

    Gerc, Amy J; Diepold, Andreas; Trunk, Katharina; Porter, Michael; Rickman, Colin; Armitage, Judith P; Stanley-Wall, Nicola R; Coulthurst, Sarah J

    2015-09-29

    The Type VI secretion system (T6SS) is a bacterial nanomachine that fires toxic proteins into target cells. Deployment of the T6SS represents an efficient and widespread means by which bacteria attack competitors or interact with host organisms and may be triggered by contact from an attacking neighbor cell as a defensive strategy. Here, we use the opportunist pathogen Serratia marcescens and functional fluorescent fusions of key components of the T6SS to observe different subassemblies of the machinery simultaneously and on multiple timescales in vivo. We report that the localization and dynamic behavior of each of the components examined is distinct, revealing a multi-stage and dynamic assembly process for the T6SS machinery. We also show that the T6SS can assemble and fire without needing a cell contact trigger, defining an aggressive strategy that broadens target range and suggesting that activation of the T6SS is tailored to survival in specific niches. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Visualization of the Serratia Type VI Secretion System Reveals Unprovoked Attacks and Dynamic Assembly

    Directory of Open Access Journals (Sweden)

    Amy J. Gerc

    2015-09-01

    Full Text Available The Type VI secretion system (T6SS is a bacterial nanomachine that fires toxic proteins into target cells. Deployment of the T6SS represents an efficient and widespread means by which bacteria attack competitors or interact with host organisms and may be triggered by contact from an attacking neighbor cell as a defensive strategy. Here, we use the opportunist pathogen Serratia marcescens and functional fluorescent fusions of key components of the T6SS to observe different subassemblies of the machinery simultaneously and on multiple timescales in vivo. We report that the localization and dynamic behavior of each of the components examined is distinct, revealing a multi-stage and dynamic assembly process for the T6SS machinery. We also show that the T6SS can assemble and fire without needing a cell contact trigger, defining an aggressive strategy that broadens target range and suggesting that activation of the T6SS is tailored to survival in specific niches.

  9. Interactive molecular dynamics

    CERN Document Server

    Schroeder, Daniel V

    2015-01-01

    Physics students now have access to interactive molecular dynamics simulations that can model and animate the motions of hundreds of particles, such as noble gas atoms, that attract each other weakly at short distances but repel strongly when pressed together. Using these simulations, students can develop an understanding of forces and motions at the molecular scale, nonideal fluids, phases of matter, thermal equilibrium, nonequilibrium states, the Boltzmann distribution, the arrow of time, and much more. This article summarizes the basic features and capabilities of such a simulation, presents a variety of student exercises using it at the introductory and intermediate levels, and describes some enhancements that can further extend its uses. A working simulation code, in HTML5 and JavaScript for running within any modern Web browser, is provided as an online supplement.

  10. Interaction of chromium(III) or chromium(VI) with catalase and its effect on the structure and function of catalase: An in vitro study.

    Science.gov (United States)

    Chen, Linfeng; Zhang, Jing; Zhu, Yaxian; Zhang, Yong

    2018-04-01

    Heavy metal chromium (Cr) poses a severe health risk to humans via food chain contamination. In this study, the interactions of either trivalent chromium (Cr(III)) or hexavalent chromium (Cr(VI)) with catalase (CAT) were investigated via multi-spectroscopic studies and computational simulations. The fluorescence analysis showed that Cr(III) and Cr(VI) quenched the fluorescence of CAT through a dynamic and a static quenching mechanism, respectively. The binding constant of Cr(VI) with CAT was 3.44×10(4)lmol(-1) at 298K. Other detailed binding characterizations of the Cr(VI)-CAT complex were also obtained using spectra analysis and molecular docking. Synchronous fluorescence, UV-vis and circular dichroism (CD) spectral studies showed that either Cr(III) or Cr(VI) induced conformational changes of CAT, but the degree of influence was different. The response of CAT activity to Cr(III) or Cr(VI) was found to be variable depending on their valence states and concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. System dynamics with interaction discontinuity

    CERN Document Server

    Luo, Albert C J

    2015-01-01

    This book describes system dynamics with discontinuity caused by system interactions and presents the theory of flow singularity and switchability at the boundary in discontinuous dynamical systems. Based on such a theory, the authors address dynamics and motion mechanism of engineering discontinuous systems due to interaction. Stability and bifurcations of fixed points in nonlinear discrete dynamical systems are presented, and mapping dynamics are developed for analytical predictions of periodic motions in engineering discontinuous dynamical systems. Ultimately, the book provides an alternative way to discuss the periodic and chaotic behaviors in discontinuous dynamical systems.

  12. Interactive Dynamic-System Simulation

    CERN Document Server

    Korn, Granino A

    2010-01-01

    Showing you how to use personal computers for modeling and simulation, Interactive Dynamic-System Simulation, Second Edition provides a practical tutorial on interactive dynamic-system modeling and simulation. It discusses how to effectively simulate dynamical systems, such as aerospace vehicles, power plants, chemical processes, control systems, and physiological systems. Written by a pioneer in simulation, the book introduces dynamic-system models and explains how software for solving differential equations works. After demonstrating real simulation programs with simple examples, the author

  13. Exploring the Interaction Natures in Plutonyl (VI) Complexes with Topological Analyses of Electron Density.

    Science.gov (United States)

    Du, Jiguang; Sun, Xiyuan; Jiang, Gang

    2016-04-11

    The interaction natures between Pu and different ligands in several plutonyl (VI) complexes are investigated by performing topological analyses of electron density. The geometrical structures in both gaseous and aqueous phases are obtained with B3LYP functional, and are generally in agreement with available theoretical and experimental results when combined with all-electron segmented all-electron relativistic contracted (SARC) basis set. The Pu- O y l bond orders show significant linear dependence on bond length and the charge of oxygen atoms in plutonyl moiety. The closed-shell interactions were identified for Pu-Ligand bonds in most complexes with quantum theory of atoms in molecules (QTAIM) analyses. Meanwhile, we found that some Pu-Ligand bonds, like Pu-OH(-), show weak covalent. The interactive nature of Pu-ligand bonds were revealed based on the interaction quantum atom (IQA) energy decomposition approach, and our results indicate that all Pu-Ligand interactions is dominated by the electrostatic attraction interaction as expected. Meanwhile it is also important to note that the quantum mechanical exchange-correlation contributions can not be ignored. By means of the non-covalent interaction (NCI) approach it has been found that some weak and repulsion interactions existed in plutonyl(VI) complexes, which can not be distinguished by QTAIM, can be successfully identified.

  14. Exploring the Interaction Natures in Plutonyl (VI Complexes with Topological Analyses of Electron Density

    Directory of Open Access Journals (Sweden)

    Jiguang Du

    2016-04-01

    Full Text Available The interaction natures between Pu and different ligands in several plutonyl (VI complexes are investigated by performing topological analyses of electron density. The geometrical structures in both gaseous and aqueous phases are obtained with B3LYP functional, and are generally in agreement with available theoretical and experimental results when combined with all-electron segmented all-electron relativistic contracted (SARC basis set. The Pu– O y l bond orders show significant linear dependence on bond length and the charge of oxygen atoms in plutonyl moiety. The closed-shell interactions were identified for Pu-Ligand bonds in most complexes with quantum theory of atoms in molecules (QTAIM analyses. Meanwhile, we found that some Pu–Ligand bonds, like Pu–OH−, show weak covalent. The interactive nature of Pu–ligand bonds were revealed based on the interaction quantum atom (IQA energy decomposition approach, and our results indicate that all Pu–Ligand interactions is dominated by the electrostatic attraction interaction as expected. Meanwhile it is also important to note that the quantum mechanical exchange-correlation contributions can not be ignored. By means of the non-covalent interaction (NCI approach it has been found that some weak and repulsion interactions existed in plutonyl(VI complexes, which can not be distinguished by QTAIM, can be successfully identified.

  15. Exploring the Interaction Natures in Plutonyl (VI) Complexes with Topological Analyses of Electron Density

    OpenAIRE

    Jiguang Du; Xiyuan Sun; Gang Jiang

    2016-01-01

    The interaction natures between Pu and different ligands in several plutonyl (VI) complexes are investigated by performing topological analyses of electron density. The geometrical structures in both gaseous and aqueous phases are obtained with B3LYP functional, and are generally in agreement with available theoretical and experimental results when combined with all-electron segmented all-electron relativistic contracted (SARC) basis set. The Pu– O y l bond orders show significant line...

  16. Spectroscopic studies on the interaction of U(VI) with Bacillus sphaericus

    Energy Technology Data Exchange (ETDEWEB)

    Panak, P.J.; Knopp, R.; Booth, C.H. [Lawrence Berkeley National Lab., The Glenn T. Seaborg Center, Berkeley, CA (United States); Nitsche, H. [Lawrence Berkeley National Lab., The Glenn T. Seaborg Center, Berkeley, CA (United States); Univ. of California at Berkeley, Dept. of Chemistry, Berkeley, CA (United States)

    2002-07-01

    We studied the interaction of U(VI) with vegetative cells, heat killed cells, spores, and decomposed cells of Bacillus sphaericus. The characterization of the formed complexes was performed by time-resolved laser fluorescence spectroscopy (TRLFS) and extended X-ray absorption fine structure spectroscopy (EXAFS). We observed no significant differences in the sorption behavior of vegetative and heat killed cells, whereas the spores showed a higher sorption of U(VI) (related to their dry weight). Regardless of the higher relative sorption of the spores of B. sphaericus, the fluorescence and EXAFS spectra of the vegetative cells, heat killed cells and spores were almost identical. Analysis of the data proved that U(VI) forms inner sphere complexes with organic bound phosphate groups on the cell surface. We observed no significant differences in the coordination numbers and the distances of the oxygen and phosphorus atoms in the inner coordination sphere. After eight weeks, the vegetative cells of B. sphaericus were completely decomposed. Lysing of the cell walls and activity of enzymes led to a release of various decomposition products. We found that large amounts of H{sub 2}PO{sub 4}{sup -} were released which caused a quantitative precipitation of bacterial U(VI) as UO{sub 2}(H{sub 2}PO{sub 4}){sub 2}. The H{sub 2}PO{sub 4}{sup -} was detected by Raman spectroscopy. The decomposed bacterial suspension showed the same fluorescence spectrum as UO{sub 2}(H{sub 2}PO{sub 4}){sub 2} which differed significantly from those of the bacterial U(VI) surface complexes. (orig.)

  17. Aqueous U(VI) interaction with magnetite nanoparticles in a mixed flow reactor system: HR-XANES study

    Science.gov (United States)

    Pidchenko, I.; Heberling, F.; Kvashnina, KO; Finck, N.; Schild, D.; Bohnert, E.; Schäfer, T.; Rothe, J.; Geckeis, H.; Vitova, T.

    2016-05-01

    The redox variations and changes in local atomic environment of uranium (U) interacted with the magnetite nanoparticles were studied in a proof of principle experiment by the U L3 and M4 edges high energy resolution X-ray absorption near edge structure (HR-XANES) technique. We designed and applied a mixed flow reactor (MFR) set-up to maintain dynamic flow conditions during U-magnetite interactions. Formation of hydrolyzed, bi- and poly-nuclear U species were excluded by slow continuous injection of U(VI) (10-6 M) and pH control integrated in the MFR set-up. The applied U HR-XANES technique is more sensitive to minor changes in the U redox states and bonding compared to the conventional XANES method. Major U(VI) contribution in uranyl type of bonding is found in the magnetite nanoparticles after three days operation time of the MFR. Indications for shortening of the U-Oaxial bond length for the magnetite compared to the maghemite system are present too.

  18. Fha Interaction with Phosphothreonine of TssL Activates Type VI Secretion in Agrobacterium tumefaciens

    Science.gov (United States)

    Lin, Jer-Sheng; Wu, Hsin-Hui; Hsu, Pang-Hung; Ma, Lay-Sun; Pang, Yin-Yuin; Tsai, Ming-Daw; Lai, Erh-Min

    2014-01-01

    The type VI secretion system (T6SS) is a widespread protein secretion system found in many Gram-negative bacteria. T6SSs are highly regulated by various regulatory systems at multiple levels, including post-translational regulation via threonine (Thr) phosphorylation. The Ser/Thr protein kinase PpkA is responsible for this Thr phosphorylation regulation, and the forkhead-associated (FHA) domain-containing Fha-family protein is the sole T6SS phosphorylation substrate identified to date. Here we discovered that TssL, the T6SS inner-membrane core component, is phosphorylated and the phosphorylated TssL (p-TssL) activates type VI subassembly and secretion in a plant pathogenic bacterium, Agrobacterium tumefaciens. Combining genetic and biochemical approaches, we demonstrate that TssL is phosphorylated at Thr 14 in a PpkA-dependent manner. Further analysis revealed that the PpkA kinase activity is responsible for the Thr 14 phosphorylation, which is critical for the secretion of the T6SS hallmark protein Hcp and the putative toxin effector Atu4347. TssL phosphorylation is not required for the formation of the TssM-TssL inner-membrane complex but is critical for TssM conformational change and binding to Hcp and Atu4347. Importantly, Fha specifically interacts with phosphothreonine of TssL via its pThr-binding motif in vivo and in vitro and this interaction is crucial for TssL interaction with Hcp and Atu4347 and activation of type VI secretion. In contrast, pThr-binding ability of Fha is dispensable for TssM structural transition. In conclusion, we discover a novel Thr phosphorylation event, in which PpkA phosphorylates TssL to activate type VI secretion via its direct binding to Fha in A. tumefaciens. A model depicting an ordered TssL phosphorylation-induced T6SS assembly pathway is proposed. PMID:24626341

  19. Dynamic reservoir well interaction

    NARCIS (Netherlands)

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.

    2004-01-01

    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady

  20. SDI: Statistical dynamic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Blann, M.; Mustafa, M.G. (Lawrence Livermore National Lab., CA (USA)); Peilert, G.; Stoecker, H.; Greiner, W. (Frankfurt Univ. (Germany, F.R.). Inst. fuer Theoretische Physik)

    1991-04-01

    We focus on the combined statistical and dynamical aspects of heavy ion induced reactions. The overall picture is illustrated by considering the reaction {sup 36}Ar + {sup 238}U at a projectile energy of 35 MeV/nucleon. We illustrate the time dependent bound excitation energy due to the fusion/relaxation dynamics as calculated with the Boltzmann master equation. An estimate of the mass, charge and excitation of an equilibrated nucleus surviving the fast (dynamic) fusion-relaxation process is used as input into an evaporation calculation which includes 20 heavy fragment exit channels. The distribution of excitations between residue and clusters is explicitly calculated, as is the further deexcitation of clusters to bound nuclei. These results are compared with the exclusive cluster multiplicity measurements of Kim et al., and are found to give excellent agreement. We consider also an equilibrated residue system at 25% lower initial excitation, which gives an unsatisfactory exclusive multiplicity distribution. This illustrates that exclusive fragment multiplicity may provide a thermometer for system excitation. This analysis of data involves successive binary decay with no compressional effects nor phase transitions. Several examples of primary versus final (stable) cluster decay probabilities for an A = 100 nucleus at excitations of 100 to 800 MeV are presented. From these results a large change in multifragmentation patterns may be understood as a simple phase space consequence, invoking neither phase transitions, nor equation of state information. These results are used to illustrate physical quantities which are ambiguous to deduce from experimental fragment measurements. 14 refs., 4 figs.

  1. Evolutionary dynamics under interactive diversity

    Science.gov (United States)

    Su, Qi; Li, Aming; Wang, Long

    2017-10-01

    As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

  2. Dynamic Soil-Structure-Interaction

    DEFF Research Database (Denmark)

    Kellezi, Lindita

    1998-01-01

    The aim of this thesis is to investigate and develop alternative methods of analyzing problems in dynamic soil-structure-interaction. The main focus is the major difficulty posed by such an analysis - the phenomenon of waves which radiate outward from the excited structures towards infinity...... transmitting boundary at the edges of the computational mesh. To start with, an investigation of the main effects of the interaction phenomena is carried out employing a widely used model, considering dynamic stiffness of the unbounded soil as frequency independent. Then a complete description...... represents an attempt to construct a local stiffness for the unbounded soil domain....

  3. Burkholderia type VI secretion systems have distinct roles in eukaryotic and bacterial cell interactions

    DEFF Research Database (Denmark)

    Schwarz, Sandra; West, T Eoin; Boyer, Frédéric

    2010-01-01

    Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs) of Burkholderia thailandensis (B. thai) in eukaryotic and bacteri...... of bacterial cells of one species in intimate association with those of another, such as in polymicrobial communities present both in the environment and in many infections....... displaced in mixed biofilms with P. putida, whereas wild-type cells persisted and overran the competitor. Our data show that T6SSs within a single organism can have distinct functions in eukaryotic versus bacterial cell interactions. These systems are likely to be a decisive factor in the survival......Bacteria that live in the environment have evolved pathways specialized to defend against eukaryotic organisms or other bacteria. In this manuscript, we systematically examined the role of the five type VI secretion systems (T6SSs) of Burkholderia thailandensis (B. thai) in eukaryotic and bacterial...

  4. Dynamic sensorimotor interactions in locomotion.

    Science.gov (United States)

    Rossignol, Serge; Dubuc, Réjean; Gossard, Jean-Pierre

    2006-01-01

    Locomotion results from intricate dynamic interactions between a central program and feedback mechanisms. The central program relies fundamentally on a genetically determined spinal circuitry (central pattern generator) capable of generating the basic locomotor pattern and on various descending pathways that can trigger, stop, and steer locomotion. The feedback originates from muscles and skin afferents as well as from special senses (vision, audition, vestibular) and dynamically adapts the locomotor pattern to the requirements of the environment. The dynamic interactions are ensured by modulating transmission in locomotor pathways in a state- and phase-dependent manner. For instance, proprioceptive inputs from extensors can, during stance, adjust the timing and amplitude of muscle activities of the limbs to the speed of locomotion but be silenced during the opposite phase of the cycle. Similarly, skin afferents participate predominantly in the correction of limb and foot placement during stance on uneven terrain, but skin stimuli can evoke different types of responses depending on when they occur within the step cycle. Similarly, stimulation of descending pathways may affect the locomotor pattern in only certain phases of the step cycle. Section ii reviews dynamic sensorimotor interactions mainly through spinal pathways. Section iii describes how similar sensory inputs from the spinal or supraspinal levels can modify locomotion through descending pathways. The sensorimotor interactions occur obviously at several levels of the nervous system. Section iv summarizes presynaptic, interneuronal, and motoneuronal mechanisms that are common at these various levels. Together these mechanisms contribute to the continuous dynamic adjustment of sensorimotor interactions, ensuring that the central program and feedback mechanisms are congruous during locomotion.

  5. Molecular Interactions of Plutonium(VI) with Synthetic Manganese-Substituted Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yung-Jin; Schwaiger, Luna Kestrel; Booth, Corwin H.; Kukkadapu, Ravi K.; Cristiano, Elena; Kaplan, Daniel; Nitsche, Heino

    2010-03-09

    Plutonium(VI) sorption on the surface of well-characterized synthetic manganese-substituted goethite minerals (Fe1-xMnxOOH) was studied using X-ray absorption spectroscopy. We chose to study the influence of manganese as a minor component in goethite, because goethite rarely exists as a pure phase in nature. Manganese X-ray absorption near-edge structure measurements indicated that essentially all the Mn in the goethite existed as Mn(III), even though Mn was added during mineral synthesis as Mn(II). Importantly, energy dispersive X-ray analysis demonstrated that Mn did not exist as discrete phases and that it was homogeneously mixed into the goethite to within the limit of detection of the method. Furthermore, Mössbauer spectra demonstrated that all Fe existed as Fe(III), with no Fe(II) present. Plutonium(VI) sorption experiments were conducted open to air and no attempt was made to exclude carbonate. The use of X-ray absorption spectroscopy allows us to directly and unambiguously measure the oxidation state of plutonium in situ at the mineral surface. Plutonium X-ray absorption near-edge structure measurements carried out on these samples showed that Pu(VI) was reduced to Pu(IV) upon contact with the mineral. This reduction appears to be strongly correlated with mineral solution pH, coinciding with pH transitions across the point of zero charge of the mineral. Furthermore, extended X-ray absorption fine structure measurements show evidence of direct plutonium binding to the metal surface as an inner-sphere complex. This combination of extensive mineral characterization and advanced spectroscopy suggests that sorption of the plutonium onto the surface of the mineral was followed by reduction of the plutonium at the surface of the mineral to form an inner-sphere complex. Because manganese is often found in the environment as a minor component associated with major mineral components, such as goethite, understanding the molecular-level interactions of plutonium with

  6. Interaction of Pu(IV,VI) hydroxides/oxides with metal hydroxides/oxides in alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Fedoseev, A.M.; Krot, N.N.; Budantseva, N.A.; Bessonov, A.A.; Nikonov, M.V.; Grigoriev, M.S.; Garnov, A.Y.; Perminov, V.P.; Astafurova, L.N. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

    1998-08-01

    The primary goal of this investigation was to obtain data on the possibility, extent, and characteristics of interaction of Pu(IV) and (VI) with hydroxides and oxides of d-elements and other metals [Al(III), LA(III), and U(VI)] in alkaline media. Such information is important in fundamental understanding of plutonium disposition and behavior in Hanford Site radioactive tank waste sludge. These results supply essential data for determining criticality safety and in understanding transuranic waste behavior in storage, retrieval, and treatment of Hanford Site tank waste.

  7. Nonlinear dynamics of interacting populations

    CERN Document Server

    Bazykin, Alexander D

    1998-01-01

    This book contains a systematic study of ecological communities of two or three interacting populations. Starting from the Lotka-Volterra system, various regulating factors are considered, such as rates of birth and death, predation and competition. The different factors can have a stabilizing or a destabilizing effect on the community, and their interplay leads to increasingly complicated behavior. Studying and understanding this path to greater dynamical complexity of ecological systems constitutes the backbone of this book. On the mathematical side, the tool of choice is the qualitative the

  8. /sup 57/Fe impurity atom lattice dynamics and systematics in group V and VI host metals

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R.D.; Kitchens, T.A. Jr.; Erickson, D.J.

    1976-01-01

    The Moessbauer recoil-free fraction f and thermal shift have been measured for very dilute /sup 57/Fe impurities in body-centered cubic V, Nb, Mo, Ta, and W host metals in the range 4 to 860/sup 0/K. These experimental quantities have been interpreted in terms of an impurity-atom lattice-dynamical model of Mannheim where the important parameter ..gamma../sub ih//..gamma../sub hh/ is a measure of the coupling of the impurity atom to the host lattice relative to the corresponding coupling in the pure host lattice. Values of ..gamma../sub ih//..gamma../sub hh/ for each host from the f-value data were obtained and, independently, from the shift data, and for each host rather good agreement is obtained. The general trend of the data shows that for neighboring hosts of the same row of the periodic table, the relative /sup 57/Fe impurity binding is stronger for the Group V host than for the Group VI host. The results also support a previous conjecture that the nearest-neighbor binding between the impurity and the host should be proportional to a geometric mean of the nearest-neighbor couplings for a lattice consisting entirely of impurity atoms and for a lattice of host atoms only.

  9. Wigner method dynamics in the interaction picture

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Dahl, Jens Peder; Henriksen, Niels Engholm

    1994-01-01

    The possibility of introducing an interaction picture in the semiclassical Wigner method is investigated. This is done with an interaction Picture description of the density operator dynamics as starting point. We show that the dynamics of the density operator dynamics as starting point. We show...... that the dynamics of the interaction picture Wigner function is solved by running a swarm of trajectories in the classical interaction picture introduced previously in the literature. Solving the Wigner method dynamics of collision processes in the interaction picture ensures that the calculated transition...... probabilities are unambiguous even when the asymptotic potentials are anharmonic. An application of the interaction picture Wigner method to a Morse oscillator interacting with a laser field is presented. The calculated transition probabilities are in good agreement with results obtained by a numerical...

  10. Elucidating the mechanism of Cr(VI) formation upon the interaction with metal oxides during coal oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Juan [Department of Chemical Engineering, Monash University, Clayton, GPO Box 36, Victoria 3800 (Australia); State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Jiao, Facun [Department of Applied Chemistry, Chubu University, 1200 Matsumoto-Cho, Kasugai, Aichi 487-8501 (Japan); Zhang, Lian, E-mail: lian.zhang@monash.edu [Department of Chemical Engineering, Monash University, Clayton, GPO Box 36, Victoria 3800 (Australia); Yao, Hong [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Ninomiya, Yoshihiko [Department of Applied Chemistry, Chubu University, 1200 Matsumoto-Cho, Kasugai, Aichi 487-8501 (Japan)

    2013-10-15

    Highlights: • The presence of Ca{sup 2+}/K{sup +} oxide in coal favored the enrichment of toxic Cr(VI) in coal combustion derived fly ash. • Fe{sub 2}O{sub 3} and MgO in coal are critical on the inhibition of Cr(VI) formation during coal combustion. • Cr(VI) formation extent is correlated positively with the standard reduction potential of metal oxide in coal. -- Abstract: The thermodynamics underpinning the interaction of Cr-bearing species with basic metal oxides, i.e. K{sub 2}O, Fe{sub 2}O{sub 3}, MgO and CaO, during the air and oxy-fuel combustion of coal have been examined. The synchrotron-based X-ray adsorption near-edge spectroscopy (XANES) was used for Cr speciation. For the oxides tested, Cr(VI) formation is dominated by the reduction potential of the metals. The oxides of Ca{sup 2+} with high reduction potential favored the oxidation of Cr(III), same for K{sup +}. The other two basic metals, Fe{sub 2}O{sub 3} and MgO with lower reduction potentials reacted with Cr(III) to form the corresponding chromites at the temperatures above 600 °C. Coal combustion experiments in drop-tube furnace have confirmed the rapid capture of Cr vapors, either trivalent or hexavalent, by CaO into solid ash. The existence of HCl in flue gas favored the vaporization of Cr as CrO{sub 2}Cl{sub 2}, which was in turn captured by CaO into chromate. Both Fe{sub 2}O{sub 3} and MgO exhibited less capability on scavenging the Cr(VI) vapor. Particularly, MgO alone exhibited a low capability for capturing the vaporized Cr(III) vapors. However, its co-existence with CaO in the furnace inhibited the Cr(VI) formation. This is beneficial for minimizing the toxicity of Cr in the coal combustion-derived fly ash.

  11. Ab initio molecular dynamics investigation of structural, dynamic and spectroscopic aspects of Se(vi) species in the aqueous environment.

    Science.gov (United States)

    Borah, Sangkha; Padma Kumar, P

    2016-06-07

    Microscopic investigation of solvation of selenic acid (H2SeO4) in the aqueous environment has been carried out using the Car-Parrinello molecular dynamics simulation technique. The species deprotonates to HSeO4(-) in a few picoseconds owing to its low pKa1 value of -3.0. A dynamic equilibrium between HSeO4(-) and SeO4(2-), is observed in qualitative agreement with the reported pKa2 value of 1.70. The governing deprotonation mechanism and the structural and dynamic evolutions of the system, particularly the nature of hydrogen bonding, their strengths and lifetimes are investigated comprehensively. A comparison of the vibrational spectra of the species recorded in the gas phase and in the aqueous environment provides further insights on the nature of the interaction between the solute species and water. The results are in good agreement with the available experimental data and other recent computational studies.

  12. Uranium(VI) interactions with mackinawite in the presence and absence of bicarbonate and oxygen

    Science.gov (United States)

    Gallegos, Tanya J.; Fuller, Christopher C.; Webb, Samuel M.; Betterton, William J.

    2013-01-01

    Mackinawite, Fe(II)S, samples loaded with uranium (10-5, 10-4, and 10-3 mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10-5 M uranium(VI) to below 30 ppb (1.26 × 10-7 M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium–oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water.

  13. Dynamics of Bianchi type-VI0 holographic dark energy models in ...

    Indian Academy of Sciences (India)

    In this paper, we have studied the anisotropic and homogeneous Bianchi type-VI 0 Universe filled with dark matter and holographic dark energy components in the framework of general relativity and Lyra's geometry. The Einstein's field equations have been solved exactly by taking the expansion scalar ( θ ) in the model is ...

  14. Adenovirus protein-protein interactions: molecular parameters governing the binding of protein VI to hexon and the activation of the adenovirus 23K protease.

    Science.gov (United States)

    Matthews, D A; Russell, W C

    1995-08-01

    A variety of recombinant proteins derived from protein pVI of human adenovirus type 2 (Ad2) were analysed for their ability to bind Ad2 hexon in vitro. As pVI is also required for activation of the adenovirus-coded protease, the same pVI derivatives were assessed for their ability to activate recombinant adenovirus-coded 23K protease. Two regions, between amino acid residues 48-74 and 233-239 of pVI, were required for the interaction with hexon. These regions are highly conserved amongst mastadenovirus pVI proteins. Both these regions are capable on their own of binding hexon weakly but must be provided in cis for strong hexon binding. In addition, we found evidence to indicate than conformation as well as sequence was important for good hexon binding in our assays. Authentic processing of the appropriate recombinant pVI derivatives, by the recombinant protease, was obtained without the addition of other cofactors. These findings are discussed in relation to the role of pVI in triggering the adenovirus maturation pathway.

  15. Symbolic dynamics of animal interaction.

    Science.gov (United States)

    Porfiri, Maurizio; Ruiz Marín, Manuel

    2017-12-21

    Since its introduction nearly two decades ago, transfer entropy has contributed to an improved understanding of cause-and-effect relationships in coupled dynamical systems from raw time series. In the context of animal behavior, transfer entropy might help explain the determinants of leadership in social groups and elucidate escape response to predator attacks. Despite its promise, the potential of transfer entropy in animal behavior is yet to be fully tested, and a number of technical challenges in information theory and statistics remain open. Here, we examine an alternative approach to the computation of transfer entropy based on symbolic dynamics. In this context, a symbol is associated with a specific locomotory bout across two or more consecutive time instants, such as reversing the swimming direction. Symbols encapsulate salient locomotory patterns and the associated permutation transfer entropy quantifies the ability to predict the patterns of an individual given those of another individual. We demonstrate this framework on an existing dataset on fish, for which we have knowledge of the underlying cause-and-effect relationship between the focal subject and the stimulus. Symbolic dynamics offers an intuitive and robust approach to study animal behavior, which could enable the inference of causal relationship from noisy experimental observations of limited duration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Dynamics of interacting information waves in networks

    CERN Document Server

    Mirshahvalad, Atieh; Lizana, Ludvig; Rosvall, Martin

    2013-01-01

    To better understand the inner workings of information spreading, network researchers often use simple models to capture the spreading dynamics. But most models only highlight the effect of local interactions on the global spreading of a single information wave, and ignore the effects of interactions between multiple waves. Here we take into account the effect of multiple interacting waves by using an agent-based model in which the interaction between information waves is based on their novelty. We analyzed the global effects of such interactions and found that information that actually reaches nodes reaches them faster. This effect is caused by selection between information waves: slow waves die out and only fast waves survive. As a result, and in contrast to models with non-interacting information dynamics, the access to information decays with the distance from the source. Moreover, when we analyzed the model on various synthetic and real spatial road networks, we found that the decay rate also depends on ...

  17. Network Physiology: How Organ Systems Dynamically Interact.

    Directory of Open Access Journals (Sweden)

    Ronny P Bartsch

    Full Text Available We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS, we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  18. Network Physiology: How Organ Systems Dynamically Interact.

    Science.gov (United States)

    Bartsch, Ronny P; Liu, Kang K L; Bashan, Amir; Ivanov, Plamen Ch

    2015-01-01

    We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  19. Dynamics of colloidal particles with capillary interactions.

    Science.gov (United States)

    Domínguez, Alvaro; Oettel, Martin; Dietrich, S

    2010-07-01

    We investigate the dynamics of colloids at a fluid interface driven by attractive capillary interactions. At submillimeter length scales, the capillary attraction is formally analogous to two-dimensional gravity. In particular it is a nonintegrable interaction and it can be actually relevant for collective phenomena in spite of its weakness at the level of the pair potential. We introduce a mean-field model for the dynamical evolution of the particle number density at the interface. For generic values of the physical parameters the homogeneous distribution is found to be unstable against large-scale clustering driven by the capillary attraction. We also show that for the instability to be observable, the appropriate values for the relevant parameters (colloid radius, surface charge, external electric field, etc.) are experimentally well accessible. Our analysis contributes to current studies of the structure and dynamics of systems governed by long-ranged interactions and points toward their experimental realizations via colloidal suspensions.

  20. Highly integrated flow assembly for automated dynamic extraction and determination of readily bioaccessible chromium(VI) in soils exploiting carbon nanoparticle-based solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Rosende, Maria; Miro, Manuel; Cerda, Victor [University of the Balearic Islands, Department of Chemistry, Palma de Mallorca (Spain); Segundo, Marcela A.; Lima, Jose L.F.C. [University of Porto, REQUIMTE, Department of Chemistry, Faculty of Pharmacy, Porto (Portugal)

    2011-06-15

    An automated dynamic leaching test integrated in a portable flow-based setup is herein proposed for reliable determination of readily bioaccessible Cr(VI) under worst-case scenarios in soils containing varying levels of contamination. The manifold is devised to accommodate bi-directional flow extraction followed by processing of extracts via either in-line clean-up/preconcentration using multi-walled carbon nanotubes or automatic dilution at will, along with Cr(VI) derivatization and flow-through spectrophotometric detection. The magnitude of readily mobilizable Cr(VI) pools was ascertained by resorting to water extraction as promulgated by current standard leaching tests. The role of carbon nanomaterials for the uptake of Cr(VI) in soil leachates and the configuration of the packed column integrated in the flow manifold were investigated in detail. The analytical performance of the proposed system for in vitro bioaccessibility tests was evaluated in chromium-enriched soils at environmentally relevant levels and in a standard reference soil material (SRM 2701) with a certified value of total hexavalent chromium. The automated method was proven to afford unbiased assessment of water-soluble Cr(VI) in soils as a result of the minimization of the chromium species transformation. By combination of the kinetic leaching profile and a first-order leaching model, the water-soluble Cr(VI) fraction in soils was determined in merely 6 h against >24 h taken in batchwise steady-state standard methods. (orig.)

  1. Dynamic Map: Representation of interactions between robots

    Energy Technology Data Exchange (ETDEWEB)

    Zanardi, C. [GRPR, Ecole Polytechnique de Montreal (Canada)

    1996-12-31

    As robotics applications become more complex, the need for tools to analyze and explain interactions between robots has become more acute. We introduce the concept of Dynamic Map (DM), which can serve as a generic tool to analyze interactions between robots or with their environment. We show that this concept can be applied to different kinds of applications, like a predator-prey situation, or collision avoidance.

  2. Quantitative single-cell characterization of bacterial interactions reveals type VI secretion is a double-edged sword.

    Science.gov (United States)

    LeRoux, Michele; De Leon, Justin A; Kuwada, Nathan J; Russell, Alistair B; Pinto-Santini, Delia; Hood, Rachel D; Agnello, Danielle M; Robertson, Stephen M; Wiggins, Paul A; Mougous, Joseph D

    2012-11-27

    Interbacterial interaction pathways play an important role in defining the structure and complexity of bacterial associations. A quantitative description of such pathways offers promise for understanding the forces that contribute to community composition. We developed time-lapse fluorescence microscopy methods for quantitation of interbacterial interactions and applied these to the characterization of type VI secretion (T6S) in Pseudomonas aeruginosa. Our analyses allowed a direct determination of the efficiency of recipient cell lysis catalyzed by this intercellular toxin delivery pathway and provided evidence that its arsenal extends beyond known effector proteins. Measurement of T6S apparatus localization revealed correlated activation among neighboring cells, which, taken together with genetic data, implicate the elaboration of a functional T6S apparatus with a marked increase in susceptibility to intoxication. This possibility was supported by the identification of T6S-inactivating mutations in a genome-wide screen for resistance to T6S-mediated intoxication and by time-lapse fluorescence microscopy analyses showing a decreased lysis rate of recipient cells lacking T6S function. Our discoveries highlight the utility of single-cell approaches for measuring interbacterial phenomena and provide a foundation for studying the contribution of a widespread bacterial interaction pathway to community structure.

  3. Simulation of Gas-Surface Dynamical Interactions

    Science.gov (United States)

    2007-07-01

    surface. The substrate with lattice constant a is represented in a simple ball and spring picture. on the particular problem. Time-independent...παvwell , (26) Simulation of Gas-Surface Dynamical Interactions 4 - 10 RTO-EN-AVT-142 g E ad v mvc ∆ v’well vc cM Figure 4

  4. Interactions Dominate the Dynamics of Visual Cognition

    Science.gov (United States)

    Stephen, Damian G.; Mirman, Daniel

    2010-01-01

    Many cognitive theories have described behavior as the summation of independent contributions from separate components. Contrasting views have emphasized the importance of multiplicative interactions and emergent structure. We describe a statistical approach to distinguishing additive and multiplicative processes and apply it to the dynamics of…

  5. Dynamical and bursty interactions in social networks

    Science.gov (United States)

    Stehlé, Juliette; Barrat, Alain; Bianconi, Ginestra

    2010-03-01

    We present a modeling framework for dynamical and bursty contact networks made of agents in social interaction. We consider agents’ behavior at short time scales in which the contact network is formed by disconnected cliques of different sizes. At each time a random agent can make a transition from being isolated to being part of a group or vice versa. Different distributions of contact times and intercontact times between individuals are obtained by considering transition probabilities with memory effects, i.e., the transition probabilities for each agent depend both on its state (isolated or interacting) and on the time elapsed since the last change in state. The model lends itself to analytical and numerical investigations. The modeling framework can be easily extended and paves the way for systematic investigations of dynamical processes occurring on rapidly evolving dynamical networks, such as the propagation of an information or spreading of diseases.

  6. Interactions Dominate the Dynamics of Visual Cognition

    Science.gov (United States)

    Stephen, Damian G.; Mirman, Daniel

    2010-01-01

    Many cognitive theories have described behavior as the summation of independent contributions from separate components. Contrasting views have emphasized the importance of multiplicative interactions and emergent structure. We describe a statistical approach to distinguishing additive and multiplicative processes and apply it to the dynamics of eye movements during classic visual cognitive tasks. The results reveal interaction-dominant dynamics in eye movements in each of the three tasks, and that fine-grained eye movements are modulated by task constraints. These findings reveal the interactive nature of cognitive processing and are consistent with theories that view cognition as an emergent property of processes that are broadly distributed over many scales of space and time rather than a componential assembly line. PMID:20070957

  7. Molecular interactions of Leucoagaricus naucinus with uranium(VI) and europium(III)

    Energy Technology Data Exchange (ETDEWEB)

    Wollenberg, Anne; Raff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Guenther, A. [Helmholtz Institute Freiberg for Resource Technology, Freiberg (Germany)

    2017-06-01

    With regard to a molecular understanding of the interaction of fungal mycelium with radionuclides and its possible application for precautionary radiation protection and bio-remediation, the binding mechanism of the radionuclide uranium and the metal europium, as surrogate for trivalent actinides, where investigated with different starting conditions by the living fungal cells of Leucoagaricus naucinus.

  8. Interactive macroeconomics stochastic aggregate dynamics with heterogeneous and interacting agents

    CERN Document Server

    Di Guilmi, Corrado

    2017-01-01

    One of the major problems of macroeconomic theory is the way in which the people exchange goods in decentralized market economies. There are major disagreements among macroeconomists regarding tools to influence required outcomes. Since the mainstream efficient market theory fails to provide an internal coherent framework, there is a need for an alternative theory. The book provides an innovative approach for the analysis of agent based models, populated by the heterogeneous and interacting agents in the field of financial fragility. The text is divided in two parts; the first presents analytical developments of stochastic aggregation and macro-dynamics inference methods. The second part introduces macroeconomic models of financial fragility for complex systems populated by heterogeneous and interacting agents. The concepts of financial fragility and macroeconomic dynamics are explained in detail in separate chapters. The statistical physics approach is applied to explain theories of macroeconomic modelling a...

  9. Non-Linear Dynamics and Fundamental Interactions

    CERN Document Server

    Khanna, Faqir

    2006-01-01

    The book is directed to researchers and graduate students pursuing an advanced degree. It provides details of techniques directed towards solving problems in non-linear dynamics and chos that are, in general, not amenable to a perturbative treatment. The consideration of fundamental interactions is a prime example where non-perturbative techniques are needed. Extension of these techniques to finite temperature problems is considered. At present these ideas are primarily used in a perturbative context. However, non-perturbative techniques have been considered in some specific cases. Experts in the field on non-linear dynamics and chaos and fundamental interactions elaborate the techniques and provide a critical look at the present status and explore future directions that may be fruitful. The text of the main talks will be very useful to young graduate students who are starting their studies in these areas.

  10. Dynamic neurotransmitter interactions measured with PET

    Energy Technology Data Exchange (ETDEWEB)

    Schiffer, W.K.; Dewey, S.L.

    2001-04-02

    Positron emission tomography (PET) has become a valuable interdisciplinary tool for understanding physiological, biochemical and pharmacological functions at a molecular level in living humans, whether in a healthy or diseased state. The utility of tracing chemical activity through the body transcends the fields of cardiology, oncology, neurology and psychiatry. In this, PET techniques span radiochemistry and radiopharmaceutical development to instrumentation, image analysis, anatomy and modeling. PET has made substantial contributions in each of these fields by providing a,venue for mapping dynamic functions of healthy and unhealthy human anatomy. As diverse as the disciplines it bridges, PET has provided insight into an equally significant variety of psychiatric disorders. Using the unique quantitative ability of PET, researchers are now better able to non-invasively characterize normally occurring neurotransmitter interactions in the brain. With the knowledge that these interactions provide the fundamental basis for brain response, many investigators have recently focused their efforts on an examination of the communication between these chemicals in both healthy volunteers and individuals suffering from diseases classically defined as neurotransmitter specific in nature. In addition, PET can measure the biochemical dynamics of acute and sustained drug abuse. Thus, PET studies of neurotransmitter interactions enable investigators to describe a multitude of specific functional interactions in the human brain. This information can then be applied to understanding side effects that occur in response to acute and chronic drug therapy, and to designing new drugs that target multiple systems as opposed to single receptor types. Knowledge derived from PET studies can be applied to drug discovery, research and development (for review, see (Fowler et al., 1999) and (Burns et al., 1999)). Here, we will cover the most substantial contributions of PET to understanding

  11. Evaluation of interaction dynamics of concurrent processes

    Science.gov (United States)

    Sobecki, Piotr; Białasiewicz, Jan T.; Gross, Nicholas

    2017-03-01

    The purpose of this paper is to present the wavelet tools that enable the detection of temporal interactions of concurrent processes. In particular, the determination of interaction coherence of time-varying signals is achieved using a complex continuous wavelet transform. This paper has used electrocardiogram (ECG) and seismocardiogram (SCG) data set to show multiple continuous wavelet analysis techniques based on Morlet wavelet transform. MATLAB Graphical User Interface (GUI), developed in the reported research to assist in quick and simple data analysis, is presented. These software tools can discover the interaction dynamics of time-varying signals, hence they can reveal their correlation in phase and amplitude, as well as their non-linear interconnections. The user-friendly MATLAB GUI enables effective use of the developed software what enables to load two processes under investigation, make choice of the required processing parameters, and then perform the analysis. The software developed is a useful tool for researchers who have a need for investigation of interaction dynamics of concurrent processes.

  12. The Type VI Secretion System: A Dynamic System for Bacterial Communication?

    Directory of Open Access Journals (Sweden)

    Mathias Gallique

    2017-07-01

    Full Text Available Numerous studies in Gram-negative bacteria have focused on the Type VISecretion Systems (T6SSs, Quorum Sensing (QS, and social behavior, such as in biofilms. These interconnected mechanisms are important for bacterial survival; T6SSs allow bacteria to battle other cells, QS is devoted to the perception of bacterial cell density, and biofilm formation is essentially controlled by QS. Here, we review data concerning T6SS dynamics and T6SS–QS cross-talk that suggest the existence of inter-bacterial communication via T6SSs.

  13. Semiclassical approach to dynamics of interacting fermions

    Science.gov (United States)

    Davidson, Shainen M.; Sels, Dries; Polkovnikov, Anatoli

    2017-09-01

    Understanding the behaviour of interacting fermions is of fundamental interest in many fields ranging from condensed matter to high energy physics. Developing numerically efficient and accurate simulation methods is an indispensable part of this. Already in equilibrium, fermions are notoriously hard to handle due to the sign problem. Out of equilibrium, an important outstanding problem is the efficient numerical simulation of the dynamics of these systems. In this work we develop a new semiclassical phase-space approach (a.k.a. the truncated Wigner approximation) for simulating the dynamics of interacting fermions in arbitrary dimensions. As fermions are essentially non-classical objects, a phase-space is constructed out of all fermionic bilinears. Classical phase-space is thus comprised of highly non-local (hidden) variables representing these bilinears, and the cost of the method is that it scales quadratic rather than linear with system size. We demonstrate the strength of the method by comparing the results to the exact quantum dynamics of fermion expansion in the Hubbard model and quantum thermalization in the Sachdev-Ye-Kitaev (SYK) model for small systems, where the semiclassics nearly perfectly reproduces correct results. We furthermore analyse fermion expansion in a larger, intractable by exact methods, 2D Hubbard model, which is directly relevant to recent cold atom experiments.

  14. Competing dynamical processes on two interacting networks

    CERN Document Server

    Alvarez-Zuzek, L G; Braunstein, L A; Vazquez, F

    2016-01-01

    We propose and study a model for the competition between two different dynamical processes, one for opinion formation and the other for decision making, on two interconnected networks. The networks represent two interacting social groups, the society and the Congress. An opinion formation process takes place on the society, where the opinion S of each individual can take one of four possible values (S=-2,-1,1,2), describing its level of agreement on a given issue, from totally against (S=-2) to totally in favor (S=2). The dynamics is controlled by a reinforcement parameter r, which measures the ratio between the likelihood to become an extremist or a moderate. The dynamics of the Congress is akin to that of the Abrams-Strogatz model, where congressmen can adopt one of two possible positions, to be either in favor (+) or against (-) the issue. The probability that a congressman changes his decision is proportional to the fraction of interacting neighbors that hold the opposite opinion raised to a power $\\beta$...

  15. The brain decade in debate: VI. Sensory and motor maps: dynamics and plasticity

    Directory of Open Access Journals (Sweden)

    A. Das

    2001-12-01

    Full Text Available This article is an edited transcription of a virtual symposium promoted by the Brazilian Society of Neuroscience and Behavior (SBNeC. Although the dynamics of sensory and motor representations have been one of the most studied features of the central nervous system, the actual mechanisms of brain plasticity that underlie the dynamic nature of sensory and motor maps are not entirely unraveled. Our discussion began with the notion that the processing of sensory information depends on many different cortical areas. Some of them are arranged topographically and others have non-topographic (analytical properties. Besides a sensory component, every cortical area has an efferent output that can be mapped and can influence motor behavior. Although new behaviors might be related to modifications of the sensory or motor representations in a given cortical area, they can also be the result of the acquired ability to make new associations between specific sensory cues and certain movements, a type of learning known as conditioning motor learning. Many types of learning are directly related to the emotional or cognitive context in which a new behavior is acquired. This has been demonstrated by paradigms in which the receptive field properties of cortical neurons are modified when an animal is engaged in a given discrimination task or when a triggering feature is paired with an aversive stimulus. The role of the cholinergic input from the nucleus basalis to the neocortex was also highlighted as one important component of the circuits responsible for the context-dependent changes that can be induced in cortical maps.

  16. Ice-dammed lateral lake and epishelf lake insights into Holocene dynamics of Marguerite Trough Ice Stream and George VI Ice Shelf, Alexander Island, Antarctic Peninsula

    Science.gov (United States)

    Davies, Bethan J.; Hambrey, Michael J.; Glasser, Neil F.; Holt, Tom; Rodés, Angél; Smellie, John L.; Carrivick, Jonathan L.; Blockley, Simon P. E.

    2017-12-01

    We present new data regarding the past dynamics of Marguerite Trough Ice Stream, George VI Ice Shelf and valley glaciers from Ablation Point Massif on Alexander Island, Antarctic Peninsula. This ice-free oasis preserves a geological record of ice stream lateral moraines, ice-dammed lakes, ice-shelf moraines and valley glacier moraines, which we dated using cosmogenic nuclide ages. We provide one of the first detailed sediment-landform assemblage descriptions of epishelf lake shorelines. Marguerite Trough Ice Stream imprinted lateral moraines against eastern Alexander Island at 120 m at Ablation Point Massif. During deglaciation, lateral lakes formed in the Ablation and Moutonnée valleys, dammed against the ice stream in George VI Sound. Exposure ages from boulders on these shorelines yielded ages of 13.9 to 9.7 ka. Following recession of the ice stream, George VI Ice Shelf formed in George VI Sound. An epishelf lake formed at 15-20 m asl in Ablation and Moutonnée valleys, dated from 9.4 to 4.6 ka, suggesting that the lake was stable and persistent for some 5000 years. Lake-level lowering occurred after this, with the lake level at 12 m at 3.1 ± 0.4 ka and at 5 m asl today. A readvance of the valley glaciers on Alexander Island at 4.4 ± 0.7 ka is recorded by valley glacier moraines overlying epishelf lake sediments. We speculate that the glacier readvance, which occurred during a period of warmth, may have been caused by a dynamic response of the glaciers to a lowering in surface elevation of George VI Ice Shelf.

  17. Multiphase Flow Dynamics 2 Mechanical Interactions

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present second volume the methods for describing the mechanical interactions in multiphase dynamics are provided. This fourth edition includes various updates, extensions, improvements and corrections.   "The literature in the field of multiphase flows is numerous. Therefore, it i...

  18. Multiphase Flow Dynamics 3 Thermal Interactions

    CERN Document Server

    Kolev, Nikolay Ivanov

    2012-01-01

    Multi-phase flows are part of our natural environment such as tornadoes, typhoons, air and water pollution and volcanic activities as well as part of industrial technology such as power plants, combustion engines, propulsion systems, or chemical and biological industry. The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. .In its fourth extended edition the successful monograph package “Multiphase Flow Daynmics” contains theory, methods and practical experience for describing complex transient multi-phase processes in arbitrary geometrical configurations, providing a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics. In the present third volume methods for describing of the thermal interactions in multiphase dynamics are provided. In addition a large number of valuable experiments is collected and predicted using the methods introduced in this monograph. In this way the accuracy of the methods is reve...

  19. Crystal structure and self-interaction of the type VI secretion tail-tube protein from enteroaggregative Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Badreddine Douzi

    Full Text Available The type VI secretion system (T6SS is a widespread machine used by bacteria to control their environment and kill or disable bacterial species or eukaryotes through toxin injection. The T6SS comprises a central tube formed of stacked hexamers of hemolysin co-regulated proteins (Hcp and terminated by a trimeric valine-glycine repeat protein G (VgrG component, the cell puncturing device. A contractile tail sheath, formed by the TssB and TssC proteins, surrounds this tube. This syringe-like machine has been compared to an inverted phage, as both Hcp and VgrG share structural homology with tail components of Caudovirales. Here we solved the crystal structure of a tryptophan-substituted double mutant of Hcp1 from enteroaggregative Escherichia coli and compared it to the structures of other Hcps. Interestingly, we observed that the purified Hcp native protein is unable to form tubes in vitro. To better understand the rationale for observation, we measured the affinity of Hcp1 hexamers with themselves by surface plasmon resonance. The intra-hexamer interaction is weak, with a KD value of 7.2 µM. However, by engineering double cysteine mutants at defined positions, tubes of Hcp1 gathering up to 15 stacked hexamers formed in oxidative conditions. These results, together with those available in the literature regarding TssB and TssC, suggest that assembly of the T6SS tube differs significantly from that of Sipho- or Myoviridae.

  20. Dynamic interactions between ionospheric plasma and spacecraft

    Science.gov (United States)

    Snyder, David B.

    1995-01-01

    Studies of the interactions between the Space Station Freedom and ionospheric plasma led to an improved understanding of the dynamics of these interactions. Some of the issues related to developing and sustaining arcs in ionospheric conditions are considered. A technique for the estimation of the amplitude and duration of arcs is presented. The technique uses the capacitance of the system to estimate the peak current and then uses the charge stored to estimate the arc duration. As new technologies are implemented on spacecraft, new environmental compatibility issues will arise. Some of the issues related to driving dielectric surfaces with alternating current voltages are considered. The steady state charging criteria is that over an oscillation, the ion charge collected is compensated for by the electron charge collected. This tends to drive the average potential negative so that the dielectric surface is positive for only a small portion of the cycle.

  1. Interaction of uranium(VI) with bioligands present in human biological fluids. The case study of urea and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Osman, A.A.A.; Geipel, G.; Bernhard, G. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Resource Ecology

    2013-05-01

    The complexation of uranium(VI) with bioligands found in human biological fluids, viz, urea and uric acid in aqueous solutions, has been investigated using time-resolved laser-induced fluorescence spectroscopy (TRLFS) at room temperature, I = 0.1 M (NaClO4) and pH (3 for uric acid; 4 for urea). In both complex systems a static quench effect with increasing ligand concentration and no peaks shift upon complexation were observed. With uranium(VI) both ligands formed a fairly weak 1:1 complex with average stability constants of log {beta}{sub 110} = 4.67 {+-} 0.29 for uric acid and log {beta}{sub 110} = 3.79 {+-} 0.15 and 2.12 {+-} 0.18 for relatively low and relatively high urea concentrations, respectively. Application of the newly generated data on the U(VI) speciation modelling in biofluids, e.g., human urine was also discussed.

  2. Predicting Protein Interactions by Brownian Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Xuan-Yu Meng

    2012-01-01

    Full Text Available We present a newly adapted Brownian-Dynamics (BD-based protein docking method for predicting native protein complexes. The approach includes global BD conformational sampling, compact complex selection, and local energy minimization. In order to reduce the computational costs for energy evaluations, a shell-based grid force field was developed to represent the receptor protein and solvation effects. The performance of this BD protein docking approach has been evaluated on a test set of 24 crystal protein complexes. Reproduction of experimental structures in the test set indicates the adequate conformational sampling and accurate scoring of this BD protein docking approach. Furthermore, we have developed an approach to account for the flexibility of proteins, which has been successfully applied to reproduce the experimental complex structure from the structure of two unbounded proteins. These results indicate that this adapted BD protein docking approach can be useful for the prediction of protein-protein interactions.

  3. Geometric evolutionary dynamics of protein interaction networks.

    Science.gov (United States)

    Przulj, Natasa; Kuchaiev, Oleksii; Stevanović, Aleksandar; Hayes, Wayne

    2010-01-01

    Understanding the evolution and structure of protein-protein interaction (PPI) networks is a central problem of systems biology. Since most processes in the cell are carried out by groups of proteins acting together, a theoretical model of how PPI networks develop based on duplications and mutations is an essential ingredient for understanding the complex wiring of the cell. Many different network models have been proposed, from those that follow power-law degree distributions and those that model complementarity of protein binding domains, to those that have geometric properties. Here, we introduce a new model for PPI network (and thus gene) evolution that produces well-fitting network models for currently available PPI networks. The model integrates geometric network properties with evolutionary dynamics of PPI network evolution.

  4. Geometry VI

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 8. Geometry VI - Space-the Final Frontier. Kapil H Paranjape. Series Article Volume 1 Issue 8 August 1996 pp 28-33. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/08/0028-0033 ...

  5. VI KA’

    DEFF Research Database (Denmark)

    Sprogøe, Jonas

    2012-01-01

    Artiklen handler om hvordan man kan bruge et spil til at udvikle og måle kompetencer. Artiklen diskuterer forskellige forståelser kompetencebegrebet og diskuterer hvordan Vi Ka'-spillet bidrager til at indfange den mere aktive forståelse af kompetence, som noget du gør i en bestemt kontekst....

  6. Affective Dynamics in Triadic Peer Interactions in Early Childhood

    NARCIS (Netherlands)

    Lavictoire, L.A.; Snyder, J.; Stoolmiller, M.; Hollenstein, T.P.

    2012-01-01

    In interpersonal interaction research, moving beyond dyadic to triadic dynamics can be analytically daunting. We explored the affective states expressed during triadic peer interactions to understand how patterns were associated with childhood psychopathology and sociometric status. High-risk

  7. Dynamics simulations for engineering macromolecular interactions

    Science.gov (United States)

    Robinson-Mosher, Avi; Shinar, Tamar; Silver, Pamela A.; Way, Jeffrey

    2013-06-01

    The predictable engineering of well-behaved transcriptional circuits is a central goal of synthetic biology. The artificial attachment of promoters to transcription factor genes usually results in noisy or chaotic behaviors, and such systems are unlikely to be useful in practical applications. Natural transcriptional regulation relies extensively on protein-protein interactions to insure tightly controlled behavior, but such tight control has been elusive in engineered systems. To help engineer protein-protein interactions, we have developed a molecular dynamics simulation framework that simplifies features of proteins moving by constrained Brownian motion, with the goal of performing long simulations. The behavior of a simulated protein system is determined by summation of forces that include a Brownian force, a drag force, excluded volume constraints, relative position constraints, and binding constraints that relate to experimentally determined on-rates and off-rates for chosen protein elements in a system. Proteins are abstracted as spheres. Binding surfaces are defined radially within a protein. Peptide linkers are abstracted as small protein-like spheres with rigid connections. To address whether our framework could generate useful predictions, we simulated the behavior of an engineered fusion protein consisting of two 20 000 Da proteins attached by flexible glycine/serine-type linkers. The two protein elements remained closely associated, as if constrained by a random walk in three dimensions of the peptide linker, as opposed to showing a distribution of distances expected if movement were dominated by Brownian motion of the protein domains only. We also simulated the behavior of fluorescent proteins tethered by a linker of varying length, compared the predicted Förster resonance energy transfer with previous experimental observations, and obtained a good correspondence. Finally, we simulated the binding behavior of a fusion of two ligands that could

  8. Mucopolysaccharidosis VI

    Science.gov (United States)

    2010-01-01

    Mucopolysaccharidosis VI (MPS VI) is a lysosomal storage disease with progressive multisystem involvement, associated with a deficiency of arylsulfatase B leading to the accumulation of dermatan sulfate. Birth prevalence is between 1 in 43,261 and 1 in 1,505,160 live births. The disorder shows a wide spectrum of symptoms from slowly to rapidly progressing forms. The characteristic skeletal dysplasia includes short stature, dysostosis multiplex and degenerative joint disease. Rapidly progressing forms may have onset from birth, elevated urinary glycosaminoglycans (generally >100 μg/mg creatinine), severe dysostosis multiplex, short stature, and death before the 2nd or 3rd decades. A more slowly progressing form has been described as having later onset, mildly elevated glycosaminoglycans (generally sialidosis and mucolipidosis. Before enzyme replacement therapy (ERT) with galsulfase (Naglazyme®), clinical management was limited to supportive care and hematopoietic stem cell transplantation. Galsulfase is now widely available and is a specific therapy providing improved endurance with an acceptable safety profile. Prognosis is variable depending on the age of onset, rate of disease progression, age at initiation of ERT and on the quality of the medical care provided. PMID:20385007

  9. Mucopolysaccharidosis VI

    Directory of Open Access Journals (Sweden)

    Harmatz Paul

    2010-04-01

    Full Text Available Abstract Mucopolysaccharidosis VI (MPS VI is a lysosomal storage disease with progressive multisystem involvement, associated with a deficiency of arylsulfatase B leading to the accumulation of dermatan sulfate. Birth prevalence is between 1 in 43,261 and 1 in 1,505,160 live births. The disorder shows a wide spectrum of symptoms from slowly to rapidly progressing forms. The characteristic skeletal dysplasia includes short stature, dysostosis multiplex and degenerative joint disease. Rapidly progressing forms may have onset from birth, elevated urinary glycosaminoglycans (generally >100 μg/mg creatinine, severe dysostosis multiplex, short stature, and death before the 2nd or 3rd decades. A more slowly progressing form has been described as having later onset, mildly elevated glycosaminoglycans (generally ARSB gene, located in chromosome 5 (5q13-5q14. Over 130 ARSB mutations have been reported, causing absent or reduced arylsulfatase B (N-acetylgalactosamine 4-sulfatase activity and interrupted dermatan sulfate and chondroitin sulfate degradation. Diagnosis generally requires evidence of clinical phenotype, arylsulfatase B enzyme activity ®, clinical management was limited to supportive care and hematopoietic stem cell transplantation. Galsulfase is now widely available and is a specific therapy providing improved endurance with an acceptable safety profile. Prognosis is variable depending on the age of onset, rate of disease progression, age at initiation of ERT and on the quality of the medical care provided.

  10. Interactive effects of sulfur and chromium on antioxidative defense systems and BnMP1 gene expression in canola (Brassica napus L.) cultivars differing in Cr(VI) tolerance.

    Science.gov (United States)

    Terzi, Hakan; Yıldız, Mustafa

    2015-07-01

    Plants suffer with combined stress of sulfur (S) deficiency and hexavalent chromium [Cr(VI)] in soils. There are a few reports on the interactive effects of S-deficiency and Cr(VI) stress. Therefore, the interactions between S nutrition and Cr(VI) stress were investigated in hydroponically grown canola (Brassica napus L.) cultivars differing in Cr(VI) tolerance. The relatively Cr(VI)-tolerant (NK Petrol) and Cr(VI)-susceptible (Sary) cultivars were grown in S-sufficient nutrient solution and then exposed to variable S concentrations [deficient (0 mM S, -S) and sufficient (1 mM S, +S)]. The seedlings were then exposed to 100 μM Cr(VI) for 3 days. S-deficiency (-S/-Cr) and combined stress (-S/+Cr) caused a significant decrease in growth parameters of Sary than NK Petrol (P < 0.05). In -S/+Cr treatment, Cr accumulation in Sary was significantly higher than NK Petrol. The higher level of Cr in Sary increased lipid peroxidation and decreased chlorophyll content. The activities of antioxidant enzymes and cysteine content were significantly higher in NK Petrol than in Sary under combined stress. The levels of ascorbate (AsA) and glutathione (GSH) were significantly decreased by S deficiency. The expression level of metallothionein gene (BnMP1) in the tolerant NK Petrol was increased by -S/+Cr treatment. However, expression level of BnMP1 gene in the susceptible Sary was enhanced by +S/+Cr treatment. This result suggests metallothionein (MT) may be involved in Cr(VI) tolerance under S-deficient condition. In conclusion, S nutrition influenced Cr accumulation and enhanced tolerance caused by a positive effect on defense systems and gene expression.

  11. The dynamic multisite interactions between two intrinsically disordered proteins

    KAUST Repository

    Wu, Shaowen

    2017-05-11

    Protein interactions involving intrinsically disordered proteins (IDPs) comprise a variety of binding modes, from the well characterized folding upon binding to dynamic fuzzy complex. To date, most studies concern the binding of an IDP to a structured protein, while the Interaction between two IDPs is poorly understood. In this study, we combined NMR, smFRET, and molecular dynamics (MD) simulation to characterize the interaction between two IDPs, the C-terminal domain (CTD) of protein 4.1G and the nuclear mitotic apparatus (NuMA) protein. It is revealed that CTD and NuMA form a fuzzy complex with remaining structural disorder. Multiple binding sites on both proteins were identified by MD and mutagenesis studies. Our study provides an atomic scenario in which two IDPs bearing multiple binding sites interact with each other in dynamic equilibrium. The combined approach employed here could be widely applicable for investigating IDPs and their dynamic interactions.

  12. Dynamics of DNA conformations and DNA-protein interaction

    DEFF Research Database (Denmark)

    Metzler, R.; Ambjörnsson, T.; Lomholt, Michael Andersen

    2005-01-01

    Optical tweezers, atomic force microscopes, patch clamping, or fluorescence techniques make it possible to study both the equilibrium conformations and dynamics of single DNA molecules as well as their interaction with binding proteins. In this paper we address the dynamics of local DNA denaturat......Optical tweezers, atomic force microscopes, patch clamping, or fluorescence techniques make it possible to study both the equilibrium conformations and dynamics of single DNA molecules as well as their interaction with binding proteins. In this paper we address the dynamics of local DNA...

  13. Dynamics of cavitation-structure interaction

    Science.gov (United States)

    Wang, Guoyu; Wu, Qin; Huang, Biao

    2017-08-01

    Cavitation-structure interaction has become one of the major issues for most engineering applications. The present work reviews recent progress made toward developing experimental and numerical investigation for unsteady turbulent cavitating flow and cavitation-structure interaction. The goal of our overall efforts is to (1) summarize the progress made in the experimental and numerical modeling and approaches for unsteady cavitating flow and cavitation-structure interaction, (2) discuss the global multiphase structures for different cavitation regimes, with special emphasis on the unsteady development of cloud cavitation and corresponding cavitating flow-induced vibrations, with a high-speed visualization system and a structural vibration measurement system, as well as a simultaneous sampling system, (3) improve the understanding of the hydroelastic response in cavitating flows via combined physical and numerical analysis, with particular emphasis on the interaction between unsteady cavitation development and structural deformations. Issues including unsteady cavitating flow structures and cavitation-structure interaction mechanism are discussed.

  14. Dynamics of social balance under temporal interaction

    Science.gov (United States)

    Nishi, Ryosuke; Masuda, Naoki

    2014-08-01

    Real social contacts are often intermittent such that a link between a pair of nodes in a social network is only temporarily used. The effects of such temporal networks on social dynamics have been investigated for several phenomenological models such as epidemic spreading, linear diffusion processes, and nonlinear oscillations. Here, we numerically investigate nonlinear social balance dynamics in such a situation. Social balance is a classical psychological theory, which dictates that a triad is balanced if the three agents are mutual friends or if the two of them are the friends of each other and hostile to the other agent. We show that the social balance dynamics is slowed down on the temporal complete graph as compared to the corresponding static complete graph.

  15. Dynamical Engineering of Interactions in Qudit Ensembles

    Science.gov (United States)

    Choi, Soonwon; Yao, Norman Y.; Lukin, Mikhail D.

    2017-11-01

    We propose and analyze a method to engineer effective interactions in an ensemble of d -level systems (qudits) driven by global control fields. In particular, we present (i) a necessary and sufficient condition under which a given interaction can be decoupled, (ii) the existence of a universal sequence that decouples any (cancelable) interaction, and (iii) an efficient algorithm to engineer a target Hamiltonian from an initial Hamiltonian (if possible). We illustrate the potential of this method with two examples. Specifically, we present a 6-pulse sequence that decouples effective spin-1 dipolar interactions and demonstrate that a spin-1 Ising chain can be engineered to study transitions among three distinct symmetry protected topological phases. Our work enables new approaches for the realization of both many-body quantum memories and programmable analog quantum simulators using existing experimental platforms.

  16. Dynamic representations on the interactive whiteboard

    NARCIS (Netherlands)

    van der Meij, Hans; van der Meij, Jan; de Vries, Erica; Scheiter, Katharina

    2012-01-01

    In this study we assessed whether presenting dynamic representations on an IWB would lead to better learning gains compared to presenting static representations. Participants were 7-8 year old primary school children learning about views (N = 151) and the water cycle (N = 182). The results showed

  17. Live interaction distinctively shapes social gaze dynamics in rhesus macaques

    Science.gov (United States)

    Piva, Matthew; Morris, Jason A.; Chang, Steve W. C.

    2016-01-01

    The dynamic interaction of gaze between individuals is a hallmark of social cognition. However, very few studies have examined social gaze dynamics after mutual eye contact during real-time interactions. We used a highly quantifiable paradigm to assess social gaze dynamics between pairs of monkeys and modeled these dynamics using an exponential decay function to investigate sustained attention after mutual eye contact. When monkeys were interacting with real partners compared with static images and movies of the same monkeys, we found a significant increase in the proportion of fixations to the eyes and a smaller dispersion of fixations around the eyes, indicating enhanced focal attention to the eye region. Notably, dominance and familiarity between the interacting pairs induced separable components of gaze dynamics that were unique to live interactions. Gaze dynamics of dominant monkeys after mutual eye contact were associated with a greater number of fixations to the eyes, whereas those of familiar pairs were associated with a faster rate of decrease in this eye-directed attention. Our findings endorse the notion that certain key aspects of social cognition are only captured during interactive social contexts and dependent on the elapsed time relative to socially meaningful events. PMID:27486105

  18. Electron dynamics controlled via self-interaction

    CERN Document Server

    Tamburini, Matteo; Di Piazza, Antonino

    2013-01-01

    The dynamics of an electron in a strong laser field can be significantly altered by radiation reaction. This usually results in a strongly damped motion, with the electron losing a large fraction of its initial energy. Here we show that the electron dynamics in a bichromatic laser pulse can be indirectly controlled by a comparatively small radiation reaction force through its interplay with the Lorentz force. By changing the relative phase between the two frequency components of the bichromatic laser field, an ultrarelativistic electron bunch colliding head-on with the laser pulse can be deflected in a controlled way, with the deflection angle being independent of the initial electron energy. The effect is predicted to be observable with intensities available at upcoming laser facilities.

  19. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  20. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  1. Dynamical Equilibrium of Interacting Ant Societies

    CERN Document Server

    Leok, B T M

    1996-01-01

    The sustainable biodiversity associated with a specific ecological niche as a function of land area is analysed computationally by considering the interaction of ant societies over a collection of islands. A power law relationship between sustainable species and land area is observed. We will further consider the effect a perturbative inflow of ants has upon the model.

  2. Dynamic Interactions for Network Visualization and Simulation

    Science.gov (United States)

    2009-03-01

    Unmanned Aerial Vehicle . . . . . . . . . . . . . . . . . . 7 GUI Graphical User Interface . . . . . . . . . . . . . . . . . . . 8 MVC Model-View...applications, and web applets. Comprising a library of design algorithms, navigation and interaction techniques, prefuse aims to significantly sim- plify the...Information Visualization Reference Model of the Prefuse toolkit [15]. The prefuse toolkit is suitable for the Model-View-Controller ( MVC ) [15] soft- ware

  3. Dynamical theory of weak and electromagnetic interactions

    CERN Document Server

    Englert, F

    1974-01-01

    The gauge theory of unified weak and electromagnetic interactions is developed without the use of scalar mesons. It is shown that the Glashow Weinberg scheme is unrealistic, but that a similar such scheme is possible if one includes two pairs of leptons, identified with e-, νe and μ-, νμ.

  4. Models for the dynamics of interacting magnetic nanoparticles

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Mørup, Steen

    1998-01-01

    A critical review of models for the dynamics of interacting magnetic nanoparticles is given. It is shown that the basic assumptions in the Dormann-Bessais-Fiorani model are unrealistic. The experimental observations on systems of interacting magnetic nanoparticles can, at least qualitatively...

  5. Interfacial interaction between polypropylene and nanotube: A molecular dynamics simulation

    Science.gov (United States)

    Zhang, Danhui; Yang, Houbo; Liu, Zhongkui; Liu, Anmin; Li, Yunfang

    2017-09-01

    The interfacial interaction between polypropylene (PE) and single walled carbon nanotube (SWCNT) was studied using molecular dynamics (MD) simulations. The result showed that the PE chain could stabilize the SWCNT and then extended along the direction of SWCNT. The mechanism of interfacial interaction between PE and SWCNT was also discussed. Furthermore, the interfacial interaction between more PE and SWCNT was also investigated and the position also deeply influenced the interaction. This will be beneficial to understanding the interfacial interaction between polymer and CNT in solution, and also guiding the fabrication of high performance polymer/CNT nanocomposites.

  6. Shape Displays: Spatial Interaction with Dynamic Physical Form.

    Science.gov (United States)

    Leithinger, Daniel; Follmer, Sean; Olwal, Alex; Ishii, Hiroshi

    2015-01-01

    Shape displays are an emerging class of devices that emphasize actuation to enable rich physical interaction, complementing concepts in virtual and augmented reality. The ability to render form introduces new opportunities to touch, grasp, and manipulate dynamic physical content and tangible objects, in both nearby and remote environments. This article presents novel hardware, interaction techniques, and applications, which point to the potential for extending the ways that we traditionally interact with the physical world, empowered by digital computation.

  7. Spin, Isospin and Strong Interaction Dynamics

    Directory of Open Access Journals (Sweden)

    Comay E.

    2011-10-01

    Full Text Available The structure of spin and isospin is analyzed. Although both spin and isospin are related to the same SU(2 group, they represent different dynamical effects. The Wigner-Racah algebra is used for providing a description of bound states of several Dirac particles in general and of the proton state in particular. Isospin states of the four ∆ (1232 baryons are discussed. The work explains the small contribution of quarks spin to the overall proton spin (the proton spin crisis. It is also proved that the addition of QCD’s color is not required for a construction of an antisymmetric state for the ∆ ++ (1232 baryon.

  8. Detecting Friendship Within Dynamic Online Interaction Networks

    OpenAIRE

    Merritt, Sears; Jacobs, Abigail Z.; Mason, Winter; Clauset, Aaron

    2013-01-01

    In many complex social systems, the timing and frequency of interactions between individuals are observable but friendship ties are hidden. Recovering these hidden ties, particularly for casual users who are relatively less active, would enable a wide variety of friendship-aware applications in domains where labeled data are often unavailable, including online advertising and national security. Here, we investigate the accuracy of multiple statistical features, based either purely on temporal...

  9. Modeling human dynamics of face-to-face interaction networks

    CERN Document Server

    Starnini, Michele; Pastor-Satorras, Romualdo

    2013-01-01

    Face-to-face interaction networks describe social interactions in human gatherings, and are the substrate for processes such as epidemic spreading and gossip propagation. The bursty nature of human behavior characterizes many aspects of empirical data, such as the distribution of conversation lengths, of conversations per person, or of inter-conversation times. Despite several recent attempts, a general theoretical understanding of the global picture emerging from data is still lacking. Here we present a simple model that reproduces quantitatively most of the relevant features of empirical face-to-face interaction networks. The model describes agents which perform a random walk in a two dimensional space and are characterized by an attractiveness whose effect is to slow down the motion of people around them. The proposed framework sheds light on the dynamics of human interactions and can improve the modeling of dynamical processes taking place on the ensuing dynamical social networks.

  10. Dynamical system analysis of interacting models

    Science.gov (United States)

    Carneiro, S.; Borges, H. A.

    2018-01-01

    We perform a dynamical system analysis of a cosmological model with linear dependence between the vacuum density and the Hubble parameter, with constant-rate creation of dark matter. We show that the de Sitter spacetime is an asymptotically stable critical point, future limit of any expanding solution. Our analysis also shows that the Minkowski spacetime is an unstable critical point, which eventually collapses to a singularity. In this way, such a prescription for the vacuum decay not only predicts the correct future de Sitter limit, but also forbids the existence of a stable Minkowski universe. We also study the effect of matter creation on the growth of structures and their peculiar velocities, showing that it is inside the current errors of redshift space distortions observations.

  11. Virtual Partner Interaction (VPI: exploring novel behaviors via coordination dynamics.

    Directory of Open Access Journals (Sweden)

    J A Scott Kelso

    Full Text Available Inspired by the dynamic clamp of cellular neuroscience, this paper introduces VPI -- Virtual Partner Interaction -- a coupled dynamical system for studying real time interaction between a human and a machine. In this proof of concept study, human subjects coordinate hand movements with a virtual partner, an avatar of a hand whose movements are driven by a computerized version of the Haken-Kelso-Bunz (HKB equations that have been shown to govern basic forms of human coordination. As a surrogate system for human social coordination, VPI allows one to examine regions of the parameter space not typically explored during live interactions. A number of novel behaviors never previously observed are uncovered and accounted for. Having its basis in an empirically derived theory of human coordination, VPI offers a principled approach to human-machine interaction and opens up new ways to understand how humans interact with human-like machines including identification of underlying neural mechanisms.

  12. Study on the binding interaction of chromium(VI) with humic acid using UV-vis, fluorescence spectroscopy and molecular modeling.

    Science.gov (United States)

    Gu, Yun-Lan; Yin, Ming-Xing; Zhang, Hong-Mei; Wang, Yan-Qing; Shi, Jing-Hua

    2015-02-05

    In this report, the binding interaction of chromium(VI), as Cr2O7(2-), with humic acid was studied by using UV-visible absorption, fluorescence spectroscopy, and molecular modeling method. The fluorescence spectral data indicated that the binding interaction existed between Cr2O7(2-) and humic acid and the order of magnitude of binding constants were 10(3). The rise in temperature caused a decrease in the values of the binding constant of humic acid with Cr2O7(2-). Thermodynamic analysis presented that multi-intermolecular forces including hydrogen bonding, hydrophobic, and electrostatic forces were involved in the binding process at pH 6.5. The spectral data also indicated that Cr2O7(2-) affected the aromatic ring structures in humic acid. Furthermore, the molecular modeling analysis indicated that a lot of reactive groups and binding cavities in HA played a key role in its binding with Cr2O7(2-). Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Red Queen dynamics with non-standard fitness interactions.

    Directory of Open Access Journals (Sweden)

    Jan Engelstädter

    2009-08-01

    Full Text Available Antagonistic coevolution between hosts and parasites can involve rapid fluctuations of genotype frequencies that are known as Red Queen dynamics. Under such dynamics, recombination in the hosts may be advantageous because genetic shuffling can quickly produce disproportionately fit offspring (the Red Queen hypothesis. Previous models investigating these dynamics have assumed rather simple models of genetic interactions between hosts and parasites. Here, we assess the robustness of earlier theoretical predictions about the Red Queen with respect to the underlying host-parasite interactions. To this end, we created large numbers of random interaction matrices, analysed the resulting dynamics through simulation, and ascertained whether recombination was favoured or disfavoured. We observed Red Queen dynamics in many of our simulations provided the interaction matrices exhibited sufficient 'antagonicity'. In agreement with previous studies, strong selection on either hosts or parasites favours selection for increased recombination. However, fast changes in the sign of linkage disequilibrium or epistasis were only infrequently observed and do not appear to be a necessary condition for the Red Queen hypothesis to work. Indeed, recombination was often favoured even though the linkage disequilibrium remained of constant sign throughout the simulations. We conclude that Red Queen-type dynamics involving persistent fluctuations in host and parasite genotype frequencies appear to not be an artefact of specific assumptions about host-parasite fitness interactions, but emerge readily with the general interactions studied here. Our results also indicate that although recombination is often favoured, some of the factors previously thought to be important in this process such as linkage disequilibrium fluctuations need to be reassessed when fitness interactions between hosts and parasites are complex.

  14. Red Queen dynamics with non-standard fitness interactions.

    Science.gov (United States)

    Engelstädter, Jan; Bonhoeffer, Sebastian

    2009-08-01

    Antagonistic coevolution between hosts and parasites can involve rapid fluctuations of genotype frequencies that are known as Red Queen dynamics. Under such dynamics, recombination in the hosts may be advantageous because genetic shuffling can quickly produce disproportionately fit offspring (the Red Queen hypothesis). Previous models investigating these dynamics have assumed rather simple models of genetic interactions between hosts and parasites. Here, we assess the robustness of earlier theoretical predictions about the Red Queen with respect to the underlying host-parasite interactions. To this end, we created large numbers of random interaction matrices, analysed the resulting dynamics through simulation, and ascertained whether recombination was favoured or disfavoured. We observed Red Queen dynamics in many of our simulations provided the interaction matrices exhibited sufficient 'antagonicity'. In agreement with previous studies, strong selection on either hosts or parasites favours selection for increased recombination. However, fast changes in the sign of linkage disequilibrium or epistasis were only infrequently observed and do not appear to be a necessary condition for the Red Queen hypothesis to work. Indeed, recombination was often favoured even though the linkage disequilibrium remained of constant sign throughout the simulations. We conclude that Red Queen-type dynamics involving persistent fluctuations in host and parasite genotype frequencies appear to not be an artefact of specific assumptions about host-parasite fitness interactions, but emerge readily with the general interactions studied here. Our results also indicate that although recombination is often favoured, some of the factors previously thought to be important in this process such as linkage disequilibrium fluctuations need to be reassessed when fitness interactions between hosts and parasites are complex.

  15. Unsteady modelling of the oscillating S809 aerofoil and NREL phase VI parked blade using the Beddoes-Leishman dynamic stall model

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Alvaro; Munduate, Xabier [Wind Energy Department, CENER - National Renewable Energy Centre, Ciudad de la Innovacion 7, Sarriguren, Navarra, 31621 (Spain)

    2007-07-15

    An implementation of the Beddoes-Leishman dynamic stall model has been developed at CENER, for modelling the unsteady aerodynamics on oscillating blade sections. The parameters of the model were adjusted for the S809 aerofoil, using an optimization based on genetic algorithms, and taking into account the values found in the literature and the physics of the aerodynamic process. Once the parameters were fixed to a unique set, oscillating cases of the 2D S809 aerofoil were computed, and compared with experimental data. Thus, the accuracy of the model was evaluated. On the other hand, oscillating cases of different span stations of the NREL phase VI parked blade were computed and compared with experimental data, to analyze the three-dimensionality of the dynamic stall on the blade sections. For the unsteady computations on the blade, the model was fed with the steady data of the blade section, to directly consider the geometry influence. In general, the results of the computations for the 2D aerofoil and 3D blade sections were very encouraging.

  16. Reaction-Diffusion Modeling ERK- and STAT-Interaction Dynamics

    Directory of Open Access Journals (Sweden)

    Georgiev Nikola

    2006-01-01

    Full Text Available The modeling of the dynamics of interaction between ERK and STAT signaling pathways in the cell needs to establish the biochemical diagram of the corresponding proteins interactions as well as the corresponding reaction-diffusion scheme. Starting from the verbal description available in the literature of the cross talk between the two pathways, a simple diagram of interaction between ERK and STAT5a proteins is chosen to write corresponding kinetic equations. The dynamics of interaction is modeled in a form of two-dimensional nonlinear dynamical system for ERK—and STAT5a —protein concentrations. Then the spatial modeling of the interaction is accomplished by introducing an appropriate diffusion-reaction scheme. The obtained system of partial differential equations is analyzed and it is argued that the possibility of Turing bifurcation is presented by loss of stability of the homogeneous steady state and forms dissipative structures in the ERK and STAT interaction process. In these terms, a possible scaffolding effect in the protein interaction is related to the process of stabilization and destabilization of the dissipative structures (pattern formation inherent to the model of ERK and STAT cross talk.

  17. Social Dynamics in Web Page through Inter-Agent Interaction

    Science.gov (United States)

    Takeuchi, Yugo; Katagiri, Yasuhiro

    Social persuasion abounds in human-human interactions. Attitudes and behaviors of people are invariably influenced by the attitudes and behaviors of other people as well as our social roles/relationships toward them. In the pedagogic scene, the relationship between teacher and learner produces one of the most typical interactions, in which the teacher makes the learner spontaneously study what he/she teaches. This study is an attempt to elucidate the nature and effectiveness of social persuasion in human-computer interaction environments. We focus on the social dynamics of multi-party interactions that involve both human-agent and inter-agent interactions. An experiment is conducted in a virtual web-instruction setting employing two types of agents: conductor agents who accompany and guide each learner throughout his/her learning sessions, and domain-expert agents who provide explanations and instructions for each stage of the instructional materials. In this experiment, subjects are assigned two experimental conditions: the authorized condition, in which an agent respectfully interacts with another agent, and the non-authorized condition, in which an agent carelessly interacts with another agent. The results indicate performance improvements in the authorized condition of inter-agent interactions. An analysis is given from the perspective of the transfer of authority from inter-agent to human-agent interactions based on social conformity. We argue for pedagogic advantages of social dynamics created by multiple animated character agents.

  18. Dynamic interactions of neutrophils and biofilms

    Directory of Open Access Journals (Sweden)

    Josefine Hirschfeld

    2014-12-01

    Full Text Available Background: The majority of microbial infections in humans are biofilm-associated and difficult to treat, as biofilms are highly resistant to antimicrobial agents and protect themselves from external threats in various ways. Biofilms are tenaciously attached to surfaces and impede the ability of host defense molecules and cells to penetrate them. On the other hand, some biofilms are beneficial for the host and contain protective microorganisms. Microbes in biofilms express pathogen-associated molecular patterns and epitopes that can be recognized by innate immune cells and opsonins, leading to activation of neutrophils and other leukocytes. Neutrophils are part of the first line of defense and have multiple antimicrobial strategies allowing them to attack pathogenic biofilms. Objective/design: In this paper, interaction modes of neutrophils with biofilms are reviewed. Antimicrobial strategies of neutrophils and the counteractions of the biofilm communities, with special attention to oral biofilms, are presented. Moreover, possible adverse effects of neutrophil activity and their biofilm-promoting side effects are discussed. Results/conclusion: Biofilms are partially, but not entirely, protected against neutrophil assault, which include the processes of phagocytosis, degranulation, and formation of neutrophil extracellular traps. However, virulence factors of microorganisms, microbial composition, and properties of the extracellular matrix determine whether a biofilm and subsequent microbial spread can be controlled by neutrophils and other host defense factors. Besides, neutrophils may inadvertently contribute to the physical and ecological stability of biofilms by promoting selection of more resistant strains. Moreover, neutrophil enzymes can degrade collagen and other proteins and, as a result, cause harm to the host tissues. These parameters could be crucial factors in the onset of periodontal inflammation and the subsequent tissue breakdown.

  19. Bubble interaction dynamics in Lagrangian and Hamiltonian mechanics.

    Science.gov (United States)

    Ilinskii, Yurii A; Hamilton, Mark F; Zabolotskaya, Evgenia A

    2007-02-01

    Two models of interacting bubble dynamics are presented, a coupled system of second-order differential equations based on Lagrangian mechanics, and a first-order system based on Hamiltonian mechanics. Both account for pulsation and translation of an arbitrary number of spherical bubbles. For large numbers of interacting bubbles, numerical solution of the Hamiltonian equations provides greater stability. The presence of external acoustic sources is taken into account explicitly in the derivation of both sets of equations. In addition to the acoustic pressure and its gradient, it is found that the particle velocity associated with external sources appears in the dynamical equations.

  20. A Contribution to Documenting and Validating Dynamic Interaction Effects

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2007-01-01

    . Controlled laboratory tests, employing a vibrating test floor carrying stationary crowds of people, are designed and carried out to investigate the dynamic interaction. The paper describes the tests and the modal identification procedures employed for the assessment of model validity. Besides from aspects......On structures carrying humans (e.g. floors, grandstands in stadia etc.) there may be two different types of crowds present: Active and passive crowds of people. The active crowd, comprising people in motion, may generate dynamic loads causing the structure to vibrate. The passive (stationary) crowd...... and a floor in vertical motion. The mechanism of crowd-structure interaction is not well understood and the primary aim of the paper is to present results of experimental investigations documenting effects of crowd-structure interaction and to exploring the validity of a crowd-structure interaction model...

  1. Interaction dynamics of multiple mobile robots with simple navigation strategies

    Science.gov (United States)

    Wang, P. K. C.

    1989-01-01

    The global dynamic behavior of multiple interacting autonomous mobile robots with simple navigation strategies is studied. Here, the effective spatial domain of each robot is taken to be a closed ball about its mass center. It is assumed that each robot has a specified cone of visibility such that interaction with other robots takes place only when they enter its visibility cone. Based on a particle model for the robots, various simple homing and collision-avoidance navigation strategies are derived. Then, an analysis of the dynamical behavior of the interacting robots in unbounded spatial domains is made. The article concludes with the results of computer simulations studies of two or more interacting robots.

  2. Entanglement Growth in Quench Dynamics with Variable Range Interactions

    Directory of Open Access Journals (Sweden)

    J. Schachenmayer

    2013-09-01

    Full Text Available Studying entanglement growth in quantum dynamics provides both insight into the underlying microscopic processes and information about the complexity of the quantum states, which is related to the efficiency of simulations on classical computers. Recently, experiments with trapped ions, polar molecules, and Rydberg excitations have provided new opportunities to observe dynamics with long-range interactions. We explore nonequilibrium coherent dynamics after a quantum quench in such systems, identifying qualitatively different behavior as the exponent of algebraically decaying spin-spin interactions in a transverse Ising chain is varied. Computing the buildup of bipartite entanglement as well as mutual information between distant spins, we identify linear growth of entanglement entropy corresponding to propagation of quasiparticles for shorter-range interactions, with the maximum rate of growth occurring when the Hamiltonian parameters match those for the quantum phase transition. Counterintuitively, the growth of bipartite entanglement for long-range interactions is only logarithmic for most regimes, i.e., substantially slower than for shorter-range interactions. Experiments with trapped ions allow for the realization of this system with a tunable interaction range, and we show that the different phenomena are robust for finite system sizes and in the presence of noise. These results can act as a direct guide for the generation of large-scale entanglement in such experiments, towards a regime where the entanglement growth can render existing classical simulations inefficient.

  3. The human dynamic clamp as a paradigm for social interaction.

    Science.gov (United States)

    Dumas, Guillaume; de Guzman, Gonzalo C; Tognoli, Emmanuelle; Kelso, J A Scott

    2014-09-02

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject's own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual "teacher." We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof.

  4. Water-Protein Interactions: The Secret of Protein Dynamics

    Directory of Open Access Journals (Sweden)

    Silvia Martini

    2013-01-01

    Full Text Available Water-protein interactions help to maintain flexible conformation conditions which are required for multifunctional protein recognition processes. The intimate relationship between the protein surface and hydration water can be analyzed by studying experimental water properties measured in protein systems in solution. In particular, proteins in solution modify the structure and the dynamics of the bulk water at the solute-solvent interface. The ordering effects of proteins on hydration water are extended for several angstroms. In this paper we propose a method for analyzing the dynamical properties of the water molecules present in the hydration shells of proteins. The approach is based on the analysis of the effects of protein-solvent interactions on water protons NMR relaxation parameters. NMR relaxation parameters, especially the nonselective (R1NS and selective (R1SE spin-lattice relaxation rates of water protons, are useful for investigating the solvent dynamics at the macromolecule-solvent interfaces as well as the perturbation effects caused by the water-macromolecule interactions on the solvent dynamical properties. In this paper we demonstrate that Nuclear Magnetic Resonance Spectroscopy can be used to determine the dynamical contributions of proteins to the water molecules belonging to their hydration shells.

  5. Component Based System Framework for Dynamic B2B Interaction

    NARCIS (Netherlands)

    Hu jinmin, Jinmin; Grefen, P.W.P.J.

    Business-to-Business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support

  6. Emergence of junction dynamics in a strongly interacting Bose mixture

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Foerster, Angela; Zinner, Nikolaj Thomas

    We study the dynamics of a one-dimensional system composed of a bosonic background and one impurity in single- and double-well trapping geometries. In the limit of strong interactions, this system can be modeled by a spin chain where the exchange coefficients are determined by the geometry of the...

  7. Nonequilibrium dynamics in an interacting Fe-C nanoparticle system

    DEFF Research Database (Denmark)

    Jönsson, P.; Hansen, Mikkel Fougt; Nordblad, P.

    2000-01-01

    Nonequilibrium dynamics in an interacting Fe-C nanoparticle sample, exhibiting a low-temperature spin-glass-like phase, has been studied by low-frequency ac susceptibility and magnetic relaxation experiments. The nonequilibrium behavior shows characteristic spin-glass features, but some qualitative...

  8. Cranial mononeuropathy VI

    Science.gov (United States)

    ... Abducens palsy; Lateral rectus palsy; VIth nerve palsy; Cranial nerve VI palsy; Sixth nerve palsy; Neuropathy - sixth nerve ... Cranial mononeuropathy VI is damage to the sixth cranial nerve. This nerve is also called the abducens nerve. ...

  9. Coupling functions: Universal insights into dynamical interaction mechanisms

    Science.gov (United States)

    Stankovski, Tomislav; Pereira, Tiago; McClintock, Peter V. E.; Stefanovska, Aneta

    2017-10-01

    The dynamical systems found in nature are rarely isolated. Instead they interact and influence each other. The coupling functions that connect them contain detailed information about the functional mechanisms underlying the interactions and prescribe the physical rule specifying how an interaction occurs. A coherent and comprehensive review is presented encompassing the rapid progress made recently in the analysis, understanding, and applications of coupling functions. The basic concepts and characteristics of coupling functions are presented through demonstrative examples of different domains, revealing the mechanisms and emphasizing their multivariate nature. The theory of coupling functions is discussed through gradually increasing complexity from strong and weak interactions to globally coupled systems and networks. A variety of methods that have been developed for the detection and reconstruction of coupling functions from measured data is described. These methods are based on different statistical techniques for dynamical inference. Stemming from physics, such methods are being applied in diverse areas of science and technology, including chemistry, biology, physiology, neuroscience, social sciences, mechanics, and secure communications. This breadth of application illustrates the universality of coupling functions for studying the interaction mechanisms of coupled dynamical systems.

  10. Galaxy Zoo: Mergers - Dynamical models of interacting galaxies

    Science.gov (United States)

    Holincheck, Anthony J.; Wallin, John F.; Borne, Kirk; Fortson, Lucy; Lintott, Chris; Smith, Arfon M.; Bamford, Steven; Keel, William C.; Parrish, Michael

    2016-06-01

    The dynamical history of most merging galaxies is not well understood. Correlations between galaxy interaction and star formation have been found in previous studies, but require the context of the physical history of merging systems for full insight into the processes that lead to enhanced star formation. We present the results of simulations that reconstruct the orbit trajectories and disturbed morphologies of pairs of interacting galaxies. With the use of a restricted three-body simulation code and the help of citizen scientists, we sample 105 points in parameter space for each system. We demonstrate a successful recreation of the morphologies of 62 pairs of interacting galaxies through the review of more than 3 million simulations. We examine the level of convergence and uniqueness of the dynamical properties of each system. These simulations represent the largest collection of models of interacting galaxies to date, providing a valuable resource for the investigation of mergers. This paper presents the simulation parameters generated by the project. They are now publicly available in electronic format at http://data.galaxyzoo.org/mergers.html. Though our best-fitting model parameters are not an exact match to previously published models, our method for determining uncertainty measurements will aid future comparisons between models. The dynamical clocks from our models agree with previous results of the time since the onset of star formation from starburst models in interacting systems and suggest that tidally induced star formation is triggered very soon after closest approach.

  11. Strategy selection in evolutionary game dynamics on group interaction networks.

    Science.gov (United States)

    Tan, Shaolin; Feng, Shasha; Wang, Pei; Chen, Yao

    2014-11-01

    Evolutionary game theory provides an appropriate tool for investigating the competition and diffusion of behavioral traits in biological or social populations. A core challenge in evolutionary game theory is the strategy selection problem: Given two strategies, which one is favored by the population? Recent studies suggest that the answer depends not only on the payoff functions of strategies but also on the interaction structure of the population. Group interactions are one of the fundamental interactive modes within populations. This work aims to investigate the strategy selection problem in evolutionary game dynamics on group interaction networks. In detail, the strategy selection conditions are obtained for some typical networks with group interactions. Furthermore, the obtained conditions are applied to investigate selection between cooperation and defection in populations. The conditions for evolution of cooperation are derived for both the public goods game and volunteer's dilemma game. Numerical experiments validate the above analytical results.

  12. ViSIT: Visitor Survey Information Tool

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — ViSIT is an interactive web tool created by USGS to visualize the data collected as part of the National Wildlife Refuge Visitor Survey. The national survey was...

  13. Nonlinear dynamic susceptibilities of interacting and noninteracting magnetic nanoparticles

    CERN Document Server

    Joensson, P; García-Palacios, J L; Svedlindh, P

    2000-01-01

    The linear and cubic dynamic susceptibilities of solid dispersions of nanosized maghemite gamma-Fe sub 2 O sub 3 particles have been measured for three samples with a volume concentration of magnetic particles ranging from 0.3% to 17%, in order to study the effect of dipole-dipole interactions. Significant differences between the dynamic response of the samples are observed. While the linear and cubic dynamic susceptibilities of the most dilute sample compare reasonably well with the corresponding expressions proposed by Raikher and Stepanov for noninteracting particles, the nonlinear dynamic response of the most concentrated sample exhibits at low temperatures similar features as observed in a Ag(11 at% Mn) spin glass.

  14. Thin viscous elliptical accretion discs with orbits sharing a common longitude of periastron. VI. Simplification of the dynamical equation

    Science.gov (United States)

    Dimitrov, D.

    2012-10-01

    We continue the series of papers, devoted to the investigation and simplification of the dynamical equation, governing the structure of the stationary elliptical accretion discs. These studies are in the frameworks, specified according to the model of Lyubarskij et al. [7]. In addition to the previous examinations, we find one more linear relation between the coefficients of this second order ordinary differential equation, which enables us to eliminate effectively at least four of them. This is in the course of our approach to reduce the number of these functions, depending on the eccentricity, its derivative and the power n in the viscosity law η = β Σ n. They appear in the equation during the process of averaging (i.e. integrating) over the azimuthal angle of the elliptical orbits. At the present stage of the investigations, there still remain three integrals of the indicated type. Except the case of integer values of n, their analytical solutions are not known. In connection with the linear dependence or independence of these functions (this is a subject of our future studies), the dynamical equation of the elliptical accretion discs may be split into a system of corresponding number of more simple equations about the unknown eccentricities of the particle orbits. Such an approach is in accordance with our base line, carried out through the referred series of papers, to make a progress, as much as possible, into the solving of the task by means of purely analytical methods. And only when the further advance in this way (if the final solution is not already attained) is so complicated, that it is impasse, to use numerical simulations.

  15. Spray characterization and droplet interactions study using particle dynamic analyzer

    Science.gov (United States)

    Yurteri, C. U.; Kadambi, Jaikrishnan R.; Arik, Engin B.

    1993-08-01

    Nozzles are utilized in atomizing liquids in many industrial and domestic applications. Examples include domestic and industrial heating units (furnaces and boilers), internal combustion engines, agricultural spraying, spray painting, etc. To improve atomizer design, it is necessary to obtain spray characteristics which include the simultaneous droplet size and velocity information. Also droplet interactions in the dense spray region affect the characteristics. Interacting spray configurations are also encountered in many industrial applications and lead to direct interactions among the droplets. The Particle Dynamic Analyzer which utilizes a combination of Laser Doppler Anemometry and Phase Doppler Interferometry to simultaneously measure droplet velocity and diameter was used to study (1) the spray characteristics of Delavan nozzles and (2) the interaction between two sprays. The results of the tests are discussed in this paper.

  16. Integrating empirically dissolved organic matter quality for WHAM VI using the DOM optical properties: a case study of Cu-Al-DOM interactions.

    Science.gov (United States)

    Chappaz, Anthony; Curtis, P Jeff

    2013-02-19

    Metal speciation is important for understanding the toxicity of metals in aquatic systems, and can be predicted for mixtures of metals in presence of dissolved organic matter (DOM) with thermodynamic models such as WHAM VI. The influence of the DOM source (quality) has been demonstrated, but is presently neglected in predicting Cu activity (WHAM VI). Here we determined the effect of aluminum (Al) competition on copper (Cu) complexation for four different DOMs, from a high-colored DOM (more humic) to a low-colored DOM (less humic). In presence of Al, free Cu activities (defined as free ion activity) increased, consistent with competition between Cu and Al for the same binding sites on all DOM. The apparent competition decreased with increasing DOM color. Equilibrium modeling of Cu speciation with WHAM VI explained 49% of the variance in measured Cu activity. When modified to integrate DOM quality using a new empirical coefficient F related to DOM optical properties, Cu activities predicted from WHAM VI were significantly improved to about 80% of the observed variance explained. The effects of Al on Cu activity were well predicted by WHAM VI. Subsequently, we compared the relative effects of DOM concentration, DOM quality, and Al competition with other determinants of Cu activity represented in legislation and scientific literature (pH and hardness), and qualitatively ranked them by their influence on Cu activity for normal ranges encountered in fresh waters using WHAM VI. Our experimental results indicate that DOM quality is an important variable that should be included in predictive models of ion speciation (WHAM VI) and eco-toxicological models such as the biotic ligand model (BLM).

  17. Combined use of flow cytometry and microscopy to study the interactions between the gram-negative betaproteobacterium Acidovorax facilis and uranium(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, U., E-mail: u.gerber@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, P.O. Box 510119, 01314 Dresden (Germany); Zirnstein, I. [Research Institute of Leather and Plastic Sheeting (FILK) gGmbH, Meissner Ring 1-5, 09599 Freiberg (Germany); Krawczyk-Bärsch, E. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, P.O. Box 510119, 01314 Dresden (Germany); Lünsdorf, H. [Helmholtz Centre for Infection Research, Central Facility for Microscopy, Inhoffenstr. 7, D-38124 Braunschweig (Germany); Arnold, T. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Resource Ecology, P.O. Box 510119, 01314 Dresden (Germany); Merroun, M.L. [University of Granada, Department of Microbiology, Campus Fuentenueva, E-18071 Granada (Spain)

    2016-11-05

    Highlights: • Acidovorax facilis is able to remove 130 mg U/g dry biomass from solution. • Kinetically temperature-dependent uranium removal was studied. • Cell viability and metabolic activity was tested by flow cytometry. • Uranium was removed by active biosorption and passive bioaccumulation. - Abstract: The former uranium mine Königstein (Saxony, Germany) is currently in the process of remediation by means of controlled underground flooding. Nevertheless, the flooding water has to be cleaned up by a conventional wastewater treatment plant. In this study, the uranium(VI) removal and tolerance mechanisms of the gram-negative betaproteobacterium Acidovorax facilis were investigated by a multidisciplinary approach combining wet chemistry, flow cytometry, and microscopy. The kinetics of uranium removal and the corresponding mechanisms were investigated. The results showed a biphasic process of uranium removal characterized by a first phase where 95% of uranium was removed within the first 8 h followed by a second phase that reached equilibrium after 24 h. The bacterial cells displayed a total uranium removal capacity of 130 mg U/g dry biomass. The removal of uranium was also temperature-dependent, indicating that metabolic activity heavily influenced bacterial interactions with uranium. TEM analyses showed biosorption on the cell surface and intracellular accumulation of uranium. Uranium tolerance tests showed that A. facilis was able to withstand concentrations up to 0.1 mM. This work demonstrates that A. facilis is a suitable candidate for in situ bioremediation of flooding water in Königstein as well as for other contaminated waste waters.

  18. Dynamics of Entangled Polymers: Role of Attractive Interactions

    Science.gov (United States)

    Grest, Gary S.; Koski, Jason

    The coupled dynamics of entangled polymers, which span broad time and length scales, govern their unique viscoelastic properties. Numerical simulations of highly coarse grained models are often used to follow chain mobility from the intermediate Rouse and reptation regimes to the late time diffusive regime. In these models, purely repulsive interactions between monomers are typically used because it is less computationally expensive than including attractive interactions. The effect of including the attractive interaction on the local and macroscopic properties of entangled polymer melts is explored over a wide temperature range using large scale molecular dynamics simulations. Attractive interactions are shown to have little effect on the local packing for all temperatures T and chain mobility for T higher than about twice the glass transition Tg. For lower T, the attractive interactions play a significant role, reducing the chain mobility compared to the repulsive case. As T approaches Tg breakdown of time-temperature superposition for the stress autocorrelation function is observed. Sandia National Labs is a multiprogram laboratory managed and operated by Sandia Corporation, a Lockheed-Martin Company, for the U.S. Dept of Energy under Contract No. DEAC04-94AL85000.

  19. Evolutionary dynamics of general group interactions in structured populations

    Science.gov (United States)

    Li, Aming; Broom, Mark; Du, Jinming; Wang, Long

    2016-02-01

    The evolution of populations is influenced by many factors, and the simple classical models have been developed in a number of important ways. Both population structure and multiplayer interactions have been shown to significantly affect the evolution of important properties, such as the level of cooperation or of aggressive behavior. Here we combine these two key factors and develop the evolutionary dynamics of general group interactions in structured populations represented by regular graphs. The traditional linear and threshold public goods games are adopted as models to address the dynamics. We show that for linear group interactions, population structure can favor the evolution of cooperation compared to the well-mixed case, and we see that the more neighbors there are, the harder it is for cooperators to persist in structured populations. We further show that threshold group interactions could lead to the emergence of cooperation even in well-mixed populations. Here population structure sometimes inhibits cooperation for the threshold public goods game, where depending on the benefit to cost ratio, the outcomes are bistability or a monomorphic population of defectors or cooperators. Our results suggest, counterintuitively, that structured populations are not always beneficial for the evolution of cooperation for nonlinear group interactions.

  20. Introduction to weak interaction theories with dynamical symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Lane, K.D.; Peskin, M.E.

    1980-07-01

    A straightforward introduction to theories of the weak interactions with dynamical symmetry breaking-theories of technicolor or hypercolor is presented. The intent is to inform experimentalists, but also to goad theorists. The motivation for considering theories of this type is described. The structure that such a theory must possess, including new gauge interactions at mass scales of 1-100 TeV is then outlined. Despite their reliance on phenomena at such enormous energies, these theories contain new phenomena observable at currently accessible energies. Three such effects which are especially likely to be observed are described.

  1. Effective Dynamics of Microorganisms That Interact with Their Own Trail

    Science.gov (United States)

    Kranz, W. Till; Gelimson, Anatolij; Zhao, Kun; Wong, Gerard C. L.; Golestanian, Ramin

    2016-07-01

    Like ants, some microorganisms are known to leave trails on surfaces to communicate. We explore how trail-mediated self-interaction could affect the behavior of individual microorganisms when diffusive spreading of the trail is negligible on the time scale of the microorganism using a simple phenomenological model for an actively moving particle and a finite-width trail. The effective dynamics of each microorganism takes on the form of a stochastic integral equation with the trail interaction appearing in the form of short-term memory. For a moderate coupling strength below an emergent critical value, the dynamics exhibits effective diffusion in both orientation and position after a phase of superdiffusive reorientation. We report experimental verification of a seemingly counterintuitive perpendicular alignment mechanism that emerges from the model.

  2. A Numerical Study on Hydrodynamic Interactions between Dynamic Positioning Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Doo Hwa; Lee, Sang Wook [University of Ulsan, Ulsan (Korea, Republic of)

    2017-06-15

    In this study, we conducted computational fluid dynamics (CFD) simulations for the unsteady hydrodynamic interaction of multiple thrusters by solving Reynolds averaged Navier-Stokes equations. A commercial CFD software, STAR-CCM+ was used for all simulations by employing a ducted thruster model with combination of a propeller and No. 19a duct. A sliding mesh technique was used to treat dynamic motion of propeller rotation and non-conformal hexahedral grid system was considered. Four different combinations in tilting and azimuth angles of the thrusters were considered to investigate the effects on the propulsion performance. We could find that thruster-hull and thruster-thruster interactions has significant effect on propulsion performance and further study will be required for the optimal configurations with the best tilting and relative azimuth angle between thrusters.

  3. Fluid-Solid Interaction and Multiscale Dynamic Processes: Experimental Approach

    Science.gov (United States)

    Arciniega-Ceballos, Alejandra; Spina, Laura; Mendo-Pérez, Gerardo M.; Guzmán-Vázquez, Enrique; Scheu, Bettina; Sánchez-Sesma, Francisco J.; Dingwell, Donald B.

    2017-04-01

    The speed and the style of a pressure drop in fluid-filled conduits determines the dynamics of multiscale processes and the elastic interaction between the fluid and the confining solid. To observe this dynamics we performed experiments using fluid-filled transparent tubes (15-50 cm long, 2-4 cm diameter and 0.3-1 cm thickness) instrumented with high-dynamic piezoelectric sensors and filmed the evolution of these processes with a high speed camera. We analyzed the response of Newtonian fluids to slow and sudden pressure drops from 3 bar-10 MPa to ambient pressure. We used fluids with viscosities of mafic to intermediate silicate melts of 1 to 1000 Pa s and water. The processes observed are fluid mass expansion, fluid flow, jets, bubbles nucleation, growth, coalescence and collapse, degassing, foam building at the surface and vertical wagging. All these processes (in fine and coarse scales) are triggered by the pressure drop and are sequentially coupled in time while interacting with the solid. During slow decompression, the multiscale processes are recognized occurring within specific pressure intervals, and exhibit a localized distribution along the conduit. In this, degassing predominates near the surface and may present piston-like oscillations. In contrast, during sudden decompression the fluid-flow reaches higher velocities, the dynamics is dominated by a sequence of gas-packet pulses driving jets of the gas-fluid mixture. The evolution of this multiscale phenomenon generates complex non-stationary microseismic signals recorded along the conduit. We discuss distinctive characteristics of these signals depending on the decompression style and compare them with synthetics. These synthetics are obtained numerically under an averaging modeling scheme, that accounted for the stress-strain of the cyclic dynamic interaction between the fluid and the solid wall, assuming an incompressible and viscous fluid that flows while the elastic solid responds oscillating

  4. Dynamic fluctuations of protein-carbohydrate interactions promote protein aggregation.

    Directory of Open Access Journals (Sweden)

    Vladimir Voynov

    2009-12-01

    Full Text Available Protein-carbohydrate interactions are important for glycoprotein structure and function. Antibodies of the IgG class, with increasing significance as therapeutics, are glycosylated at a conserved site in the constant Fc region. We hypothesized that disruption of protein-carbohydrate interactions in the glycosylated domain of antibodies leads to the exposure of aggregation-prone motifs. Aggregation is one of the main problems in protein-based therapeutics because of immunogenicity concerns and decreased efficacy. To explore the significance of intramolecular interactions between aromatic amino acids and carbohydrates in the IgG glycosylated domain, we utilized computer simulations, fluorescence analysis, and site-directed mutagenesis. We find that the surface exposure of one aromatic amino acid increases due to dynamic fluctuations. Moreover, protein-carbohydrate interactions decrease upon stress, while protein-protein and carbohydrate-carbohydrate interactions increase. Substitution of the carbohydrate-interacting aromatic amino acids with non-aromatic residues leads to a significantly lower stability than wild type, and to compromised binding to Fc receptors. Our results support a mechanism for antibody aggregation via decreased protein-carbohydrate interactions, leading to the exposure of aggregation-prone regions, and to aggregation.

  5. Dynamic Soil-Pile Interaction for large diameter monopile foundations

    DEFF Research Database (Denmark)

    Zania, Varvara

    2013-01-01

    so far driven by their dynamic performance. The excitation frequencies are imposed by the rotation of the rotor, hence they are lumped close to the rotation frequency of the rotor (1P) and the lower blade multiples (2P, 3P). The prevailing design concepts originate from an ‘avoidance of resonance...... of the study is to analyse the dynamic interaction of the soil and a single pile embedded in it by accounting for the geometric and stiffness properties of the pile. In doing so, a semi – analytical approach is adopted based on the fundamental solution of horizontal pile vibration by Novak and Nogami (1977......). The dynamic impedance functions of the monopile foundation are obtained for varying soil conditions and it is shown that the first eigenfrequency of the soil layer controls the reduction of the stiffness and the increase of the radiation damping induced by the vibration of the monopile. Higher...

  6. Flight Dynamic Simulation with Nonlinear Aeroelastic Interaction using the ROM-ROM Procedure Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc. proposes to develop an integrated flight dynamics simulation capability with nonlinear aeroelastic interactions by combining a flight dynamics...

  7. Dynamic interactions among badgers: implications for sociality and disease transmission.

    Science.gov (United States)

    Böhm, Monika; Palphramand, Kate L; Newton-Cross, Geraldine; Hutchings, Michael R; White, Piran C L

    2008-07-01

    1. Direct interactions between individuals play an important part in the sociality of group-living animals, their mating system and disease transmission. Here, we devise a methodology to quantify relative rates of proximity interaction from radio-tracking data and highlight potential asymmetries within the contact network of a moderate-density badger population in the north-east of England. 2. We analysed radio-tracking data from four contiguous social groups, collected over a 3-year period. Dynamic interaction analysis of badger dyads was used to assess the movement of individuals in relation to the movement of others, both within and between social groups. Dyads were assessed with regard to season, sex, age and sett use pattern of the badgers involved. 3. Intragroup separation distances were significantly shorter than intergroup separation distances, and interactions between groups were rare. Within groups, individuals interacted with each other more often than expected, and interaction patterns varied significantly with season and sett use pattern. Non-mover dyads (using the main sett for day-resting on > 50% of occasions) interacted more frequently than mover dyads (using an outlier sett for day-resting on > 50% of occasions) or mover-non-mover dyads. Interactions between group members occurred most frequently in winter. 4. Of close intragroup interactions (sociality and support the suggestion that badger social groups are comprised of different subgroups, in our case based on differential sett use patterns. 5. Asymmetries in contact structure within a population will affect the way in which diseases are transmitted through a social network. Assessment of these networks is essential for understanding the persistence and spread of disease within populations which do not mix freely or which exhibit heterogeneities in their spatial or social behaviour.

  8. Dynamics and interactions of particles in a thermophoretic trap

    Science.gov (United States)

    Foster, Benjamin; Fung, Frankie; Fieweger, Connor; Usatyuk, Mykhaylo; Gaj, Anita; DeSalvo, B. J.; Chin, Cheng

    2017-08-01

    We investigate dynamics and interactions of particles levitated and trapped by the thermophoretic force in a vacuum cell. Our analysis is based on footage taken by orthogonal cameras that are able to capture the three dimensional trajectories of the particles. In contrast to spherical particles, which remain stationary at the center of the cell, here we report new qualitative features of the motion of particles with non-spherical geometry. Singly levitated particles exhibit steady spinning around their body axis and rotation around the symmetry axis of the cell. When two levitated particles approach each other, repulsive or attractive interactions between the particles are observed. Our levitation system offers a wonderful platform to study interaction between particles in a microgravity environment.

  9. An Aspect of Dynamic Human-structure Interaction

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2008-01-01

    on the structure) influence the dynamic behaviour and modal characteristics of the structure carrying them, whether being a grandstand, an office floor or similar. However, the interaction between the stationary humans and the structure is generally not well understood, and the paper addresses this interaction......It is known that humans and structures interact. Humans can cause structures to vibrate, and excessive vibrations may occur if the motion frequency of humans coincides with a resonant frequency of the structural system. It is also known that stationary humans (such as humans sitting or standing....... Focus is on how modal characteristics of the structure, i.e. its frequency and damping, are influenced by the presence of stationary humans. Vertical vibrations are considered, and particular focus is given the influence of human posture on modal characteristics of the supporting structure. Insight...

  10. Interspecies interactions are an integral determinant of microbial community dynamics

    Directory of Open Access Journals (Sweden)

    Fatma Azwani Abdul Aziz

    2015-10-01

    Full Text Available This study investigated the factor that the determine the dynamics of bacterial communities in a complex system using multidisciplinary methods. Since real and engineered microbial ecosystems are too complex, six types of synthetic microbial ecosystems (SMEs were constructed under chemostat conditions with phenol as the sole carbon and energy source. 2-4 phenol-degrading, phylogenetically and physiologically different bacterial strains were used in each SEM. Phylogeny was based on the nucleotide sequence of 16S rRNA genes, while physiologic traits were based on kinetic and growth parameters on phenol. Two metrics, J parameter and ‘complex interaction’, were compared to predict which strain would become dominant in a SME. The J parameter is calculated from kinetic and growth parameters, whereas ‘complex interaction’, which was developed here, evaluated bacterial community dynamics by measuring specific growth activity as affected by the other strains. The specific growth activity was calculated as the proportion of growth activity under the presence of supernatant compared to control conditions. Population densities of strains used in SMEs were enumerated by real-time PCR targeting the gene encoding the large subunit of phenol hydroxylase and were compared to predictions made from J parameter and complex interaction calculations. In 4 of 6 SEMs tested the final dominant strain shown by real-time PCR analyses coincided with the strain predicted by both the J parameter and the complex interaction. However, in SMEII-2 and SMEII-3 the final dominant Variovorax strains coincided with prediction of the complex interaction but not the J parameter. These results demonstrate that the effects of complex interactions within microbial communities contribute to determining the dynamics of the microbial ecosystem.

  11. Development of a Dynamic Biomechanical Model for Load Carriage: Phase VI: Assessing Physiological and Biomechanical Loading Using the Portable Measurement System and the Dynamic Biomechanical Model

    Science.gov (United States)

    2007-12-01

    Cholewicki, J., McGill, S.M. (1996) Mechanical stability of the in vivo lumbar spine: Implications for injury and chronic low back pain. Clin. Biomech. 11...the user in the form of text files should a user wish to do additional statistical analyses. Injury mechanisms The mechanisms of tissue injury ...fall into several categories and include dynamic overload causing strains, sprains or tears, impact injury causing tearing or bruising, cumulative

  12. The interaction of cannibalism and omnivory: consequences for community dynamics.

    Science.gov (United States)

    Rudolf, Volker H W

    2007-11-01

    Although cannibalism is ubiquitous in food webs and frequent in systems where a predator and its prey also share a common resource (intraguild predation, IGP), its impacts on species interactions and the dynamics and structure of communities are still poorly understood. In addition, the few existing studies on cannibalism have generally focused on cannibalism in the top-predator, ignoring that it is frequent at intermediate trophic levels. A set of structured models shows that cannibalism can completely alter the dynamics and structure of three-species IGP systems depending on the trophic position where cannibalism occurs. Contrary to the expectations of simple models, the IG predator can exploit the resources more efficiently when it is cannibalistic, enabling the predator to persist at lower resource densities than the IG prey. Cannibalism in the IG predator can also alter the effect of enrichment, preventing predator-mediated extinction of the IG prey at high productivities predicted by simple models. Cannibalism in the IG prey can reverse the effect of top-down cascades, leading to an increase in the resource with decreasing IG predator density. These predictions are consistent with current data. Overall, cannibalism promotes the coexistence of the IG predator and IG prey. These results indicate that including cannibalism in current models can overcome the discrepancy between theory and empirical data. Thus, we need to measure and account for cannibalistic interactions to reliably predict the structure and dynamics of communities.

  13. Unveiling protein functions through the dynamics of the interaction network.

    Directory of Open Access Journals (Sweden)

    Irene Sendiña-Nadal

    Full Text Available Protein interaction networks have become a tool to study biological processes, either for predicting molecular functions or for designing proper new drugs to regulate the main biological interactions. Furthermore, such networks are known to be organized in sub-networks of proteins contributing to the same cellular function. However, the protein function prediction is not accurate and each protein has traditionally been assigned to only one function by the network formalism. By considering the network of the physical interactions between proteins of the yeast together with a manual and single functional classification scheme, we introduce a method able to reveal important information on protein function, at both micro- and macro-scale. In particular, the inspection of the properties of oscillatory dynamics on top of the protein interaction network leads to the identification of misclassification problems in protein function assignments, as well as to unveil correct identification of protein functions. We also demonstrate that our approach can give a network representation of the meta-organization of biological processes by unraveling the interactions between different functional classes.

  14. Interaction between telencephalic signals and respiratory dynamics in songbirds.

    Science.gov (United States)

    Méndez, Jorge M; Mindlin, Gabriel B; Goller, Franz

    2012-06-01

    The mechanisms by which telencephalic areas affect motor activities are largely unknown. They could either take over motor control from downstream motor circuits or interact with the intrinsic dynamics of these circuits. Both models have been proposed for telencephalic control of respiration during learned vocal behavior in birds. The interactive model postulates that simple signals from the telencephalic song control areas are sufficient to drive the nonlinear respiratory network into producing complex temporal sequences. We tested this basic assumption by electrically stimulating telencephalic song control areas and analyzing the resulting respiratory patterns in zebra finches and in canaries. We found strong evidence for interaction between the rhythm of stimulation and the intrinsic respiratory rhythm, including naturally emerging subharmonic behavior and integration of lateralized telencephalic input. The evidence for clear interaction in our experimental paradigm suggests that telencephalic vocal control also uses a similar mechanism. Furthermore, species differences in the response of the respiratory system to stimulation show parallels to differences in the respiratory patterns of song, suggesting that the interactive production of respiratory rhythms is manifested in species-specific specialization of the involved circuitry.

  15. Dynamics of tandem bubble interaction in a microfluidic channel

    Science.gov (United States)

    Yuan, Fang; Sankin, Georgy; Zhong, Pei

    2011-01-01

    The dynamics of tandem bubble interaction in a microfluidic channel (800 × 21 μm, W × H) have been investigated using high-speed photography, with resultant fluid motion characterized by particle imaging velocimetry. A single or tandem bubble is produced reliably via laser absorption by micron-sized gold dots (6 μm in diameter with 40 μm in separation distance) coated on a glass surface of the microfluidic channel. Using two pulsed Nd:YAG lasers at λ = 1064 nm and ∼10 μJ/pulse, the dynamics of tandem bubble interaction (individual maximum bubble diameter of 50 μm with a corresponding collapse time of 5.7 μs) are examined at different phase delays. In close proximity (i.e., interbubble distance = 40 μm or γ = 0.8), the tandem bubbles interact strongly with each other, leading to asymmetric deformation of the bubble walls and jet formation, as well as the production of two pairs of vortices in the surrounding fluid rotating in opposite directions. The direction and speed of the jet (up to 95 m/s), as well as the orientation and strength of the vortices can be varied by adjusting the phase delay. PMID:22088007

  16. Retraction With Face Saving: modelling conversational interaction through dynamic hypermedia

    Directory of Open Access Journals (Sweden)

    Roberto Bolognesi

    1994-12-01

    Full Text Available This paper describes RWFS (Retraction With Face Saving, a hypermedia application which models an interview between a lawyer and his client - a lorry driver - facing court charges of reckless driving. At one level RWFS takes the form of a sophisticated game in which different outcomes to the interview are possible according to the learner's degree of skill. At another level, RWFS is designed to encourage the language learner's awareness and understanding of the pragmatic features of conversation. RWFS runs on HyperContext, a hybrid hypertextlexpert system developed in Pavia by two of the authors, Marco Piastra and Roberto Bolognesi, and which supports dynamic hypermedia units. HyperContext's dynamic linking capacity plays a vital role in simulating significant conversational features such as the conditioning of a current move in the conversation by information acquired much earlier in the course of the interview. In this connection, the paper discusses the contribution of RMCI (Re-usable Model of Conversational Interaction, a re-usable application-independent applied model of interaction on which the game is based, and which links a tactical level (the conversation to a metalevel which provides a moveby- move commentary on interactional theory. In its turn, RMCFs metalevel is linked to a strategic level which interprets the structure of the conversation in terms of a pyramid-like hierarchy of increasingly abstract theoretical concepts.

  17. Aircraft-based investigation of Dynamics-Aerosol-Chemistry-Cloud Interactions in Southern West Africa

    Science.gov (United States)

    Flamant, Cyrille

    2017-04-01

    The EU-funded project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa, http://www.dacciwa.eu) is investigating the relationship between weather, climate and air pollution in southern West Africa. The air over the coastal region of West Africa is a unique mixture of natural and anthropogenic gases, liquids and particles, emitted in an environment, in which multi-layer cloud decks frequently form. These exert a large influence on the local weather and climate, mainly due to their impact on radiation, the surface energy balance and thus the diurnal cycle of the atmospheric boundary layer. The main objective for the aircraft detachment was to build robust statistics of cloud properties in southern West Africa in different chemical landscapes to investigate the physical processes involved in their life cycle in such a complex chemical environment. As part of the DACCIWA field campaigns, three European aircraft (the German DLR Falcon 20, the French SAFIRE ATR 42 and the British BAS Twin Otter) conducted a total of 50 research flights across Ivory Coast, Ghana, Togo, and Benin from 27 June to 16 July 2016 for a total of 155 flight hours, including hours sponsored through 3 EUFAR projects. The aircraft were used in different ways based on their strengths, but all three had comparable instrumentation with the the capability to do gas-phase chemistry, aerosol and clouds, thereby generating a rich dataset of atmospheric conditions across the region. Eight types of flight objectives were conducted to achieve the goals of the DACCIWA: (i) Stratus clouds, (ii) Land-sea breeze clouds, (iii) Mid-level clouds, (iv) Biogenic emission, (v) City emissions, (vi) Flaring and ship emissions, (vii) Dust and biomass burning aerosols, and (viii) air-sea interactions. An overview of the DACCIWA aircraft campaign as well as first highlights from the airborne observations will be presented.

  18. The Dynamic Reactance Interaction - How Vested Interests Affect People's Experience, Behavior, and Cognition in Social Interactions.

    Science.gov (United States)

    Steindl, Christina; Jonas, Eva

    2015-01-01

    In social interactions, individuals may sometimes pursue their own interests at the expense of their interaction partner. Such self-interested behaviors impose a threat to the interaction partner's freedom to act. The current article investigates this threat in the context of interdependence and reactance theory. We explore how vested interests influence reactance process stages of an advisor-client interaction. We aim to explore the interactional process that evolves. In two studies, participants took the perspective of a doctor (advisor) or a patient (client). In both studies we incorporated a vested interest. In Study 1 (N = 82) we found that in response to a vested interest of their interaction partner, patients indicated a stronger experience of reactance, more aggressive behavioral intentions, and more biased cognitions than doctors. A serial multiple mediation revealed that a vested interest engendered mistrust toward the interaction partner and this mistrust led to an emerging reactance process. Study 2 (N = 207) further demonstrated that doctors expressed their reactance in a subtle way: they revealed a classic confirmation bias when searching for additional information on their preliminary decision preference, indicating stronger defense motivation. We discuss how these findings can help us to understand how social interactions develop dynamically.

  19. Interactions Controlling the Slow Dynamic Conformational Motions of Ubiquitin

    Directory of Open Access Journals (Sweden)

    Soichiro Kitazawa

    2017-08-01

    Full Text Available Rational mutation of proteins based on their structural and dynamic characteristics is a useful strategy for amplifying specific fluctuations in proteins. Here, we show the effects of mutation on the conformational fluctuations and thermodynamic stability of ubiquitin. In particular, we focus on the salt bridge between K11 and E34 and the hydrogen bond between I36 and Q41, which are predicted to control the fluctuation between the basic folded state, N1, and the alternatively folded state, N2, of the protein, using high-pressure NMR spectroscopy. The E34A mutation, which disrupts the salt bridge, did not alter picosecond–to–nanosecond, microsecond–to–millisecond dynamic motions, and stability of the protein, while the Q41N mutation, which destabilizes the hydrogen bond, specifically amplified the N1–N2 conformational fluctuation and decreased stability. Based on the observed thermodynamic stabilities of the various conformational states, we showed that in the Q41N mutant, the N1 state is more significantly destabilized than the N2 state, resulting in an increase in the relative population of N2. Identifying the interactions controlling specific motions of a protein will facilitate molecular design to achieve functional dynamics beyond native state dynamics.

  20. Dynamic soil-structure interaction of monopod and polypod foundations

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2016-01-01

    The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...... within the time domain, frequency-independent lumped-parameter models are developed. The paper proposes a decision criterion for determination of which components must be included within a lumped-parameter model in order to account for the structure–soil–structure interaction in an adequate and efficient...... manner. As a computational example, the dynamic response of a plane frame structure with two footings is compared for two cases: one with and one without the cross coupling. Homogeneous as well as layered soil is considered....

  1. Vortex dynamics and their interactions in quantum trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Wisniacki, D A [Departamento de Fisica ' J. J. Giambiagi' , FCEN, UBA, Pabellon 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Pujals, E R [IMPA-OS, Dona Castorina 110, 22460-320, Rio de Janeiro (Brazil); Borondo, F [Departamento de Quimica C-IX, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2007-12-30

    Vortices are known to play a key role in many important processes in physics and chemistry. Here, we study vortices in connection with the quantum trajectories that can be defined in the framework provided by the de Broglie-Bohm formalism of quantum mechanics. In a previous work, it was shown that the presence of a single moving vortex is enough to induce chaos in these trajectories. Here, this situation is explored in more detail by discussing the relationship between Lyapunov exponents and the parameters characterizing the vortex dynamics. We also consider the issue when more than one vortex exists. In this case, the interaction among them can annihilate or create pairs of vortices with opposite vorticity. This phenomenon is analyzed from a dynamical point of view, showing how the size of the regular regions in phase space grows, as vortices disappear.

  2. Dynamic soil-structure interaction of monopod and polypod foundations

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2016-01-01

    within the time domain, frequency-independent lumped-parameter models are developed. The paper proposes a decision criterion for determination of which components must be included within a lumped-parameter model in order to account for the structure–soil–structure interaction in an adequate and efficient......The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...... manner. As a computational example, the dynamic response of a plane frame structure with two footings is compared for two cases: one with and one without the cross coupling. Homogeneous as well as layered soil is considered....

  3. Fault Diagnosis in Dynamic Systems Using Fuzzy Interacting Observers

    Directory of Open Access Journals (Sweden)

    N. V. Kolesov

    2013-01-01

    Full Text Available A method of fault diagnosis in dynamic systems based on a fuzzy approach is proposed. The new method possesses two basic specific features which distinguish it from the other known fuzzy methods based on the application of fuzzy logic and a bank of state observers. First, this method uses a bank of interacting observers instead of traditional independent observers. The second specific feature of the proposed method is the assumption that there is no strict boundary between the serviceable and disabled technical states of the system, which makes it possible to specify a decision making rule for fault diagnosis.

  4. Dynamics of vortex interactions in two-dimensional flows

    DEFF Research Database (Denmark)

    Juul Rasmussen, J.; Nielsen, A.H.; Naulin, V.

    2002-01-01

    The dynamics and interaction of like-signed vortex structures in two dimensional flows are investigated by means of direct numerical solutions of the two-dimensional Navier-Stokes equations. Two vortices with distributed vorticity merge when their distance relative to their radius, d/R-0l. is below...... a critical value, a(c). Using the Weiss-field, a(c) is estimated for vortex patches. Introducing an effective radius for vortices with distributed vorticity, we find that 3.3 ... with the formation of "vortex crystals"....

  5. Neoantigen landscape dynamics during human melanoma-T cell interactions

    DEFF Research Database (Denmark)

    Verdegaal, Els M. E.; De Miranda, Noel F. C. C.; Visser, Marten

    2016-01-01

    is constant over time is unclear. Here we analyse the stability of neoantigen-specific T-cell responses and the antigens they recognize in two patients with stage IV melanoma treated by adoptive T-cell transfer. The T-cell-recognized neoantigens can be selectively lost from the tumour cell population, either...... by overall reduced expression of the genes or loss of the mutant alleles. Notably, loss of expression of T-cell-recognized neoantigens was accompanied by development of neoantigen-specific T-cell reactivity in tumour-infiltrating lymphocytes. These data demonstrate the dynamic interactions between cancer...

  6. Emotional contagion and proto-organizing in human interaction dynamics.

    Science.gov (United States)

    Hazy, James K; Boyatzis, Richard E

    2015-01-01

    This paper combines the complexity notions of phase transitions and tipping points with recent advances in cognitive neuroscience to propose a general theory of human proto-organizing. It takes as a premise that a necessary prerequisite for organizing, or "proto-organizing," occurs through emotional contagion in subpopulations of human interaction dynamics in complex ecosystems. Emotional contagion is posited to engender emotional understanding and identification with others, a social process that acts as a mechanism that enables (or precludes) cooperative responses to opportunities and risks. Propositions are offered and further research is suggested.

  7. Emotional Contagion and Proto-Organizing in Human Interaction Dynamics

    Directory of Open Access Journals (Sweden)

    James K. Hazy

    2015-06-01

    Full Text Available This paper combines the complexity notions of phase transitions and tipping points with recent advances in cognitive neuroscience to propose a general theory of human proto-organizing. It takes as a premise that a necessary prerequisite for organizing, or proto-organizing, occurs through emotional contagion in subpopulations of human interaction dynamics in complex ecosystems. Emotional contagion is posited to engender emotional understanding and identification with others, a social process that acts as a mechanism that enables (or precludes cooperative responses to opportunities and risks. Propositions are offered and further research is suggested.

  8. Analysis of the dynamic interaction between SVOCs and airborne particles

    DEFF Research Database (Denmark)

    Liu, Cong; Shi, Shanshan; Weschler, Charles J.

    2013-01-01

    A proper quantitative understanding of the dynamic interaction between gas-phase semivolatile organic compounds (SVOCs) and airborne particles is important for human exposure assessment and risk evaluation. Questions regarding how to properly address gas/particle interactions have introduced...... of aerosols) is negligible compared with the external one (from bulk air to aerosol surfaces) is presented. The analysis is applicable regardless of the phase state of particles (either liquid or amorphous semisolid/solid). It is found that for both porous and nonporous particles, the internal resistance can...... cause a two orders of magnitude error in the estimation of the gas-phase concentration and a factor of two error in the estimation of the particle-phase concentration. Copyright © American Association for Aerosol Research....

  9. Simple physics-based analytical formulas for the potentials of mean force of the interaction of amino-acid side chains in water. VI. Oppositely charged side chains.

    Science.gov (United States)

    Makowski, Mariusz; Liwo, Adam; Scheraga, Harold A

    2011-05-19

    The two-site coarse-grained model for the interactions of charged side chains, to be used with our coarse-grained UNRES force field for protein simulations proposed in the accompanying paper, has been extended to pairs of oppositely charged side chains. The potentials of mean force of four pairs of molecules modeling charged amino-acid side chains, i.e., propionate-n-pentylamine cation (for aspartic acid-lysine), butyrate-n-pentylamine cation (for glutamic acid-lysine), propionate-1-butylguanidine (for aspartic acid-arginine), and butyrate-1-butylguanidine (for glutamic acid-arginine) pairs were determined by umbrella-sampling molecular dynamics simulations in explicit water as functions of distance and orientation, and the analytical expression was fitted to the potentials of mean force. Compared to pairs of like-charged side chains discussed in the accompanying paper, an average quadrupole-quadrupole interaction term had to be introduced to reproduce the Coulombic interactions, and a multistate model of charge distribution had to be introduced to fit the potentials of mean force of all oppositely charged pairs well. The model reproduces all salt-bridge minima and, consequently, is likely to improve the performance of the UNRES force field. © 2011 American Chemical Society

  10. Opinion dynamics on interacting networks: media competition and social influence

    Science.gov (United States)

    Quattrociocchi, Walter; Caldarelli, Guido; Scala, Antonio

    2014-01-01

    The inner dynamics of the multiple actors of the informations systems – i.e, T.V., newspapers, blogs, social network platforms, – play a fundamental role on the evolution of the public opinion. Coherently with the recent history of the information system (from few main stream media to the massive diffusion of socio-technical system), in this work we investigate how main stream media signed interaction might shape the opinion space. In particular we focus on how different size (in the number of media) and interaction patterns of the information system may affect collective debates and thus the opinions' distribution. We introduce a sophisticated computational model of opinion dynamics which accounts for the coexistence of media and gossip as separated mechanisms and for their feedback loops. The model accounts also for the effect of the media communication patterns by considering both the simple case where each medium mimics the behavior of the most successful one (to maximize the audience) and the case where there is polarization and thus competition among media memes. We show that plurality and competition within information sources lead to stable configurations where several and distant cultures coexist. PMID:24861995

  11. Opinion dynamics on interacting networks: media competition and social influence.

    Science.gov (United States)

    Quattrociocchi, Walter; Caldarelli, Guido; Scala, Antonio

    2014-05-27

    The inner dynamics of the multiple actors of the informations systems - i.e, T.V., newspapers, blogs, social network platforms, - play a fundamental role on the evolution of the public opinion. Coherently with the recent history of the information system (from few main stream media to the massive diffusion of socio-technical system), in this work we investigate how main stream media signed interaction might shape the opinion space. In particular we focus on how different size (in the number of media) and interaction patterns of the information system may affect collective debates and thus the opinions' distribution. We introduce a sophisticated computational model of opinion dynamics which accounts for the coexistence of media and gossip as separated mechanisms and for their feedback loops. The model accounts also for the effect of the media communication patterns by considering both the simple case where each medium mimics the behavior of the most successful one (to maximize the audience) and the case where there is polarization and thus competition among media memes. We show that plurality and competition within information sources lead to stable configurations where several and distant cultures coexist.

  12. Molecular Dynamics of "Fuzzy" Transcriptional Activator-Coactivator Interactions.

    Directory of Open Access Journals (Sweden)

    Natalie S Scholes

    2016-05-01

    Full Text Available Transcriptional activation domains (ADs are generally thought to be intrinsically unstructured, but capable of adopting limited secondary structure upon interaction with a coactivator surface. The indeterminate nature of this interface made it hitherto difficult to study structure/function relationships of such contacts. Here we used atomistic accelerated molecular dynamics (aMD simulations to study the conformational changes of the GCN4 AD and variants thereof, either free in solution, or bound to the GAL11 coactivator surface. We show that the AD-coactivator interactions are highly dynamic while obeying distinct rules. The data provide insights into the constant and variable aspects of orientation of ADs relative to the coactivator, changes in secondary structure and energetic contributions stabilizing the various conformers at different time points. We also demonstrate that a prediction of α-helical propensity correlates directly with the experimentally measured transactivation potential of a large set of mutagenized ADs. The link between α-helical propensity and the stimulatory activity of ADs has fundamental practical and theoretical implications concerning the recruitment of ADs to coactivators.

  13. Opinion dynamics on interacting networks: media competition and social influence

    Science.gov (United States)

    Quattrociocchi, Walter; Caldarelli, Guido; Scala, Antonio

    2014-05-01

    The inner dynamics of the multiple actors of the informations systems - i.e, T.V., newspapers, blogs, social network platforms, - play a fundamental role on the evolution of the public opinion. Coherently with the recent history of the information system (from few main stream media to the massive diffusion of socio-technical system), in this work we investigate how main stream media signed interaction might shape the opinion space. In particular we focus on how different size (in the number of media) and interaction patterns of the information system may affect collective debates and thus the opinions' distribution. We introduce a sophisticated computational model of opinion dynamics which accounts for the coexistence of media and gossip as separated mechanisms and for their feedback loops. The model accounts also for the effect of the media communication patterns by considering both the simple case where each medium mimics the behavior of the most successful one (to maximize the audience) and the case where there is polarization and thus competition among media memes. We show that plurality and competition within information sources lead to stable configurations where several and distant cultures coexist.

  14. Fractional Dynamics of Network Growth Constrained by Aging Node Interactions.

    Science.gov (United States)

    Safdari, Hadiseh; Zare Kamali, Milad; Shirazi, Amirhossein; Khalighi, Moein; Jafari, Gholamreza; Ausloos, Marcel

    2016-01-01

    In many social complex systems, in which agents are linked by non-linear interactions, the history of events strongly influences the whole network dynamics. However, a class of "commonly accepted beliefs" seems rarely studied. In this paper, we examine how the growth process of a (social) network is influenced by past circumstances. In order to tackle this cause, we simply modify the well known preferential attachment mechanism by imposing a time dependent kernel function in the network evolution equation. This approach leads to a fractional order Barabási-Albert (BA) differential equation, generalizing the BA model. Our results show that, with passing time, an aging process is observed for the network dynamics. The aging process leads to a decay for the node degree values, thereby creating an opposing process to the preferential attachment mechanism. On one hand, based on the preferential attachment mechanism, nodes with a high degree are more likely to absorb links; but, on the other hand, a node's age has a reduced chance for new connections. This competitive scenario allows an increased chance for younger members to become a hub. Simulations of such a network growth with aging constraint confirm the results found from solving the fractional BA equation. We also report, as an exemplary application, an investigation of the collaboration network between Hollywood movie actors. It is undubiously shown that a decay in the dynamics of their collaboration rate is found, even including a sex difference. Such findings suggest a widely universal application of the so generalized BA model.

  15. Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Mastoridis, Themistoklis [Stanford Univ., CA (United States)

    2010-08-01

    The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC

  16. Correlative microscopy for 3D structural analysis of dynamic interactions.

    Science.gov (United States)

    Jun, Sangmi; Zhao, Gongpu; Ning, Jiying; Gibson, Gregory A; Watkins, Simon C; Zhang, Peijun

    2013-06-24

    Cryo-electron tomography (cryoET) allows 3D visualization of cellular structures at molecular resolution in a close-to-physiological state(1). However, direct visualization of individual viral complexes in their host cellular environment with cryoET is challenging(2), due to the infrequent and dynamic nature of viral entry, particularly in the case of HIV-1. While time-lapse live-cell imaging has yielded a great deal of information about many aspects of the life cycle of HIV-1(3-7), the resolution afforded by live-cell microscopy is limited (~200 nm). Our work was aimed at developing a correlation method that permits direct visualization of early events of HIV-1 infection by combining live-cell fluorescent light microscopy, cryo-fluorescent microscopy, and cryoET. In this manner, live-cell and cryo-fluorescent signals can be used to accurately guide the sampling in cryoET. Furthermore, structural information obtained from cryoET can be complemented with the dynamic functional data gained through live-cell imaging of fluorescent labeled target. In this video article, we provide detailed methods and protocols for structural investigation of HIV-1 and host-cell interactions using 3D correlative high-speed live-cell imaging and high-resolution cryoET structural analysis. HeLa cells infected with HIV-1 particles were characterized first by confocal live-cell microscopy, and the region containing the same viral particle was then analyzed by cryo-electron tomography for 3D structural details. The correlation between two sets of imaging data, optical imaging and electron imaging, was achieved using a home-built cryo-fluorescence light microscopy stage. The approach detailed here will be valuable, not only for study of virus-host cell interactions, but also for broader applications in cell biology, such as cell signaling, membrane receptor trafficking, and many other dynamic cellular processes.

  17. Optimization of production of extracellular polymeric substances by Arthrobacter viscosus and their interaction with a 13X zeolite for the biosorption of Cr(VI).

    Science.gov (United States)

    Quintelas, Cristina; da Silva, Vítor B; Silva, Bruna; Figueiredo, Hugo; Tavares, Teresa

    2011-10-01

    In this work we aimed to optimize the production of extracellular polymeric substances (EPS) by an Arthrobacter viscosus biofilm supported on 13X zeolite to be used in the biosorption of Cr(VI). The optimization parameters were agitation rate, work volume, pH and glucose concentration. Following the optimization of EPS production, the biofilm was used in the biosorption of hexavalent Cr from liquid solutions. Differences between the use of dead or active biomass and between the performance of zeolite in powder or in pellet form were also studied. The optimized EPS production allowed values of metal uptake between 2.72 mg/g(biosorbent) and 7.88 mg/g(biosorbent) for initial Cr(VI) concentrations of 20-60 mg/L. For an initial concentration of 20 mg/L, the optimal conditions of EPS production allowed an increase of 10% on the removal percentage of total Cr, and the use of zeolite as a powder rather than the pelleted form produced an increase of 46.5% in the removal percentage. For the initial concentration of 60 mg/L, the use of active biomass compared to dried biomass allowed a reduction of the time required for the total removal of Cr(VI) from 20 to 13 days.

  18. ARE THE FIVE ASEAN STOCK PRICE INDICES DYNAMICALLY INTERACTED?

    Directory of Open Access Journals (Sweden)

    Adwin Surja Atmadja

    2005-01-01

    Full Text Available This study seeks to examine the dynamic interactions of stock price indices in five ASEAN countries, Indonesia; Malaysia; the Philippines; Singapore; and Thailand with particular attention to the 1997 Asian financial crisis and period onwards. Using monthly time series data of the stock price indices countries, a vector error correction model (VECM is employed to empirically examine the interaction among the variables. The finding is that the five ASEAN stock market prices were found to be integrated with two cointegrating vectors during the sample period, and that accounting innovation analyses show the short run dynamic interactions among those stock markets. The important implication might be drawn from the finding is that portfolio diversification across the five ASEAN stock markets is unlikely to reduce investment risk due to high degree of financial integration of these markets. Abstract in Bahasa Indonesia : Studi ini bertujuan meneliti interaksi dinamis antara indeks harga saham yang terdapat di lima negara ASEAN, yaitu Indonesia, Malaysia, Filipina, Singapura, dan Thailan yang terjadi selama masa krisis finansial Asia tahun 1997 dan periode sesudahnya. Dengan menggunakan data time series bulanan indeks harga saham dari kelima negara tersebut selama periode penelitian, suatu vector error correction model (VECM diaplikasikan untuk meneliti secara empiris interaksi dinamis yang terjadi diantara berbagai variabel yang dipergunakan dalam penelitian ini. Dari hasil penelitian ditemukan dua vektor kointegrasi (cointegration vector selama masa penelitian, dan analisa inovasi akuntansi (accounting innovation analyses menunjukan adanya interaksi dinamis jangka pendek diantara pasar saham tersebut. Implikasi penting yang mungkin perlu diperhatikan dari penemuan ini adalah bahwa diversifikasi portofolio saham pada lima pasar saham tersebut agaknya tidak akan secara signifikan mengurangi tingkat resiko investasi. Hal ini dikarenakan oleh tingginya

  19. An Interactive Simulator for Imposing Virtual Musculoskeletal Dynamics.

    Science.gov (United States)

    Hasson, Christopher

    2017-05-10

    Disease processes are often marked by both neural and muscular changes that alter movement control and execution, but these adaptations are difficult to tease apart because they occur simultaneously. This is addressed by swapping an individual's limb dynamics with a neurally-controlled facsimile using an interactive musculoskeletal simulator (IMS) that allows controlled modifications of musculoskeletal dynamics. This paper details the design and operation of the IMS, quantifies and describes human adaptation to the IMS, and determines whether the IMS allows users to move naturally, a prerequisite for manipulation experiments. Healthy volunteers (n = 4) practiced a swift goal-directed task (back-and-forth elbow flexion/extension) for 90 trials with the IMS off (normal dynamics) and 240 trials with the IMS on, i.e. the actions of a user's personalized electromyography-driven musculoskeletal model are robotically imposed back on to the user. After practicing with the IMS on, subjects could complete the task with end-point errors of 1.56°, close to the speed-matched IMS-off error of 0.57°. Muscle activity, joint torque, and arm kinematics for IMS-on and -off conditions were well matched for three subjects (root-meansquared error [RMSE] = 0.16 Nm), but the error was higher for one subject with a small stature (RMSE = 0.25 Nm). A well-matched musculoskeletal model allowed IMS users to perform a goal-directed task nearly as well as when the IMS was not active. This advancement permits real-time manipulations of musculoskeletal dynamics, which could increase our understanding of muscular and neural co-adaptations to injury, disease, disuse, and aging.

  20. A field-scale reactive transport model for U(VI) migration influenced by coupled multirate mass transfer and surface complexation reactions

    Science.gov (United States)

    Ma, R.; Zheng, C.; Prommer, H.; Greskowiak, J.; Liu, C.; Zachara, J.; Rockhold, M.

    2010-05-01

    This study explores field-scale modeling of U(VI) reactive transport through incorporation of laboratory and field data. A field-scale reactive transport model was developed on the basis of laboratory-characterized U(VI) surface complexation reactions (SCRs) and multirate mass transfer processes, as well as field-measured hydrogeochemical conditions at the U.S. Department of Energy, Hanford 300 Area (300 A), Washington. The model was used to assess the importance of multirate mass transfer processes on U(VI) reactive transport and to evaluate the effect of variable geochemical conditions caused by dynamic river water-groundwater interactions on U(VI) plume migration. Model simulations revealed complex spatiotemporal relationships between groundwater composition and U(VI) speciation, adsorption, and plume migration. In general, river water intrusion enhances uranium adsorption and lowers aqueous uranium concentration because river water dilution increases pH and decreases aqueous bicarbonate concentration, leading to overall enhanced U(VI) surface complexation. Strong U(VI) retardation was computed for the field-measured hydrogeochemical conditions, suggesting a slow dissipation of the U(VI) plume, a phenomenon consistent with field observations. The simulations also showed that SCR-retarded U(VI) migration becomes more dynamic and synchronous with the groundwater flow field when multirate mass transfer processes are involved. Breakthrough curves at selected locations and the temporal changes in the calculated mass during the 20 year simulation period indicated that uranium adsorption/desorption never attained steady state because of the dynamic flow field and groundwater composition variations caused by river water intrusion. Thus, the multirate SCR model appears to be a crucial consideration for future reactive transport simulations of uranium contaminants at the Hanford 300 A site and elsewhere under similar hydrogeochemical conditions.

  1. Water–Soil–Vegetation Dynamic Interactions in Changing Climate

    Directory of Open Access Journals (Sweden)

    Xixi Wang

    2017-09-01

    Full Text Available Previous studies of land degradation, topsoil erosion, and hydrologic alteration typically focus on these subjects individually, missing important interrelationships among these important aspects of the Earth’s system. However, an understanding of water–soil–vegetation dynamic interactions is needed to develop practical and effective solutions to sustain the globe’s eco-environment and grassland agriculture, which depends on grasses, legumes, and other fodder or soil-building crops. This special issue is intended to be a platform for a discussion of the relevant scientific findings based on experimental and/or modeling studies. Its 12 peer-reviewed articles present data, novel analysis/modeling approaches, and convincing results of water–soil–vegetation interactions under historical and future climates. Two of the articles examine how lake/pond water quality is related to human activity and climate. Overall, these articles can serve as important references for future studies to further advance our understanding of how water, soil, and vegetation interactively affect the health and productivity of the Earth’s ecosystem.

  2. An iterative method for hydrodynamic interactions in Brownian dynamics simulations of polymer dynamics

    Science.gov (United States)

    Miao, Linling; Young, Charles D.; Sing, Charles E.

    2017-07-01

    Brownian Dynamics (BD) simulations are a standard tool for understanding the dynamics of polymers in and out of equilibrium. Quantitative comparison can be made to rheological measurements of dilute polymer solutions, as well as direct visual observations of fluorescently labeled DNA. The primary computational challenge with BD is the expensive calculation of hydrodynamic interactions (HI), which are necessary to capture physically realistic dynamics. The full HI calculation, performed via a Cholesky decomposition every time step, scales with the length of the polymer as O(N3). This limits the calculation to a few hundred simulated particles. A number of approximations in the literature can lower this scaling to O(N2 - N2.25), and explicit solvent methods scale as O(N); however both incur a significant constant per-time step computational cost. Despite this progress, there remains a need for new or alternative methods of calculating hydrodynamic interactions; large polymer chains or semidilute polymer solutions remain computationally expensive. In this paper, we introduce an alternative method for calculating approximate hydrodynamic interactions. Our method relies on an iterative scheme to establish self-consistency between a hydrodynamic matrix that is averaged over simulation and the hydrodynamic matrix used to run the simulation. Comparison to standard BD simulation and polymer theory results demonstrates that this method quantitatively captures both equilibrium and steady-state dynamics after only a few iterations. The use of an averaged hydrodynamic matrix allows the computationally expensive Brownian noise calculation to be performed infrequently, so that it is no longer the bottleneck of the simulation calculations. We also investigate limitations of this conformational averaging approach in ring polymers.

  3. Fractional dynamics of coupled oscillators with long-range interaction.

    Science.gov (United States)

    Tarasov, Vasily E; Zaslavsky, George M

    2006-06-01

    We consider a one-dimensional chain of coupled linear and nonlinear oscillators with long-range powerwise interaction. The corresponding term in dynamical equations is proportional to 1//n-m/alpha+1. It is shown that the equation of motion in the infrared limit can be transformed into the medium equation with the Riesz fractional derivative of order alpha, when 0coupled oscillators and show how their synchronization can appear as a result of bifurcation, and how the corresponding solutions depend on alpha. The presence of a fractional derivative also leads to the occurrence of localized structures. Particular solutions for fractional time-dependent complex Ginzburg-Landau (or nonlinear Schrodinger) equation are derived. These solutions are interpreted as synchronized states and localized structures of the oscillatory medium.

  4. Dynamic interaction potential and the scattering cross sections of the semiclassical plasma particles

    Energy Technology Data Exchange (ETDEWEB)

    Dzhumagulova, K. N.; Shalenov, E. O.; Gabdullina, G. L. [IETP, Al Farabi Kazakh National University, 71al Farabi Street, Almaty 050040 (Kazakhstan)

    2013-04-15

    The dynamic model of the charged particles interaction in non-ideal semiclassical plasma is presented. This model takes into account the quantum mechanical diffraction effect and the dynamic screening effect. On the basis of the dynamic interaction potential, the electron scattering cross sections are investigated. Comparison with the results obtained on the basis of other models and conclusions were made.

  5. Cryptic population dynamics: rapid evolution masks trophic interactions.

    Science.gov (United States)

    Yoshida, Takehito; Ellner, Stephen P; Jones, Laura E; Bohannan, Brendan J M; Lenski, Richard E; Hairston, Nelson G

    2007-09-01

    Trophic relationships, such as those between predator and prey or between pathogen and host, are key interactions linking species in ecological food webs. The structure of these links and their strengths have major consequences for the dynamics and stability of food webs. The existence and strength of particular trophic links has often been assessed using observational data on changes in species abundance through time. Here we show that very strong links can be completely missed by these kinds of analyses when changes in population abundance are accompanied by contemporaneous rapid evolution in the prey or host species. Experimental observations, in rotifer-alga and phage-bacteria chemostats, show that the predator or pathogen can exhibit large-amplitude cycles while the abundance of the prey or host remains essentially constant. We know that the species are tightly linked in these experimental microcosms, but without this knowledge, we would infer from observed patterns in abundance that the species are weakly or not at all linked. Mathematical modeling shows that this kind of cryptic dynamics occurs when there is rapid prey or host evolution for traits conferring defense against attack, and the cost of defense (in terms of tradeoffs with other fitness components) is low. Several predictions of the theory that we developed to explain the rotifer-alga experiments are confirmed in the phage-bacteria experiments, where bacterial evolution could be tracked. Modeling suggests that rapid evolution may also confound experimental approaches to measuring interaction strength, but it identifies certain experimental designs as being more robust against potential confounding by rapid evolution.

  6. Cryptic population dynamics: rapid evolution masks trophic interactions.

    Directory of Open Access Journals (Sweden)

    Takehito Yoshida

    2007-09-01

    Full Text Available Trophic relationships, such as those between predator and prey or between pathogen and host, are key interactions linking species in ecological food webs. The structure of these links and their strengths have major consequences for the dynamics and stability of food webs. The existence and strength of particular trophic links has often been assessed using observational data on changes in species abundance through time. Here we show that very strong links can be completely missed by these kinds of analyses when changes in population abundance are accompanied by contemporaneous rapid evolution in the prey or host species. Experimental observations, in rotifer-alga and phage-bacteria chemostats, show that the predator or pathogen can exhibit large-amplitude cycles while the abundance of the prey or host remains essentially constant. We know that the species are tightly linked in these experimental microcosms, but without this knowledge, we would infer from observed patterns in abundance that the species are weakly or not at all linked. Mathematical modeling shows that this kind of cryptic dynamics occurs when there is rapid prey or host evolution for traits conferring defense against attack, and the cost of defense (in terms of tradeoffs with other fitness components is low. Several predictions of the theory that we developed to explain the rotifer-alga experiments are confirmed in the phage-bacteria experiments, where bacterial evolution could be tracked. Modeling suggests that rapid evolution may also confound experimental approaches to measuring interaction strength, but it identifies certain experimental designs as being more robust against potential confounding by rapid evolution.

  7. Vi, de civiliserede

    DEFF Research Database (Denmark)

    Nyemann, Dorthe

    2016-01-01

    Vi har i årtier troet på, at mennesker under de rette omstændigheder kan lykkes med at leve i fred og fordragelighed med hinanden. Skal vi til at erkende, at også vores samfundsstrukturer kun er en tynd fernis ovenpå et utæmmeligt voldspotentiale og egoisme?......Vi har i årtier troet på, at mennesker under de rette omstændigheder kan lykkes med at leve i fred og fordragelighed med hinanden. Skal vi til at erkende, at også vores samfundsstrukturer kun er en tynd fernis ovenpå et utæmmeligt voldspotentiale og egoisme?...

  8. Cortical oscillatory dynamics in a social interaction model.

    Science.gov (United States)

    Knyazev, Gennady G; Slobodskoj-Plusnin, Jaroslav Y; Bocharov, Andrey V; Pylkova, Liudmila V

    2013-03-15

    In this study we sought to investigate cortical oscillatory dynamics accompanying three major kinds of social behavior: aggressive, friendly, and avoidant. Behavioral and EEG data were collected in 48 participants during a computer game modeling social interactions with virtual 'persons'. 3D source reconstruction and independent component analysis were applied to EEG data. Results showed that social behavior was partly reactive and partly proactive with subject's personality playing an important role in shaping this behavior. Most salient differences were found between avoidance and approach behaviors, whereas the two kinds of approach behavior (i.e., aggression and friendship) did not differ from each other. Comparative to avoidance, approach behaviors were associated with higher induced responses in most frequency bands which were mostly observed in cortical areas overlapping with the default mode network. The difference between approach- and avoidance-related oscillatory dynamics was more salient in subjects predisposed to approach behaviors (i.e., in aggressive or sociable subjects) and was less pronounced in subjects predisposed to avoidance behavior (i.e., in high trait anxiety scorers). There was a trend to higher low frequency phase-locking in motor area in approach than in avoid condition. Results are discussed in light of the concept linking induced responses with top-down and evoked responses with bottom-up processes. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Dynamic interactions between dermal macrophages and Staphylococcus aureus.

    Science.gov (United States)

    Feuerstein, Reinhild; Kolter, Julia; Henneke, Philipp

    2017-01-01

    The dermis, a major reservoir of immune cells in immediate vicinity to the colonizing skin microflora, serves as an important site of host-pathogen interactions. Macrophages (Mϕ) are the most frequent resident immune cell type in the dermis. They protect the host from invasive infections by highly adapted bacteria, such as staphylococci via pattern recognition of bacterial effectors, phagocytosis, and recruitment of other myeloid cells from the blood. Already under homeostatic conditions, the dermal Mϕ population receives a dynamic input of monocytes invading from the bloodstream. This quantitative renewal is promoted further at the beginning of life, when prenatally seeded cells are rapidly replaced and in healing phases after injuries or infections. Here, we discuss the potential implications of the dynamic dermal Mϕ biology on the establishment and maintenance of immunity against Staphylococcus aureus, which can either be a harmless colonizer or an invasive pathogen. The understanding of the heterogeneity of the "mature" dermal Mϕ compartment driven both by the influx of differentiating monocytes and by a bone marrow-independent Mϕ persistence and expansion may help to explain failing immunity and immunopathology originating from the skin, the important interface between host and environment. © Society for Leukocyte Biology.

  10. Interaction Dynamics Determine Signaling and Output Pathway Responses

    Directory of Open Access Journals (Sweden)

    Klement Stojanovski

    2017-04-01

    Full Text Available The understanding of interaction dynamics in signaling pathways can shed light on pathway architecture and provide insights into targets for intervention. Here, we explored the relevance of kinetic rate constants of a key upstream osmosensor in the yeast high-osmolarity glycerol-mitogen-activated protein kinase (HOG-MAPK pathway to signaling output responses. We created mutant pairs of the Sln1-Ypd1 complex interface that caused major compensating changes in the association (kon and dissociation (koff rate constants (kinetic perturbations but only moderate changes in the overall complex affinity (Kd. Yeast cells carrying a Sln1-Ypd1 mutant pair with moderate increases in kon and koff displayed a lower threshold of HOG pathway activation than wild-type cells. Mutants with higher kon and koff rates gave rise to higher basal signaling and gene expression but impaired osmoadaptation. Thus, the kon and koff rates of the components in the Sln1 osmosensor determine proper signaling dynamics and osmoadaptation.

  11. Fractional Dynamics of Network Growth Constrained by Aging Node Interactions.

    Directory of Open Access Journals (Sweden)

    Hadiseh Safdari

    Full Text Available In many social complex systems, in which agents are linked by non-linear interactions, the history of events strongly influences the whole network dynamics. However, a class of "commonly accepted beliefs" seems rarely studied. In this paper, we examine how the growth process of a (social network is influenced by past circumstances. In order to tackle this cause, we simply modify the well known preferential attachment mechanism by imposing a time dependent kernel function in the network evolution equation. This approach leads to a fractional order Barabási-Albert (BA differential equation, generalizing the BA model. Our results show that, with passing time, an aging process is observed for the network dynamics. The aging process leads to a decay for the node degree values, thereby creating an opposing process to the preferential attachment mechanism. On one hand, based on the preferential attachment mechanism, nodes with a high degree are more likely to absorb links; but, on the other hand, a node's age has a reduced chance for new connections. This competitive scenario allows an increased chance for younger members to become a hub. Simulations of such a network growth with aging constraint confirm the results found from solving the fractional BA equation. We also report, as an exemplary application, an investigation of the collaboration network between Hollywood movie actors. It is undubiously shown that a decay in the dynamics of their collaboration rate is found, even including a sex difference. Such findings suggest a widely universal application of the so generalized BA model.

  12. Robust Generation of Dynamic Data Structure Visualizations with Multiple Interaction Approaches

    Science.gov (United States)

    Cross, James H., II; Hendrix, T. Dean; Umphress, David A.; Barowski, Larry A.; Jain, Jhilmil; Montgomery, Lacey N.

    2009-01-01

    jGRASP has three integrated approaches for interacting with its dynamic viewers for data structures: debugger, workbench, and text-based interactions that allow individual Java statements and expressions to be executed/evaluated. These approaches can be used together to provide a complementary set of interactions with the dynamic viewers. Data…

  13. Relaxation dynamics of interacting skyrmions in thin films

    Science.gov (United States)

    Brown, Bart; Pleimling, Michel

    Magnetic skyrmions are topologically protected spin textures which were recently observed in certain chiral magnets and thin films. Skyrmions can be moved by very low current densities which makes them very promising in spintronic applications such as data storage devices and logic gates. A thorough understanding of the relaxation processes for systems of interacting skyrmions far from equilibrium could prove invaluable in real world applications but is currently lacking in the literature. The dynamics are described by the Landau-Lifshitz-Gilbert (LLG) equation, however, simulating many interacting skyrmions by solving the LLG equation is computationally infeasible. We employ a suitable two-dimensional particle based model derived from Thiele's approach to study the two-time density correlation function and other quantities. The particle model differs most notably from similar models which describe vortices in type-II superconductors by the addition of the Magnus force which points perpendicular to the skyrmion velocity in the plane. Numerical studies reveal non-universal scaling of the correlation function where the scaling exponent is a function of the ratio of the Magnus force strength to damping coefficient as well as of the Gaussian noise. This research is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award DE-FG02-09ER46613.

  14. Dynamic metabolic exchange governs a marine algal-bacterial interaction.

    Science.gov (United States)

    Segev, Einat; Wyche, Thomas P; Kim, Ki Hyun; Petersen, Jörn; Ellebrandt, Claire; Vlamakis, Hera; Barteneva, Natasha; Paulson, Joseph N; Chai, Liraz; Clardy, Jon; Kolter, Roberto

    2016-11-18

    Emiliania huxleyi is a model coccolithophore micro-alga that generates vast blooms in the ocean. Bacteria are not considered among the major factors influencing coccolithophore physiology. Here we show through a laboratory model system that the bacterium Phaeobacter inhibens, a well-studied member of the Roseobacter group, intimately interacts with E. huxleyi. While attached to the algal cell, bacteria initially promote algal growth but ultimately kill their algal host. Both algal growth enhancement and algal death are driven by the bacterially-produced phytohormone indole-3-acetic acid. Bacterial production of indole-3-acetic acid and attachment to algae are significantly increased by tryptophan, which is exuded from the algal cell. Algal death triggered by bacteria involves activation of pathways unique to oxidative stress response and programmed cell death. Our observations suggest that bacteria greatly influence the physiology and metabolism of E. huxleyi. Coccolithophore-bacteria interactions should be further studied in the environment to determine whether they impact micro-algal population dynamics on a global scale.

  15. Accessing Wireless Sensor Networks Via Dynamically Reconfigurable Interaction Models

    Directory of Open Access Journals (Sweden)

    Maria Cecília Gomes

    2012-12-01

    Full Text Available The Wireless Sensor Networks (WSNs technology is already perceived as fundamental for science across many domains, since it provides a low cost solution for environment monitoring. WSNs representation via the service concept and its inclusion in Web environments, e.g. through Web services, supports particularly their open/standard access and integration. Although such Web enabled WSNs simplify data access, network parameterization and aggregation, the existing interaction models and run-time adaptation mechanisms available to clients are still scarce. Nevertheless, applications increasingly demand richer and more flexible accesses besides the traditional client/server. For instance, applications may require a streaming model in order to avoid sequential data requests, or the asynchronous notification of subscribed data through the publish/subscriber. Moreover, the possibility to automatically switch between such models at runtime allows applications to define flexible context-based data acquisition. To this extent, this paper discusses the relevance of the session and pattern abstractions on the design of a middleware prototype providing richer and dynamically reconfigurable interaction models to Web enabled WSNs.

  16. Temporal dynamics of top predators interactions in the Barents Sea.

    Directory of Open Access Journals (Sweden)

    Joël M Durant

    Full Text Available The Barents Sea system is often depicted as a simple food web in terms of number of dominant feeding links. The most conspicuous feeding link is between the Northeast Arctic cod Gadus morhua, the world's largest cod stock which is presently at a historical high level, and capelin Mallotus villosus. The system also holds diverse seabird and marine mammal communities. Previous diet studies may suggest that these top predators (cod, bird and sea mammals compete for food particularly with respect to pelagic fish such as capelin and juvenile herring (Clupea harengus, and krill. In this paper we explored the diet of some Barents Sea top predators (cod, Black-legged kittiwake Rissa tridactyla, Common guillemot Uria aalge, and Minke whale Balaenoptera acutorostrata. We developed a GAM modelling approach to analyse the temporal variation diet composition within and between predators, to explore intra- and inter-specific interactions. The GAM models demonstrated that the seabird diet is temperature dependent while the diet of Minke whale and cod is prey dependent; Minke whale and cod diets depend on the abundance of herring and capelin, respectively. There was significant diet overlap between cod and Minke whale, and between kittiwake and guillemot. In general, the diet overlap between predators increased with changes in herring and krill abundances. The diet overlap models developed in this study may help to identify inter-specific interactions and their dynamics that potentially affect the stocks targeted by fisheries.

  17. Dynamic protein interaction modules in human hepatocellular carcinoma progression.

    Science.gov (United States)

    Yu, Hui; Lin, Chen-Ching; Li, Yuan-Yuan; Zhao, Zhongming

    2013-01-01

    Gene expression profiles have been frequently integrated with the human protein interactome to uncover functional modules under specific conditions like disease state. Beyond traditional differential expression analysis, differential co-expression analysis has emerged as a robust approach to reveal condition-specific network modules, with successful applications in a few human disease studies. Hepatocellular carcinoma (HCC), which is often interrelated with the Hepatitis C virus, typically develops through multiple stages. A comprehensive investigation of HCC progression-specific differential co-expression modules may advance our understanding of HCC's pathophysiological mechanisms. Compared with differentially expressed genes, differentially co-expressed genes were found more likely enriched with Hepatitis C virus binding proteins and cancer-mutated genes, and they were clustered more densely in the human reference protein interaction network. These observations indicated that a differential co-expression approach could outperform the standard differential expression network analysis in searching for disease-related modules. We then proposed a differential co-expression network approach to uncover network modules involved in HCC development. Specifically, we discovered subnetworks that enriched differentially co-expressed gene pairs in each HCC transition stage, and further resolved modules with coherent co-expression change patterns over all HCC developmental stages. Our identified network modules were enriched with HCC-related genes and implicated in cancer-related biological functions. In particular, APC and YWHAZ were highlighted as two most remarkable genes in the network modules, and their dynamic interaction partnership was resolved in HCC development. We demonstrated that integration of differential co-expression with the protein interactome could outperform the traditional differential expression approach in discovering network modules of human diseases

  18. Nonperturbative Dynamics of Strong Interactions from Gauge/Gravity Duality

    Energy Technology Data Exchange (ETDEWEB)

    Grigoryan, Hovhannes [Louisiana State Univ., Baton Rouge, LA (United States)

    2008-08-01

    This thesis studies important dynamical observables of strong interactions such as form factors. It is known that Quantum Chromodynamics (QCD) is a theory which describes strong interactions. For large energies, one can apply perturbative techniques to solve some of the QCD problems. However, for low energies QCD enters into the nonperturbative regime, where di erent analytical or numerical tools have to be applied to solve problems of strong interactions. The holographic dual model of QCD is such an analytical tool that allows one to solve some nonperturbative QCD problems by translating them into a dual ve-dimensional theory de ned on some warped Anti de Sitter (AdS) background. Working within the framework of the holographic dual model of QCD, we develop a formalism to calculate form factors and wave functions of vector mesons and pions. As a result, we provide predictions of the electric radius, the magnetic and quadrupole moments which can be directly veri ed in lattice calculations or even experimentally. To nd the anomalous pion form factor, we propose an extension of the holographic model by including the Chern-Simons term required to reproduce the chiral anomaly of QCD. This allows us to nd the slope of the form factor with one real and one slightly o -shell photon which appeared to be close to the experimental ndings. We also analyze the limit of large virtualities (when the photon is far o -shell) and establish that predictions of the holographic model analytically coincide with those of perturbative QCD with asymptotic pion distribution amplitude. We also study the e ects of higher dimensional terms in the AdS/QCD model and show that these terms improve the holographic description towards a more realistic scenario. We show this by calculating corrections to the vector meson form factors and corrections to the observables such as electric radii, magnetic and quadrupole moments.

  19. ARCHITECTURAL LARGE CONSTRUCTED ENVIRONMENT. MODELING AND INTERACTION USING DYNAMIC SIMULATIONS

    Directory of Open Access Journals (Sweden)

    P. Fiamma

    2012-09-01

    Full Text Available How to use for the architectural design, the simulation coming from a large size data model? The topic is related to the phase coming usually after the acquisition of the data, during the construction of the model and especially after, when designers must have an interaction with the simulation, in order to develop and verify their idea. In the case of study, the concept of interaction includes the concept of real time "flows". The work develops contents and results that can be part of the large debate about the current connection between "architecture" and "movement". The focus of the work, is to realize a collaborative and participative virtual environment on which different specialist actors, client and final users can share knowledge, targets and constraints to better gain the aimed result. The goal is to have used a dynamic micro simulation digital resource that allows all the actors to explore the model in powerful and realistic way and to have a new type of interaction in a complex architectural scenario. On the one hand, the work represents a base of knowledge that can be implemented more and more; on the other hand the work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. The architectural design before, and the architectural fact after, both happen in a sort of "Spatial Analysis System". The way is open to offer to this "system", knowledge and theories, that can support architectural design work for every application and scale. We think that the presented work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. Architecture like a spatial configuration, that can be reconfigurable too through designing.

  20. Dynamic interactions between visual working memory and saccade target selection

    Science.gov (United States)

    Schneegans, Sebastian; Spencer, John P.; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

    2014-01-01

    Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. PMID:25228628

  1. Dynamic interactions between visual working memory and saccade target selection.

    Science.gov (United States)

    Schneegans, Sebastian; Spencer, John P; Schöner, Gregor; Hwang, Seongmin; Hollingworth, Andrew

    2014-09-16

    Recent psychophysical experiments have shown that working memory for visual surface features interacts with saccadic motor planning, even in tasks where the saccade target is unambiguously specified by spatial cues. Specifically, a match between a memorized color and the color of either the designated target or a distractor stimulus influences saccade target selection, saccade amplitudes, and latencies in a systematic fashion. To elucidate these effects, we present a dynamic neural field model in combination with new experimental data. The model captures the neural processes underlying visual perception, working memory, and saccade planning relevant to the psychophysical experiment. It consists of a low-level visual sensory representation that interacts with two separate pathways: a spatial pathway implementing spatial attention and saccade generation, and a surface feature pathway implementing color working memory and feature attention. Due to bidirectional coupling between visual working memory and feature attention in the model, the working memory content can indirectly exert an effect on perceptual processing in the low-level sensory representation. This in turn biases saccadic movement planning in the spatial pathway, allowing the model to quantitatively reproduce the observed interaction effects. The continuous coupling between representations in the model also implies that modulation should be bidirectional, and model simulations provide specific predictions for complementary effects of saccade target selection on visual working memory. These predictions were empirically confirmed in a new experiment: Memory for a sample color was biased toward the color of a task-irrelevant saccade target object, demonstrating the bidirectional coupling between visual working memory and perceptual processing. © 2014 ARVO.

  2. The new geographic information system in ETVA VI.PE.

    Science.gov (United States)

    Xagoraris, Zafiris; Soulis, George

    2016-08-01

    ETVA VI.PE. S.A. is a member of the Piraeus Bank Group of Companies and its activities include designing, developing, exploiting and managing Industrial Areas throughout Greece. Inside ETVA VI.PE.'s thirty-one Industrial Parks there are currently 2,500 manufacturing companies established, with 40,000 employees and € 2.5 billion of invested funds. In each one of the industrial areas ETVA VI.PE guarantees the companies industrial lots of land (sites) with propitious building codes and complete infrastructure networks of water supply, sewerage, paved roads, power supply, communications, cleansing services, etc. The development of Geographical Information System for ETVA VI.PE.'s Industrial Parks started at the beginning of 1992 and consists of three subsystems: Cadastre, that manages the information for the land acquisition of Industrial Areas; Street Layout - Sites, that manages the sites sold to manufacturing companies; Networks, that manages the infrastructure networks (roads, water supply, sewerage etc). The mapping of each Industrial Park is made incorporating state-of-the-art photogrammetric, cartographic and surveying methods and techniques. Passing through the phases of initial design (hybrid GIS) and system upgrade (integrated Gis solution with spatial database), the system is currently operating on a new upgrade (integrated gIS solution with spatial database) that includes redesigning and merging the system's database schemas, along with the creation of central security policies, and the development of a new web GIS application for advanced data entry, highly customisable and standard reports, and dynamic interactive maps. The new GIS bring the company to advanced levels of productivity and introduce the new era for decision making and business management.

  3. Modelling social interaction as perceptual crossing: an investigation into the dynamics of the interaction process

    Science.gov (United States)

    Froese, Tom; Di Paolo, Ezequiel A.

    2010-03-01

    This paper continues efforts to establish a mutually informative dialogue between psychology and evolutionary robotics in order to investigate the dynamics of social interaction. We replicate a recent simulation model of a minimalist experiment in perceptual crossing and confirm the results with significantly simpler artificial agents. A series of psycho-physical tests of their behaviour informs a hypothetical circuit model of their internal operation. However, a detailed study of the actual internal dynamics reveals this circuit model to be unfounded, thereby offering a tale of caution for those hypothesising about sub-personal processes in terms of behavioural observations. In particular, it is shown that the behaviour of the agents largely emerges out of the interaction process itself rather than being an individual achievement alone. We also extend the original simulation model in two novel directions in order to test further the extent to which perceptual crossing between agents can self-organise in a robust manner. These modelling results suggest new hypotheses that can become the basis for further psychological experiments.

  4. Stress, strain, and structural dynamics an interactive handbook of formulas, solutions, and Matlab toolboxes

    CERN Document Server

    Yang, Bingen

    2005-01-01

    Stress, Strain, and Structural Dynamics is a comprehensive and definitive reference to statics and dynamics of solids and structures, including mechanics of materials, structural mechanics, elasticity, rigid-body dynamics, vibrations, structural dynamics, and structural controls. This text integrates the development of fundamental theories, formulas and mathematical models with user-friendly interactive computer programs, written in the powerful and popular MATLAB. This unique merger of technical referencing and interactive computing allows instant solution of a variety of engineering problems

  5. Flight Dynamic Simulation with Nonlinear Aeroelastic Interaction using the ROM-ROM Procedure Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZONA Technology, Inc. (ZONA) proposes to develop an integrated flight dynamics simulation capability with nonlinear aeroelastic interactions by combining a flight...

  6. Dynamic Interaction between Cap & Trade and Electricity Markets

    Science.gov (United States)

    Jeev, Kumar

    Greenhouse Gases (GHG), such as Carbon-Dioxide (CO2), which is released in the atmosphere due to anthropogenic activities like power production, are now accepted as the main culprits for global warming. The Regional Greenhouse Gas Initiative (RGGI), an initiative of the North East and Mid-Atlantic States of the United States (US) for limiting the emission of GHG, has developed a regional cap-and-trade program for CO2 emissions for power plants. Existing cap-and-trade programs in US and Europe for Greenhouse Gases have recently been plagued by over-allocation. Carbon prices recently collapsed in all these markets during the global recession. Since then, there have been significant policy changes, which have resulted in the adoption of aggressive emission cap targets by most major carbon emission markets. This is expected to make carbon emissions availability more restrictive, raising the prices of these credits. These emissions markets are expected to have a major impact on the wholesale electricity markets. Two models to study the interaction of these two markets are presented. These models assess the impact of the emissions market on wholesale electricity prices. The first model characterizes the competition between two types of power plants (coal and gas) in both the electricity and emissions markets as a dynamic game using the Cournot approximation. Under this approximation, we find that in the Nash equilibrium the plants increase their permit allocation to high-demand periods and the marginal value of each credit for a plant is identical in all periods under their optimal equilibrium strategy. The second numerical model allows us to explicitly evaluate the closed loop equilibrium of the dynamic interaction of two competitors in these markets. We find that plants often try to corner the market and push prices all the way to the price cap. Power plants derive most of their profits from these extreme price regimes. In the experiments where trading is allowed

  7. Nonlinear modeling of dynamic interactions within neuronal ensembles using Principal Dynamic Modes.

    Science.gov (United States)

    Marmarelis, Vasilis Z; Shin, Dae C; Song, Dong; Hampson, Robert E; Deadwyler, Sam A; Berger, Theodore W

    2013-02-01

    A methodology for nonlinear modeling of multi-input multi-output (MIMO) neuronal systems is presented that utilizes the concept of Principal Dynamic Modes (PDM). The efficacy of this new methodology is demonstrated in the study of the dynamic interactions between neuronal ensembles in the Pre-Frontal Cortex (PFC) of a behaving non-human primate (NHP) performing a Delayed Match-to-Sample task. Recorded spike trains from Layer-2 and Layer-5 neurons were viewed as the "inputs" and "outputs", respectively, of a putative MIMO system/model that quantifies the dynamic transformation of multi-unit neuronal activity between Layer-2 and Layer-5 of the PFC. Model prediction performance was evaluated by means of computed Receiver Operating Characteristic (ROC) curves. The PDM-based approach seeks to reduce the complexity of MIMO models of neuronal ensembles in order to enable the practicable modeling of large-scale neural systems incorporating hundreds or thousands of neurons, which is emerging as a preeminent issue in the study of neural function. The "scaling-up" issue has attained critical importance as multi-electrode recordings are increasingly used to probe neural systems and advance our understanding of integrated neural function. The initial results indicate that the PDM-based modeling methodology may greatly reduce the complexity of the MIMO model without significant degradation of performance. Furthermore, the PDM-based approach offers the prospect of improved biological/physiological interpretation of the obtained MIMO models.

  8. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Robert [Lockheed Martin Corporation, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates, Houston, TX (United States); Johnson, Peter [BMT Scientific Marine Services, Inc., Houston, TX (United States); Shi, Shan [Houston Offshore Engineering, Houston, TX (United States); Marinho, Thiago [Federal Univ. of Rio de Janeiro (Brazil). LabOceano

    2014-05-09

    A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

  9. Elucidating nitric oxide synthase domain interactions by molecular dynamics.

    Science.gov (United States)

    Hollingsworth, Scott A; Holden, Jeffrey K; Li, Huiying; Poulos, Thomas L

    2016-02-01

    Nitric oxide synthase (NOS) is a multidomain enzyme that catalyzes the production of nitric oxide (NO) by oxidizing L-Arg to NO and L-citrulline. NO production requires multiple interdomain electron transfer steps between the flavin mononucleotide (FMN) and heme domain. Specifically, NADPH-derived electrons are transferred to the heme-containing oxygenase domain via the flavin adenine dinucleotide (FAD) and FMN containing reductase domains. While crystal structures are available for both the reductase and oxygenase domains of NOS, to date there is no atomic level structural information on domain interactions required for the final FMN-to-heme electron transfer step. Here, we evaluate a model of this final electron transfer step for the heme-FMN-calmodulin NOS complex based on the recent biophysical studies using a 105-ns molecular dynamics trajectory. The resulting equilibrated complex structure is very stable and provides a detailed prediction of interdomain contacts required for stabilizing the NOS output state. The resulting equilibrated complex model agrees well with previous experimental work and provides a detailed working model of the final NOS electron transfer step required for NO biosynthesis. © 2015 The Protein Society.

  10. Star-planet interactions and dynamical evolution of exoplanetary systems

    Directory of Open Access Journals (Sweden)

    Damiani Cilia

    2015-01-01

    Full Text Available The dynamical evolution 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 evolution 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.

  11. Dynamic protein interaction networks and new structural paradigms in signaling

    Science.gov (United States)

    Csizmok, Veronika; Follis, Ariele Viacava; Kriwacki, Richard W.; Forman-Kay, Julie D.

    2017-01-01

    Understanding signaling and other complex biological processes requires elucidating the critical roles of intrinsically disordered proteins and regions (IDPs/IDRs), which represent ~30% of the proteome and enable unique regulatory mechanisms. In this review we describe the structural heterogeneity of disordered proteins that underpins these mechanisms and the latest progress in obtaining structural descriptions of ensembles of disordered proteins that are needed for linking structure and dynamics to function. We describe the diverse interactions of IDPs that can have unusual characteristics such as “ultrasensitivity” and “regulated folding and unfolding”. We also summarize the mounting data showing that large-scale assembly and protein phase separation occurs within a variety of signaling complexes and cellular structures. In addition, we discuss efforts to therapeutically target disordered proteins with small molecules. Overall, we interpret the remodeling of disordered state ensembles due to binding and post-translational modifications within an expanded framework for allostery that provides significant insights into how disordered proteins transmit biological information. PMID:26922996

  12. Dynamic Interaction between Reinforcement Learning and Attention in Multidimensional Environments.

    Science.gov (United States)

    Leong, Yuan Chang; Radulescu, Angela; Daniel, Reka; DeWoskin, Vivian; Niv, Yael

    2017-01-18

    Little is known about the relationship between attention and learning during decision making. Using eye tracking and multivariate pattern analysis of fMRI data, we measured participants' dimensional attention as they performed a trial-and-error learning task in which only one of three stimulus dimensions was relevant for reward at any given time. Analysis of participants' choices revealed that attention biased both value computation during choice and value update during learning. Value signals in the ventromedial prefrontal cortex and prediction errors in the striatum were similarly biased by attention. In turn, participants' focus of attention was dynamically modulated by ongoing learning. Attentional switches across dimensions correlated with activity in a frontoparietal attention network, which showed enhanced connectivity with the ventromedial prefrontal cortex between switches. Our results suggest a bidirectional interaction between attention and learning: attention constrains learning to relevant dimensions of the environment, while we learn what to attend to via trial and error. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. THE CONSEQUENCES ON BLOOD GSH DYNAMICS ON WISTAR FEMALE RATS AT AD LIBITUM CHROMIUM (VI ADMINISTRATION DURING THE GESTATION AFTER THE WEAN

    Directory of Open Access Journals (Sweden)

    CORINA GRĂVILĂ

    2009-05-01

    Full Text Available Chromium (VI is a widely used industrial chemical, extensively used in paints, metal finishes, steel including stainless steel manufacturing, alloy cast irons, chrome, and wood treatment. In nature chromium occurs in divalent, trivalent and hexavalent forms. Hexavalent chromium predominates over the trivalent form in natural waters. We have studied the influence of potassium dichromate (K2Cr2O7 on blood GSH values in rats. This study was carried out on 28 Wistar adult female rats, divided in 3 experimental groups (E and one control group (C. The rats were feed with 25ppm (LOAEL, 50ppm and 75ppm potassium dichromate, ad libitum, in drinking water, during the gestation. The control batch received tap water. Reduced glutathione (GSH was measured quantitatively after the wean using a Perkin-Elmer spectrophotometer, through Beutler et al. method, at 412nm. This study reports that potassium dichromate exposure induced the depletion of blood GSH because Cr(VI can generate reactive oxygen species (ROS. It can induce oxidative stress and toxicity.

  14. Close-packed structure dynamics with finite-range interaction: computational mechanics with individual layer interaction.

    Science.gov (United States)

    Rodriguez-Horta, Edwin; Estevez-Rams, Ernesto; Lora-Serrano, Raimundo; Neder, Reinhard

    2017-09-01

    This is the second contribution in a series of papers dealing with dynamical models in equilibrium theories of polytypism. A Hamiltonian introduced by Ahmad & Khan [Phys. Status Solidi B (2000), 218, 425-430] avoids the unphysical assignment of interaction terms to fictitious entities given by spins in the Hägg coding of the stacking arrangement. In this paper an analysis of polytype generation and disorder in close-packed structures is made for such a Hamiltonian. Results are compared with a previous analysis using the Ising model. Computational mechanics is the framework under which the analysis is performed. The competing effects of disorder and structure, as given by entropy density and excess entropy, respectively, are discussed. It is argued that the Ahmad & Khan model is simpler and predicts a larger set of polytypes than previous treatments.

  15. Visual Design Guidelines for Improving Learning from Dynamic and Interactive Digital Text

    Science.gov (United States)

    Jin, Sung-Hee

    2013-01-01

    Despite the dynamic and interactive features of digital text, the visual design guidelines for digital text are similar to those for printed text. The purpose of this study was to develop visual design guidelines for improving learning from dynamic and interactive digital text and to validate them by controlled testing. Two structure design…

  16. Nuclear proton dynamics and interactions with calcium signaling.

    Science.gov (United States)

    Hulikova, Alzbeta; Swietach, Pawel

    2016-07-01

    Biochemical signals acting on the nucleus can regulate gene expression. Despite the inherent affinity of nucleic acids and nuclear proteins (e.g. transcription factors) for protons, little is known about the mechanisms that regulate nuclear pH (pHnuc), and how these could be exploited to control gene expression. Here, we show that pHnuc dynamics can be imaged using the DNA-binding dye Hoechst 33342. Nuclear pores allow the passage of medium-sized molecules (calcein), but protons must first bind to mobile buffers in order to gain access to the nucleoplasm. Fixed buffering residing in the nucleus of permeabilized cells was estimated to be very weak on the basis of the large amplitude of pHnuc transients evoked by photolytic H(+)-uncaging or exposure to weak acids/bases. Consequently, the majority of nuclear pH buffering is sourced from the cytoplasm in the form of mobile buffers. Effective proton diffusion was faster in nucleoplasm than in cytoplasm, in agreement with the higher mobile-to-fixed buffering ratio in the nucleus. Cardiac myocyte pHnuc changed in response to maneuvers that alter nuclear Ca(2+) signals. Blocking Ca(2+) release from inositol-1,4,5-trisphosphate receptors stably alkalinized the nucleus. This Ca(2+)-pH interaction may arise from competitive binding to common chemical moieties. Competitive binding to mobile buffers may couple the efflux of Ca(2+)via nuclear pores with a counterflux of protons. This would generate a stable pH gradient between cytoplasm and nucleus that is sensitive to the state of nuclear Ca(2+) signaling. The unusual behavior of protons in the nucleus provides new mechanisms for regulating cardiac nuclear biology. Copyright © 2015. Published by Elsevier Ltd.

  17. and dioxouranium(vi)

    African Journals Online (AJOL)

    a

    Thorium(IV) and uranium(VI) with atomic radii of 1.65 and .... to ν(NH) vibrations. Practically no effect on these frequencies after complexation precludes the possibility of metal-coordination at this group. The absorptions at 1600 ... observation suggests involvement of unsaturated nitrogen atoms of the two azomethine groups.

  18. Diet-dependent modular dynamic interactions of the equine cecal microbiota

    DEFF Research Database (Denmark)

    Kristoffersen, Camilla; Jensen, Rasmus Bovbjerg; Avershina, Ekaterina

    2016-01-01

    Knowledge on dynamic interactions in microbiota is pivotal for understanding the role of bacteria in the gut. We herein present comprehensive dynamic models of the horse cecal microbiota, which include short-chained fatty acids, carbohydrate metabolic networks, and taxonomy. Dynamic models were d...

  19. Interaction of the Space Shuttle on-orbit autopilot with tether dynamics

    Science.gov (United States)

    Bergmann, Edward V.

    1988-01-01

    The effect of Orbiter flight control on tether dynamics is studied by simulation. Open-loop effects of Orbiter jet firing on tether dynamics are shown, and the potential for closed-loop interaction between tether dynamics and Orbiter flight control is determined. The significance of these effects on Orbiter flight control and tether control is assessed.

  20. Three-dimensional interactive Molecular Dynamics program for the study of defect dynamics in crystals

    Science.gov (United States)

    Patriarca, M.; Kuronen, A.; Robles, M.; Kaski, K.

    2007-01-01

    The study of crystal defects and the complex processes underlying their formation and time evolution has motivated the development of the program ALINE for interactive molecular dynamics experiments. This program couples a molecular dynamics code to a Graphical User Interface and runs on a UNIX-X11 Window System platform with the MOTIF library, which is contained in many standard Linux releases. ALINE is written in C, thus giving the user the possibility to modify the source code, and, at the same time, provides an effective and user-friendly framework for numerical experiments, in which the main parameters can be interactively varied and the system visualized in various ways. We illustrate the main features of the program through some examples of detection and dynamical tracking of point-defects, linear defects, and planar defects, such as stacking faults in lattice-mismatched heterostructures. Program summaryTitle of program:ALINE Catalogue identifier:ADYJ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYJ_v1_0 Program obtainable from: CPC Program Library, Queen University of Belfast, N. Ireland Computer for which the program is designed and others on which it has been tested: Computers:DEC ALPHA 300, Intel i386 compatible computers, G4 Apple Computers Installations:Laboratory of Computational Engineering, Helsinki University of Technology, Helsinki, Finland Operating systems under which the program has been tested:True64 UNIX, Linux-i386, Mac OS X 10.3 and 10.4 Programming language used:Standard C and MOTIF libraries Memory required to execute with typical data:6 Mbytes but may be larger depending on the system size No. of lines in distributed program, including test data, etc.:16 901 No. of bytes in distributed program, including test data, etc.:449 559 Distribution format:tar.gz Nature of physical problem:Some phenomena involving defects take place inside three-dimensional crystals at times which can be hardly predicted. For this reason they are

  1. Application of Brazilian kaolinite clay as adsorbent to removal of U(VI) from aqueous solution: Kinetic and thermodynamic of cation-basic interactions

    Science.gov (United States)

    Guerra, Denis L.; Leidens, Victor L.; Viana, Rúbia R.; Airoldi, Claudio

    2010-05-01

    The compound N 1-[3-(trimethoxysilyl)propyl]diethylenetriamine was anchored onto Amazon kaolinite surface by heterogeneous route. The modified and natural kaolinite samples were characterized by transmission electron microscopy, scanning electron microscopic, X-ray diffraction, and nuclear magnetic nuclei of 29Si and 13C. The well-defined peaks obtained in the 13C NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The kinetic parameters analyzed by the Lagergren and Elovich models gave a good fit for a pseudo-second order reaction with k2 values 16.0 and 25.1 mmol g -1 min -1 ranges for natural and modified kaolinite clays, respectively. The energetic effects caused by metal ion adsorption were determined through calorimetric titrations.

  2. Dynamic nonlinear modeling of interactions between neuronal ensembles using principal dynamic modes.

    Science.gov (United States)

    Marmarelis, V Z; Shin, D C; Song, D; Hampson, R E; Deadwyler, S A; Berger, T W

    2011-01-01

    We present a novel methodology for modeling the interactions between neuronal ensembles that utilizes the concept of Principal Dynamic Modes (PDM) and their associated nonlinear functions (ANF). This new approach seeks to reduce the complexity of the multi-input/multi-output (MIMO) model of the interactions between neuronal ensembles--an issue of critical practical importance in scaling up the MIMO models to incorporate hundreds (or even thousands) of input-output neurons. Global PDMs were extracted from the data using estimated first-order and second-order kernels and singular value decomposition (SVD). These global PDMs represent an efficient "coordinate system" for the representation of the MIMO model. The ANFs of the PDMs are estimated from the histograms of the combinations of PDM output values that lead to output spikes. For initial testing and validation of this approach, we applied it to a set of data collected at the pre-frontal cortex of a non-human primate during a behavioral task (Delayed Match-to-Sample). Recorded spike trains from Layer-2 neurons were viewed as the "inputs" and from Layer-5 neurons as the outputs. Model prediction performance was evaluated by means of computed Receiver Operating Characteristic (ROC) curves. The results indicate that this methodology may greatly reduce the complexity of the MIMO model without significant degradation of performance.

  3. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  4. Econophys-Kolkata VI Conference

    CERN Document Server

    Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2013-01-01

    The primary goal of the book is to present the ideas and research findings of active researchers such as physicists, economists, mathematicians and financial engineers working in the field of “Econophysics,” who have undertaken the task of modeling and analyzing systemic risk, network dynamics and other topics. Of primary interest in these studies is the aspect of systemic risk, which has long been identified as a potential scenario in which financial institutions trigger a dangerous contagion mechanism, spreading from the financial economy to the real economy. This type of risk, long confined to the monetary market, has spread considerably in the recent past, culminating in the subprime crisis of 2008. As such, understanding and controlling systemic risk has become an extremely important societal and economic challenge. The Econophys-Kolkata VI conference proceedings are dedicated to addressing a number of key issues involved. Several leading researchers in these fields report on their recent work and al...

  5. Biosorption of uranium (VI) by immobilized Aspergillus fumigatus beads

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jingsong, E-mail: xhwjs@163.co [School of Urban Construction, University of South China, 28 West Changsheng Road, Hengyang, Hunan 421001 (China) and Hunan Key Laboratory of Pollution Control and Resource Reuse, University of South China, Henyang, Hunan 421001 (China); Hu Xinjiang [School of Urban Construction, University of South China, 28 West Changsheng Road, Hengyang, Hunan 421001 (China); College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Liu Yunguo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Xie Shuibo [School of Urban Construction, University of South China, 28 West Changsheng Road, Hengyang, Hunan 421001 (China); Hunan Key Laboratory of Pollution Control and Resource Reuse, University of South China, Henyang, Hunan 421001 (China); Bao Zhenglei [School of Urban Construction, University of South China, 28 West Changsheng Road, Hengyang, Hunan 421001 (China)

    2010-06-15

    Biosorption of uranium (VI) ions by immobilized Aspergillus fumigatus beads was investigated in a batch system. The influences of solution pH, biosorbent dose, U (VI) concentration, and contact time on U (VI) biosorption were studied. The results indicated that the adsorption capacity was strongly affected by the solution pH, the biosorbent dose and initial U (VI) concentration. Optimum biosorption was observed at pH 5.0, biosrobent dose (w/v) 2.5%, initial U (VI) concentration 60 mg L{sup -1}. Biosorption equilibrium was established in 120 min. The adsorption process conformed to the Freunlich and Temkin isothermal adsorption models. The dynamic adsorption model conformed to pseudo-second order model.

  6. Magnetic dynamics of weakly and strongly interacting hematite nanoparticles

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Bender Koch, Christian; Mørup, Steen

    2000-01-01

    The magnetic dynamics of two differently treated samples of hematite nanoparticles from the same batch with a particle size of about 20 nm have been studied by Mossbauer spectroscopy. The dynamics of the first sample, in which the particles are coated and dispersed in water, is in accordance...

  7. Simulating market dynamics : Interactions between consumer psychology and social networks

    NARCIS (Netherlands)

    Janssen, M.A; Jager, W.

    2003-01-01

    Markets can show different types of dynamics, from quiet markets dominated by one or a few products, to markets with continual penetration of new and reintroduced products. in a previous article we explored the dynamics of markets from a psychological perspective using a multi-agent simulation

  8. ADSORPTION OF Cr(VI ON BLACK WATER

    Directory of Open Access Journals (Sweden)

    Rasti Januarita

    2010-06-01

    Full Text Available The effect of initial concentration of Cr(VI on adsorption to black water of Gambut, District of Banjar, South Borneo has been investigated, as well as interaction between Cr(VI species and functional black water organic fraction. The initial work was optimization of Cr(VI determination using UV-Visible Spectrophotometry with diphenylcarbacide as complexing agent and preparation of black water using mixture of 2% HCl and 5% HF with HCl-HF ratio of 1 : 1 (v/v. The quantity of Cr(VI species adsorbed on black water was calculated by determining the amount of Cr(VI species in solution before and after interaction. The functional groups in interaction between Cr(VI species and black water organic fraction was studied qualitatively using infrared spectroscopy. The results showed that optimum condition for Cr(VI species analysis using UV-Visible spectrophotometry with diphenylcarbacide as complexing agent was at wave length of 540 nm, pH 1,5, 15 - 60 minutes at which complex remain stable, and minimum mol ratio of diphenylcarbacide : Cr(VI 45 : 1, and has a sensitivity of 1.134 mg/L and detection limit of 0.00495 mg/L. The analysis was not affected by the presence of Cr(III in concentration less than 40 times of Cr(VI concentration. After treatment with HCl-HF the quantity of black water organic fraction showing humic acid properties decreased 0,1998 percent. Organic fraction of black water used adsorpted Cr(VIwith capacity of 4,050 mg/g.   Keywords: Adsorption, Cr(VI, Black Water

  9. Dynamic interactions between coastal storms and salt marshes: A review

    Science.gov (United States)

    Leonardi, Nicoletta; Carnacina, Iacopo; Donatelli, Carmine; Ganju, Neil Kamal; Plater, Andrew James; Schuerch, Mark; Temmerman, Stijn

    2018-01-01

    This manuscript reviews the progresses made in the understanding of the dynamic interactions between coastal storms and salt marshes, including the dissipation of extreme water levels and wind waves across marsh surfaces, the geomorphic impact of storms on salt marshes, the preservation of hurricanes signals and deposits into the sedimentary records, and the importance of storms for the long term survival of salt marshes to sea level rise. A review of weaknesses, and strengths of coastal defences incorporating the use of salt marshes including natural, and hybrid infrastructures in comparison to standard built solutions is then presented. Salt marshes are effective in dissipating wave energy, and storm surges, especially when the marsh is highly elevated, and continuous. This buffering action reduces for storms lasting more than one day. Storm surge attenuation rates range from 1.7 to 25 cm/km depending on marsh and storms characteristics. In terms of vegetation properties, the more flexible stems tend to flatten during powerful storms, and to dissipate less energy but they are also more resilient to structural damage, and their flattening helps to protect the marsh surface from erosion, while stiff plants tend to break, and could increase the turbulence level and the scour. From a morphological point of view, salt marshes are generally able to withstand violent storms without collapsing, and violent storms are responsible for only a small portion of the long term marsh erosion. Our considerations highlight the necessity to focus on the indirect long term impact that large storms exerts on the whole marsh complex rather than on sole after-storm periods. The morphological consequences of storms, even if not dramatic, might in fact influence the response of the system to normal weather conditions during following inter-storm periods. For instance, storms can cause tidal flats deepening which in turn promotes wave energy propagation, and exerts a long term detrimental

  10. Dynamic interactions between hypersonic vehicle aerodynamics and propulsion system performance

    Science.gov (United States)

    Flandro, G. A.; Roach, R. L.; Buschek, H.

    1992-01-01

    Described here is the development of a flexible simulation model for scramjet hypersonic propulsion systems. The primary goal is determination of sensitivity of the thrust vector and other system parameters to angle of attack changes of the vehicle. Such information is crucial in design and analysis of control system performance for hypersonic vehicles. The code is also intended to be a key element in carrying out dynamic interaction studies involving the influence of vehicle vibrations on propulsion system/control system coupling and flight stability. Simple models are employed to represent the various processes comprising the propulsion system. A method of characteristics (MOC) approach is used to solve the forebody and external nozzle flow fields. This results in a very fast computational algorithm capable of carrying out the vast number of simulation computations needed in guidance, stability, and control studies. The three-dimensional fore- and aft body (nozzle) geometry is characterized by the centerline profiles as represented by a series of coordinate points and body cross-section curvature. The engine module geometry is represented by an adjustable vertical grid to accommodate variations of the field parameters throughout the inlet and combustor. The scramjet inlet is modeled as a two-dimensional supersonic flow containing adjustable sidewall wedges and multiple fuel injection struts. The inlet geometry including the sidewall wedge angles, the number of injection struts, their sweepback relative to the vehicle reference line, and strut cross-section are user selectable. Combustion is currently represented by a Rayleigh line calculation including corrections for variable gas properties; improved models are being developed for this important element of the propulsion flow field. The program generates (1) variation of thrust magnitude and direction with angle of attack, (2) pitching moment and line of action of the thrust vector, (3) pressure and temperature

  11. Network biomarkers, interaction networks and dynamical network biomarkers in respiratory diseases

    OpenAIRE

    Wu, Xiaodan; Chen, Luonan; Wang, Xiangdong

    2014-01-01

    Identification and validation of interaction networks and network biomarkers have become more critical and important in the development of disease-specific biomarkers, which are functionally changed during disease development, progression or treatment. The present review headlined the definition, significance, research and potential application for network biomarkers, interaction networks and dynamical network biomarkers (DNB). Disease-specific interaction networks, network biomarkers, or DNB...

  12. Dynamic Flow Impacts Cell-Particle Interactions: Sedimentation and Particle Shape Effects.

    Science.gov (United States)

    Björnmalm, Mattias; Faria, Matthew; Chen, Xi; Cui, Jiwei; Caruso, Frank

    2016-10-17

    The interaction of engineered particles with biological systems determines their performance in biomedical applications. Although standard static cell cultures remain the norm for in vitro studies, modern models mimicking aspects of the dynamic in vivo environment have been developed. Herein, we investigate fundamental cell-particle interactions under dynamic flow conditions using a simple and self-contained device together with standard multiwell cell culture plates. We engineer two particle systems and evaluate their cell interactions under dynamic flow, and we compare the results to standard static cell cultures. We find substantial differences between static and dynamic flow conditions and attribute these to particle shape and sedimentation effects. These results demonstrate how standard static assays can be complemented by dynamic flow assays for a more comprehensive understanding of fundamental cell-particle interactions.

  13. Polyurethane-Keratin Membranes: Structural Changes by Isocyanate and pH, and the Repercussion on Cr(VI Removal

    Directory of Open Access Journals (Sweden)

    María D. Manrique-Juárez

    2013-01-01

    Full Text Available Keratin has the capacity to interact with metal ions. In order to take advantage of this potential, a novel membrane with polyurethane and keratin has been developed and studied for removal of Cr(VI from aqueous solution. Physicochemical and morphological properties of these hybrid membranes were studied, varying synthesis parameters such as the type of isocyanate and pH in keratin solution. The effects of using diphenyl-methane-diisocyanate or toluene-diisocyanate and modifying the pH in keratin solutions were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy, and dynamical mechanical analysis. Results show that pH has a strong influence on morphology and on Cr(VI removal efficiency. When pH in keratin solution is low (2.5, the protein separates from water, and a more closed cell in the membrane is obtained affecting its mechanical properties. The removal efficiency of Cr(VI was also assessed at different pH values of chromium solutions. These results show that when pH of the Cr solution is acidic (at 1.5, the Cr(VI removal percentages increase significantly, reaching up to a 58%. Thus this paper demonstrates the successful combination of synthetic and natural polymers depending on the process parameters to be applied in the critical purpose of remediation of Cr(VI contamination.

  14. Long-range Interactions, Stochasticity and Fractional Dynamics Dedicated to George M Zaslavsky (1935–2008)

    CERN Document Server

    Luo, Albert C J

    2011-01-01

    In memory of Dr. George Zaslavsky, "Long-range Interactions, Stochasticity and Fractional Dynamics" covers the recent developments of long-range interaction, fractional dynamics, brain dynamics and stochastic theory of turbulence, each chapter was written by established scientists in the field. The book is dedicated to Dr. George Zaslavsky, who was one of three founders of the theory of Hamiltonian chaos. The book discusses self-similarity and stochasticity and fractionality for discrete and continuous dynamical systems, as well as long-range interactions and diluted networks. A comprehensive theory for brain dynamics is also presented. In addition, the complexity and stochasticity for soliton chains and turbulence are addressed. The book is intended for researchers in the field of nonlinear dynamics in mathematics, physics and engineering. Dr. Albert C.J. Luo is a Professor at Southern Illinois University Edwardsville, USA. Dr. Valentin Afraimovich is a Professor at San Luis Potosi University, Mexico.

  15. Dioxouranium(VI)-carboxylate complexes. A calorimetric and potentiometric investigation of interaction with oxalate at infinite dilution and in NaCl aqueous solution at I=1.0 mol L(-1) and T=25 degrees C.

    Science.gov (United States)

    Crea, Francesco; De Robertis, Alessandro; De Stefano, Concetta; Sammartano, Silvio

    2007-02-15

    In this paper we investigated the interactions between dioxouranium(VI) and oxalate using (H(+)-glass electrode) potentiometry and titration calorimetry. Potentiometric measurements were carried out in NaCl aqueous solutions and at T=25 degrees C in a wide range of experimental conditions (concentrations, ligand/metal molar ratio, pH, titrants) at low ionic strength values (INaCl. The stability of UO(2)(2+)-oxalate(2-) complexes is fairly high and their main contribution to stability is entropic in nature. Some linear empirical relationships were found which make it possible to calculate (i) the contribution of a single bond: DeltaG(sb) degrees =-16.6+/-0.2kJ mol(-1) and TDeltaS(sb) degrees =16.2+/-0.5kJ mol(-1); (ii) chelate stabilisation per ring: DeltaG(r) degrees =-1.30+/-0.04kJ mol(-1) and TDeltaS(r) degrees =1.27+/-0.23kJ mol(-1) and (iii) the mean stability of negatively charged Na(+)-ion pair complexes: log(T)K=(0.46+/-0.02).|z| (z=charge of complex species), DeltaG degrees =-(2.60+/-0.1).|z|kJ mol(-1) and TDeltaS degrees =2.5+/-0.5kJ mol(-1). Both potentiometric and calorimetric results provide evidence of the penta-coordination of the species UO(2)(ox)(3)(4-). SIT parameters were calculated from the data at I=0 and I=1.02mol kg(-1). Comparisons are made with literature data. An insoluble dioxouranium(VI) ternary complex was synthesised (at I=1.0mol L(-1) in NaCl) and characterised by thermoanalysis and elemental analysis.

  16. Interacting relativistic quantum dynamics for multi-time wave functions

    Directory of Open Access Journals (Sweden)

    Lienert Matthias

    2016-01-01

    Full Text Available In this paper, we report on recent progress about a rigorous and manifestly covariant interacting model for two Dirac particles in 1+1 dimensions [9, 10]. It is formulated using the multi-time formalism of Dirac, Tomonaga and Schwinger. The mechanism of interaction is a relativistic generalization of contact interactions, and it is achieved going beyond the usual functional-analytic Hamiltonian method.

  17. Batch sorption dynamics, kinetics and equilibrium studies of Cr(VI), Ni(II) and Cu(II) from aqueous phase using agricultural residues

    Science.gov (United States)

    Kaur, Rajvinder; Singh, Joginder; Khare, Rajshree; Cameotra, Swaranjit Singh; Ali, Amjad

    2013-03-01

    In the present study, the agricultural residues viz., Syzygium cumini and Populus deltoides leaves powder have been used for the biosorption of Cu(II), Ni(II), and Cr(VI) from aqueous solutions. FTIR and SEM analysis of the biosorbents were performed to explore the type of functional groups available for metal binding and to study the surface morphology. Various physico-chemical parameters such as pH, adsorbent dosage, initial metal ion concentration, and equilibrium contact time were studied. Thermodynamic studies were carried out and the results demonstrated the spontaneous and endothermic nature of the biosorption process. The equilibrium data were tested using four isotherm models—Langmuir, Freundlich, Temkin and Dubinin-Radushkevich and the maximum biosorption capacities were evaluated. The Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models were applied to study the reaction kinetics with pseudo-second order model giving the best fit ( R 2 = 0.99) to the experimental data.

  18. Structure of local interactions in complex financial dynamics

    Science.gov (United States)

    Jiang, X. F.; Chen, T. T.; Zheng, B.

    2014-06-01

    With the network methods and random matrix theory, we investigate the interaction structure of communities in financial markets. In particular, based on the random matrix decomposition, we clarify that the local interactions between the business sectors (subsectors) are mainly contained in the sector mode. In the sector mode, the average correlation inside the sectors is positive, while that between the sectors is negative. Further, we explore the time evolution of the interaction structure of the business sectors, and observe that the local interaction structure changes dramatically during a financial bubble or crisis.

  19. VI Nukitsa konkurss

    Index Scriptorium Estoniae

    2002-01-01

    VI Nukitsa konkursi auhinnad: Kirjanikud: I - Henno Käo ("Kusagil mujal"); II - Aidi Vallik ("Kuidas elad, Ann?"); III - Artur Jurin ("Piletijaht: uued segadused Kilulibeda teel"). Kunstnikud: I - Karel Korp (Leelo Tungla ja Karel Korbi "Tema amet"); II - Edgar Valter ("Kuidas õppida vaatama?"); III - Artur Jurin - ("Piletijaht: uued segadused Kilulibeda teel"). Täiskasvanute küsitluse võitis nii teksti kui piltidega Ene-Maris Tali ja Tarmo Tali "Tähtraamat. Aastaring Maarjamaal"

  20. Political dynamics determined by interactions between political leaders and voters.

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Michael Lewis; Bier, Asmeret; Backus, George A.; Hills, Richard Guy

    2010-03-01

    The political dynamics associated with an election are typically a function of the interplay between political leaders and voters, as well as endogenous and exogenous factors that impact the perceptions and goals of the electorate. This paper describes an effort by Sandia National Laboratories to model the attitudes and behaviors of various political groups along with that population's primary influencers, such as government leaders. To accomplish this, Sandia National Laboratories is creating a hybrid system dynamics-cognitive model to simulate systems- and individual-level political dynamics in a hypothetical society. The model is based on well-established psychological theory, applied to both individuals and groups within the modeled society. Confidence management processes are being incorporated into the model design process to increase the utility of the tool and assess its performance. This project will enhance understanding of how political dynamics are determined in democratic society.

  1. Critical dynamics of an interacting magnetic nanoparticle system

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Jonsson, P.E.; Nordblad, P.

    2002-01-01

    Effects of dipole-dipole interactions on the magnetic relaxation have been investigated for three Fe-C nanoparticle samples with volume concentrations of 0.06, 5 and 17 vol%. While both the 5 and 17 vol% samples exhibit collective behaviour due to dipolar interactions, only the 17 vol% sample...

  2. Interactivity in Health Care: Bodies, Values and Dynamics

    Science.gov (United States)

    Pedersen, Sarah Bro

    2012-01-01

    This paper discusses recent paradigm changes in linguistics as well as other scientific disciplines in order to stress how such changes affect interactional approaches to health care. It argues that moving from a reductionist to a more holistic and trans-disciplinary approach to human interactivity entails a rethinking of both theory and…

  3. Wine microbiome: A dynamic world of microbial interactions.

    Science.gov (United States)

    Liu, Youzhong; Rousseaux, Sandrine; Tourdot-Maréchal, Raphaëlle; Sadoudi, Mohand; Gougeon, Régis; Schmitt-Kopplin, Philippe; Alexandre, Hervé

    2017-03-04

    Most fermented products are generated by a mixture of microbes. These microbial consortia perform various biological activities responsible for the nutritional, hygienic, and aromatic qualities of the product. Wine is no exception. Substantial yeast and bacterial biodiversity is observed on grapes, and in both must and wine. The diverse microorganisms present interact throughout the winemaking process. The interactions modulate the hygienic and sensorial properties of the wine. Many studies have been conducted to elucidate the nature of these interactions, with the aim of establishing better control of the two fermentations occurring during wine processing. However, wine is a very complex medium making such studies difficult. In this review, we present the current state of research on microbial interactions in wines. We consider the different kinds of interactions between different microorganisms together with the consequences of these interactions. We underline the major challenges to obtaining a better understanding of how microbes interact. Finally, strategies and methodologies that may help unravel microbe interactions in wine are suggested.

  4. Dynamic Brain-Machine Interface: a novel paradigm for bidirectional interaction between brains and dynamical systems.

    Science.gov (United States)

    Szymanski, Francois D; Semprini, Marianna; Mussa-Ivaldi, Ferdinando A; Fadiga, Luciano; Panzeri, Stefano; Vato, Alessandro

    2011-01-01

    Brain-Machine Interfaces (BMIs) are systems which mediate communication between brains and artificial devices. Their long term goal is to restore motor functions, and this ultimately demands the development of a new generation of bidirectional brain-machine interfaces establishing a two-way brain-world communication channel, by both decoding motor commands from neural activity and providing feedback to the brain by electrical stimulation. Taking inspiration from how the spinal cord of vertebrates mediates communication between the brain and the limbs, here we present a model of a bidirectional brain-machine interface that interacts with a dynamical system by generating a control policy in the form of a force field. In our model, bidirectional communication takes place via two elements: (a) a motor interface decoding activities recorded from a motor cortical area, and (b) a sensory interface encoding the state of the controlled device into electrical stimuli delivered to a somatosensory area. We propose a specific mathematical model of the sensory and motor interfaces guiding a point mass moving in a viscous medium, and we demonstrate its performance by testing it on realistically simulated neural responses.

  5. Interacting trophic forcing and the population dynamics of herring

    DEFF Research Database (Denmark)

    Lindegren, Martin; Ostman, Orjan; Gardmark, Anna

    2011-01-01

    Small pelagic fish occupy a central position in marine ecosystems worldwide, largely by determining the energy transfer from lower trophic levels to predators at the top of the food web, including humans. Population dynamics of small pelagic fish may therefore be regulated neither strictly bottom......-up nor top-down, but rather through multiple external and internal drivers. While in many studies single drivers have been identified, potential synergies of multiple factors, as well as their relative importance in regulating population dynamics of small pelagic fish, is a largely unresolved issue....... Using a statistical, age-structured modeling approach, we demonstrate the relative importance and influence of bottom-up (e.g., climate, zooplankton availability) and top-down (i.e., fishing and predation) factors on the population dynamics of Bothnian Sea herring (Clupea harengus) throughout its life...

  6. Development and assessment of transparent soil and particle image velocimetry in dynamic soil-structure interaction

    Science.gov (United States)

    2007-02-01

    This research combines Particle Image Velocimetry (PIV) and transparent soil to investigate the dynamic rigid block and soil interaction. In order to get a low viscosity pore fluid for the transparent soil, 12 different types of chemical solvents wer...

  7. Self-interacting scalar field trapped in a DGP brane: The dynamical systems perspective

    Energy Technology Data Exchange (ETDEWEB)

    Quiros, Israel [Departamento de Fisica, Universidad Central de Las Villas, 54830 Santa Clara (Cuba)], E-mail: israel@uclv.edu.cu; Garcia-Salcedo, Ricardo [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-Legaria del IPN, Mexico D.F. (Mexico)], E-mail: rigarcias@ipn.mx; Matos, Tonatiuh [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico)], E-mail: tmatos@fis.cinvestav.mx; Moreno, Claudia [Departamento de Fisica y Matematicas, Centro Universitario de Ciencias Exactas e Ingenierias, Corregidora 500 S.R., Universidad de Guadalajara, 44420 Guadalajara, Jalisco (Mexico)], E-mail: claudia.moreno@cucei.udg.mx

    2009-01-05

    We apply the dynamical systems tools to study the linear dynamics of a self-interacting scalar field trapped on a DGP brane. The simplest kinds of self-interaction potentials are investigated: (a) constant potential, and (b) exponential potential. It is shown that the dynamics of DGP models can be very rich and complex. One of the most interesting results of this study shows that dynamical screening of the scalar field self-interaction potential, occurring within the Minkowski cosmological phase of the DGP model and that mimics 4D phantom behaviour, is an attractor solution for a constant self-interaction potential but not for the exponential one. In the latter case gravitational screening is not even a critical point of the corresponding autonomous system of ordinary differential equations.

  8. How interactions between animal movement and landscape processes modify range dynamics and extinction risk

    Science.gov (United States)

    Range dynamics models now incorporate many of the mechanisms and interactions that drive species distributions. However, connectivity continues to be studied using overly simple distance-based dispersal models with little consideration of how the individual behavior of dispersin...

  9. Langevin dynamics of conformational transformations induced by the charge-curvature interaction

    DEFF Research Database (Denmark)

    Gaididei, Yuri Borisovich; Gorria, C.; Christiansen, Peter Leth

    2009-01-01

    The role of thermal fluctuations in the conformational dynamics of a single closed filament is studied. It is shown that, due to the interaction between charges and bending degrees of freedom, initially circular chains may undergo transformation to polygonal shape.......The role of thermal fluctuations in the conformational dynamics of a single closed filament is studied. It is shown that, due to the interaction between charges and bending degrees of freedom, initially circular chains may undergo transformation to polygonal shape....

  10. Multiphase flow dynamics 2 thermal and mechanical interactions

    CERN Document Server

    Kolev, Nikolay I

    2007-01-01

    The industrial use of multi-phase systems requires analytical and numerical strategies for predicting their behavior. This book contains theory, methods and practical experience for describing complex transient multi-phase processes. It provides a systematic presentation of the theory and practice of numerical multi-phase fluid dynamics.

  11. Dynamic Classifier Aggregation using Interaction-Sensitive Fuzzy Measures

    Czech Academy of Sciences Publication Activity Database

    Štefka, D.; Holeňa, Martin

    2015-01-01

    Roč. 270, 1 July (2015), s. 25-52 ISSN 0165-0114 R&D Projects: GA ČR GA13-17187S Institutional support: RVO:67985807 Keywords : Fuzzy integral * Fuzzy measure * Dynamic classifier aggregation Subject RIV: IN - Informatics, Computer Science Impact factor: 2.098, year: 2015

  12. Dynamic soil-structure interaction of monopod and polypod foundations

    DEFF Research Database (Denmark)

    Andersen, Lars Vabbersgaard

    2016-01-01

    The paper concerns the importance of through–soil coupling for structures having foundations with more footings. First, a model for dynamic analysis of polypod footings is established in the frequency domain, employing Green’s function for wave propagation in a layered half-space. To allow analysis...

  13. Dynamics of cascade three-level system interacting with the ...

    Indian Academy of Sciences (India)

    For the semiclassical model, it is found that if the atom is initially in the middle level, the time-dependent populations of the upper and lower levels are always equal. This dynamical symmetry exhibited by the classical field is spoiled on quantization of the field mode. To reveal this non-classical effect, a Euler matrix formalism ...

  14. Fluid Dynamic Mechanisms and Interactions within Separated Flows.

    Science.gov (United States)

    1986-07-01

    of redevelop- It is now worthwhile to note that with ZR and 6,*,, as the charn ’ . ., eter .o.. I ., . ’ i rre,; pond - ’.,-’A 392 W. L. CHOW AIAA...161. 12. Mazumder, M. K., B. D. Hoyle , and K. J. Kirsch, "Generation and Fluid Dynamics of Scattering Aerosols in Laser Doppler Velocimetry," Proc. of

  15. Dynamic Adaptation in Child-Adult Language Interaction

    NARCIS (Netherlands)

    van Dijk, Marijn; van Geert, Paul; Korecky-Kroell, Katharina; Maillochon, Isabelle; Laaha, Sabine; Dressler, Wolfgang U.; Bassano, Dominique

    When speaking to young children, adults adapt their language to that of the child. In this article, we suggest that this child-directed speech (CDS) is the result of a transactional process of dynamic adaptation between the child and the adult. The study compares developmental trajectories of three

  16. On the interaction between wheels and rails in railway dynamics

    DEFF Research Database (Denmark)

    Slivsgaard, Eva Charlotte

    The present thesis is concerned with the mathematical modelling of a railway vehicle. The modelling does not only deal with the vehicle but also the track it runs on. Different models are described and investigated as to how they affect the dynamics of the vehicle. The bulk of the investigations ...

  17. Size-structured interactions and the dynamics of aquatic systems

    NARCIS (Netherlands)

    Persson, L.; de Roos, A.M.

    2006-01-01

    Size variation within species as a result of individual growth and development over the life cycle is a ubiquitous feature of many aquatic organisms. We review the implications of this size variation for the dynamics of aquatic systems. Ontogenetic development results in differences in size

  18. Dynamic Adaptation in Child-Adult Language Interaction

    Science.gov (United States)

    van Dijk, Marijn; van Geert, Paul; Korecky-Kröll, Katharina; Maillochon, Isabelle; Laaha, Sabine; Dressler, Wolfgang U.; Bassano, Dominique

    2013-01-01

    When speaking to young children, adults adapt their language to that of the child. In this article, we suggest that this child-directed speech (CDS) is the result of a transactional process of dynamic adaptation between the child and the adult. The study compares developmental trajectories of three children to those of the CDS of their caregivers.…

  19. Optimal Passive Dynamics for Physical Interaction: Catching a Mass

    Directory of Open Access Journals (Sweden)

    Kevin Kemper

    2013-05-01

    Full Text Available For manipulation tasks in uncertain environments, intentionally designed series impedance in mechanical systems can provide significant benefits that cannot be achieved in software. Traditionally, the design of actuated systems revolves around sizing torques, speeds, and control strategies without considering the system’s passive dynamics. However, the passive dynamics of the mechanical system, including inertia, stiffness, and damping along with other parameters such as torque and stroke limits often impose performance limitations that cannot be overcome with software control. In this paper, we develop relationships between an actuator’s passive dynamics and the resulting performance for the purpose of better understanding how to tune the passive dynamics for catching an unexpected object. We use a mathematically optimal controller subject to force limitations to stop the incoming object without breaking contact and bouncing. The use of an optimal controller is important so that our results directly reflect the physical system’s performance. We analytically calculate the maximum velocity that can be caught by a realistic actuator with limitations such as force and stroke limits. The results show that in order to maximize the velocity of an object that can be caught without exceeding the actuator’s torque and stroke limits, a soft spring along with a strong damper will be desired.

  20. Resource use dynamics and interactions in the tropics: Scaling up in space and time

    NARCIS (Netherlands)

    Giller, K.E.; Rowe, E.C.; Ridder, de N.; Keulen, van H.

    2006-01-01

    We discuss the temporal and spatial dynamics of nutrient resources and water within cropping and livestock systems, their interactions and those with other resources such as labour. Short-term dynamics (within season) revolve around nutrient availability and losses as a function of soil moisture

  1. SIMULATION OF DYNAMIC INTERACTION BETWEEN THE BODY OF THE PASSENGER CAR AND TRUCKS

    Directory of Open Access Journals (Sweden)

    V. I. Prykhodko

    2008-03-01

    Full Text Available The results of mathematical simulation of spatial oscillations of passenger coaches for determination of forces of dynamical interaction of bodies and bogies, which are used in determination of dynamic run and strength characteristics, are presented in this paper.

  2. Dynamics of interacting electrons under effect of a Morse potential

    Science.gov (United States)

    dos Santos, J. L. L.; Sales, M. O.; Neto, A. Ranciaro; de Moura, F. A. B. F.

    2017-05-01

    We consider interacting electrons moving in a nonlinear Morse lattice. We set the initial conditions as follows: electrons were initially localized at the center of the chain and a solitonic deformation was produced by an impulse excitation on the center of the chain. By solving quantum and classical equations for this system numerically, we found that a fraction of electronic wave function was trapped by the solitonic excitation, and trapping specificities depend on the degree of interaction among electrons. Also, there is evidence that the effective electron velocity depends on Coulomb interaction and electron-phonon coupling in a nontrivial way. This association is explained in detail along this work. In addition, we briefly discuss the dependence of our results with the type of initial condition we choose for the electrons and lattice.

  3. Evolutionary Dynamics of Tumor-Stroma Interactions in Multiple Myeloma.

    Directory of Open Access Journals (Sweden)

    Javad Salimi Sartakhti

    Full Text Available Cancer cells and stromal cells cooperate by exchanging diffusible factors that sustain tumor growth, a form of frequency-dependent selection that can be studied in the framework of evolutionary game theory. In the case of multiple myeloma, three types of cells (malignant plasma cells, osteoblasts and osteoclasts exchange growth factors with different effects, and tumor-stroma interactions have been analysed using a model of cooperation with pairwise interactions. Here we show that a model in which growth factors have autocrine and paracrine effects on multiple cells, a more realistic assumption for tumor-stroma interactions, leads to different results, with implications for disease progression and treatment. In particular, the model reveals that reducing the number of malignant plasma cells below a critical threshold can lead to their extinction and thus to restore a healthy balance between osteoclast and osteoblast, a result in line with current therapies against multiple myeloma.

  4. Dynamic control of spin states in interacting magnetic elements

    Science.gov (United States)

    Jain, Shikha; Novosad, Valentyn

    2014-10-07

    A method for the control of the magnetic states of interacting magnetic elements comprising providing a magnetic structure with a plurality of interacting magnetic elements. The magnetic structure comprises a plurality of magnetic states based on the state of each interacting magnetic element. The desired magnetic state of the magnetic structure is determined. The active resonance frequency and amplitude curve of the desired magnetic state is determined. Each magnetic element of the magnetic structure is then subjected to an alternating magnetic field or electrical current having a frequency and amplitude below the active resonance frequency and amplitude curve of said desired magnetic state and above the active resonance frequency and amplitude curve of the current state of the magnetic structure until the magnetic state of the magnetic structure is at the desired magnetic state.

  5. Dynamic Socio-technical System Design based on Stakeholder Interaction

    Directory of Open Access Journals (Sweden)

    Albert Fleischmann

    2015-07-01

    Full Text Available In order to directly involve stakeholders in socio-technical system design, we argue for streamlining executable process specifications with business process modeling. Due to current agility requirements of organizations, socio-technical system development is considered one of the key activities of members of the organizations. Dynamic process adaptation enable handling the volatility of business operation and IT infrastructure. Subject-oriented process representations are key enablers to dynamic adaptation due to their capability for stakeholders to create directly executable models. In this way stakeholder can be involved in change management pro-actively. Subject-oriented models (i represent all relevant features required for system control and decision making, and (ii are executable on demand. This effectiveness enables organizational change in a creative and efficient way, while establishing innovative design and change management tools. Subject-oriented Business Process Management capabilities are reflected in this realm revealing benefits and potential for further research.

  6. Dynamic Interactions Between Health, Human Capital and Wealth

    Directory of Open Access Journals (Sweden)

    Wei-Bin Zhang

    2018-03-01

    Full Text Available This paper proposes a dynamic economic model with health, human capital and wealth accumulation with elastic labor supply. The economic system consists of one industrial, one health, and one education sector. Our model is a synthesis of four main models in economic theory: Solow’s one-sector neoclassical growth mode, the Uzawa-Lucas two sector model, Arrow’s learning by doing model, and Grossman’s growth model with health. The model also includes Zhang’s idea about creative leisure or learning by consuming. Demand and supply of health service and education are determined by market mechanism. The model describes dynamic interdependence among wealth, health, human capital, economic structure, and time distribution among work, health caring, and education under perfect competition. We simulate the model and examine effects of changes in the propensity to consume health caring, the efficiency of producing health caring, the propensity to receive education, and the propensity to save.

  7. Interpersonal Dynamics; Essays and Readings on Human Interaction.

    Science.gov (United States)

    Bennis, Warren G.; And Others

    This book delineates underlying concepts, areas of concern, and research findings in the field of interpersonal relations. Section 1 deals with the expressive or emotional aspects of interaction (love, hate, ambivalence, alienation) as they occur in marriage, friendship, family life, and less permanent social situations. The next three sections…

  8. Interpersonal dynamics in teacher-student interactions and relationships

    NARCIS (Netherlands)

    Pennings, H.J.M.|info:eu-repo/dai/nl/323242588

    2017-01-01

    Many studies have demonstrated the crucial role of teacher-student relationships for the quality of teaching and learning. Teacher-student relationships are associated with student cognitive learning outcomes and motivation and with teachers’ well-being. As daily interactions in classrooms are the

  9. Players and arenas: the interactive dynamics of protest

    NARCIS (Netherlands)

    Jasper, J.M.; Duyvendak, J.W.

    2015-01-01

    Players and Arenas brings together a diverse group of experts to examine the interactions between political protestors and the many strategic players they encounter, such as cultural institutions, religious organizations, and the mass media"as well as potential allies, competitors, recruits, and

  10. Dynamics of cascade three-level system interacting with the ...

    Indian Academy of Sciences (India)

    On the contrary, the plot of Case II where the atom is ini- tially in the middle level depicted in figure 1b shows that the system oscillates with a Rabi frequency of νII =ω1/π such that the probabilities of |+)and |-)states are always equal. When the atom is initially in the middle level, the exactly sinusoidal resonant field interacts.

  11. Opinion Dynamics with Heterogeneous Interactions and Information Assimilation

    Science.gov (United States)

    Mir Tabatabaei, Seydeh Anahita

    2013-01-01

    In any modern society, individuals interact to form opinions on various topics, including economic, political, and social aspects. Opinions evolve as the result of the continuous exchange of information among individuals and of the assimilation of information distributed by media. The impact of individuals' opinions on each other forms a network,…

  12. Multi-Dimensional Analysis of Dynamic Human Information Interaction

    Science.gov (United States)

    Park, Minsoo

    2013-01-01

    Introduction: This study aims to understand the interactions of perception, effort, emotion, time and performance during the performance of multiple information tasks using Web information technologies. Method: Twenty volunteers from a university participated in this study. Questionnaires were used to obtain general background information and…

  13. Importance of dynamic properties of idiotopes in interactions with anti-Id antibodies.

    Science.gov (United States)

    Voss, E W; Weidner, K M; Denzin, L K

    1992-02-01

    The concept of fluctuating conformational substates in equilibrium characterizing variable-regions of immunoglobulin idiotypes is discussed in terms of the dynamic properties of idiotopes and their stabilization upon interactions with anti-idiotope antibodies. Uniquely, polyclonal anti-Id antibodies are viewed in cooperative immobilizing interactions with the idiotopes thereby facilitating formation of stable complexes.

  14. Uncovering new strong dynamics via topological interactions at the 100 TeV collider

    DEFF Research Database (Denmark)

    Molinaro, Emiliano; Sannino, Francesco; Thomsen, Anders Eller

    2017-01-01

    In models of composite Higgs dynamics, new composite pseudoscalars can interact with the Higgs and electroweak gauge bosons via anomalous interactions, stemming from the topological sector of the underlying theory. We show that a future 100 TeV proton-proton collider (FCC-pp) will be able to test...

  15. Real-Time Probing of Structural Dynamics by Interaction between Chromophores

    DEFF Research Database (Denmark)

    Brogaard, Rasmus Y.; Møller, Klaus Braagaard; Sølling, Theis Ivan

    2011-01-01

    We present an investigation of structural dynamics in excited-state cations probed in real-time by femtosecond timeresolved ion photofragmentation spectroscopy. From photoelectron spectroscopy data on 1,3-dibromopropane we conclude that the pump pulse ionizes the molecule, populating an excited...... of the cation in 1.6 ps. The real-time probing of the excited-state dynamics is made possible by exploiting the interaction between the two bromine chromophores and its dependence on molecular conformation. This experiment therefore illustrates the applicability of the concept of probing ultrafast molecular...... dynamics using the intramolecular interaction between two chromophores....

  16. Molecular Dynamic Simulations of Interaction of an AFM Probe with the Surface of an SCN Sample

    Science.gov (United States)

    Bune, Adris; Kaukler, William; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Molecular dynamic (MD) simulations is conducted in order to estimate forces of probe-substrate interaction in the Atomic Force Microscope (AFM). First a review of available molecular dynamic techniques is given. Implementation of MD simulation is based on an object-oriented code developed at the University of Delft. Modeling of the sample material - succinonitrile (SCN) - is based on the Lennard-Jones potentials. For the polystyrene probe an atomic interaction potential is used. Due to object-oriented structure of the code modification of an atomic interaction potential is straight forward. Calculation of melting temperature is used for validation of the code and of the interaction potentials. Various fitting parameters of the probe-substrate interaction potentials are considered, as potentials fitted to certain properties and temperature ranges may not be reliable for the others. This research provides theoretical foundation for an interpretation of actual measurements of an interaction forces using AFM.

  17. Vi tror, vi forstår hinanden, men det gør vi ikke

    DEFF Research Database (Denmark)

    Boysen, Mikkel Snorre Wilms

    2016-01-01

    Vores verdensbillede er baseret på en tro på, at vi forstår hinanden. Men meget tyder på, at denne tro snarere er en illusion. Derfor må vi indstille os på, at der skal en særlig indsats til, hvis vi skal kunne forstå vores omverden og menneskene i den......Vores verdensbillede er baseret på en tro på, at vi forstår hinanden. Men meget tyder på, at denne tro snarere er en illusion. Derfor må vi indstille os på, at der skal en særlig indsats til, hvis vi skal kunne forstå vores omverden og menneskene i den...

  18. Dynamic hubs show competitive and static hubs non-competitive regulation of their interaction partners.

    Directory of Open Access Journals (Sweden)

    Apurv Goel

    Full Text Available Date hub proteins have 1 or 2 interaction interfaces but many interaction partners. This raises the question of whether all partner proteins compete for the interaction interface of the hub or if the cell carefully regulates aspects of this process? Here, we have used real-time rendering of protein interaction networks to analyse the interactions of all the 1 or 2 interface hubs of Saccharomyces cerevisiae during the cell cycle. By integrating previously determined structural and gene expression data, and visually hiding the nodes (proteins and their edges (interactions during their troughs of expression, we predict when interactions of hubs and their partners are likely to exist. This revealed that 20 out of all 36 one- or two- interface hubs in the yeast interactome fell within two main groups. The first was dynamic hubs with static partners, which can be considered as 'competitive hubs'. Their interaction partners will compete for the interaction interface of the hub and the success of any interaction will be dictated by the kinetics of interaction (abundance and affinity and subcellular localisation. The second was static hubs with dynamic partners, which we term 'non-competitive hubs'. Regulatory mechanisms are finely tuned to lessen the presence and/or effects of competition between the interaction partners of the hub. It is possible that these regulatory processes may also be used by the cell for the regulation of other, non-cell cycle processes.

  19. Contribution of non-resonant wave-wave interactions in the dynamics of long-crested sea wave fields

    Science.gov (United States)

    Benoit, Michel

    2017-04-01

    Gravity waves fields at the surface of the oceans evolve under the combined effects of several physical mechanisms, of which nonlinear wave-wave interactions play a dominant role. These interactions transfer energy between components within the energy spectrum and allow in particular to explain the shape of the distribution of wave energy according to the frequencies and directions of propagation. In the oceanic domain (deep water conditions), dominant interactions are third-order resonant interactions, between quadruplets (or quartets) of wave components, and the evolution of the wave spectrum is governed by a kinetic equation, established by Hasselmann (1962) and Zakharov (1968). The kinetic equation has a number of interesting properties, including the existence of self-similar solutions and cascades to small and large wavelengths of waves, which can be studied in the framework of the wave (or weak) turbulence theory (e.g. Badulin et al., 2005). With the aim to obtain more complete and precise modelling of sea states dynamics, we investigate here the possibility and consequences of taking into account the non-resonant interactions -quasi-resonant in practice- among 4 waves. A mathematical formalism has recently been proposed to account for these non-resonant interactions in a statistical framework by Annenkov & Shrira (2006) (Generalized Kinetic Equation, GKE) and Gramstad & Stiassnie (2013) (Phase Averaged Equation, PAE). In order to isolate the non-resonant contributions, we limit ourselves here to monodirectional (i.e. long-crested) wave trains, since in this case the 4-wave resonant interactions vanish. The (stochastic) modelling approaches proposed by Annenkov & Shrira (2006) and Gramstad & Stiassnie (2013) are compared to phase-resolving (deterministic) simulations based on a fully nonlinear potential approach (using a high-order spectral method, HOS). We study and compare the evolution dynamics of the wave spectrum at different time scales (i.e. over

  20. Spin segregation via dynamically induced long-range interactions in a system of ultracold fermions

    Energy Technology Data Exchange (ETDEWEB)

    Ebling, Ulrich [ICFO-Institut de Ciencies Fotoniques, Avenida Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona (Spain); Eckardt, Andre [ICFO-Institut de Ciencies Fotoniques, Avenida Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona (Spain); Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Lewenstein, Maciej [ICFO-Institut de Ciencies Fotoniques, Avenida Carl Friedrich Gauss, 3, 08860 Castelldefels, Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats, Lluis Companys 23, E-08010 Barcelona (Spain)

    2011-12-15

    We investigate theoretically the time evolution of a one-dimensional system of spin-1/2 fermions in a harmonic trap after, initially, a spiral spin configuration far from equilibrium is created. We predict a spin segregation building up in time already for weak interaction under realistic experimental conditions. The effect relies on the interplay between exchange interaction and the harmonic trap, and it is found for a wide range of parameters. It can be understood as a consequence of an effective, dynamically induced long-range interaction that is derived by integrating out the rapid oscillatory dynamics in the trap.

  1. Plant-soil interactions and soil carbon dynamics under climate extremes

    Science.gov (United States)

    Bahn, Michael

    2016-04-01

    Climate extremes have been suggested to increase significantly in intensity and frequency in the coming decades, and may influence ecosystem processes and the carbon cycle more profoundly than gradual climate warming. While there is a growing understanding of plant-soil interactions in extreme environments and from lab experiments, we still know very little about how such interactions affect soil carbon dynamics in real-world ecosystems exposed to climate extremes. In this talk I will give a brief overview of the topic and will present evidence from in-situ experiments on plant-soil interactions and their consequences for soil carbon dynamics under severe drought.

  2. Interactive and fuzzy search: a dynamic way to explore MEDLINE.

    Science.gov (United States)

    Wang, Jiannan; Cetindil, Inci; Ji, Shengyue; Li, Chen; Xie, Xiaohui; Li, Guoliang; Feng, Jianhua

    2010-09-15

    The MEDLINE database, consisting of over 19 million publication records, is the primary source of information for biomedicine and health questions. Although the database itself has been growing rapidly, the search paradigm of MEDLINE has remained largely unchanged. Here, we propose a new system for exploring the entire MEDLINE collection, represented by two unique features: (i) interactive: providing instant feedback to users' query letter by letter, and (ii) fuzzy: allowing approximate search. We develop novel index structures and search algorithms to make such a search model possible. We also develop incremental-update techniques to keep the data up to date. Interactive and fuzzy searching algorithms for exploring MEDLINE are implemented in a system called iPubMed, freely accessible over the web at http://ipubmed.ics.uci.edu/ and http://tastier.cs.tsinghua.edu.cn/ipubmed.

  3. Dynamic circadian protein-protein interaction networks predict temporal organization of cellular functions.

    Directory of Open Access Journals (Sweden)

    Thomas Wallach

    2013-03-01

    Full Text Available Essentially all biological processes depend on protein-protein interactions (PPIs. Timing of such interactions is crucial for regulatory function. Although circadian (~24-hour clocks constitute fundamental cellular timing mechanisms regulating important physiological processes, PPI dynamics on this timescale are largely unknown. Here, we identified 109 novel PPIs among circadian clock proteins via a yeast-two-hybrid approach. Among them, the interaction of protein phosphatase 1 and CLOCK/BMAL1 was found to result in BMAL1 destabilization. We constructed a dynamic circadian PPI network predicting the PPI timing using circadian expression data. Systematic circadian phenotyping (RNAi and overexpression suggests a crucial role for components involved in dynamic interactions. Systems analysis of a global dynamic network in liver revealed that interacting proteins are expressed at similar times likely to restrict regulatory interactions to specific phases. Moreover, we predict that circadian PPIs dynamically connect many important cellular processes (signal transduction, cell cycle, etc. contributing to temporal organization of cellular physiology in an unprecedented manner.

  4. Non Linear Dynamics in Language and Psychobiological Interactions

    Science.gov (United States)

    Orsucci, Franco

    Language and thinking give us access to what is usually called natural and social reality. Language and thinking can be considered as parts of a semiotic universe of different entities from which emerge different subsets. Some of these can have peculiar functions in interpersonal interactions and biological transductions. Nonlinear studies at the morphological level of language are opening new perpectives in this area of the Mind-Sciences.

  5. Uncovering the dynamics of interaction in development cooperation

    DEFF Research Database (Denmark)

    Fejerskov, Adam Moe; Lundsgaarde, Erik; Cold-Ravnkilde, Signe

    critically reflects on the substantial body of scholarship that seeks to document the characteristics of new actors in international development and chart the consequences of their engagement for global development governance. This review underlines the importance of questioning the homogeneity of actor...... adopting more analytically and conceptually diverse approaches to study the interaction between heterogeneous development actors and homogenising forces in the field of development cooperation, recognising the complexity and (dis)continuities of stability and change in this arena....

  6. Quantum dynamics and topological excitations in interacting dipolar particles

    Science.gov (United States)

    Rey, Ana

    2016-05-01

    Dipole-dipole interactions, long-range and anisotropic interactions that arise due to the virtual exchange of photons, are of fundamental importance in optical physics, and are enabling a range of new quantum technologies including quantum networks and optical lattice atomic clocks. In this talk I will first discuss how arrays of dipolar particles with a simple J = 0- J = 1 internal level structure can naturally host topological and chiral excitations including Weyl quasi-particles. Weyl fermions were first predicted to exist in the context of high energy physics but only recently have been observed in solid state systems. I will discuss a proposal of using Mott insulators of Sr atoms to observe and probe the Weyl excitation spectrum and its non-trivial chirality. Finally I will report on a recent experiment done at JILA which validates the underlying microscopic model that predicts the existence of these excitations. The experiment measured the collective emission from a coherently driven gas of ultracold 88 Sr atoms and observed a highly directional and anisotropic emission intensity and a substantial broadening of the atomic spectral lines. All of the measurements are well reproduced by the theoretical model. These investigations open the door for the exploration of novel quantum many-body systems involving strongly interacting atoms and photons, and are useful guides for further developments of optical atomic clocks and other applications involving dense atomic ensembles. AFOSR, MURI-AFOSR, ARO,NSF-PHY-1521080, JILA-NSF-PFC-1125844.

  7. NMR and computational methods in the structural and dynamic characterization of ligand-receptor interactions.

    Science.gov (United States)

    Ghitti, Michela; Musco, Giovanna; Spitaleri, Andrea

    2014-01-01

    The recurrent failures in drug discovery campaigns, the asymmetry between the enormous financial investments and the relatively scarce results have fostered the development of strategies based on complementary methods. In this context in recent years the rigid lock-and-key binding concept had to be revisited in favour of a dynamic model of molecular recognition accounting for conformational changes of both the ligand and the receptor. The high level of complexity required by a dynamic description of the processes underlying molecular recognition requires a multidisciplinary investigation approach. In this perspective, the combination of nuclear magnetic resonance spectroscopy with molecular docking, conformational searches along with molecular dynamics simulations has given new insights into the dynamic mechanisms governing ligand receptor interactions, thus giving an enormous contribution to the identification and design of new and effective drugs. Herein a succinct overview on the applications of both NMR and computational methods to the structural and dynamic characterization of ligand-receptor interactions will be presented.

  8. The dynamic reactance interaction – How vested interests affect people’s experience, behavior, and cognition in social interactions

    Directory of Open Access Journals (Sweden)

    Christina eSteindl

    2015-11-01

    Full Text Available In social interactions, individuals may sometimes pursue their own interests at the expense of their interaction partner. Such self-interested behaviors impose a threat to the interaction partner’s freedom to act. The current article investigates this threat in the context of interdependence and reactance theory. We explore how vested interests influence reactance process stages of an advisor-client interaction. We aim to explore the interactional process that evolves. In two studies, participants took the perspective of a doctor (advisor or a patient (client. In both studies we incorporated a vested interest. In Study 1 (N=82 we found that in response to a vested interest of their interaction partner, patients indicated a stronger experience of reactance, more aggressive behavioral intentions, and more biased cognitions than doctors. A serial multiple mediation revealed that a vested interest engendered mistrust toward the interaction partner and this mistrust led to an emerging reactance process. Study 2 (N=207 further demonstrated that doctors expressed their reactance in a subtle way: They revealed a classic confirmation bias when searching for additional information on their preliminary decision preference, indicating stronger defense motivation. We discuss how these findings can help us to understand how social interactions develop dynamically.

  9. Direct Observation of Dynamical Quantum Phase Transitions in an Interacting Many-Body System.

    Science.gov (United States)

    Jurcevic, P; Shen, H; Hauke, P; Maier, C; Brydges, T; Hempel, C; Lanyon, B P; Heyl, M; Blatt, R; Roos, C F

    2017-08-25

    The theory of phase transitions represents a central concept for the characterization of equilibrium matter. In this work we study experimentally an extension of this theory to the nonequilibrium dynamical regime termed dynamical quantum phase transitions (DQPTs). We investigate and measure DQPTs in a string of ions simulating interacting transverse-field Ising models. During the nonequilibrium dynamics induced by a quantum quench we show for strings of up to 10 ions the direct detection of DQPTs by revealing nonanalytic behavior in time. Moreover, we provide a link between DQPTs and the dynamics of other quantities such as the magnetization, and we establish a connection between DQPTs and entanglement production.

  10. A digital computer program for the dynamic interaction simulation of controls and structure (DISCOS), volume 1

    Science.gov (United States)

    Bodley, C. S.; Devers, A. D.; Park, A. C.; Frisch, H. P.

    1978-01-01

    A theoretical development and associated digital computer program system for the dynamic simulation and stability analysis of passive and actively controlled spacecraft are presented. The dynamic system (spacecraft) is modeled as an assembly of rigid and/or flexible bodies not necessarily in a topological tree configuration. The computer program system is used to investigate total system dynamic characteristics, including interaction effects between rigid and/or flexible bodies, control systems, and a wide range of environmental loadings. In addition, the program system is used for designing attitude control systems and for evaluating total dynamic system performance, including time domain response and frequency domain stability analyses.

  11. Brain connectivity dynamics during social interaction reflect social network structure.

    Science.gov (United States)

    Schmälzle, Ralf; Brook O'Donnell, Matthew; Garcia, Javier O; Cascio, Christopher N; Bayer, Joseph; Bassett, Danielle S; Vettel, Jean M; Falk, Emily B

    2017-05-16

    Social ties are crucial for humans. Disruption of ties through social exclusion has a marked effect on our thoughts and feelings; however, such effects can be tempered by broader social network resources. Here, we use fMRI data acquired from 80 male adolescents to investigate how social exclusion modulates functional connectivity within and across brain networks involved in social pain and understanding the mental states of others (i.e., mentalizing). Furthermore, using objectively logged friendship network data, we examine how individual variability in brain reactivity to social exclusion relates to the density of participants' friendship networks, an important aspect of social network structure. We find increased connectivity within a set of regions previously identified as a mentalizing system during exclusion relative to inclusion. These results are consistent across the regions of interest as well as a whole-brain analysis. Next, examining how social network characteristics are associated with task-based connectivity dynamics, we find that participants who showed greater changes in connectivity within the mentalizing system when socially excluded by peers had less dense friendship networks. This work provides insight to understand how distributed brain systems respond to social and emotional challenges and how such brain dynamics might vary based on broader social network characteristics.

  12. Statics and Dynamics of Selfish Interactions in Distributed Service Systems.

    Directory of Open Access Journals (Sweden)

    Fabrizio Altarelli

    Full Text Available We study a class of games which models the competition among agents to access some service provided by distributed service units and which exhibits congestion and frustration phenomena when service units have limited capacity. We propose a technique, based on the cavity method of statistical physics, to characterize the full spectrum of Nash equilibria of the game. The analysis reveals a large variety of equilibria, with very different statistical properties. Natural selfish dynamics, such as best-response, usually tend to large-utility equilibria, even though those of smaller utility are exponentially more numerous. Interestingly, the latter actually can be reached by selecting the initial conditions of the best-response dynamics close to the saturation limit of the service unit capacities. We also study a more realistic stochastic variant of the game by means of a simple and effective approximation of the average over the random parameters, showing that the properties of the average-case Nash equilibria are qualitatively similar to the deterministic ones.

  13. Interactions among bioenergy feedstock choices, landscape dynamics, and land use.

    Science.gov (United States)

    Dale, Virginia H; Kline, Keith L; Wright, Lynn L; Perlack, Robert D; Downing, Mark; Graham, Robin L

    2011-06-01

    Landscape implications of bioenergy feedstock choices are significant and depend on land-use practices and their environmental impacts. Although land-use changes and carbon emissions associated with bioenergy feedstock production are dynamic and complicated, lignocellulosic feedstocks may offer opportunities that enhance sustainability when compared to other transportation fuel alternatives. For bioenergy sustainability, major drivers and concerns revolve around energy security, food production, land productivity, soil carbon and erosion, greenhouse gas emissions, biodiversity, air quality, and water quantity and quality. The many implications of bioenergy feedstock choices require several indicators at multiple scales to provide a more complete accounting of effects. Ultimately, the long-term sustainability of bioenergy feedstock resources (as well as food supplies) throughout the world depends on land-use practices and landscape dynamics. Land-management decisions often invoke trade-offs among potential environmental effects and social and economic factors as well as future opportunities for resource use. The hypothesis being addressed in this paper is that sustainability of bioenergy feedstock production can be achieved via appropriately designed crop residue and perennial lignocellulosic systems. We find that decision makers need scientific advancements and adequate data that both provide quantitative and qualitative measures of the effects of bioenergy feedstock choices at different spatial and temporal scales and allow fair comparisons among available options for renewable liquid fuels.

  14. Protostars and Planets VI

    Science.gov (United States)

    Beuther, Henrik; Klessen, Ralf S.; Dullemond, Cornelis P.; Henning, Thomas

    star and planet formation. They are used by students to dive into new topics, and they are much valued by experienced researchers as a comprehensive overview of the field with all its interactions. We hope that you will enjoy reading (and learning from) this book as much as we do. The organization of the Protostars and Planets conference was carried out in close collaboration between the Max Planck Institute for Astronomy and the Center for Astronomy of the University Heidelberg, with generous support from the German Science Foundation. This volume is a product of effort and care by many people. First and foremost, we want to acknowledge the 250 contributing authors, as it is only due to their expertise and knowledge that such a comprehensive review compendium in all its depth and breadth is possible. The Protostars and Planets VI conference and this volume was a major undertaking, with support and contributions by many people and institutions. We like to thank the members of the Scientific Advisory Committee who selected the 38 teams and chapters out of more than 120 submitted proposals. Similarly, we are grateful to the reviewers, who provided valuable input and help to the chapter authors. The book would also not have been possible without the great support of Renée Dotson and other staff from USRA’s Lunar and Planetary Institute, who handled the detailed processing of all manuscripts and the production of the book, and of Allyson Carter and other staff from the University of Arizona Press. We are also grateful to Richard Binzel, the General Editor of the Space Science Series, for his constant support during the long process, from the original concept to this final product. Finally, we would like to express a very special thank you to the entire conference local organizing committee, and in particular, Carmen Cuevas and Natali Jurina, for their great commitment to the project and for a very fruitful and enjoyable collaboration.

  15. Planck intermediate results: VI. The dynamical structure of PLCKG214.6+37.0, a Planck discovered triple system of galaxy clusters

    DEFF Research Database (Denmark)

    Bartlett, J.G.; Cardoso, J.-F.; Castex, G.

    2013-01-01

    components has allowed us to build a template model to extract the total SZ signal of this system with Planck data. We have partly reconciled the discrepancy between the expected SZ signal derived from X-rays and the observed one, which are now consistent within 1.2σ. We measured the redshift of the three...... components with the iron lines in the X-ray spectrum, and confirm that the three clumps are likely part of the same supercluster structure. The analysis of the dynamical state of the three components, as well as the absence of detectable excess X-ray emission, suggests that we are witnessing the formation...

  16. Non-interacting surface solvation and dynamics in protein-protein interactions

    NARCIS (Netherlands)

    Visscher, Koen M.; Kastritis, Panagiotis L.|info:eu-repo/dai/nl/315886668; Bonvin, Alexandre M J J|info:eu-repo/dai/nl/113691238

    2015-01-01

    Protein-protein interactions control a plethora of cellular processes, including cell proliferation, differentiation, apoptosis, and signal transduction. Understanding how and why proteins interact will inevitably lead to novel structure-based drug design methods, as well as design of de novo

  17. In situ oxygen dynamics in coral-algal interactions.

    Directory of Open Access Journals (Sweden)

    Daniel Wangpraseurt

    Full Text Available BACKGROUND: Coral reefs degrade globally at an alarming rate, with benthic algae often replacing corals. However, the extent to which benthic algae contribute to coral mortality, and the potential mechanisms involved, remain disputed. Recent laboratory studies suggested that algae kill corals by inducing hypoxia on the coral surface, through stimulated microbial respiration. METHODS/FINDINGS: We examined the main premise of this hypothesis by measuring in situ oxygen microenvironments at the contact interface between the massive coral Porites spp. and turf algae, and between Porites spp. and crustose coralline algae (CCA. Oxygen levels at the interface were similar to healthy coral tissue and ranged between 300-400 µM during the day. At night, the interface was hypoxic (~70 µM in coral-turf interactions and close to anoxic (~2 µM in coral-CCA interactions, but these values were not significantly different from healthy tissue. The diffusive boundary layer (DBL was about three times thicker at the interface than above healthy tissue, due to a depression in the local topography. A numerical model, developed to analyze the oxygen profiles above the irregular interface, revealed strongly reduced net photosynthesis and dark respiration rates at the coral-algal interface compared to unaffected tissue during the day and at night, respectively. CONCLUSIONS/SIGNIFICANCE: Our results showed that hypoxia was not a consistent feature in the microenvironment of the coral-algal interface under in situ conditions. Therefore, hypoxia alone is unlikely to be the cause of coral mortality. Due to the modified topography, the interaction zone is distinguished by a thicker diffusive boundary layer, which limits the local metabolic activity and likely promotes accumulation of potentially harmful metabolic products (e.g., allelochemicals and protons. Our study highlights the importance of mass transfer phenomena and the need for direct in situ measurements of

  18. Particle Dynamics under Quasi-linear Interaction with Electromagnetic Waves

    Energy Technology Data Exchange (ETDEWEB)

    Castejon, F.; Eguilior, S.

    2003-07-01

    Langevin equations for quasi-linear wave particle interaction are obtained taking advantage of the unique vocal equivalence between Fokker-Plank equation and the former ones. Langevin equations are solved numerically and, hence, the evolution of a single particle embedded in an electromagnetic field in momentum space is obtained. The equations are relativistic and valid for any wave. It is also shown that the stochastic part of the equations is negligible in comparison with the deterministic term, except for the momentum to the resonance condition for the main parallel refractive index. (Author) 24 refs.

  19. Interactions in charged colloidal suspensions: A molecular dynamics simulation study

    Science.gov (United States)

    Padidela, Uday Kumar; Behera, Raghu Nath

    2017-07-01

    Colloidal suspensions are extensively used in everyday life and find several applications in the pharmaceutical, chemical, food industries, etc. We present the classical molecular dynamics simulation results of the structural and transport properties of charged colloidal suspensions as a function of its size, charge and concentration. The system is viewed as a two-component (colloids and counterions) primitive model consisting of spherical colloid particle (macroion) and the counterions (micro-particles), which are treated explicitly. The solvent is treated as dielectric continuum. A systematic trend in the radial distribution functions g(r), potential of mean force W(r), different thermodynamic properties and diffusion coefficients is obtained as a function of colloid charge, size and concentration. An attractive minimum in W(r) is obtained at short interparticle distance.

  20. Interpersonal interactions and human dynamics in a large social network

    Science.gov (United States)

    Grabowski, Andrzej

    2007-11-01

    We study a large social network consisting of over 106 individuals, who form an Internet community and organize themselves in groups of different sizes. On the basis of the users’ list of friends and other data registered in the database we investigate the structure and time development of the network. The structure of this friendship network is very similar to the structure of different social networks. However, here a degree distribution exhibiting two scaling regimes, power-law for low connectivity and exponential for large connectivity, was found. The groups size distribution and distribution of number of groups of an individual have power-law form. We found very interesting scaling laws concerning human dynamics. Our research has shown how long people are interested in a single task.

  1. Human Machine Interaction by Simulation of Dynamics of Construction Machinery

    DEFF Research Database (Denmark)

    Langer, Thomas Heegaard

    on long term basis. Whole-body vibrations are potential damaging for the human operator in a frequency range for which the dynamics of the machines are dominated by the inputs of the operator. The objective of this project is to reduce the amount of potential damaging wholebody vibrations for two...... different kinds of machinery; an articulated backhoe loader and an articulated dump truck. In this work a standardized procedure containing a set of duty cycles for measuring and declaring whole-body vibrations has been proposed for both of these machines. The result of the measuring is important......-body vibration exposure was more than 20 percent and at the same time the fuel consumption was reduced significant. Training of operators is hence beneficial for both employees and employers of the construction industry. The whole-body vibration exposure on operators of dump trucks are dominated by off...

  2. MOLECULAR DYNAMICS SIMULATION OF LYSINE DENDRIMER AND SEMAX PEPTIDES INTERACTION

    Directory of Open Access Journals (Sweden)

    E. V. Popova

    2016-07-01

    Full Text Available The paper deals with the possibility of complex formation of therapeutic Semax peptides with lysine dendrimer by molecular modeling methods. Dendrimers are often used for delivery of drugs and biological molecules (e.g., DNA, peptides and polysaccharides. Since lysine dendrimers are less toxic than conventional synthetic dendrimers (e.g., polyamidoamine (PAMAM dendrimer, we chose them and studied two systems containing dendrimer and the different number of Semax peptides. The study was carried out by molecular dynamics method. It was obtained that the stable complexes were formed in both cases. The equilibrium structures of these complexes were investigated. These complexes can be used in the future in therapy of various diseases as Semax peptides have significant antioxidant, antihypoxic and neuroprotecting action.

  3. The dynamics of interacting nonlinearities governing long wavelength driftwave turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Newman, David E. [Univ. of Wisconsin, Madison, WI (United States)

    1993-09-01

    Because of the ubiquitous nature of turbulence and the vast array of different systems which have turbulent solutions, the study of turbulence is an area of active research. Much present day understanding of turbulence is rooted in the well established properties of homogeneous Navier-Stokes turbulence, which, due to its relative simplicity, allows for approximate analytic solutions. This work examines a group of turbulent systems with marked differences from Navier-Stokes turbulence, and attempts to quantify some of their properties. This group of systems represents a variety of drift wave fluctuations believed to be of fundamental importance in laboratory fusion devices. From extensive simulation of simple local fluid models of long wavelength drift wave turbulence in tokamaks, a reasonably complete picture of the basic properties of spectral transfer and saturation has emerged. These studies indicate that many conventional notions concerning directions of cascades, locality and isotropy of transfer, frequencies of fluctuations, and stationarity of saturation are not valid for moderate to long wavelengths. In particular, spectral energy transfer at long wavelengths is dominated by the E x B nonlinearity, which carries energy to short scale in a manner that is highly nonlocal and anisotropic. In marked contrast to the canonical self-similar cascade dynamics of Kolmogorov, energy is efficiently passed between modes separated by the entire spectrum range in a correlation time. At short wavelengths, transfer is dominated by the polarization drift nonlinearity. While the standard dual cascade applies in this subrange, it is found that finite spectrum size can produce cascades that are reverse directed and are nonconservative in enstrophy and energy similarity ranges. In regions where both nonlinearities are important, cross-coupling between the nolinearities gives rise to large no frequency shifts as well as changes in the spectral dynamics.

  4. Linking ecomechanics and ecophysiology to interspecific interactions and community dynamics.

    Science.gov (United States)

    Harley, Christopher D G

    2013-09-01

    To predict community-level responses to climate change, we must understand how variation in environmental conditions drives changes in an organism's ability to acquire resources and translate those resources into growth, reproduction, and survival. This challenge can be approached mechanistically by establishing linkages from biophysics to community ecology. For example, body temperature can be predicted from environmental conditions and species-specific morphological and behavioral traits. Variation in body temperature within and among species dictates physiological performance, rates of resource acquisition, and growth. These ecological characteristics, along with population size, define the strength with which species interact. Finally, the direct (individual level) and indirect (community level) effects of temperature jointly determine community structure. This mechanistic framework can complement correlational approaches to better predict ecological responses to climate change and identify which characteristics of a species or community act as leverage points for change. Research priorities for further development of the mechanistic approach include documentation and prediction of relevant spatial and temporal variation in body temperature and the relationships between body temperature, individual performance, and interspecific interactions. © 2013 New York Academy of Sciences.

  5. The endogenous dynamics of financial markets: Interaction and information dissemination

    Science.gov (United States)

    Yang, ChunXia; Hu, Sen; Xia, BingYing

    2012-06-01

    We investigate the process that different interactions between investors will prompt information to propagate along a differentiated path and construct a financial market model. As information spreads, increasingly investors are attracted to participate in trading, then the “herding effect” is magnified gradually, which will induce the topology of market network to change and the price to fluctuate. Especially, under different initial conditions or parameters, the peak and fat-tail property is produced and the obtained statistic values coincide with empirical results: the power-law exponents between the peak value of return probability distribution and the time scales range from 0.579 to 0.747, and the exponents between the accumulation distribution and the return on the tail are close to 3. Besides, the extent of volatility clustering in our produced price series is close to that of S&P 500 and locates between NASDAQ and HSI. All the results obtained here indicate that the continuous variation of the “herding effect” resulting from information propagation among interacting investors may be the origin of stylized facts of price fluctuations.

  6. Membrane dynamics and interactions in measles virus dendritic cell infections.

    Science.gov (United States)

    Avota, Elita; Koethe, Susanne; Schneider-Schaulies, Sibylle

    2013-02-01

    Viral entry, compartmentalization and transmission depend on the formation of membrane lipid/protein microdomains concentrating receptors and signalosomes. Dendritic cells (DCs) are prime targets for measles virus (MV) infection, and this interaction promotes immune activation and generalized immunosuppression, yet also MV transport to secondary lymphatics where transmission to T cells occurs. In addition to MV trapping, DC-SIGN interaction can enhance MV uptake by activating cellular sphingomyelinases and, thereby, vertical surface transport of its entry receptor CD150. To exploit DCs as Trojan horses for transport, MV promotes DC maturation accompanied by mobilization, and restrictions of viral replication in these cells may support this process. MV-infected DCs are unable to support formation of functional immune synapses with conjugating T cells and signalling via viral glycoproteins or repulsive ligands (such as semaphorins) plays a key role in the induction of T-cell paralysis. In the absence of antigen recognition, MV transmission from infected DCs to T cells most likely involves formation of polyconjugates which concentrate viral structural proteins, viral receptors and with components enhancing either viral uptake or conjugate stability. Because DCs barely support production of infectious MV particles, these organized interfaces are likely to represent virological synapses essential for MV transmission. © 2012 Blackwell Publishing Ltd.

  7. Dynamic Analysis of Wind Turbines Including Soil-Structure Interaction

    DEFF Research Database (Denmark)

    Harte, M.; Basu, B.; Nielsen, Søren R.K.

    2012-01-01

    blades and includes the effect of centrifugal stiffening due to rotation. The foundation of the structure is modeled as a rigid gravity based foundation with two DOF whose movement is related to the surrounding soil by means of complex impedance functions generated using cone model. Transfer functions...... for displacement of the turbine system are obtained and the modal frequencies of the combined turbine-foundation system are estimated. Simulations are presented for the MDOF turbine structure subjected to wind loading for different soil stiffness conditions. Steady state and turbulent wind loading, developed using...... blade element momentum theory and the Kaimal spectrum, have been considered. Soil stiffness and damping properties acquired from DNV/Risø standards are used as a comparison. The soil-structure interaction is shown to affect the response of the wind turbine. This is examined in terms of the turbine...

  8. Nuclear envelope and nuclear matrix: interactions and dynamics.

    Science.gov (United States)

    Vlcek, S; Dechat, T; Foisner, R

    2001-11-01

    The peripheral nuclear lamina is located near the nuclear inner membrane and consists of lamin filaments and integral membrane proteins, including the lamin B receptor and various isoforms of lamina-associated polypeptides (LAP) 1 and 2. Several nuclear membrane proteins also interact with chromatin proteins BAF and Hp1. Lamins in the nuclear interior associate with at least one soluble (non-membrane-bound) LAP2 isoform named LAP2alpha. The internal lamins, together with Tpr-based filaments that connect to nuclear pore complexes, are proposed to be major structural elements of the internal nuclear matrix. We describe the structural links between the peripheral lamina and the internal nuclear matrix that are thought to be mediated by LAP2 family members, filament protein Tpr and nucleoporin Nup153. These findings are discussed in relation to human diseases that arise from mutations in nuclear lamina proteins.

  9. Deciphering the Dynamics of Non-Covalent Interactions Affecting Thermal Stability of a Protein: Molecular Dynamics Study on Point Mutant of Thermus thermophilus Isopropylmalate Dehydrogenase

    National Research Council Canada - National Science Library

    Sharma, Reetu; Sastry, G Narahari

    2015-01-01

    .... Exploring the dynamic properties of non-covalent interactions such as saltbridges, hydrogen bonds and hydrophobic interactions to explain thermal stability of a protein is interesting in its own right...

  10. Role of Interactions and Correlations on Collective Dynamics of Molecular Motors Along Parallel Filaments

    Science.gov (United States)

    Midha, Tripti; Gupta, Arvind Kumar

    2017-11-01

    Cytoskeletal motors known as motor proteins are molecules that drive cellular transport along several parallel cytoskeletal filaments and support many biological processes. Experimental evidences suggest that they interact with the nearest molecules of their filament while performing any mechanical work. These interactions modify the microscopic level properties of motor proteins. In this work, a new version of two-channel totally asymmetric simple exclusion process, that incorporates the intra-channel interactions in a thermodynamically consistent way, is proposed. As the existing approaches for multi-channel systems deviate from analyzing the combined effect of inter and intra-channel interactions, a new approach known as modified vertical cluster mean field is developed. The approach along with Monte Carlo simulations successfully encounters some correlations and computes the complex dynamic properties of the system. Role of symmetry of interactions and inter-channel coupling is observed on the phase diagrams, maximal particle current and its corresponding optimal interaction strength. Surprisingly, for all values of coupling rate and most of the interaction splittings, the optimal interaction strength corresponding to maximal current belongs to the case of weak repulsive interactions. Moreover, for weak interaction splittings and with an increase in the coupling rate, the optimal interaction strength tends towards the known experimental results. The effect of coupling as well as interaction energy is also measured for correlations. They are found to be short-range and weaker for repulsive and weak attractive interactions while they are long-range and stronger for large attractions.

  11. Interacting opinion and disease dynamics in multiplex networks: Discontinuous phase transition and nonmonotonic consensus times

    Science.gov (United States)

    Velásquez-Rojas, Fátima; Vazquez, Federico

    2017-05-01

    Opinion formation and disease spreading are among the most studied dynamical processes on complex networks. In real societies, it is expected that these two processes depend on and affect each other. However, little is known about the effects of opinion dynamics over disease dynamics and vice versa, since most studies treat them separately. In this work we study the dynamics of the voter model for opinion formation intertwined with that of the contact process for disease spreading, in a population of agents that interact via two types of connections, social and contact. These two interacting dynamics take place on two layers of networks, coupled through a fraction q of links present in both networks. The probability that an agent updates its state depends on both the opinion and disease states of the interacting partner. We find that the opinion dynamics has striking consequences on the statistical properties of disease spreading. The most important is that the smooth (continuous) transition from a healthy to an endemic phase observed in the contact process, as the infection probability increases beyond a threshold, becomes abrupt (discontinuous) in the two-layer system. Therefore, disregarding the effects of social dynamics on epidemics propagation may lead to a misestimation of the real magnitude of the spreading. Also, an endemic-healthy discontinuous transition is found when the coupling q overcomes a threshold value. Furthermore, we show that the disease dynamics delays the opinion consensus, leading to a consensus time that varies nonmonotonically with q in a large range of the model's parameters. A mean-field approach reveals that the coupled dynamics of opinions and disease can be approximately described by the dynamics of the voter model decoupled from that of the contact process, with effective probabilities of opinion and disease transmission.

  12. Remediation of chromium-slag leakage with electricity cogeneration via a urea-Cr(VI) cell

    OpenAIRE

    Binbin Yu; Huimin Zhang; Wei Xu; Gang Li; Zucheng Wu

    2014-01-01

    Chromium pollution has been historically widespread throughout the world. Most available remediation technologies often require energy consumption. This study is aimed to develop electrochemical remediation for Cr(VI) in chromium-slag leakage with self-generated electricity. Dynamic leaching experiments of chromium-slag samples were conducted to survey the release and leaching behavior of Cr(VI). Based on previous work, a unique urea-Cr(VI) was designed, in which urea was employed as the fuel...

  13. Particle dynamics and particle-cell interaction in microfluidic systems

    Science.gov (United States)

    Stamm, Matthew T.

    Particle-laden flow in a microchannel resulting in aggregation of microparticles was investigated to determine the dependence of the cluster growth rate on the following parameters: suspension void fraction, shear strain rate, and channel-height to particle-diameter ratio. The growth rate of an average cluster was found to increase linearly with suspension void fraction, and to obey a power-law relationships with shear strain rate as S 0.9 and channel-height to particle-diameter ratio as (h/d )--3.5. Ceramic liposomal nanoparticles and silica microparticles were functionalized with antibodies that act as targeting ligands. The bio-functionality and physical integrity of the cerasomes were characterized. Surface functionalization allows cerasomes to deliver drugs with selectivity and specificity that is not possible using standard liposomes. The functionalized particle-target cell binding process was characterized using BT-20 breast cancer cells. Two microfluidic systems were used; one with both species in suspension, the other with cells immobilized inside a microchannel and particle suspension as the mobile phase. Effects of incubation time, particle concentration, and shear strain rate on particle-cell binding were investigated. With both species in suspension, the particle-cell binding process was found to be reasonably well-described by a first-order model. Particle desorption and cellular loss of binding affinity in time were found to be negligible; cell-particle-cell interaction was identified as the limiting mechanism in particle-cell binding. Findings suggest that separation of a bound particle from a cell may be detrimental to cellular binding affinity. Cell-particle-cell interactions were prevented by immobilizing cells inside a microchannel. The initial stage of particle-cell binding was investigated and was again found to be reasonably well-described by a first-order model. For both systems, the time constant was found to be inversely proportional to

  14. Molecular dynamics simulations of protein-tyrosine phosphatase 1B: II. Substrate-enzyme interactions and dynamics

    DEFF Research Database (Denmark)

    Peters, Günther H.j.; Frimurer, T. M.; Andersen, J. N.

    2000-01-01

    Molecular dynamics simulations of protein tyrosine phosphatase 1B (PTP1B) complexed with the phosphorylated peptide substrate DADEpYL and the free substrate have been conducted to investigate 1) the physical forces involved in substrate-protein interactions, 2) the importance of enzyme...... to substrate binding. Based on essential dynamics analysis of the PTP1B/DADEpYL trajectory, it is shown that internal motions in the binding pocket occur in a subspace of only a few degrees of freedom. in particular, relatively large flexibilities are observed along several eigenvectors in the segments: Arg(24...... for catalysis. Analysis of the individual enzyme-substrate interaction energies revealed that mainly electrostatic forces contribute to binding. Indeed, calculation of the electrostatic field of the enzyme reveals that only the field surrounding the binding pocket is positive, while the remaining protein...

  15. Dynamic analysis methods for detecting anomalies in asynchronously interacting systems

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Akshat; Solis, John Hector; Matschke, Benjamin

    2014-01-01

    Detecting modifications to digital system designs, whether malicious or benign, is problematic due to the complexity of the systems being analyzed. Moreover, static analysis techniques and tools can only be used during the initial design and implementation phases to verify safety and liveness properties. It is computationally intractable to guarantee that any previously verified properties still hold after a system, or even a single component, has been produced by a third-party manufacturer. In this paper we explore new approaches for creating a robust system design by investigating highly-structured computational models that simplify verification and analysis. Our approach avoids the need to fully reconstruct the implemented system by incorporating a small verification component that dynamically detects for deviations from the design specification at run-time. The first approach encodes information extracted from the original system design algebraically into a verification component. During run-time this component randomly queries the implementation for trace information and verifies that no design-level properties have been violated. If any deviation is detected then a pre-specified fail-safe or notification behavior is triggered. Our second approach utilizes a partitioning methodology to view liveness and safety properties as a distributed decision task and the implementation as a proposed protocol that solves this task. Thus the problem of verifying safety and liveness properties is translated to that of verifying that the implementation solves the associated decision task. We develop upon results from distributed systems and algebraic topology to construct a learning mechanism for verifying safety and liveness properties from samples of run-time executions.

  16. Host-Parasite Interactions and Population Dynamics of Rock Ptarmigan.

    Science.gov (United States)

    Stenkewitz, Ute; Nielsen, Ólafur K; Skírnisson, Karl; Stefánsson, Gunnar

    2016-01-01

    evidence that E. muta through time-lag in prevalence with respect to host population size and by showing significant relations with host body condition, mortality, and fecundity could destabilize ptarmigan population dynamics in Iceland.

  17. Quantifying Long-Range Interactions and Coherent Structure in Multi-Agent Dynamics.

    Science.gov (United States)

    Cliff, Oliver M; Lizier, Joseph T; Wang, X Rosalind; Wang, Peter; Obst, Oliver; Prokopenko, Mikhail

    2017-01-01

    We develop and apply several novel methods quantifying dynamic multi-agent team interactions. These interactions are detected information-theoretically and captured in two ways: via (i) directed networks (interaction diagrams) representing significant coupled dynamics between pairs of agents, and (ii) state-space plots (coherence diagrams) showing coherent structures in Shannon information dynamics. This model-free analysis relates, on the one hand, the information transfer to responsiveness of the agents and the team, and, on the other hand, the information storage within the team to the team's rigidity and lack of tactical flexibility. The resultant interaction and coherence diagrams reveal implicit interactions, across teams, that may be spatially long-range. The analysis was verified with a statistically significant number of experiments (using simulated football games, produced during RoboCup 2D Simulation League matches), identifying the zones of the most intense competition, the extent and types of interactions, and the correlation between the strength of specific interactions and the results of the matches.

  18. Dynamics of relaxation to a stationary state for interacting molecular motors

    Science.gov (United States)

    Gomes, Luiza V. F.; Kolomeisky, Anatoly B.

    2018-01-01

    Motor proteins are active enzymatic molecules that drive a variety of biological processes, including transfer of genetic information, cellular transport, cell motility and muscle contraction. It is known that these biological molecular motors usually perform their cellular tasks by acting collectively, and there are interactions between individual motors that specify the overall collective behavior. One of the fundamental issues related to the collective dynamics of motor proteins is the question if they function at stationary-state conditions. To investigate this problem, we analyze a relaxation to the stationary state for the system of interacting molecular motors. Our approach utilizes a recently developed theoretical framework, which views the collective dynamics of motor proteins as a totally asymmetric simple exclusion process of interacting particles, where interactions are taken into account via a thermodynamically consistent approach. The dynamics of relaxation to the stationary state is analyzed using a domain-wall method that relies on a mean-field description, which takes into account some correlations. It is found that the system quickly relaxes for repulsive interactions, while attractive interactions always slow down reaching the stationary state. It is also predicted that for some range of parameters the fastest relaxation might be achieved for a weak repulsive interaction. Our theoretical predictions are tested with Monte Carlo computer simulations. The implications of our findings for biological systems are briefly discussed.

  19. Molecular Dynamics Simulations of Protein-Tyrosine Phosphatase 1B. II. Substrate-Enzyme Interactions and Dynamics

    OpenAIRE

    Peters, Günther H.; Frimurer, Thomas M.; Andersen, Jannik N.; Olsen, Ole H.

    2000-01-01

    Molecular dynamics simulations of protein tyrosine phosphatase 1B (PTP1B) complexed with the phosphorylated peptide substrate DADEpYL and the free substrate have been conducted to investigate 1) the physical forces involved in substrate-protein interactions, 2) the importance of enzyme and substrate flexibility for binding, 3) the electrostatic properties of the enzyme, and 4) the contribution from solvation. The simulations were performed for 1 ns, using explicit water molecules. The last 70...

  20. Ecological dynamics and complex interactions of Agrobacterium megaplasmids

    Directory of Open Access Journals (Sweden)

    Thomas Gene Platt

    2014-11-01

    Full Text Available As with many pathogenic bacteria, agrobacterial plant pathogens carry most of their virulence functions on a horizontally transmissible genetic element. The tumor-inducing (Ti plasmid encodes the majority of virulence functions for the crown gall agent Agrobacterium tumefaciens. This includes the vir genes which drive genetic transformation of host cells and the catabolic genes needed to utilize the opines produced by infected plants. The Ti plasmid also encodes, an opine-dependent quorum sensing system that tightly regulates Ti plasmid copy number and its conjugal transfer to other agrobacteria. Many natural agrobacteria are avirulent, lacking the Ti plasmid. The burden of harboring the Ti plasmid depends on the environmental context. Away from diseased hosts, plasmid costs are low but the benefit of the plasmid is also absent. Consequently, plasmidless genotypes are favored. On infected plants the costs of the Ti plasmid can be very high, but balanced by the opine benefits, locally favoring plasmid bearing cells. Cheating derivatives which do not incur virulence costs but can benefit from opines are favored on infected plants and in most other environments, and these are frequently isolated from nature. Many agrobacteria also harbor an At plasmid which can stably coexist with a Ti plasmid. At plasmid genes are less well characterized but in general facilitate metabolic activities in the rhizosphere and bulk soil, such as the ability to breakdown plant exudates. Examination of A. tumefaciens C58, revealed that harboring it’s At plasmid is much more costly than harboring it’s Ti plasmid, but conversely the At plasmid is extremely difficult to cure. The interactions between these co-resident plasmids are complex, and depend on environmental context. However, the presence of a Ti plasmid appears to mitigate At plasmid costs, consistent with the high frequency with which they are found together.

  1. The Theory of Dynamics of Living Systems Activity in Interpersonal Interaction

    Directory of Open Access Journals (Sweden)

    Sergei V. Kharitonov

    2014-05-01

    Full Text Available The work deals with the study of the dynamics of the interaction between people. The theoretical basis of the research is the model of the dynamics of living systems activity, stating the existence of three phases of systems dynamics: termnet, affinity and involvement. The equivalents of these phrases in interpersonal communication are the following: prudence during interaction (equivalent to termnet phase, readiness to avow one’s goals (equivalent to affinity phase, readiness to plan united actions (equivalent to involvement phase. The goal of the research is to study the process of interaction between two persons from the perspective of the theory of dynamics of living systems activity. The participants were offered to enter into agreement during an hour. The time limit of their dialogue had three 20-minute periods. The level of prudence, readiness to discuss goals and plan united actions were estimated every three time segments, using visual-analogue scale. The research was conducted in the group, involving 42 people. The obtained results showed that the communication structure, projected by the theory of dynamics activity seems to be convincing and can be used to describe communicative interactions.

  2. Tungstate (VI) sorption on hematite: An in situ ATR-FTIR probe on the mechanism.

    Science.gov (United States)

    Rakshit, Sudipta; Sallman, Bryan; Davantés, Athénais; Lefèvre, Grégory

    2017-02-01

    Owing to the suspected toxicity and carcinogenicity of tungstate (VI) oxyanions [i.e. mono tungstate and several polytungstate, generally represented by W (VI)], the environmental fate of W (VI) has been widely studied. Sorption is regarded as a major mechanism by which W (VI) species are retained in the solid/water interface. Iron (hydr)oxides have been considered important environmental sinks for W (VI) species. Here we report sorption mechanisms of W (VI) on a common iron oxide mineral-hematite under environmentally relevant solution properties using in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic probes. Initial W (VI) loadings varied from 10 to 200 μM at fixed pH values ranged from 4.6 to 8.1. For pH envelop (pHs = 4.6, 5.0, 5.5, 6.0, 6.5, 7.5, and 8.1) experiments, fixed W (VI) concentrations (i.e. 10 & 200 μM) were used to understand the effects of pH. The results indicated that at acidic pH values (pH hematite surface and the strength of the interaction increases with decreasing pH. In addition, initial W (VI) concentration affected the sorption mechanisms of W (VI) on hematite. Our study will aid the molecular level understanding of W (VI) retention on iron oxide surfaces. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Equilibration Dynamics of Strongly Interacting Bosons in 2D Lattices with Disorder.

    Science.gov (United States)

    Yan, Mi; Hui, Hoi-Yin; Rigol, Marcos; Scarola, V W

    2017-08-18

    Motivated by recent optical lattice experiments [J.-y. Choi et al., Science 352, 1547 (2016)SCIEAS0036-807510.1126/science.aaf8834], we study the dynamics of strongly interacting bosons in the presence of disorder in two dimensions. We show that Gutzwiller mean-field theory (GMFT) captures the main experimental observations, which are a result of the competition between disorder and interactions. Our findings highlight the difficulty in distinguishing glassy dynamics, which can be captured by GMFT, and many-body localization, which cannot be captured by GMFT, and indicate the need for further experimental studies of this system.

  4. Dynamic Dipole-Dipole Interactions between Excitons in Quantum Dots of Different Sizes

    DEFF Research Database (Denmark)

    Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

    2005-01-01

    Micro-photoluminescence spectra of GaAs/AlGaAs coupled quantum dots (QDs) are given, and proposed to be analyzed by our resonance dynamic dipole-dipole interaction (RDDDI) model, based on parity inheritance and exchange of virtual photons among QDs of different sizes.......Micro-photoluminescence spectra of GaAs/AlGaAs coupled quantum dots (QDs) are given, and proposed to be analyzed by our resonance dynamic dipole-dipole interaction (RDDDI) model, based on parity inheritance and exchange of virtual photons among QDs of different sizes....

  5. Influence of gain dynamics on dissipative soliton interaction in the presence of a continuous wave

    Science.gov (United States)

    Niang, A.; Amrani, F.; Salhi, M.; Leblond, H.; Sanchez, F.

    2015-09-01

    We investigate the effect of the gain dynamics on the motion and interactions of solitons in the frame of a complex Ginzburg-Landau-type model, which accounts for dissipative soliton formation and propagation in a ring fiber laser. It is shown that the gain dynamics modifies the soliton velocity and their interactions. In the presence of an injected continuous wave, an initial crystal of a few solitons gets broken, either into bunches or into individual solitons. Quasielastic collisions analogous to Newton's cradle have been seen. The soliton set may evolve into gas, solitons, or harmonic mode-locked patterns. The time jitter present in the last situation has been considered.

  6. Dynamic strength of the interaction between lung surfactant protein D (SP-D) and saccharide ligands

    DEFF Research Database (Denmark)

    Thormann, Esben; Dreyer, Jakob K; Simonsen, Adam C

    2007-01-01

    In order to investigate the dynamic strength of the interaction between lung surfactant protein D (SP-D) and different sugars, maltose, mannose, glucose, and galactose, we have used an atomic force microscope to monitor the interaction on a single molecule scale. The experiment is performed...... by measuring the rupture force when the SP-D-sugar bond is subjected to a continuously increasing force. Under these dynamic conditions, SP-D binds strongest to d-mannose and weakest to maltose and d-galactose. These results differ from equilibrium measurements wherein SP-D exhibits preference for maltose...

  7. Mapping dynamic protein interactions to insulin secretory granule behavior with TIRF-FRET.

    Science.gov (United States)

    Lam, Alice D; Ismail, Sahar; Wu, Ray; Yizhar, Ofer; Passmore, Daniel R; Ernst, Stephen A; Stuenkel, Edward L

    2010-08-09

    Biological processes are governed by extensive networks of dynamic molecular interactions. Yet, establishing a spatial and temporal map of these interactions and their direct relationship to specific cell functions has remained a challenge. Here, we implement sensitized emission Förster resonance energy transfer (FRET) stoichiometry under total internal reflection fluorescence (TIRF) microscopy. We demonstrate through quantitative analysis and modeling that evanescent fields must be precisely matched between FRET excitation wavelengths to isolate dynamic interactions between bimolecular FRET pairs that are not entirely membrane-delimited. We then use TIRF-FRET to monitor the behavior of individual insulin-containing secretory granules at the plasma membrane of living cells, while simultaneously tracking the dynamic interaction between the GTPase Rab27A and its effector Slp4A, on those same granules. Notably, insulin granules that underwent exocytosis demonstrated a specific increase in Rab27A-GTP/Slp4A FRET in the 5 s before membrane fusion, which coincided temporally with an increase in granule displacement and mobility. These results demonstrate an initial spatiotemporal mapping of a dynamic protein-protein interaction on individual secretory granules that is linked to a specific granule behavior in living cells. 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. Dynamic functional modules in co-expressed protein interaction networks of dilated cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Oyang Yen-Jen

    2010-10-01

    Full Text Available Abstract Background Molecular networks represent the backbone of molecular activity within cells and provide opportunities for understanding the mechanism of diseases. While protein-protein interaction data constitute static network maps, integration of condition-specific co-expression information provides clues to the dynamic features of these networks. Dilated cardiomyopathy is a leading cause of heart failure. Although previous studies have identified putative biomarkers or therapeutic targets for heart failure, the underlying molecular mechanism of dilated cardiomyopathy remains unclear. Results We developed a network-based comparative analysis approach that integrates protein-protein interactions with gene expression profiles and biological function annotations to reveal dynamic functional modules under different biological states. We found that hub proteins in condition-specific co-expressed protein interaction networks tended to be differentially expressed between biological states. Applying this method to a cohort of heart failure patients, we identified two functional modules that significantly emerged from the interaction networks. The dynamics of these modules between normal and disease states further suggest a potential molecular model of dilated cardiomyopathy. Conclusions We propose a novel framework to analyze the interaction networks in different biological states. It successfully reveals network modules closely related to heart failure; more importantly, these network dynamics provide new insights into the cause of dilated cardiomyopathy. The revealed molecular modules might be used as potential drug targets and provide new directions for heart failure therapy.

  9. Coupled quintessence and the impossibility of an interaction: a dynamical analysis study

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, Fabrizio F.; Landim, Ricardo G. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil)

    2017-05-15

    We analyze the coupled quintessence in the light of the linear dynamical systems theory, with two different interactions: (1) proportional to the energy density of the dark energy and (2) proportional to the sum of the energy densities of the dark matter and dark energy. The results presented here enlarge the previous analyses in the literature, wherein the interaction has been only proportional to the energy density of the dark matter. In the first case it is possible to get the well-known sequence of cosmological eras. For the second interaction only the radiation and the dark-energy era can be described by the fixed points. Therefore, from the point of view of dynamical system theory, the interaction proportional to the sum of the energy densities of the dark matter and dark energy does not describe the universe we live in. (orig.)

  10. Channel-interacting PDZ protein, 'CIPP', interacts with proteins involved in cytoskeletal dynamics.

    Science.gov (United States)

    Alpi, Emanuele; Landi, Elena; Barilari, Manuela; Serresi, Michela; Salvadori, Piero; Bachi, Angela; Dente, Luciana

    2009-04-15

    Neuronal CIPP (channel-interacting PDZ protein) is a multivalent PDZ protein that interacts with specific channels and receptors highly expressed in the brain. It is composed of four PDZ domains that behave as a scaffold to clusterize functionally connected proteins. In the present study, we selected a set of potential CIPP interactors that are involved directly or indirectly in mechanisms of cytoskeletal remodelling and membrane protrusion formation. For some of these, we first proved the direct binding to specific CIPP PDZ domains considered as autonomous elements, and then confirmed the interaction with the whole protein. In particular, the small G-protein effector IRSp53 (insulin receptor tyrosine kinase substrate protein p53) specifically interacts with the second PDZ domain of CIPP and, when co-transfected in cultured mammalian cells with a tagged full-length CIPP, it induces a marked reorganization of CIPP cytoplasmic localization. Large punctate structures are generated as a consequence of CIPP binding to the IRSp53 C-terminus. Analysis of the puncta nature, using various endocytic markers, revealed that they are not related to cytoplasmic vesicles, but rather represent multi-protein assemblies, where CIPP can tether other potential interactors.

  11. What makes for a pleasant social interaction? Motivational dynamics of interpersonal relations.

    Science.gov (United States)

    Downie, Michelle; Mageau, Genevieve A; Koestner, Richard

    2008-10-01

    The authors used an event-contingent daily recording strategy, the Rochester Interaction Record (RIR), to examine the motivational dynamics of interpersonal relations. Using hierarchical linear modeling, the authors demonstrated that social interactions were more pleasant when participants felt autonomous, competent, and related. Autonomy, competence, and relatedness consistently predicted interaction quality, regardless of (a) the length of the interaction; (b) whether it was dyadic or in a group; and (c) whether it was an interaction with family, friends, or acquaintances. However, participants were more likely to report feeling autonomous and related when they were interacting either with family members and friends or in a dyadic situation. These results suggest that experiences of autonomy, competence, and relatedness may make a good day partly because they produce satisfying interpersonal experiences.

  12. A molecular dynamics study on the interaction between epoxy and functionalized graphene sheets

    DEFF Research Database (Denmark)

    Melro, Liliana Sofia S. F. P.; Pyrz, Ryszard; Jensen, Lars Rosgaard

    2016-01-01

    The interaction between graphene and epoxy resin was studied using molecular dynamics simulations. The interfacial shear strength and pull out force were calculated for functionalised graphene layers (carboxyl, carbonyl, and hydroxyl) and epoxy composites interfaces. The influence of functional...... groups, as well as their distribution and coverage density on the graphene sheets were also analysed through the determination of the Young's modulus. Functionalisation proved to be detrimental to the mechanical properties, nonetheless according to interfacial studies the interaction between graphene...

  13. Dynamical networks of person to person interactions from RFID sensor networks

    Science.gov (United States)

    Isella, Lorenzo; Cattuto, Ciro; Barrat, Alain

    2010-03-01

    We present a scalable experimental framework for gathering real-time data on face-to-face social interactions with tunable spatial and temporal resolution. We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We show results on the analysis of the dynamical networks of person-to-person interaction obtained in four high- resolution experiments carried out at different orders of magnitude in community size.

  14. Contact point generation for convex polytopes in interactive rigid body dynamics

    DEFF Research Database (Denmark)

    Silcowitz-Hansen, Morten; Abel, Sarah Maria Niebe; Erleben, Kenny

    When computing contact forces in rigid body dynamics systems, most state-of-the-art solutions use iterative methods such as the projected Gauss–Seidel (PGS) method. Methods such as the PGS method are preferred for their robustness. However, the time-critical nature of interactive applications...... for convex polytopes. A novel contact point generation method is presented, which is based on growth distances and Gauss maps. We demonstrate improvements when using our method in the context of interactive rigid body simulation...

  15. Dynamical aspects on FEL interaction in single passage and storage ring devices

    Energy Technology Data Exchange (ETDEWEB)

    Dattoli, G.; Renieri, A. [ENEA, Frascati (Italy)

    1995-12-31

    The dynamical behaviour of the free-electron lasers is investigated using appropriate scaling relations valid for devices operating in the low and high gain regimes, including saturation. The analysis is applied to both single passage and storage ring configurations. In the latter case the interplay between the interaction of the electron bean with the laser field and with the accelerator environment is investigated. In particular we discuss the effect of FEL interaction on the microwave instability.

  16. Channel-interacting PDZ protein “CIPP” interacts with proteins involved in cytoskeletal dynamics

    OpenAIRE

    Alpi, Emanuele; Landi, Elena; Barilari, Manuela; Serresi, Michela; Salvadori, Piero; Bachi, Angela; Dente, Luciana

    2009-01-01

    Abstract Neuronal CIPP is a multivalent PDZ protein that interacts with specific channels and receptors, highly expressed in the brain. It is composed of four PDZ domains that behave as a scaffold to clusterize functionally connected proteins. In this study, we selected a set of potential CIPP interactors that are directly or indirectly involved in mechanisms of cytoskeletal remodeling and membrane protrusions formation. For some of these, we first proved the direct binding to spec...

  17. ViFiLite Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ViFiLite is a wireless infrastructure that utilizes the advantages of a V-band technology in supporting data gathering for structural health monitoring as well as...

  18. Skal vi have flere krondyr?

    DEFF Research Database (Denmark)

    Pedersen, Jens Christian

    2008-01-01

    Vi kunne have væsentligt flere krondyr i den danske natur end vi har i øjeblikket. Den primære årsag er jagt. Det viser en ny undersøgelse fra Danmarks Miljøundersøgelser ved Aarhus Universitet. Bestanden af krondyr er ganske vist steget meget siden 1970, men der er både plads og føde til mange...

  19. Belavkin-Kolkoltsov watch-dog effects in interactively controlled stochastic computer-graphic dynamic systems a mathematical study

    CERN Document Server

    Juriev, D V

    1995-01-01

    Stochastic properties of the long-time behaviour of a continuously observed (and interactively controlled) quantum-field top are investigated mathematically. Applications to interactively controlled stochastic computer-graphic dynamic systems are discussed.

  20. Learning of embodied interaction dynamics with recurrent neural networks: some exploratory experiments

    Science.gov (United States)

    Oubbati, Mohamed; Kord, Bahram; Koprinkova-Hristova, Petia; Palm, Günther

    2014-04-01

    The new tendency of artificial intelligence suggests that intelligence must be seen as a result of the interaction between brains, bodies and environments. This view implies that designing sophisticated behaviour requires a primary focus on how agents are functionally coupled to their environments. Under this perspective, we present early results with the application of reservoir computing as an efficient tool to understand how behaviour emerges from interaction. Specifically, we present reservoir computing models, that are inspired by imitation learning designs, to extract the essential components of behaviour that results from agent-environment interaction dynamics. Experimental results using a mobile robot are reported to validate the learning architectures.

  1. Coherent Many-Body Spin Dynamics in a Long-Range Interacting Ising Chain

    DEFF Research Database (Denmark)

    Zeiher, Johannes; Choi, Jae-yoon; Rubio-Abadal, Antonio

    2017-01-01

    Coherent many-body quantum dynamics lies at the heart of quantum simulation and quantum computation. Both require coherent evolution in the exponentially large Hilbert space of an interacting many-body system. To date, trapped ions have defined the state of the art in terms of achievable coherence...... times in interacting spin chains. Here, we establish an alternative platform by reporting on the observation of coherent, fully interaction-driven quantum revivals of the magnetization in Rydberg-dressed Ising spin chains of atoms trapped in an optical lattice. We identify partialmany-body revivals...

  2. Molecular dynamics simulation of gas models of Lennard-Jones type interactions: Extensivity associated with interaction range and external noise

    Science.gov (United States)

    Kadijani, M. Nouri; Abbasi, H.; Nezamipour, S.

    2017-06-01

    Statistics of a two-dimensional gas model interacting through a Lennard-Jones type potential, is considered. The goal is to examine the extensivity of internal energy in respect to the potential range and external white noise through molecular dynamics simulation. Accordingly a molecular dynamics simulation model is designed that provides reasonable evidence, in this respect. It is shown that for the long range potential the internal energy scales according to non-extensive thermodynamics expectation and the criteria is specified. Besides, for the short range case we demonstrate that the external noise drastically modifies the statistics of gas and makes the internal energy non-extensive. The relation between the non-extensive parameter, q, and the relaxation time and the noise intensity is obtained.

  3. Molecular Dynamics Study on the Biophysical Interactions of Seven Green Tea Catechins with Cell Membranes

    Science.gov (United States)

    Molecular dynamics simulations were performed to study the interactions of bioactive catechins (flavonoids) commonly found in green tea with lipid bilayers, as model for cell membranes. Previously, a number of experimental studies rationalized catechin’s anticarcinogenic, antibacterial, and other be...

  4. Composite-meson--quark interactions under the condition of dynamical breaking of chiral symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, M.

    1989-03-01

    Starting from the QCD-inspired model Hamiltonian which can lead to the dynamical breakdown of chiral symmetry, we describe a vacuum consisting of a condensate of q-barq pairs and furthermore meson states and composite-meson field operators within the new Tamm-Dancoff approximation. Using these fields operators and the Hamiltonian we construct composite-meson--quark interactions.

  5. Phase 1 user instruction manual. A geological formation - drill string dynamic interaction finite element program (GEODYN)

    Energy Technology Data Exchange (ETDEWEB)

    Tinianow, M.A.; Rotelli, R.L. Jr.; Baird, J.A.

    1984-06-01

    User instructions for the GEODYN Interactive Finite Element Computer Program are presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit - Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates non-linear, time dependent, loading and boundary conditions.

  6. Geological formation - drill string dynamic interaction finite-element program (GEODYN). Phase 1. Theoretical description

    Energy Technology Data Exchange (ETDEWEB)

    Baird, J.A.; Apostal, M.C.; Rotelli, R.L. Jr.; Tinianow, M.A.; Wormley, D.N.

    1984-06-01

    The Theoretical Description for the GEODYN interactive finite-element computer program is presented. The program is capable of performing the analysis of the three-dimensional transient dynamic response of a Polycrystalline Diamond Compact Bit-Bit Sub arising from the intermittent contact of the bit with the downhole rock formations. The program accommodates nonlinear, time-dependent, loading and boundary conditions.

  7. Direction of Amygdala-Neocortex Interaction During Dynamic Facial Expression Processing.

    Science.gov (United States)

    Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Yoshikawa, Sakiko; Toichi, Motomi

    2017-03-01

    Dynamic facial expressions of emotion strongly elicit multifaceted emotional, perceptual, cognitive, and motor responses. Neuroimaging studies revealed that some subcortical (e.g., amygdala) and neocortical (e.g., superior temporal sulcus and inferior frontal gyrus) brain regions and their functional interaction were involved in processing dynamic facial expressions. However, the direction of the functional interaction between the amygdala and the neocortex remains unknown. To investigate this issue, we re-analyzed functional magnetic resonance imaging (fMRI) data from 2 studies and magnetoencephalography (MEG) data from 1 study. First, a psychophysiological interaction analysis of the fMRI data confirmed the functional interaction between the amygdala and neocortical regions. Then, dynamic causal modeling analysis was used to compare models with forward, backward, or bidirectional effective connectivity between the amygdala and neocortical networks in the fMRI and MEG data. The results consistently supported the model of effective connectivity from the amygdala to the neocortex. Further increasing time-window analysis of the MEG demonstrated that this model was valid after 200 ms from the stimulus onset. These data suggest that emotional processing in the amygdala rapidly modulates some neocortical processing, such as perception, recognition, and motor mimicry, when observing dynamic facial expressions of emotion. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. On the role of inter-nucleosomal interactions and intrinsic nucleosome dynamics in chromatin function

    Directory of Open Access Journals (Sweden)

    Wladyslaw A. Krajewski

    2016-03-01

    Full Text Available Evidence is emerging that many diseases result from defects in gene functions, which, in turn, depend on the local chromatin environment of a gene. However, it still remains not fully clear how chromatin activity code is ‘translated’ to the particular ‘activating’ or ‘repressing’ chromatin structural transition. Commonly, chromatin remodeling in vitro was studied using mononucleosomes as a model. However, recent data suggest that structural reorganization of a single mononucleosome is not equal to remodeling of a nucleosome particle under multinucleosomal content – such as, interaction of nucleosomes via flexible histone termini could significantly alter the mode (and the resulting products of nucleosome structural transitions. It is becoming evident that a nucleosome array does not constitute just a ‘polymer’ of individual ‘canonical’ nucleosomes due to multiple inter-nucleosomal interactions which affect nucleosome dynamics and structure. It could be hypothesized, that inter-nucleosomal interactions could act in cooperation with nucleosome inherent dynamics to orchestrate DNA-based processes and promote formation and stabilization of highly-dynamic, accessible structure of a nucleosome array. In the proposed paper we would like to discuss the nucleosome dynamics within the chromatin fiber mainly as it pertains to the roles of the structural changes mediated by inter-nucleosomal interactions.

  9. q-entropies and the entanglement dynamics of two-qubits interacting with an environment

    OpenAIRE

    Hamadou-Ibrahim, A.; Plastino, A. R.; Plastino, A.

    2009-01-01

    We investigate entropic aspects of the quantum entanglement dynamics of two-qubits systems interacting with an environment. In particular we consider the detection, based on the violation of classical entropic inequalities involving q-entropies, of the phenomenon of entanglement disappearance and subsequent entanglement revival during the alluded two-qubits' evolution.

  10. Towards Ultrafast Communications: Nonlinear Coupling Dynamics and Light-Semiconductor Interaction

    NARCIS (Netherlands)

    Wang, W.

    2007-01-01

    This thesis deals with some specific problems concerning the processing of ultrashort optical pulses and their interaction with semiconductors. It includes the investigation of the ultrashort optical pulse propagation and coupling dynamics in the nonlinear coupled waveguide, and the coherent and

  11. Interaction between Humic Acid and Lysozyme, Studied by Dynamic Light Scattering and Isothermal Titration Calorimetry

    NARCIS (Netherlands)

    Tan, Wen Feng; Koopal, Luuk K.; Norde, Willem

    2009-01-01

    Interactions of purified Aldrich humic acid (PAHA) with the protein lysozyme (LSZ) are studied with dynamic light scattering and isothermal titration calorimetry by mixing LSZ and PAHA at various mass ratios. In solution LSZ is positive and PAHA is negative at the investigated pH values. Up to

  12. Longitudinal analysis of flexibility and reorganization in early adolescence: A dynamic systems study of family interactions

    NARCIS (Netherlands)

    Granic, I.; Hollenstein, T.P.; Dishion, T.J.; Patterson, G.R.

    2003-01-01

    A dynamic systems (DS) approach was used to study changes in the structure of family interactions during the early adolescent transition period. Longitudinal observational data were collected in 5 waves prior to, during, and after the transition. Boys (n = 149 families) were videotaped problem

  13. Interaction-Dominant Dynamics in Human Cognition: Beyond 1/f[superscript [alpha

    Science.gov (United States)

    Ihlen, Espen A. F.; Vereijken, Beatrix

    2010-01-01

    It has been suggested that human behavior in general and cognitive performance in particular emerge from coordination between multiple temporal scales. In this article, we provide quantitative support for such a theory of interaction-dominant dynamics in human cognition by using wavelet-based multifractal analysis and accompanying multiplicative…

  14. Dynamic dipole-dipole interactions between excitons in quantum dots of different sizes

    DEFF Research Database (Denmark)

    Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

    2004-01-01

    A model of the resonance dynamic dipole-dipole interaction between excitons confined in quantum dots (QDs) of different sizes at close enough distance is given in terms of parity inheritance and exchange of virtual photons. Microphotoluminescence spectra of GaAs-AlGaAs coupled QDs are proposed to...

  15. Phonon-Magnon Interaction in Low Dimensional Quantum Magnets Observed by Dynamic Heat Transport Measurements

    NARCIS (Netherlands)

    Montagnese, Matteo; Otter, Marian; Zotos, Xenophon; Fishman, Dmitry A.; Hlubek, Nikolai; Mityashkin, Oleg; Hess, Christian; Saint-Martin, Romuald; Singh, Surjeet; Revcolevschi, Alexandre; van Loosdrecht, Paul H. M.

    2013-01-01

    Thirty-five years ago, Sanders and Walton [Phys. Rev. B 15, 1489 (1977)] proposed a method to measure the phonon-magnon interaction in antiferromagnets through thermal transport which so far has not been verified experimentally. We show that a dynamical variant of this approach allows direct

  16. Atomic force microscopy cantilever dynamics in liquid in the presence of tip sample interaction

    NARCIS (Netherlands)

    de Beer, Sissi; van den Ende, Henricus T.M.; Mugele, Friedrich

    2008-01-01

    We analyze the dynamics of an atomic force microscopy (AFM) cantilever oscillating in liquid at subnanometer amplitude in the presence of tip-sample interaction. We present AFM measurements of oscillatory solvation forces for octamethylcyclotetrasiloxane on highly oriented pyrolitic graphite and

  17. Distributed Hardware-in-the-loop simulator for autonomous continuous dynamical systems with spatially constrained interactions

    NARCIS (Netherlands)

    Verburg, D.J.; Papp, Z.; Dorrepaal, M.

    2003-01-01

    The state-of-the-art intelligent vehicle, autonomous guided vehicle and mobile robotics application domains can be described as collection of interacting highly autonomous complex dynamical systems. Extensive formal analysis of these systems – except special cases – is not feasible, consequently the

  18. The Use of Dynamic Mathematics Software and Interactive Whiteboard Technology in Mathematics Teaching

    Directory of Open Access Journals (Sweden)

    Enver Tatar

    2013-11-01

    Full Text Available The aim of this study is to determine preservice mathematics teachers’ opinions regarding the use of a dynamic software and interactive whiteboard technology in mathematics teaching. The research was conducted with 34 preservice teachers who were studying on secondary mathematics teaching program of a state university in Turkey. Case study, which is among the qualitative research approaches, was used in the research. “Semi-structured interview technique” and “opinion form” were used as data collection tools. Content analysis was used in analyzing the obtained qualitative data. At the end of the study, preservice teachers emphasized that dynamic mathematics software and interactive whiteboard technology contributed to giving courses via visualization and allowed for learning topics in an interesting learning environment. Furthermore, it was stated that dynamic mathematics software and interactive whiteboard technology must be used in mathematics teaching due to their advantages, such as the fact that their collective use contributes to the concretization of the subjects, increases retention, facilitates understanding concepts and saves time.Key Words: Dynamic mathematics software, interactive whiteboard, mathematics teaching, preservice teachers

  19. Chaotic dynamics of Heisenberg ferromagnetic spin chain with bilinear and biquadratic interactions

    Science.gov (United States)

    Blessy, B. S. Gnana; Latha, M. M.

    2017-10-01

    We investigate the chaotic dynamics of one dimensional Heisenberg ferromagnetic spin chain by constructing the Hamiltonian equations of motion. We present the trajectory and phase plots of the system with bilinear and also biquadratic interactions. The stability of the system is analysed in both cases by constructing the Jacobian matrix and by measuring the Lyapunov exponents. The results are illustrated graphically.

  20. Controlled initiation and quantitative visualization of cell interaction dynamics - a novel hybrid microscopy method -

    NARCIS (Netherlands)

    Snijder-van As, M.I.

    2010-01-01

    This thesis describes the development, validation, and application of a hybrid microscopy technique to study cell-substrate and cell-cell interactions in a controlled and quantitative manner. We studied the spatial and temporal dynamics of the selected membrane molecules CD6 and the activated

  1. The role of specific interactions on dynamical processes in a room ...

    Indian Academy of Sciences (India)

    This article describes our ongoing efforts to comprehend the role of specific interactions on the dynamical processes such as rotational diffusion and photoisomerization in a typical room temperature ionic liquid. Rotational diffusion studies carried out with a pair of structurally similar non-dipolar solutes indicate that organic ...

  2. A molecular dynamics study on the interaction between epoxy and functionalized graphene sheets

    DEFF Research Database (Denmark)

    Melro, Liliana Sofia S. F. P.; Pyrz, Ryszard; Jensen, Lars Rosgaard

    2016-01-01

    The interaction between graphene and epoxy resin was studied using molecular dynamics simulations. The interfacial shear strength and pull out force were calculated for functionalised graphene layers (carboxyl, carbonyl, and hydroxyl) and epoxy composites interfaces. The influence of functional...... and epoxy resin increases....

  3. Interactive and dynamic visualizations in teaching and learning of anatomy: A cognitive load perspective.

    NARCIS (Netherlands)

    Khalil, M.K.; Paas, Fred; Johnson, T.E.; Payer, A.F.

    2007-01-01

    With the increasing use of computers in the classroom and the advancement of information technology, a requirement to investigate and evaluate different strategies for the presentation of verbal information in interactive and dynamic visualizations has risen to a high level of importance. There is a

  4. The dynamics of meaningful social interactions and the emergence of collective knowledge.

    Science.gov (United States)

    Dankulov, Marija Mitrović; Melnik, Roderick; Tadić, Bosiljka

    2015-07-15

    Collective knowledge as a social value may arise in cooperation among actors whose individual expertise is limited. The process of knowledge creation requires meaningful, logically coordinated interactions, which represents a challenging problem to physics and social dynamics modeling. By combining two-scale dynamics model with empirical data analysis from a well-known Questions &Answers system Mathematics, we show that this process occurs as a collective phenomenon in an enlarged network (of actors and their artifacts) where the cognitive recognition interactions are properly encoded. The emergent behavior is quantified by the information divergence and innovation advancing of knowledge over time and the signatures of self-organization and knowledge sharing communities. These measures elucidate the impact of each cognitive element and the individual actor's expertise in the collective dynamics. The results are relevant to stochastic processes involving smart components and to collaborative social endeavors, for instance, crowdsourcing scientific knowledge production with online games.

  5. The dynamics of meaningful social interactions and the emergence of collective knowledge

    Science.gov (United States)

    Dankulov, Marija Mitrović; Melnik, Roderick; Tadić, Bosiljka

    2015-07-01

    Collective knowledge as a social value may arise in cooperation among actors whose individual expertise is limited. The process of knowledge creation requires meaningful, logically coordinated interactions, which represents a challenging problem to physics and social dynamics modeling. By combining two-scale dynamics model with empirical data analysis from a well-known Questions & Answers system Mathematics, we show that this process occurs as a collective phenomenon in an enlarged network (of actors and their artifacts) where the cognitive recognition interactions are properly encoded. The emergent behavior is quantified by the information divergence and innovation advancing of knowledge over time and the signatures of self-organization and knowledge sharing communities. These measures elucidate the impact of each cognitive element and the individual actor’s expertise in the collective dynamics. The results are relevant to stochastic processes involving smart components and to collaborative social endeavors, for instance, crowdsourcing scientific knowledge production with online games.

  6. Molecular dynamics simulations of membrane proteins and their interactions: from nanoscale to mesoscale.

    Science.gov (United States)

    Chavent, Matthieu; Duncan, Anna L; Sansom, Mark Sp

    2016-10-01

    Molecular dynamics simulations provide a computational tool to probe membrane proteins and systems at length scales ranging from nanometers to close to a micrometer, and on microsecond timescales. All atom and coarse-grained simulations may be used to explore in detail the interactions of membrane proteins and specific lipids, yielding predictions of lipid binding sites in good agreement with available structural data. Building on the success of protein-lipid interaction simulations, larger scale simulations reveal crowding and clustering of proteins, resulting in slow and anomalous diffusional dynamics, within realistic models of cell membranes. Current methods allow near atomic resolution simulations of small membrane organelles, and of enveloped viruses to be performed, revealing key aspects of their structure and functionally important dynamics. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  7. Discrete states of a protein interaction network govern interphase and mitotic microtubule dynamics.

    Directory of Open Access Journals (Sweden)

    Philipp Niethammer

    2007-02-01

    Full Text Available The cytoplasm of eukaryotic cells is thought to adopt discrete "states" corresponding to different steady states of protein networks that govern changes in subcellular organization. For example, in Xenopus eggs, the interphase to mitosis transition is induced solely by activation of cyclin-dependent kinase 1 (CDK1 that phosphorylates many proteins leading to a reorganization of the nucleus and assembly of the mitotic spindle. Among these changes, the large array of stable microtubules that exists in interphase is replaced by short, highly dynamic microtubules in metaphase. Using a new visual immunoprecipitation assay that quantifies pairwise protein interactions in a non-perturbing manner in Xenopus egg extracts, we reveal the existence of a network of interactions between a series of microtubule-associated proteins (MAPs. In interphase, tubulin interacts with XMAP215, which is itself interacting with XKCM1, which connects to APC, EB1, and CLIP170. In mitosis, tubulin interacts with XMAP215, which is connected to EB1. We show that in interphase, microtubules are stable because the catastrophe-promoting activity of XKCM1 is inhibited by its interactions with the other MAPs. In mitosis, microtubules are short and dynamic because XKCM1 is free and has a strong destabilizing activity. In this case, the interaction of XMAP215 with EB1 is required to counteract the strong activity of XKCM1. This provides the beginning of a biochemical description of the notion of "cytoplasmic states" regarding the microtubule system.

  8. Effects of biotic and abiotic factors on the temporal dynamic of bat-fruit interactions

    Science.gov (United States)

    Laurindo, Rafael de Souza; Gregorin, Renato; Tavares, Davi Castro

    2017-08-01

    Mutualistic interactions between animals and plants vary over time and space based on the abundance of fruits or animals and seasonality. Little is known about this temporal dynamic and the influence of biotic and abiotic factors on the structure of interaction networks. We evaluated changes in the structure of network interactions between bats and fruits in relation to variations in rainfall. Our results suggest that fruit abundance is the main variable responsible for temporal changes in network attributes, such as network size, connectance, and number of interactions. In the same way, temperature positively affected the abundance of fruits and bats. An increase in temperature and alterations in rainfall patterns, due to human induced climate change, can cause changes in phenological patterns and fruit production, with negative consequences to biodiversity maintenance, ecological interactions, and ecosystem functioning.

  9. Molecular dynamics simulation of the interaction between protein tyrosine phosphatase 1B and aryl diketoacid derivatives.

    Science.gov (United States)

    Wang, Qiang; Gao, Jun; Liu, Yongjun; Liu, Chengbu

    2012-09-01

    The protein tyrosine phosphatase 1B (PTP-1B) is acknowledged as an outstanding therapeutic target for the treatment of diabetes, obesity and cancer. In this work, six aryl diketoacid compounds have been studied on the basis of molecular dynamics simulations. Hydrogen bonds, binding energies and conformation changes of the WPD loop have been analyzed. The results indicated that their activation model falls into two parts: the target region of the monomeric aryl diketoacid compounds is the active site, whereas the target region of the dimeric aryl diketoacid compounds is the WPD loop or the R loop. The van der Waals interactions exhibit stronger effects than the short-range electrostatic interactions. The van der Waals interaction energy and the IC50 values exhibit an approximately exponential relationship. Furthermore, the van der Waals interactions cooperate with the hydrogen bond interactions. This study provides a more thorough understanding of the PTP-1B inhibitor binding processes. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Dynamics of Moment Neuronal Networks with Intra- and Inter-Interactions

    Directory of Open Access Journals (Sweden)

    Xuyan Xiang

    2015-01-01

    Full Text Available A framework of moment neuronal networks with intra- and inter-interactions is presented. It is to show how the spontaneous activity is propagated across the homogeneous and heterogeneous network. The input-output firing relationship and the stability are first explored for a homogeneous network. For heterogeneous network without the constraint of the correlation coefficients between neurons, a more sophisticated dynamics is then explored. With random interactions, the network gets easily synchronized. However, desynchronization is produced by a lateral interaction such as Mexico hat function. It is the external intralayer input unit that offers a more sophisticated and unexpected dynamics over the predecessors. Hence, the work further opens up the possibility of carrying out a stochastic computation in neuronal networks.

  11. Isobaric first-principles molecular dynamics of liquid water with nonlocal van der Waals interactions

    CERN Document Server

    Miceli, Giacomo; Pasquarello, Alfredo

    2016-01-01

    We investigate the structural properties of liquid water at near ambient conditions using first-principles molecular dynamics simulations based on a semilocal density functional augmented with nonlocal van der Waals interactions. The adopted scheme offers the advantage of simulating liquid water at essentially the same computational cost of standard semilocal functionals. Applied to the water dimer and to ice Ih, we find that the hydrogen-bond energy is only slightly enhanced compared to a standard semilocal functional. We simulate liquid water through molecular dynamics in the NpH statistical ensemble allowing for fluctuations of the system density. The structure of the liquid departs from that found with a semilocal functional leading to more compact structural arrangements. This indicates that the directionality of the hydrogen-bond interaction has a diminished role as compared to the overall attractions, as expected when dispersion interactions are accounted for. This is substantiated through a detailed a...

  12. Dynamics of Entanglement in Qubit-Qutrit with x-Component of DM Interaction

    Science.gov (United States)

    Sharma, Kapil K.; Pandey, S. N.

    2016-03-01

    In this present paper, we study the entanglement dynamics in qubit A-qutrit B pair under x component of Dzyaloshinshkii-Moriya interaction (Dx) by taking an auxiliary qubit C. Here, we consider an entangled qubit-qutrit pair initially prepared in two parameter qubit-qutrit states and one auxiliary qubit prepared in pure state interacts with the qutrit of the pair through DM interaction. We trace away the auxiliary qubit and calculate the reduced dynamics in qubit A-qutrit B pair to study the influence of the state of auxiliary qubit C and Dx on entanglement. We find that the state (probability amplitude) of auxiliary qubit does not influence the entanglement, only Dx influences the same. The phenomenon of entanglement sudden death (ESD) induced by Dx has also been observed. We also present the affected and unaffected two parameter qubit-qutrit states by Dx.

  13. Neighborhood structure effects on the Dynamic response of soil-structure interaction by harmonic analysis

    Directory of Open Access Journals (Sweden)

    Pan Dan-guang

    2015-01-01

    Full Text Available For realizing the variation of structural dynamic characteristics due to neighbor structure in buildings group, the surface structure is idealized as an equivalent single degree of freedom system with rigid base whose site consists of a single homogeneous layer. Based on the model, a equivalent method on the equivalent seismic excitation is proposed. Then, the differences of seismic response and equivalent seismic input between soil - structure interaction (SSI system and structure -soil-structure interaction (SSSI system are investigated by harmonic analysis. The numerical results show that dynamic responses would be underestimated in SSSI system when the forcing frequencies are close to the Natural frequency if the effects of neighborhood structure were ignored. Neighborhood structure would make the translational displacement increase and rocking vibration decrease. When establishing an effective seismic input, it is necessary to consider the impact of inertia interaction.

  14. U(VI) reduction at the nano, meso and meter scale: concomitant transition from simpler to more complex biogeochemical processes

    Science.gov (United States)

    Veeramani, H.; Hochella, M. F.

    2012-12-01

    Reduction of aqueous hexavalent U(VI) to the sparingly soluble nanoparticulate mineral uraninite [UO2] represents a promising strategy for the in situ immobilization of uranium in contaminated subsurface sediments and groundwater. Studies related to uranium reduction have been extensively carried out at various scales ranging from nano to meso to the meter scale with varying degrees of success. While nanoscale processes involving simple two-electron transfer reactions such as enzymatic microbial U(VI) reduction results in biogenic UO2 formation, mesoscale processes involving minerals and U(VI) are a step up in complexity and have shown varying results ranging from partial uranium reduction to the formation of mixed U(IV)/U(V) species. Although nano- and meso-scale biogeochemical processes have been helpful in predicting the contaminant dynamics at the meter scale, their occurrence is not necessarily apparent in soils and aquifers given the enormous volume of contaminated groundwater to be remediated, among other factors. The formation and long-term stability of biologically reduced uranium at the meter scale is also determined in addition by the complex interplay of aqueous geochemistry, hydrology, soil and sediment mineralogy and microbial community dynamics. For instance, indigenous subsurface microbes often encounter multiple electron acceptors in heterogeneous environments during biostimulation and can catalyze the formation of various reactive biogenic minerals. In such cases, abiotic interactions between U(VI) and reactive biogenic minerals is potentially important because the success of a remediation strategy is contingent upon the speciation of reduced uranium. This presentation will give an overview of uranium reduction ranging from simple nanoscale biological processes to increasingly complex meso and meter scale processes involving abiotic interactions between aqueous uranium and nano-biogenic minerals and the effect of mineralogy and aqueous

  15. Monitoring peptide-surface interaction by means of molecular dynamics simulation

    Energy Technology Data Exchange (ETDEWEB)

    Nonella, Marco, E-mail: mnonella@pci.uzh.ch [Physikalisch-Chemisches Institut, Universitaet Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland); Seeger, Stefan, E-mail: sseeger@pci.uzh.ch [Physikalisch-Chemisches Institut, Universitaet Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland)

    2010-12-09

    Graphical abstract: Protein-surface interactions play a crucial role in a wide field of research areas like biology, biotechnology, or pharmacology. Only recently, it has been shown that not only peptide adsorption represents an important process but also spreading and clustering of adsorbed proteins. By means of classical molecular dynamics, peptide adsorption as well as the dynamics of adsorbed peptides have been investigated in order to gain deeper insight into such processes. The picture shows a snapshot of an adsorbed peptide on a silica surface showing strong direct hydrogen bonding. Research highlights: {yields} Simulation of peptide surface interaction. {yields} Dynamics of hydrogen bond formation and destruction. {yields} Internal flexibility of adsorbed peptides. - Abstract: Protein adsorption and protein surface interactions have become an important research topic in recent years. Very recently, for example, it has been shown that protein clusters can undergo a surface-induced spreading after adsorption. Such phenomena emphasize the need of a more detailed insight into protein-silica interaction at an atomic level. Therefore, we have studied a model system consisting of a short peptide, a silica slab, and water molecules by means of classical molecular dynamics simulations. The study reveals that, besides of electrostatic interactions caused by the chosen charge distribution, the peptide interacts with the silica surface through formation of direct peptide-surface hydrogen bonds as well as indirect peptide-water-surface hydrogen bonds. The number of created hydrogen bonds varies considerably among the simulated structures. The strength of hydrogen bonding determines the mobility of the peptide on the surface and the internal flexibility of the adsorbed peptide.

  16. Entanglement dynamics in two-parameter qubit-qutrit states under Dzyaloshinskii-Moriya interaction

    Science.gov (United States)

    Sharma, Kapil K.; Pandey, S. N.

    2014-09-01

    We study entanglement dynamics in two-parameter qubit-qutrit states under the influence of Dzyaloshisnhkii-Moriya (DM) interaction. Our system consists of a qubit-qutrit pair as a closed system initially in two-parameter class of states, and one environmental qubit interacts with the qutrit of the closed system via DM interaction. We divide our analysis into two cases. In the first case, we study the entanglement dynamics in separable region, and in the second case we study the same in non-separable region. The DM interaction produces the entanglement in separable region with entanglement sudden death (ESD) and some states in this region remain unaffected by the same. In non-separable region, all the states are affected by DM interaction. The DM interaction excites the entanglement but does not produce ESD in this region. We observed that probability amplitude of environmental qubit does not affect the entanglement in two-parameter qubit-qutrit states in both the regions.

  17. Dynamically analyzing cell interactions in biological environments using multiagent social learning framework.

    Science.gov (United States)

    Zhang, Chengwei; Li, Xiaohong; Li, Shuxin; Feng, Zhiyong

    2017-09-20

    Biological environment is uncertain and its dynamic is similar to the multiagent environment, thus the research results of the multiagent system area can provide valuable insights to the understanding of biology and are of great significance for the study of biology. Learning in a multiagent environment is highly dynamic since the environment is not stationary anymore and each agent's behavior changes adaptively in response to other coexisting learners, and vice versa. The dynamics becomes more unpredictable when we move from fixed-agent interaction environments to multiagent social learning framework. Analytical understanding of the underlying dynamics is important and challenging. In this work, we present a social learning framework with homogeneous learners (e.g., Policy Hill Climbing (PHC) learners), and model the behavior of players in the social learning framework as a hybrid dynamical system. By analyzing the dynamical system, we obtain some conditions about convergence or non-convergence. We experimentally verify the predictive power of our model using a number of representative games. Experimental results confirm the theoretical analysis. Under multiagent social learning framework, we modeled the behavior of agent in biologic environment, and theoretically analyzed the dynamics of the model. We present some sufficient conditions about convergence or non-convergence and prove them theoretically. It can be used to predict the convergence of the system.

  18. Arid landscape dynamics along a precipitation gradient: addressing vegetation - landscape structure - resource interactions at different time scales

    NARCIS (Netherlands)

    Buis, E.

    2008-01-01

    This research is entitled ‘Arid landscape dynamics along a precipitation gradient: addressing vegetation – landscape structure – resource interactions at different time scales’ with as subtitle ‘A case study for the Northern Negev Desert of Israel’. Landscape dynamics describes the interactions

  19. Dynamics and thermodynamics of systems with long-range dipole-type interactions.

    Science.gov (United States)

    Atenas, Boris; Curilef, Sergio

    2017-02-01

    A Hamiltonian mean field model, where the potential is inspired by dipole-dipole interactions, is proposed to characterize the behavior of systems with long-range interactions. The dynamics of the system remains in quasistationary states before arriving at equilibrium. The equilibrium is analytically derived from the canonical ensemble and coincides with that obtained from molecular dynamics simulations (microcanonical ensemble) at only long time scales. The dynamics of the system is characterized by the behavior of the mean value of the kinetic energy. The significance of the results, compared to others in the recent literature, is that two plateaus sequentially emerge in the evolution of the model under the special considerations of the initial conditions and systems of finite size. The first plateau decays to a different second one before the system reaches equilibrium, but the dynamics of the system is expected to have only one plateau when the thermodynamics limit is reached because the difference between them tends to disappear as N tends to infinity. Hence, the first plateau is a type of quasistationary state the lifetime of which depends on a power law of N and the second seems to be a true quasistationary state as reported in the literature. We characterize the general behavior of the model according to its dynamics and thermodynamics.

  20. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Qian [Iowa State Univ., Ames, IA (United States)

    2008-01-01

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  1. Human-Structure Dynamic Interaction during Short-Distance Free Falls

    Directory of Open Access Journals (Sweden)

    E. Shahabpoor

    2016-01-01

    Full Text Available The dynamic interactions of falling human bodies with civil structures, regardless of their potentially critical effects, have sparsely been researched in contact biomechanics. The physical contact models suggested in the existing literature, particularly for short-distant falls in home settings, assume the human body falls on a “rigid” (not vibrating ground. A similar assumption is usually made during laboratory-based fall tests, including force platforms. Based on observations from a set of pediatric head-first free fall tests, the present paper shows that the dynamics of the grounded force plate are not always negligible when doing fall test in a laboratory setting. By using a similar analogy for lightweight floor structures, it is shown that ignoring the dynamics of floors in the contact model can result in an up to 35% overestimation of the peak force experienced by a falling human. A nonlinear contact model is suggested, featuring an agent-based modelling approach, where the dynamics of the falling human and the impact object (force plate or a floor structure here are each modelled using a single-degree-of-freedom model to simulate their dynamic interactions. The findings of this research can have wide applications in areas such as impact biomechanics and sports science.

  2. Discourse-voice regulatory strategies in the psychotherapeutic interaction: a state-space dynamics analysis.

    Science.gov (United States)

    Tomicic, Alemka; Martínez, Claudio; Pérez, J Carola; Hollenstein, Tom; Angulo, Salvador; Gerstmann, Adam; Barroux, Isabelle; Krause, Mariane

    2015-01-01

    This study seeks to provide evidence of the dynamics associated with the configurations of discourse-voice regulatory strategies in patient-therapist interactions in relevant episodes within psychotherapeutic sessions. Its central assumption is that discourses manifest themselves differently in terms of their prosodic characteristics according to their regulatory functions in a system of interactions. The association between discourse and vocal quality in patients and therapists was analyzed in a sample of 153 relevant episodes taken from 164 sessions of five psychotherapies using the state space grid (SSG) method, a graphical tool based on the dynamic systems theory (DST). The results showed eight recurrent and stable discourse-voice regulatory strategies of the patients and three of the therapists. Also, four specific groups of these discourse-voice strategies were identified. The latter were interpreted as regulatory configurations, that is to say, as emergent self-organized groups of discourse-voice regulatory strategies constituting specific interactional systems. Both regulatory strategies and their configurations differed between two types of relevant episodes: Change Episodes and Rupture Episodes. As a whole, these results support the assumption that speaking and listening, as dimensions of the interaction that takes place during therapeutic conversation, occur at different levels. The study not only shows that these dimensions are dependent on each other, but also that they function as a complex and dynamic whole in therapeutic dialog, generating relational offers which allow the patient and the therapist to regulate each other and shape the psychotherapeutic process that characterizes each type of relevant episode.

  3. Modeling multiple communities of interest for interactive simulation and gaming: the dynamic adversarial gaming algorithm project

    Science.gov (United States)

    Santos, Eugene, Jr.; Zhao, Qunhua; Pratto, Felicia; Pearson, Adam R.; McQueary, Bruce; Breeden, Andy; Krause, Lee

    2007-04-01

    Nowadays, there is an increasing demand for the military to conduct operations that are beyond traditional warfare. In these operations, analyzing and understanding those who are involved in the situation, how they are going to behave, and why they behave in certain ways is critical for success. The challenge lies in that behavior does not simply follow universal/fixed doctrines; it is significantly influenced by soft factors (i.e. cultural factors, societal norms, etc.). In addition, there is rarely just one isolated enemy; the behaviors and responses of all groups in the region, and the dynamics of the interaction among them composes an important part of the whole picture. The Dynamic Adversarial Gaming Algorithm (DAGA) project aims to provide a wargaming environment for automation of simulating dynamics of geopolitical crisis and eventually be applied to military simulation and training domain, and/or commercial gaming arena. The focus of DAGA is on modeling communities of interest (COIs), where various individuals, groups, and organizations as well as their interactions are captured. The framework should provide a context for COIs to interact with each other and influence others' behaviors. These behaviors must incorporate soft factors by modeling cultural knowledge. We do so by representing cultural variables and their influence on behavior using probabilistic networks. In this paper, we describe our COI modeling, the development of cultural networks, the interaction architecture, and a prototype of DAGA.

  4. Dynamic investigation of PEFC stacks in interaction with the air supply system

    Science.gov (United States)

    Philipps, F.; Simons, G.; Schiefer, K.

    This paper explores the behaviour of a dynamically operated fuel cell system regarding to an automotive application, examining the air supply and their interaction with the fuel cell stacks. The dynamic limits of stack operation are also discussed. Finally, the paper provides a description of the test facility used in these investigations. The research of dynamically operated fuel cell stacks shows that in order to achieve high energy efficiency, a power-dependent modulation of the pressure and flow rate of the air supply is necessary. A test facility designed for energy management and power train research (up to 42 kW) was used for the experiment. A number of 11.5 kW fuel cell stacks was examined experimentally with respect to performance in interaction with the air supply in stationary and dynamic operation. The stacks were tested individually and in parallel. All of them were operated "dead-end" on the hydrogen side. Experimental results varying the parameters and load curves applied to the air supply system are given in the paper. The results show different dynamic behaviours between the stacks and a substantial difference in efficiency and dynamic response of the fuel cell system operated with different strategies. The results of different operating strategies for fuel cell systems, with respect to the interaction between the fuel cell stack and the air supply and in their dependency on air mass flow and pressure level are presented. The examinations were done with the test facility using real current demand profile of the experimental car HyLite ® from zero to full load and the New European Drive Cycle (NEDC).

  5. On the Convergence of Piecewise Linear Strategic Interaction Dynamics on Networks

    KAUST Repository

    Gharesifard, Bahman

    2015-09-11

    We prove that the piecewise linear best-response dynamical systems of strategic interactions are asymptotically convergent to their set of equilibria on any weighted undirected graph. We study various features of these dynamical systems, including the uniqueness and abundance properties of the set of equilibria and the emergence of unstable equilibria. We also introduce the novel notions of social equivalence and social dominance on directed graphs, and demonstrate some of their interesting implications, including their correspondence to consensus and chromatic number of partite graphs. Examples illustrate our results.

  6. Mass spectrometry in structural biology and biophysics architecture, dynamics, and interaction of biomolecules

    CERN Document Server

    Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M

    2012-01-01

    The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol

  7. New approach in modeling Cr(VI) sorption onto biomass from metal binary mixtures solutions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chang [College of Environmental Science and Engineering, Anhui Normal University, South Jiuhua Road, 189, 241002 Wuhu (China); Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Fiol, Núria [Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Villaescusa, Isabel, E-mail: Isabel.Villaescusa@udg.edu [Chemical Engineering Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain); Poch, Jordi [Applied Mathematics Department, Escola Politècnica Superior, Universitat de Girona, Ma Aurèlia Capmany, 61, 17071 Girona (Spain)

    2016-01-15

    In the last decades Cr(VI) sorption equilibrium and kinetic studies have been carried out using several types of biomasses. However there are few researchers that consider all the simultaneous processes that take place during Cr(VI) sorption (i.e., sorption/reduction of Cr(VI) and simultaneous formation and binding of reduced Cr(III)) when formulating a model that describes the overall sorption process. On the other hand Cr(VI) scarcely exists alone in wastewaters, it is usually found in mixtures with divalent metals. Therefore, the simultaneous removal of Cr(VI) and divalent metals in binary mixtures and the interactive mechanism governing Cr(VI) elimination have gained more and more attention. In the present work, kinetics of Cr(VI) sorption onto exhausted coffee from Cr(VI)–Cu(II) binary mixtures has been studied in a stirred batch reactor. A model including Cr(VI) sorption and reduction, Cr(III) sorption and the effect of the presence of Cu(II) in these processes has been developed and validated. This study constitutes an important advance in modeling Cr(VI) sorption kinetics especially when chromium sorption is in part based on the sorbent capacity of reducing hexavalent chromium and a metal cation is present in the binary mixture. - Highlights: • A kinetic model including Cr(VI) reduction, Cr(VI) and Cr(III) sorption/desorption • Synergistic effect of Cu(II) on Cr(VI) elimination included in the model • Model validation by checking it against independent sets of data.

  8. Dynamics of audio-visual interactions in the guinea pig brain: an electrophysiological study.

    Science.gov (United States)

    Demirtas, Serdar; Goksoy, Cuneyt

    2003-11-14

    Audio-visual interactions and their specifications, evaluated by bioelectrical activities, in guinea pigs are presented in this study. The difference potential, as the evidence of an interaction, was calculated by subtracting the sum of averaged potentials recorded in visual and auditory events from the averaged potential recorded in an event where two stimuli combined in the same sweep. Dynamic investigations have shown an interaction when auditory stimulus is applied 24 ms before and 201 ms after visual stimulation. Latency between the difference potential and auditory stimulus was stable. Directional investigations have shown that the interaction is not observed when auditory and/or visual stimulation is used ipsilaterally, according to the recording side.

  9. Interactions between proteins and poly(ethylene-glycol) investigated using molecular dynamics simulations

    Science.gov (United States)

    Settanni, Giovanni; Zhou, Jiajia; Schmid, Friederike

    2017-11-01

    Poly(ethylene-glycol) (PEG) is a polymer used to coat therapeutic preparations, like drugs or drug nanocarriers, and improve their efficacy. This effect is probably due to a reduction of the interactions of the coated species with the host organism. Nevertheless, experiments show that PEGylated materials do interact with the surrounding biological milieu, and in particular with blood proteins. Here, we use atomistic molecular dynamics simulations to characterize the interactions between the polymer and several blood proteins. In these simulations, the proteins are immersed in a mixture of PEG and water molecules. We observe how PEG distributes around the protein surface and measure PEG-protein interactions in terms of preferential binding coefficients.

  10. Panel Discussion Vi: Cosmology

    Science.gov (United States)

    Anderson, E.; Dolgov, A.; Crothers, S.; Mitra, A.; Rubakov, V.; Zakharov, A.

    2014-03-01

    Questions to discuss: * To what extent are Dark Matter and Dark Energy necessary to explain the observed properties of the Universe? * Why are the Dark matter profiles so universal at the galactic scales? * Are there viable candidates of modified gravitational dynamics to exclude the dark components of Universe? * Do we have any perspectives to distinguish the Dark Energy from the cosmological constant? * Are there any certain indications for sterile neutrinos in the cosmos? * How does the Planck data change the view of inflation in the early Universe? What could be the origin of the inflaton plateau? So far, what else is interesting about the Planck data? * What are the nearest crucial points in cosmological observations? * Can we be more decisive discriminating between the anthropic principle, the superstringy landscape, fine tuning or dynamics as reasons for the cosmological coincidences?

  11. Molecular dynamics simulations of GPCR-cholesterol interaction: An emerging paradigm.

    Science.gov (United States)

    Sengupta, Durba; Chattopadhyay, Amitabha

    2015-09-01

    G protein-coupled receptors (GPCRs) are the largest class of molecules involved in signal transduction across cell membranes and represent major targets in the development of novel drug candidates. Membrane cholesterol plays an important role in GPCR structure and function. Molecular dynamics simulations have been successful in exploring the effect of cholesterol on the receptor and a general consensus molecular view is emerging. We review here recent molecular dynamics studies at multiple resolutions highlighting the main features of cholesterol-GPCR interaction. Several cholesterol interaction sites have been identified on the receptor that are reminiscent of nonannular sites. These cholesterol hot-spots are highly dynamic and have a microsecond time scale of exchange with the bulk lipids. A few consensus sites (such as the CRAC site) have been identified that correspond to higher cholesterol interaction. Interestingly, high plasticity is observed in the modes of cholesterol interaction and several sites have been suggested to have high cholesterol occupancy. We therefore believe that these cholesterol hot-spots are indicative of 'high occupancy sites' rather than 'binding sites'. The results suggest that the energy landscape of cholesterol association with GPCRs corresponds to a series of shallow minima interconnected by low barriers. These specific interactions, along with general membrane effects, have been observed to modulate GPCR organization. Membrane cholesterol effects on receptor structure and organization, that in turn influences receptor cross-talk and drug efficacy, represent a new frontier in GPCR research. This article is part of a Special Issue entitled: Lipid-protein interactions. Guest Editors: Amitabha Chattopadhyay and Jean-Marie Ruysschaert. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Coherent Many-Body Spin Dynamics in a Long-Range Interacting Ising Chain

    Directory of Open Access Journals (Sweden)

    Johannes Zeiher

    2017-12-01

    Full Text Available Coherent many-body quantum dynamics lies at the heart of quantum simulation and quantum computation. Both require coherent evolution in the exponentially large Hilbert space of an interacting many-body system. To date, trapped ions have defined the state of the art in terms of achievable coherence times in interacting spin chains. Here, we establish an alternative platform by reporting on the observation of coherent, fully interaction-driven quantum revivals of the magnetization in Rydberg-dressed Ising spin chains of atoms trapped in an optical lattice. We identify partial many-body revivals at up to about ten times the characteristic time scale set by the interactions. At the same time, single-site-resolved correlation measurements link the magnetization dynamics with interspin correlations appearing at different distances during the evolution. These results mark an enabling step towards the implementation of Rydberg-atom-based quantum annealers, quantum simulations of higher-dimensional complex magnetic Hamiltonians, and itinerant long-range interacting quantum matter.

  13. Coherent Many-Body Spin Dynamics in a Long-Range Interacting Ising Chain

    Science.gov (United States)

    Zeiher, Johannes; Choi, Jae-yoon; Rubio-Abadal, Antonio; Pohl, Thomas; van Bijnen, Rick; Bloch, Immanuel; Gross, Christian

    2017-10-01

    Coherent many-body quantum dynamics lies at the heart of quantum simulation and quantum computation. Both require coherent evolution in the exponentially large Hilbert space of an interacting many-body system. To date, trapped ions have defined the state of the art in terms of achievable coherence times in interacting spin chains. Here, we establish an alternative platform by reporting on the observation of coherent, fully interaction-driven quantum revivals of the magnetization in Rydberg-dressed Ising spin chains of atoms trapped in an optical lattice. We identify partial many-body revivals at up to about ten times the characteristic time scale set by the interactions. At the same time, single-site-resolved correlation measurements link the magnetization dynamics with interspin correlations appearing at different distances during the evolution. These results mark an enabling step towards the implementation of Rydberg-atom-based quantum annealers, quantum simulations of higher-dimensional complex magnetic Hamiltonians, and itinerant long-range interacting quantum matter.

  14. Dynamical transitions in a pollination-herbivory interaction: a conflict between mutualism and antagonism.

    Directory of Open Access Journals (Sweden)

    Tomás A Revilla

    Full Text Available Plant-pollinator associations are often seen as purely mutualistic, while in reality they can be more complex. Indeed they may also display a diverse array of antagonistic interactions, such as competition and victim-exploiter interactions. In some cases mutualistic and antagonistic interactions are carried-out by the same species but at different life-stages. As a consequence, population structure affects the balance of inter-specific associations, a topic that is receiving increased attention. In this paper, we developed a model that captures the basic features of the interaction between a flowering plant and an insect with a larval stage that feeds on the plant's vegetative tissues (e.g. leaves and an adult pollinator stage. Our model is able to display a rich set of dynamics, the most remarkable of which involves victim-exploiter oscillations that allow plants to attain abundances above their carrying capacities and the periodic alternation between states dominated by mutualism or antagonism. Our study indicates that changes in the insect's life cycle can modify the balance between mutualism and antagonism, causing important qualitative changes in the interaction dynamics. These changes in the life cycle could be caused by a variety of external drivers, such as temperature, plant nutrients, pesticides and changes in the diet of adult pollinators.

  15. Dynamic, Interactive and Visual Analysis of Population Distribution and Mobility Dynamics in an Urban Environment Using the Mobility Explorer Framework

    Directory of Open Access Journals (Sweden)

    Jan Peters-Anders

    2017-05-01

    Full Text Available This paper investigates the extent to which a mobile data source can be utilised to generate new information intelligence for decision-making in smart city planning processes. In this regard, the Mobility Explorer framework is introduced and applied to the City of Vienna (Austria by using anonymised mobile phone data from a mobile phone service provider. This framework identifies five necessary elements that are needed to develop complex planning applications. As part of the investigation and experiments a new dynamic software tool, called Mobility Explorer, has been designed and developed based on the requirements of the planning department of the City of Vienna. As a result, the Mobility Explorer enables city stakeholders to interactively visualise the dynamic diurnal population distribution, mobility patterns and various other complex outputs for planning needs. Based on the experiences during the development phase, this paper discusses mobile data issues, presents the visual interface, performs various user-defined analyses, demonstrates the application’s usefulness and critically reflects on the evaluation results of the citizens’ motion exploration that reveal the great potential of mobile phone data in smart city planning but also depict its limitations. These experiences and lessons learned from the Mobility Explorer application development provide useful insights for other cities and planners who want to make informed decisions using mobile phone data in their city planning processes through dynamic visualisation of Call Data Record (CDR data.

  16. Tango and enactivism: first steps in exploring the dynamics and experience of interaction.

    Science.gov (United States)

    van Alphen, Floor

    2014-09-01

    Tango dancing is not just ethnographically interesting, but might actually provide a way to study interaction as such. An orientation to this improvisational dance as an embodied practice and experience is given. Enactivism is proposed as an adequate framework for further study. It is argued that approaching tango in terms of participatory sense-making, mutual incorporation and consensually coordinated action helps in clarifying its possible contributions to (cultural) psychology. Possible contributions such as facilitating the study of the dynamics of interaction, of intersubjectivity and of culture as joint activity.

  17. Evaluation of Interaction Between Flat Car and Container at Dynamic Coupling of Flat Cars

    Directory of Open Access Journals (Sweden)

    Nikitchenko Andrew

    2016-01-01

    Full Text Available Innovative materials and structures are analyzed in this paper. To calculate the strength of the collision of flat wagons for the transport of large containers, there is no clear methodology for determining effort interaction between the container and the platform. At high longitudinal acceleration of the container, it is set in motion, and the consideration of this problem in a static setting impossible. The relevance of this work is to develop a methodology that is based on the equations of motion and considers dynamic interaction between container and platform.

  18. Interaction of lysozyme with a tear film lipid layer model: A molecular dynamics simulation study.

    Science.gov (United States)

    Wizert, Alicja; Iskander, D Robert; Cwiklik, Lukasz

    2017-12-01

    The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. CLASP2 interacts with p120-catenin and governs microtubule dynamics at adherens junctions

    DEFF Research Database (Denmark)

    Shahbazi, Marta N; Megias, Diego; Epifano, Carolina

    2013-01-01

    Classical cadherins and their connections with microtubules (MTs) are emerging as important determinants of cell adhesion. However, the functional relevance of such interactions and the molecular players that contribute to tissue architecture are still emerging. In this paper, we report that the MT...... plus end-binding protein CLASP2 localizes to adherens junctions (AJs) via direct interaction with p120-catenin (p120) in primary basal mouse keratinocytes. Reductions in the levels of p120 or CLASP2 decreased the localization of the other protein to cell-cell contacts and altered AJ dynamics...... and stability. These features were accompanied by decreased MT density and altered MT dynamics at intercellular junction sites. Interestingly, CLASP2 was enriched at the cortex of basal progenitor keratinocytes, in close localization to p120. Our findings suggest the existence of a new mechanism of MT targeting...

  20. Dynamic Response of Wheel-Rail Interaction at Rail Weld in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Boyang An

    2017-01-01

    Full Text Available As a main part of continuously welded rail track, rail weld widely exists in high-speed railway. However, short-wave irregularities can easily initiate and develop in rail weld due to the limitation of welding technology and thus rail weld has been a main high-frequency excitation and is responsible for deterioration of track components. This work reports a 3D finite element model of wheel-rail rolling contact which can simulate dynamic wheel-rail interaction at arbitrary contact geometry up to 400 km/h. This model is employed to investigate dynamic response of wheel-rail interaction at theoretical and measured rail weld, including wheel-rail force and axle-box acceleration. These simulation results, combined with Quality Index (QI method, are used to develop a quantitative expression, which can be easily applied for evaluating rail weld deterioration based on measured rail profiles and axle-box acceleration.

  1. Dynamic characteristics of Semi-active Hydraulic Engine Mount Based on Fluid-Structure Interaction FEA

    Directory of Open Access Journals (Sweden)

    Tian Jiande

    2015-01-01

    Full Text Available A kind of semi-active hydraulic engine mount is studied in this paper. After careful analysis of its structure and working principle, the FEA simulation of it was divided into two cases. One is the solenoid valve is open, so the air chamber connects to the atmosphere, and Fluid-Structure Interaction was used. Another is the solenoid valve is closed, and the air chamber has pressure, so Fluid-Structure-Gas Interaction was used. The test of this semi-active hydraulic engine mount was carried out to compare with the simulation results, and verify the accuracy of the model. Then the dynamic characteristics-dynamic stiffness and damping angle were analysed by simulation and test. This paper provides theoretical support for the development and optimization of the semi-active hydraulic engine mount.

  2. Inference of Network Dynamics and Metabolic Interactions in the Gut Microbiome.

    Directory of Open Access Journals (Sweden)

    Steven N Steinway

    2015-05-01

    Full Text Available We present a novel methodology to construct a Boolean dynamic model from time series metagenomic information and integrate this modeling with genome-scale metabolic network reconstructions to identify metabolic underpinnings for microbial interactions. We apply this in the context of a critical health issue: clindamycin antibiotic treatment and opportunistic Clostridium difficile infection. Our model recapitulates known dynamics of clindamycin antibiotic treatment and C. difficile infection and predicts therapeutic probiotic interventions to suppress C. difficile infection. Genome-scale metabolic network reconstructions reveal metabolic differences between community members and are used to explore the role of metabolism in the observed microbial interactions. In vitro experimental data validate a key result of our computational model, that B. intestinihominis can in fact slow C. difficile growth.

  3. Exact non-Markovian dynamics of qubits coupled to two interacting environments

    Science.gov (United States)

    Shen, H. Z.; Li, D. X.; Su, Shi-Lei; Zhou, Y. H.; Yi, X. X.

    2017-09-01

    As the memory effect may be helpful in quantum information processing, non-Markovian dynamics plays an important role in the description of many-body open systems. Among these topics, the system consisting of independent qubits interacting with several coupled environments is of particular interest. In this paper, we study the exact non-Markovian dynamics of two independent qubits. Each of the qubits interacts individually with its environment, and these two environments coupled with each other. We investigate the non-Markovianity measure of the system for the whole parameter regime without the rotating-wave approximation (RWA) and compare the results with that under the RWA. We find that the non-Markovianity measure for two qubits manifests a transition from a non-Markovian to Markovian regime regardless of the coupling strength between the environments. The physical origin of this transition is revealed, and a possible observation of the prediction in superconducting quantum interference devices is discussed.

  4. New Frontiers in Analyzing Dynamic Group Interactions: Bridging Social and Computer Science.

    Science.gov (United States)

    Lehmann-Willenbrock, Nale; Hung, Hayley; Keyton, Joann

    2017-10-01

    This special issue on advancing interdisciplinary collaboration between computer scientists and social scientists documents the joint results of the international Lorentz workshop, "Interdisciplinary Insights into Group and Team Dynamics," which took place in Leiden, The Netherlands, July 2016. An equal number of scholars from social and computer science participated in the workshop and contributed to the papers included in this special issue. In this introduction, we first identify interaction dynamics as the core of group and team models and review how scholars in social and computer science have typically approached behavioral interactions in groups and teams. Next, we identify key challenges for interdisciplinary collaboration between social and computer scientists, and we provide an overview of the different articles in this special issue aimed at addressing these challenges.

  5. Population reversal driven by unrestrained interactions in molecular dynamics simulations: A dialanine model

    Directory of Open Access Journals (Sweden)

    Filippo Pullara

    2015-10-01

    Full Text Available Standard Molecular Dynamics simulations (MD are usually performed under periodic boundary conditions using the well-established “Ewald summation”. This implies that the distance among each element in a given lattice cell and its corresponding element in another cell, as well as their relative orientations, are constant. Consequently, protein-protein interactions between proteins in different cells—important in many biological activities, such as protein cooperativity and physiological/pathological aggregation—are severely restricted, and features driven by protein-protein interactions are lost. The consequences of these restrictions, although conceptually understood and mentioned in the literature, have not been quantitatively studied before. The effect of protein-protein interactions on the free energy landscape of a model system, dialanine, is presented. This simple system features a free energy diagram with well-separated minima. It is found that, in the case of absence of peptide-peptide (p-p interactions, the ψ = 150° dihedral angle determines the most energetically favored conformation (global free-energy minimum. When strong p-p interactions are induced, the global minimum switches to the ψ = 0° conformation. This shows that the free-energy landscape of an individual molecule is dramatically affected by the presence of other freely interacting molecules of its same type. Results of the study suggest how taking into account p-p interactions in MD allows having a more realistic picture of system activity and functional conformations.

  6. Transient dynamic response and failure of composite structure under cyclic loading with fluid structure interaction

    OpenAIRE

    Teo, Hui Fen

    2014-01-01

    Approved for public release; distribution is unlimited With the growing interest in using composites in naval shipbuilding, it is crucial to understand the behavior of structures, especially the Fluid Structural Interaction (FSI) aspect of the composites under dynamic loading, to ensure the survivability of the platform at sea. The objective of this study is to perform displacement-controlled fatigue cyclic loading on quasi-isotropic E-glass laminate, which is commonly used in the shipbuil...

  7. Dynamic features of the learning activity of the future teacher as a teacher interaction subject

    OpenAIRE

    Коць, Михайло Онисимович; Kots, Mykhailo O.

    2014-01-01

    This article deals with theoretical analysis and empirical investigation of educational activity dynamics of future teachers. Activity, awareness, mutual commitment are peculiar to educational interactions by both sides – the students (student) – a teacher – who act as subjects where coordinated action is the result and amplifies by mental state of contact are grounded. Methodological meaning of the notion activity in relation to psychological research, primarily in principle activity o...

  8. Red Queen dynamics in multi-host and multi-parasite interaction system

    OpenAIRE

    Rabajante, Jomar F.; Jerrold M. Tubay; Uehara, Takashi; Morita, Satoru; Ebert, Dieter; Yoshimura, Jin

    2015-01-01

    In host-parasite systems, dominant host types are expected to be eventually replaced by other hosts due to the elevated potency of their specific parasites. This leads to changes in the abundance of both hosts and parasites exhibiting cycles of alternating dominance called Red Queen dynamics. Host-parasite models with less than three hosts and parasites have been demonstrated to exhibit Red Queen cycles, but natural host-parasite interactions typically involve many host and parasite types res...

  9. Computational strong-field quantum dynamics. Intense light-matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Dieter (ed.) [Rostock Univ. (Germany). Inst. fuer Physik

    2017-09-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time dependent Schroedinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  10. Interactions of Delta Shock Waves for Zero-Pressure Gas Dynamics with Energy Conservation Law

    Directory of Open Access Journals (Sweden)

    Wei Cai

    2016-01-01

    Full Text Available We study the interactions of delta shock waves and vacuum states for the system of conservation laws of mass, momentum, and energy in zero-pressure gas dynamics. The Riemann problems with initial data of three piecewise constant states are solved case by case, and four different configurations of Riemann solutions are constructed. Furthermore, the numerical simulations completely coinciding with theoretical analysis are shown.

  11. Computational strong-field quantum dynamics intense light-matter interactions

    CERN Document Server

    2017-01-01

    This graduate textbook introduces the computational techniques to study ultra-fast quantum dynamics of matter exposed to strong laser fields. Coverage includes methods to propagate wavefunctions according to the time-dependent Schrödinger, Klein-Gordon or Dirac equation, the calculation of typical observables, time-dependent density functional theory, multi-configurational time-dependent Hartree-Fock, time-dependent configuration interaction singles, the strong-field approximation, and the microscopic particle-in-cell approach.

  12. Better decision making in complex, dynamic tasks training with human-facilitated interactive learning environments

    CERN Document Server

    Qudrat-Ullah, Hassan

    2015-01-01

    This book describes interactive learning environments (ILEs) and their underlying concepts. It explains how ILEs can be used to improve the decision-making process and how these improvements can be empirically verified. The objective of this book is to enhance our understanding of and to gain insights into the process by which human facilitated ILEs are effectively designed and used in improving users’ decision making in complex, dynamic tasks. This book is divided into four major parts. Part I serves as an introduction to the importance and complexity of decision making in dynamic tasks. Part II provides background material, drawing upon relevant literature, for the development of an integrated process model on the effectiveness of human facilitated ILEs in improving decision making in dynamic tasks. Part III focuses on the design, development, and application of FishBankILE in laboratory experiments to gather empirical evidence for the validity of the process model. Finally, part IV presents a comprehensi...

  13. Solubilization Behavior of Polyene Antibiotics in Nanomicellar System: Insights from Molecular Dynamics Simulation of the Amphotericin B and Nystatin Interactions with Polysorbate 80

    Directory of Open Access Journals (Sweden)

    Meysam Mobasheri

    2015-12-01

    Full Text Available Amphotericin B (AmB and Nystatin (Nys are the drugs of choice for treatment of systemic and superficial mycotic infections, respectively, with their full clinical potential unrealized due to the lack of high therapeutic index formulations for their solubilized delivery. In the present study, using a coarse-grained (CG molecular dynamics (MD simulation approach, we investigated the interaction of AmB and Nys with Polysorbate 80 (P80 to gain insight into the behavior of these polyene antibiotics (PAs in nanomicellar solution and derive potential implications for their formulation development. While the encapsulation process was predominantly governed by hydrophobic forces, the dynamics, hydration, localization, orientation, and solvation of PAs in the micelle were largely controlled by hydrophilic interactions. Simulation results rationalized the experimentally observed capability of P80 in solubilizing PAs by indicating (i the dominant kinetics of drugs encapsulation over self-association; (ii significantly lower hydration of the drugs at encapsulated state compared with aggregated state; (iii monomeric solubilization of the drugs; (iv contribution of drug-micelle interactions to the solubilization; (v suppressed diffusivity of the encapsulated drugs; (vi high loading capacity of the micelle; and (vii the structural robustness of the micelle against drug loading. Supported from the experimental data, our simulations determined the preferred location of PAs to be the core-shell interface at the relatively shallow depth of 75% of micelle radius. Deeper penetration of PAs was impeded by the synergistic effects of (i limited diffusion of water; and (ii perpendicular orientation of these drug molecules with respect to the micelle radius. PAs were solvated almost exclusively in the aqueous poly-oxyethylene (POE medium due to the distance-related lack of interaction with the core, explaining the documented insensitivity of Nys solubilization to drug

  14. ENSO dynamics and diversity resulting from the recharge oscillator interacting with the slab ocean

    Science.gov (United States)

    Yu, Yanshan; Dommenget, Dietmar; Frauen, Claudia; Wang, Gang; Wales, Scott

    2016-03-01

    El Nino-Southern Oscillation (ENSO) is the leading mode of interannual global climate variability, which in its essence is often described by the equatorial dynamics of the recharge oscillator with a fixed pattern. Here we explore the idea that ENSO can be simulated in a model with a fixed pattern of sea surface temperature variability following the recharge oscillator mechanism, which interacts with the thermodynamic red noise of a slab ocean. This model is capable of simulating the leading modes of sea surface temperature variability in the tropical Pacific in good agreement with the observations and most coupled general circulation models. ENSO dynamics, amplitude, seasonality, the structure of the leading patterns, its meridional extension, its variations in an eastern and central Pacific pattern and associated positive feedbacks are all influenced and simulated well by including the interaction of recharge oscillator and the thermodynamic coupling to the slab ocean model. We further point out that much of the ENSO diversity in the spatial structure is a reflection of this interaction. However, it also has to be noted that some equatorial dynamics are missing in this model and in coupled general circulation models that are important for the ENSO diversity.

  15. Effects of ecological interactions and environmental conditions on community dynamics in an estuarine ecosystem

    Science.gov (United States)

    Liu, H.; Minello, T.; Sutton, G.

    2016-02-01

    Coastal marine ecosystems are both productive and vulnerable to human and natural stressors. Examining the relative importance of fishing, environmental variability, and habitat alteration on ecosystem dynamics is challenging. Intensive harvest and habitat loss have resulted in widespread concerns related to declines in fisheries production, but causal mechanisms are rarely clear. In this study, we modeled trophic dynamics in Galveston Bay, Texas, using fishery-independent catch data for blue crab, shrimp, red drum, Atlantic croaker and spotted seatrout along with habitat information collected by the Texas Parks and Wildlife Department during 1984 - 2014. We developed a multispecies state-space model to examine ecological interactions and partition the relative effects of trophic interactions and environmental conditions on the community dynamics. Preliminary results showed the importance of salinity, density-dependence, and trophic interactions. We are continuing to explore these results from a perspective of fish community compensatory responses to exploitation, reflecting both direct and indirect effects of harvesting under the influence of climate variability.

  16. During capacitation in bull spermatozoa, actin and PLC-ζ undergo dynamic interactions.

    Science.gov (United States)

    Mejía-Flores, Itzayana; Chiquete-Félix, Natalia; Palma-Lara, Icela; Uribe-Carvajal, Salvador; de Lourdes Juárez-Mosqueda, María

    2017-10-01

    The migration pattern of sperm-specific phospholipase C-ζ (PLC-ζ) was followed and the role of this migration in actin cytoskeleton dynamics was determined. We investigated whether PLC-ζ exits sperm, opening the possibility that PLC-ζ is the 'spermatozoidal activator factor' (SOAF). As capacitation progresses, the highly dynamic actin cytoskeleton bound different proteins to regulate their location and activity. PLC-ζ participation at the start of fertilization was established. In non-capacitated spermatozoa, PLC-ζ is in the perinuclear theca (PT) and in the flagellum, therefore it was decided to determine whether bovine sperm actin interacts with PLC-ζ to direct its relocation as it progresses from non-capacitated (NC) to capacitated (C) and to acrosome-reacted (AR) spermatozoa. PLC-ζ interacted with actin in NC spermatozoa (100%), PLC-ζ levels decreased in C spermatozoa to 32% and in AR spermatozoa to 57% (P PLC-ζ interaction was twice as high in G-actin (P PLC-ζ was partially released from the cell. It was concluded that actin cytoskeleton dynamics control the migration of PLC-ζ during capacitation and leads to its partial release at AR spermatozoa. It is suggested that liberated PLC-ζ could reach the egg and favour fertilization.

  17. Dynamic changes in the interchromosomal interaction of early histone gene loci during development of sea urchin.

    Science.gov (United States)

    Matsushita, Masaya; Ochiai, Hiroshi; Suzuki, Ken-Ichi T; Hayashi, Sayaka; Yamamoto, Takashi; Awazu, Akinori; Sakamoto, Naoaki

    2017-12-15

    The nuclear positioning and chromatin dynamics of eukaryotic genes are closely related to the regulation of gene expression, but they have not been well examined during early development, which is accompanied by rapid cell cycle progression and dynamic changes in nuclear organization, such as nuclear size and chromatin constitution. In this study, we focused on the early development of the sea urchin Hemicentrotus pulcherrimus and performed three-dimensional fluorescence in situ hybridization of gene loci encoding early histones (one of the types of histone in sea urchin). There are two non-allelic early histone gene loci per sea urchin genome. We found that during the morula stage, when the early histone gene expression levels are at their maximum, interchromosomal interactions were often formed between the early histone gene loci on separate chromosomes and that the gene loci were directed to locate to more interior positions. Furthermore, these interactions were associated with the active transcription of the early histone genes. Thus, such dynamic interchromosomal interactions may contribute to the efficient synthesis of early histone mRNA during the morula stage of sea urchin development. © 2017. Published by The Company of Biologists Ltd.

  18. Dynamical phase diagram of quantum spin chains with long-range interactions

    Science.gov (United States)

    Halimeh, Jad C.; Zauner-Stauber, Valentin

    2017-10-01

    Using an infinite matrix product state (iMPS) technique based on the time-dependent variational principle (TDVP), we study two major types of dynamical phase transitions (DPT) in the one-dimensional transverse-field Ising model (TFIM) with long-range power-law (∝1 /rα with r interspin distance) interactions out of equilibrium in the thermodynamic limit—DPT-I: based on an order parameter in a (quasi-)steady state, and DPT-II: based on nonanalyticities (cusps) in the Loschmidt-echo return rate. We construct the corresponding rich dynamical phase diagram, while considering different quench initial conditions. We find a nontrivial connection between both types of DPT based on their critical lines. Moreover, and very interestingly, we detect a new DPT-II dynamical phase in a certain range of interaction exponent α , characterized by what we call anomalous cusps that are distinct from the regular cusps usually associated with DPT-II. Our results provide the characterization of experimentally accessible signatures of the dynamical phases studied in this work.

  19. Modeling the Dynamics of Tidally Interacting Binary Neutron Stars up to the Merger.

    Science.gov (United States)

    Bernuzzi, Sebastiano; Nagar, Alessandro; Dietrich, Tim; Damour, Thibault

    2015-04-24

    The data analysis of the gravitational wave signals emitted by coalescing neutron star binaries requires the availability of an accurate analytical representation of the dynamics and waveforms of these systems. We propose an effective-one-body model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to the merger. Our effective-one-body model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model energetics and the gravitational wave phasing with new high-resolution multiorbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement within the uncertainty of the numerical data for all configurations. Our model is the first semianalytical model that captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

  20. Modelling crowd-bridge dynamic interaction with a discretely defined crowd

    Science.gov (United States)

    Carroll, S. P.; Owen, J. S.; Hussein, M. F. M.

    2012-05-01

    This paper presents a novel method of modelling crowd-bridge interaction using discrete element theory (DET) to model the pedestrian crowd. DET, also known as agent-based modelling, is commonly used in the simulation of pedestrian movement, particularly in cases where building evacuation is critical or potentially problematic. Pedestrians are modelled as individual elements subject to global behavioural rules. In this paper a discrete element crowd model is coupled with a dynamic bridge model in a time-stepping framework. Feedback takes place between both models at each time-step. An additional pedestrian stimulus is introduced that is a function of bridge lateral dynamic behaviour. The pedestrians' relationship with the vibrating bridge as well as the pedestrians around them is thus simulated. The lateral dynamic behaviour of the bridge is modelled as a damped single degree of freedom (SDoF) oscillator. The excitation and mass enhancement of the dynamic system is determined as the sum of individual pedestrian contributions at each time-step. Previous crowd-structure interaction modelling has utilised a continuous hydrodynamic crowd model. Limitations inherent in this modelling approach are identified and results presented that demonstrate the ability of DET to address these limitations. Simulation results demonstrate the model's ability to consider low density traffic flows and inter-subject variability. The emergence of the crowd's velocity-density relationship is also discussed.

  1. Detection of time delays and directional interactions based on time series from complex dynamical systems

    Science.gov (United States)

    Ma, Huanfei; Leng, Siyang; Tao, Chenyang; Ying, Xiong; Kurths, Jürgen; Lai, Ying-Cheng; Lin, Wei

    2017-07-01

    Data-based and model-free accurate identification of intrinsic time delays and directional interactions is an extremely challenging problem in complex dynamical systems and their networks reconstruction. A model-free method with new scores is proposed to be generally capable of detecting single, multiple, and distributed time delays. The method is applicable not only to mutually interacting dynamical variables but also to self-interacting variables in a time-delayed feedback loop. Validation of the method is carried out using physical, biological, and ecological models and real data sets. Especially, applying the method to air pollution data and hospital admission records of cardiovascular diseases in Hong Kong reveals the major air pollutants as a cause of the diseases and, more importantly, it uncovers a hidden time delay (about 30-40 days) in the causal influence that previous studies failed to detect. The proposed method is expected to be universally applicable to ascertaining and quantifying subtle interactions (e.g., causation) in complex systems arising from a broad range of disciplines.

  2. Dynamical Study of Guest-Host Orientational Interaction in LiquidCrystalline Materials

    Energy Technology Data Exchange (ETDEWEB)

    Truong, Thai Viet [Univ. of California, Berkeley, CA (United States)

    2005-01-01

    Guest-host interaction has long been a subject of interest in many disciplines. Emphasis is often on how a small amount of guest substance could significantly affect the properties of a host material. This thesis describe our work in studying a guest-host effect where dye-doping of liquid crystalline materials greatly enhances the optical Kerr nonlinearity of the material. The dye molecules, upon excitation and via intermolecular interaction, provides an extra torque to reorient the host molecules, leading to the enhanced optical Kerr nonlinearity. We carried out a comprehensive study on the dynamics of the photoexcited dye-doped liquid crystalline medium. Using various experimental techniques, we separately characterized the dynamical responses of the relevant molecular species present in the medium following photo-excitation, and thus were able to follow the transient process in which photo-excitation of the dye molecules exert through guest-host interaction a net torque on the host LC material, leading to the observed enhanced molecular reorientation. We also observed for the first time the enhanced reorientation in a pure liquid crystal system, where the guest population is created through photoexcitation of the host molecules themselves. Experimental results agree quantitatively with the time-dependent theory based on a mean-field model of the guest-host interaction.

  3. Collective Dynamics on a Two-Lane Asymmetrically Coupled TASEP with Mutually Interactive Langmuir Kinetics

    Science.gov (United States)

    Gupta, Arvind Kumar

    2016-03-01

    Motivated by the recent experimental observations on clustering of motor proteins on microtubule filament, we study an open system of two parallel totally asymmetric simple exclusion processes under asymmetric coupling conditions, which incorporates the mutual interaction with the surrounding environment through Langmuir Kinetics (LK) in both the lanes. In the modified LK, the attachment and detachment rates depends on the configuration of nearest neighboring sites. We analyse the model within the framework of continuum mean-field theory and the phase diagrams along with density profiles are obtained using boundary layer analysis. The effect of mutual interactions on the phase diagram for two different situations of attachment and detachment (LK) rates is discussed. Under the symmetric LK dynamics, the topological structure of the phase diagram remains similar to the one in without mutual interaction; while for the antisymmetric case, after a certain critical value of attractive/repulsive mutual attraction, significant changes are found in the qualitative nature of phase diagram. Moreover, it is shown that the type of mutual interaction affects the dynamic properties of motor proteins. The theoretical findings are examined by extensive Monte-Carlo simulations.

  4. A nuclear magnetic resonance study of the dynamics of organofluorine interactions with a dissolved humic acid.

    Science.gov (United States)

    Longstaffe, James G; Courtier-Murias, Denis; Simpson, Andre J

    2016-02-01

    A quantitative understanding of the dynamics of the interactions between organofluorine compounds and humic acids will contribute to an improved understanding of the role that Natural Organic Matter plays as a mediator in the fate, transport and distribution of these contaminants in the environment. Here, Nuclear Magnetic Resonance (NMR) spectroscopy-based diffusion measurements are used to estimate the association dynamics between dissolved humic acid and selected organofluorine compounds: pentafluoroaniline, pentafluorophenol, potassium perfluorooctane sulfonate, and perfluorooctanoic acid. Under the conditions used here, the strength of the association with humic acid increases linearly as temperature decreases for all compounds except for perfluorooctanoic acid, which exhibits divergent behavior with a non-linear decrease in the extent of interaction as temperature decreases. A general interaction mechanism controlled largely by desolvation effects is suggested for all compounds examined here except for perfluorooctanoic acid, which exhibits a specific mode of interaction consistent with a proteinaceous binding site. Reverse Heteronuclear Saturation Transfer Difference NMR is used to confirm the identity and nature of the humic acid binding sites. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Extending Spatial Interaction Models with Agents for Understanding Relationships in a Dynamic Retail Market

    Directory of Open Access Journals (Sweden)

    Mark Birkin

    2011-01-01

    Full Text Available For many years, effective model-based representations of the dynamics and evolution of urban spatial structure have proved elusive. While some progress has been made through the deployment of spatial interaction models, these approaches have been limited by the difficulty of representing behavioural mechanisms and processes. In this paper, it is demonstrated that evolutionary models grounded in the principles of spatial interaction are compatible with the more novel approaches of agent-based modelling. The incorporation of agents provides a much more flexible means for the representation of behavioural mechanisms. The paper illustrates the way in which three more complicated situations can be handled through the fusion of spatial interaction and agent modelling perspectives. These situations comprise discontinuous evolution (in which structural adjustment takes place in discrete steps, and not as a continuously smooth process; nonequilibrium dynamics (in which the underlying system parameters continue to evolve through time; the incorporation of new decision variables (which we illustrate through the addition of land rents into the model. The conclusion of the paper is that the combination of spatial interaction and agent-based modelling methods provides encouraging prospects for the social simulation of real urban systems.

  6. Interactions between ether phospholipids and cholesterol as determined by scattering and molecular dynamics simulations.

    Science.gov (United States)

    Pan, Jianjun; Cheng, Xiaolin; Heberle, Frederick A; Mostofian, Barmak; Kučerka, Norbert; Drazba, Paul; Katsaras, John

    2012-12-27

    Cholesterol and ether lipids are ubiquitous in mammalian cell membranes, and their interactions are crucial in ether lipid mediated cholesterol trafficking. We report on cholesterol's molecular interactions with ether lipids as determined using a combination of small-angle neutron and X-ray scattering, and all-atom molecular dynamics (MD) simulations. A scattering density profile model for an ether lipid bilayer was developed using MD simulations, which was then used to simultaneously fit the different experimental scattering data. From analysis of the data the various bilayer structural parameters were obtained. Surface area constrained MD simulations were also performed to reproduce the experimental data. This iterative analysis approach resulted in good agreement between the experimental and simulated form factors. The molecular interactions taking place between cholesterol and ether lipids were then determined from the validated MD simulations. We found that in ether membranes cholesterol primarily hydrogen bonds with the lipid headgroup phosphate oxygen, while in their ester membrane counterparts cholesterol hydrogen bonds with the backbone ester carbonyls. This different mode of interaction between ether lipids and cholesterol induces cholesterol to reside closer to the bilayer surface, dehydrating the headgroup's phosphate moiety. Moreover, the three-dimensional lipid chain spatial density distribution around cholesterol indicates anisotropic chain packing, causing cholesterol to tilt. These insights lend a better understanding of ether lipid-mediated cholesterol trafficking and the roles that the different lipid species have in determining the structural and dynamical properties of membrane associated biomolecules.

  7. Interactions between Ether Phospholipids and Cholesterol as Determined by Scattering and Molecular Dynamics Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Jianjun [ORNL; Cheng, Xiaolin [ORNL; Heberle, Frederick A [ORNL; Mostofian, Barmak [ORNL; Kucerka, Norbert [Canadian Neutron Beam Centre and Comelius University (Slovakia); Drazba, Paul [ORNL; Katsaras, John [ORNL

    2012-01-01

    Cholesterol and ether lipids are ubiquitous in mammalian cell membranes, and their interactions are crucial in ether lipid mediated cholesterol trafficking. We report on cholesterol s molecular interactions with ether lipids as determined using a combination of small-angle neutron and Xray scattering, and all-atom molecular dynamics (MD) simulations. A scattering density profile model for an ether lipid bilayer was developed using MD simulations, which was then used to simultaneously fit the different experimental scattering data. From analysis of the data the various bilayer structural parameters were obtained. Surface area constrained MD simulations were also performed to reproduce the experimental data. This iterative analysis approach resulted in good agreement between the experimental and simulated form factors. The molecular interactions taking place between cholesterol and ether lipids were then determined from the validated MD simulations. We found that in ether membranes cholesterol primarily hydrogen bonds with the lipid headgroup phosphate oxygen, while in their ester membrane counterparts cholesterol hydrogen bonds with the backbone ester carbonyls. This different mode of interaction between ether lipids and cholesterol induces cholesterol to reside closer to the bilayer surface, dehydrating the headgroup s phosphate moiety. Moreover, the three-dimensional lipid chain spatial density distribution around cholesterol indicates anisotropic chain packing, causing cholesterol to tilt. These insights lend a better understanding of ether lipid-mediated cholesterol trafficking and the roles that the different lipid species have in determining the structural and dynamical properties of membrane associated biomolecules.

  8. Hydrogen bonding-assisted interaction between amitriptyline hydrochloride and hemoglobin: spectroscopic and molecular dynamics studies.

    Science.gov (United States)

    Maurya, Neha; Maurya, Jitendra Kumar; Kumari, Meena; Khan, Abbul Bashar; Dohare, Ravins; Patel, Rajan

    2017-05-01

    Herein, we have explored the interaction between amitriptyline hydrochloride (AMT) and hemoglobin (Hb), using steady-state and time-resolved fluorescence spectroscopy, UV-visible spectroscopy, and circular dichroism spectroscopy, in combination with molecular docking and molecular dynamic (MD) simulation methods. The steady-state fluorescence reveals the static quenching mechanism in the interaction system, which was further confirmed by UV-visible and time-resolved fluorescence spectroscopy. The binding constant, number of binding sites, and thermodynamic parameters viz. ΔG, ΔH, ΔS are also considered; result confirms that the binding of the AMT with Hb is a spontaneous process, involving hydrogen bonding and van der Waals interactions with a single binding site, as also confirmed by molecular docking study. Synchronous fluorescence, CD data, and MD simulation results contribute toward understanding the effect of AMT on Hb to interpret the conformational change in Hb upon binding in aqueous solution.

  9. Dynamic Plant-Plant-Herbivore Interactions Govern Plant Growth-Defence Integration.

    Science.gov (United States)

    de Vries, Jorad; Evers, Jochem B; Poelman, Erik H

    2017-04-01

    Plants downregulate their defences against insect herbivores upon impending competition for light. This has long been considered a resource trade-off, but recent advances in plant physiology and ecology suggest this mechanism is more complex. Here we propose that to understand why plants regulate and balance growth and defence, the complex dynamics in plant-plant competition and plant-herbivore interactions needs to be considered. Induced growth-defence responses affect plant competition and herbivore colonisation in space and time, which has consequences for the adaptive value of these responses. Assessing these complex interactions strongly benefits from advanced modelling tools that can model multitrophic interactions in space and time. Such an exercise will allow a critical re-evaluation why and how plants integrate defence and competition for light. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Capacitance, charge dynamics, and electrolyte-surface interactions in functionalized carbide-derived carbon electrodes

    Directory of Open Access Journals (Sweden)

    Boris Dyatkin

    2015-12-01

    Full Text Available This study analyzed the dynamics of ionic liquid electrolyte inside of defunctionalized, hydrogenated, and aminated pores of carbide-derived carbon supercapacitor electrodes. The approach tailors surface functionalities and tunes nanoporous structures to decouple the influence of pore wall composition on capacitance, ionic resistance, and long-term cyclability. Quasi-elastic neutron scattering probes the self-diffusion properties and electrode-ion interactions of electrolyte molecules confined in functionalized pores. Room-temperature ionic liquid interactions in confined pores are strongest when the hydrogen-containing groups are present on the surface. This property translates into higher capacitance and greater ion transport through pores during electrochemical cycling. Unlike hydrogenated pores, aminated pores do not favorably interact with ionic liquid ions and, subsequently, are outperformed by defunctionalized surfaces.

  11. Characterization of the Interaction between Gallic Acid and Lysozyme by Molecular Dynamics Simulation and Optical Spectroscopy.

    Science.gov (United States)

    Zhan, Minzhong; Guo, Ming; Jiang, Yanke; Wang, Xiaomeng

    2015-07-01

    The binding interaction between gallic acid (GA) and lysozyme (LYS) was investigated and compared by molecular dynamics (MD) simulation and spectral techniques. The results from spectroscopy indicate that GA binds to LYS to generate a static complex. The binding constants and thermodynamic parameters were calculated. MD simulation revealed that the main driving forces for GA binding to LYS are hydrogen bonding and hydrophobic interactions. The root-mean-square deviation verified that GA and LYS bind to form a stable complex, while the root-mean-square fluctuation results showed that the stability of the GA-LYS complex at 298 K was higher than that at 310 K. The calculated free binding energies from the molecular mechanics/Poisson-Boltzmann surface area method showed that van der Waals forces and electrostatic interactions are the predominant intermolecular forces. The MD simulation was consistent with the spectral experiments. This study provides a reference for future study of the pharmacological mechanism of GA.

  12. Photoinduced charge-order melting dynamics in a one-dimensional interacting Holstein model

    Science.gov (United States)

    Hashimoto, Hiroshi; Ishihara, Sumio

    2017-07-01

    Transient quantum dynamics in an interacting fermion-phonon system are investigated with a focus on a charge order (CO) melting after a short optical-pulse irradiation and the roles of the quantum phonons in the transient dynamics. A spinless-fermion model in a one-dimensional chain coupled with local phonons is analyzed numerically. The infinite time-evolving block decimation algorithm is adopted as a reliable numerical method for one-dimensional quantum many-body systems. Numerical results for the photoinduced CO melting dynamics without phonons are well interpreted by the soliton picture for the CO domains. This interpretation is confirmed by numerical simulation of an artificial local excitation and the classical soliton model. In the case of large phonon frequencies corresponding to the antiadiabatic condition, CO melting is induced by propagations of the polaronic solitons with the renormalized soliton velocity. On the other hand, in the case of small phonon frequencies corresponding to the adiabatic condition, the first stage of the CO melting dynamics occurs due to the energy transfer from the fermionic to phononic systems, and the second stage is brought about by the soliton motions around the bottom of the soliton band. The analyses provide a standard reference for photoinduced CO melting dynamics in one-dimensional many-body quantum systems.

  13. VI Tallinna arhitektuuritriennaal / Leonhard Lapin

    Index Scriptorium Estoniae

    Lapin, Leonhard, 1947-

    2005-01-01

    15.-17. IX Tallinnas Niguliste kirikus toimuval VI Tallinna arhitektuuritriennaalil esinevad inglise arhitektuurikriitik Peter Davey, šveitsi arhitekt Peter Zumthor, soome arhitekt Juha Leviskä, eesti arhitekt Vilen Künnapu, eesti kunstiajaloolane Juhan Maiste jt. Külastatakse KUMU, tutvutab autor Pekka Vapaavuori

  14. (VI) oxide in acetic acid

    African Journals Online (AJOL)

    The oxidation of cyclohexene by chromium (VI) oxide in aqueous and acetic media was studied. The reaction products were analysed using infra red (IR) and gas chromatography coupled with mass (GC/MS) spectroscopy. The major products of the oxidation reaction in acetic acid medium were cyclohexanol, ...

  15. Impact of cannibalism on predator-prey dynamics: size-structured interactions and apparent mutualism.

    Science.gov (United States)

    Rudolf, Volker H W

    2008-06-01

    Direct and indirect interactions between two prey species can strongly alter the dynamics of predator-prey systems. Most predators are cannibalistic, and as a consequence, even systems with only one predator and one prey include two prey types: conspecifics and heterospecifics. The effects of the complex direct and indirect interactions that emerge in such cannibalistic systems are still poorly understood. This study examined how the indirect interaction between conspecific and heterospecific prey affects cannibalism and predation rates and how the direct interactions between both species indirectly alter the effect of the cannibalistic predator. I tested for these effects using larvae of the stream salamanders Eurycea cirrigera (prey) and Pseudotriton ruber (cannibalistic predator) by manipulating the relative densities of the conspecific and heterospecific prey in the presence and absence of the predator in experimental streams. The rates of cannibalism and heterospecific predation were proportional to the respective densities and negatively correlated, indicating a positive indirect interaction between conspecific and heterospecific prey, similar to "apparent mutualism." Direct interactions between prey species did not alter the effect of the predator. Although both types of prey showed a similar 30% reduction in night activity and switch in microhabitat use in response to the presence of the predator, cannibalism rates were three times higher than heterospecific predation rates irrespective of the relative densities of the two types of prey. Cumulative predation risks differed even more due to the 48% lower growth rate of conspecific prey. Detailed laboratory experiments suggest that the 3:1 difference in cannibalism and predation rate was due to the higher efficiency of heterospecific prey in escaping immediate attacks. However, no difference was observed when the predator was a closely related salamander species, Gyrinophilus porphyriticus, indicating that

  16. Visible light Cr(VI) reduction and organic chemical oxidation by TiO2 photocatalysis.

    Science.gov (United States)

    Sun, Bo; Reddy, Ettireddy P; Smirniotis, Panagiotis G

    2005-08-15

    Here we report the simultaneous Cr(VI) reduction and 4-chlorophenol (4-CP) oxidation in water under visible light (wavelength > 400 nm) using commercial Degussa P25 TiO2. This remarkable observation was attributed to a synergistic effect among TiO2, Cr(VI), and 4-CP. It is well known that TiO2 alone cannot remove either 4-CP or Cr(VI) efficiently under visible light. Moreover, the interaction between Cr(VI) and 4-CP is minimal if not negligible. However, we found that the combination of TiO2, Cr(VI), and 4-CP together can enable efficient Cr(VI) reduction and 4-CP oxidation under visible light. The specific roles of the three ingredients in the synergistic system were studied parametrically. It was found that optimal concentrations of Cr(VI) and TiO2 exist for the Cr(VI) reduction and 4-CP oxidation. Cr(VI) was compared experimentally with other metals such as Cu(ll), Fe(lll), Mn(IV), Ce(IV), and V(V). Among all these metal ions, only Cr(VI) promotes the photocatalytic oxidation of 4-CP. The amount of 4-CP removed was directly related to the initial concentration of Cr(VI). The system was also tested with four other chemicals (aniline, salicylic acid, formic acid, and diethyl phosphoramidate). We found that the same phenomenon occurred for organics containing acid and/or phenolic groups. Cr(VI) was reduced at the same time as the organic chemicals being oxidized during photoreaction under visible light. The synergistic effect was also found with pure anatase TiO2 and rutile TiO2. This study demonstrates a possible economical way for environmental cleanup under visible light.

  17. Fluid-structure interaction involving dynamic wetting: 2D modeling and simulations

    Science.gov (United States)

    Liu, Hao-Ran; Gao, Peng; Ding, Hang

    2017-11-01

    In this paper, we propose a hybrid model to compute the capillary force acting on moving solid objects, and combine it with the diffuse-interface immersed-boundary method in Liu and Ding (2015) [18] to simulate fluid-structure interaction (FSI) involving dynamic wetting. Dynamic wetting is very important in the dynamic interaction between fluid-fluid interfaces and small moving objects. Numerical simulations of these flow problems require accurate computation of the capillary force acting on the structure, which depends on the instantaneous position of and the effective surface tension at the moving contact line. In order to achieve this, we use the diffuse-interface immersed-boundary method to simulate the dynamic wetting on moving objects, and propose a hybrid model to compute the effective surface tension at the contact line. Specifically, a diffuse interface model is used for the interface profile out of equilibrium, e.g. at the onset of formation or detachment of contact lines, and a sharp interface model is used for the interface profile at equilibrium. The performance of the method is examined by a variety of numerical experiments. We simulate the sinking of a circular cylinder due to gravity, and study the capillarity-dominated impact dynamics of a solid sphere on a water pool. In both cases the numerical results are quantitatively compared against the experimental data, and good agreements have been achieved. The momentum conservation of the system is carefully checked by studying head-on collision between a drop and a solid sphere. Finally, we apply the method to the self-assembly process of multiple floating cylinders on water surface.

  18. Dynamical Integration of Language and Behavior in a Recurrent Neural Network for Human–Robot Interaction

    Science.gov (United States)

    Yamada, Tatsuro; Murata, Shingo; Arie, Hiroaki; Ogata, Tetsuya

    2016-01-01

    To work cooperatively with humans by using language, robots must not only acquire a mapping between language and their behavior but also autonomously utilize the mapping in appropriate contexts of interactive tasks online. To this end, we propose a novel learning method linking language to robot behavior by means of a recurrent neural network. In this method, the network learns from correct examples of the imposed task that are given not as explicitly separated sets of language and behavior but as sequential data constructed from the actual temporal flow of the task. By doing this, the internal dynamics of the network models both language–behavior relationships and the temporal patterns of interaction. Here, “internal dynamics” refers to the time development of the system defined on the fixed-dimensional space of the internal states of the context layer. Thus, in the execution phase, by constantly representing where in the interaction context it is as its current state, the network autonomously switches between recognition and generation phases without any explicit signs and utilizes the acquired mapping in appropriate contexts. To evaluate our method, we conducted an experiment in which a robot generates appropriate behavior responding to a human’s linguistic instruction. After learning, the network actually formed the attractor structure representing both language–behavior relationships and the task’s temporal pattern in its internal dynamics. In the dynamics, language–behavior mapping was achieved by the branching structure. Repetition of human’s instruction and robot’s behavioral response was represented as the cyclic structure, and besides, waiting to a subsequent instruction was represented as the fixed-point attractor. Thanks to this structure, the robot was able to interact online with a human concerning the given task by autonomously switching phases. PMID:27471463

  19. Discourse-Voice Regulatory Strategies in the Psychotherapeutic Interaction: A State-Space Dynamics Analysis

    Directory of Open Access Journals (Sweden)

    Alemka eTomicic

    2015-04-01

    Full Text Available This study seeks to provide evidence of the dynamics associated with the configurations of discourse-voice regulatory strategies in patient-therapist interactions in relevant episodes within psychotherapeutic sessions. Its central assumption is that discourses manifest themselves differently in terms of their prosodic characteristics according to their regulatory functions in a system of interactions. The association between discourse and vocal quality in patients and therapists was analyzed in a sample of 153 relevant episodes taken from 164 sessions of five psychotherapies using the State Space Grid (SSG method, a graphical tool based on the Dynamic Systems Theory (DST. The results showed eight recurrent and stable discourse-voice regulatory strategies of the patients and three of the therapists. Also, four specific groups of these discourse-voice strategies were identified. The latter were interpreted as regulatory configurations, that is to say, as emergent self-organized groups of discourse-voice regulatory strategies constituting specific interactional systems. Both regulatory strategies and their configurations differed between two types of relevant episodes: Change Episodes and Rupture Episodes. As a whole, these results support the assumption that speaking and listening, as dimensions of the interaction that takes place during therapeutic conversation, occur at different levels. The study not only shows that these dimensions are dependent on each other, but also that they function as a complex and dynamic whole in therapeutic dialogue, generating relational offers which allow the patient and the therapist to regulate each other and shape the psychotherapeutic process that characterizes each type of relevant episode.

  20. Dynamic simulation of concentrated macromolecular solutions with screened long-range hydrodynamic interactions: algorithm and limitations.

    Science.gov (United States)

    Ando, Tadashi; Chow, Edmond; Skolnick, Jeffrey

    2013-09-28

    Hydrodynamic interactions exert a critical effect on the dynamics of macromolecules. As the concentration of macromolecules increases, by analogy to the behavior of semidilute polymer solutions or the flow in porous media, one might expect hydrodynamic screening to occur. Hydrodynamic screening would have implications both for the understanding of macromolecular dynamics as well as practical implications for the simulation of concentrated macromolecular solutions, e.g., in cells. Stokesian dynamics (SD) is one of the most accurate methods for simulating the motions of N particles suspended in a viscous fluid at low Reynolds number, in that it considers both far-field and near-field hydrodynamic interactions. This algorithm traditionally involves an O(N(3)) operation to compute Brownian forces at each time step, although asymptotically faster but more complex SD methods are now available. Motivated by the idea of hydrodynamic screening, the far-field part of the hydrodynamic matrix in SD may be approximated by a diagonal matrix, which is equivalent to assuming that long range hydrodynamic interactions are completely screened. This approximation allows sparse matrix methods to be used, which can reduce the apparent computational scaling to O(N). Previously there were several simulation studies using this approximation for monodisperse suspensions. Here, we employ newly designed preconditioned iterative methods for both the computation of Brownian forces and the solution of linear systems, and consider the validity of this approximation in polydisperse suspensions. We evaluate the accuracy of the diagonal approximation method using an intracellular-like suspension. The diffusivities of particles obtained with this approximation are close to those with the original method. However, this approximation underestimates intermolecular correlated motions, which is a trade-off between accuracy and computing efficiency. The new method makes it possible to perform large

  1. 29 CFR 1926.1126 - Chromium (VI).

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Chromium (VI). 1926.1126 Section 1926.1126 Labor... Chromium (VI). (a) Scope. (1) This standard applies to occupational exposures to chromium (VI) in all forms... objective data demonstrating that a material containing chromium or a specific process, operation, or...

  2. 29 CFR 1915.1026 - Chromium (VI).

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Chromium (VI). 1915.1026 Section 1915.1026 Labor... § 1915.1026 Chromium (VI). (a) Scope. (1) This standard applies to occupational exposures to chromium (VI... cement; or (4) Where the employer has objective data demonstrating that a material containing chromium or...

  3. Effect of mechanical strain on the collagen VI pericellular matrix in anterior cruciate ligament fibroblasts.

    Science.gov (United States)

    Sardone, Francesca; Traina, Francesco; Tagliavini, Francesca; Pellegrini, Camilla; Merlini, Luciano; Squarzoni, Stefano; Santi, Spartaco; Neri, Simona; Faldini, Cesare; Maraldi, Nadir; Sabatelli, Patrizia

    2014-07-01

    Cell-extracellular matrix interaction plays a major role in maintaining the structural integrity of connective tissues and sensing changes in the biomechanical environment of cells. Collagen VI is a widely expressed non-fibrillar collagen, which regulates tissues homeostasis. The objective of the present investigation was to extend our understanding of the role of collagen VI in human ACL. This study shows that collagen VI is associated both in vivo and in vitro to the cell membrane of knee ACL fibroblasts, contributing to the constitution of a microfibrillar pericellular matrix. In cultured cells the localization of collagen VI at the cell surface correlated with the expression of NG2 proteoglycan, a major collagen VI receptor. The treatment of ACL fibroblasts with anti-NG2 antibody abolished the localization of collagen VI indicating that collagen VI pericellular matrix organization in ACL fibroblasts is mainly mediated by NG2 proteoglycan. In vitro mechanical strain injury dramatically reduced the NG2 proteoglycan protein level, impaired the association of collagen VI to the cell surface, and promoted cell cycle withdrawal. Our data suggest that the injury-induced alteration of specific cell-ECM interactions may lead to a defective fibroblast self-renewal and contribute to the poor regenerative ability of ACL fibroblasts. © 2013 Wiley Periodicals, Inc.

  4. Red Queen dynamics in multi-host and multi-parasite interaction system.

    Science.gov (United States)

    Rabajante, Jomar F; Tubay, Jerrold M; Uehara, Takashi; Morita, Satoru; Ebert, Dieter; Yoshimura, Jin

    2015-04-22

    In host-parasite systems, dominant host types are expected to be eventually replaced by other hosts due to the elevated potency of their specific parasites. This leads to changes in the abundance of both hosts and parasites exhibiting cycles of alternating dominance called Red Queen dynamics. Host-parasite models with less than three hosts and parasites have been demonstrated to exhibit Red Queen cycles, but natural host-parasite interactions typically involve many host and parasite types resulting in an intractable system with many parameters. Here we present numerical simulations of Red Queen dynamics with more than ten hosts and specialist parasites under the condition of no super-host nor super-parasite. The parameter region where the Red Queen cycles arise contracts as the number of interacting host and parasite types increases. The interplay between inter-host competition and parasite infectivity influences the condition for the Red Queen dynamics. Relatively large host carrying capacity and intermediate rates of parasite mortality result in never-ending cycles of dominant types.

  5. Interacting Learning Processes during Skill Acquisition: Learning to control with gradually changing system dynamics.

    Science.gov (United States)

    Ludolph, Nicolas; Giese, Martin A; Ilg, Winfried

    2017-10-16

    There is increasing evidence that sensorimotor learning under real-life conditions relies on a composition of several learning processes. Nevertheless, most studies examine learning behaviour in relation to one specific learning mechanism. In this study, we examined the interaction between reward-based skill acquisition and motor adaptation to changes of object dynamics. Thirty healthy subjects, split into two groups, acquired the skill of balancing a pole on a cart in virtual reality. In one group, we gradually increased the gravity, making the task easier in the beginning and more difficult towards the end. In the second group, subjects had to acquire the skill on the maximum, most difficult gravity level. We hypothesized that the gradual increase in gravity during skill acquisition supports learning despite the necessary adjustments to changes in cart-pole dynamics. We found that the gradual group benefits from the slow increment, although overall improvement was interrupted by the changes in gravity and resulting system dynamics, which caused short-term degradations in performance and timing of actions. In conclusion, our results deliver evidence for an interaction of reward-based skill acquisition and motor adaptation processes, which indicates the importance of both processes for the development of optimized skill acquisition schedules.

  6. Interaction between viruses and clays in static and dynamic batch systems.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2010-06-15

    Bacteriophage MS2 and PhiX174 were used as surrogates for human viruses in order to investigate the interaction between viruses and clay particles. The selected phyllosilicate clays were kaolinite and bentonite (>90% montmorillonite). A series of static and dynamic experiments were conducted at two different temperatures (4 and 25 degrees C) to investigate the effect of temperature and agitation (dynamic experiments) on virus adsorption onto clays. Appropriate adsorption isotherms were determined. Electrokinetic features of bacteriophages and clays were quantified at different pH and ionic strength (IS). Moreover, interaction energies between viruses and clays were calculated for the experimental conditions (pH 7 and IS = 2 mM) by applying the DLVO theory. The experimental results shown that virus adsorption increases linearly with suspended virus concentration. The observed distribution coefficient (K(d)) was higher for MS2 than PhiX174. The observed K(d) values were higher for the dynamic than static experiments, and increased with temperature. The results of this study provided basic information for the effectiveness of clays to remove viruses by adsorption from dilute aqueous solutions. No previous study has explored the combined effect of temperature and agitation on virus adsorption onto clays.

  7. Probing the dynamics of restriction endonuclease NgoMIV-DNA interaction by single-molecule FRET.

    Science.gov (United States)

    Tutkus, Marijonas; Sasnauskas, Giedrius; Rutkauskas, Danielis

    2017-12-01

    Many type II restriction endonucleases require two copies of their recognition sequence for optimal activity. Concomitant binding of two DNA sites by such an enzyme produces a DNA loop. Here we exploit single-molecule Förster resonance energy transfer (smFRET) of surface-immobilized DNA fragments to study the dynamics of DNA looping induced by tetrameric endonuclease NgoMIV. We have employed a DNA fragment with two NgoMIV recognition sites and a FRET dye pair such that upon protein-induced DNA looping the dyes are brought to close proximity resulting in a FRET signal. The dynamics of DNA-NgoMIV interactions proved to be heterogeneous, with individual smFRET trajectories exhibiting broadly different average looped state durations. Distinct types of the dynamics were attributed to different types of DNA-protein complexes, mediated either by one NgoMIV tetramer simultaneously bound to two specific sites ("slow" trajectories) or by semi-specific interactions of two DNA-bound NgoMIV tetramers ("fast" trajectories), as well as to conformational heterogeneity of individual NgoMIV molecules. © 2017 Wiley Periodicals, Inc.

  8. Conditional co-movement and dynamic interactions: US and BRIC equity markets

    Directory of Open Access Journals (Sweden)

    Singh Amanjot

    2017-01-01

    Full Text Available The present study attempts to capture conditional or time-varying co-movement and dynamic interactions between the US and BRIC (Brazil, Russia, India, and China equity markets across the sample period 2004 to 2014 by employing diverse econometric models. The sample period is further divided into three different sub-periods concerning the US financial crisis period, viz. pre-crisis, crisis, and post-crisis periods. The vector autoregression- dynamic conditional correlation-multivariate asymmetric generalized autoregressive conditional heteroskedastic [VAR-DCC-MVAGARCH (1.1] model and Toda-Yamamoto’s (1995 Granger causality tests are employed for the purpose of overall analysis in a multivariate framework. The results report the existence of time-varying co-movement between the US and BRIC equity markets, whereby co-movement between the US and Brazilian markets is found to be the highest, followed by the Russian, Indian, and Chinese equity markets. Dynamic interactions are also registered between the respective US/BRIC comovements during different sub-periods. The results have important implications for market participants and policymakers.

  9. Self-similar nonequilibrium dynamics of a many-body system with power-law interactions

    Science.gov (United States)

    Gutiérrez, Ricardo; Garrahan, Juan P.; Lesanovsky, Igor

    2015-12-01

    The influence of power-law interactions on the dynamics of many-body systems far from equilibrium is much less explored than their effect on static and thermodynamic properties. To gain insight into this problem we introduce and analyze here an out-of-equilibrium deposition process in which the deposition rate of a given particle depends as a power law on the distance to previously deposited particles. This model draws its relevance from recent experimental progress in the domain of cold atomic gases, which are studied in a setting where atoms that are excited to high-lying Rydberg states interact through power-law potentials that translate into power-law excitation rates. The out-of-equilibrium dynamics of this system turns out to be surprisingly rich. It features a self-similar evolution which leads to a characteristic power-law time dependence of observables such as the particle concentration, and results in a scale invariance of the structure factor. Our findings show that in dissipative Rydberg gases out of equilibrium the characteristic distance among excitations—often referred to as the blockade radius—is not a static but rather a dynamic quantity.

  10. Demonstrating universal scaling for dynamics of Yukawa one-component plasmas after an interaction quench.

    Science.gov (United States)

    Langin, T K; Strickler, T; Maksimovic, N; McQuillen, P; Pohl, T; Vrinceanu, D; Killian, T C

    2016-02-01

    The Yukawa one-component plasma (OCP) model is a paradigm for describing plasmas that contain one component of interest and one or more other components that can be treated as a neutralizing, screening background. In appropriately scaled units, interactions are characterized entirely by a screening parameter, κ. As a result, systems of similar κ show the same dynamics, regardless of the underlying parameters (e.g., density and temperature). We demonstrate this behavior using ultracold neutral plasmas (UNPs) created by photoionizing a cold (T≤10 mK) gas. The ions in UNP systems are well described by the Yukawa model, with the electrons providing the screening. Creation of the plasma through photoionization can be thought of as a rapid quench of the interaction potential from κ=∞ to a final κ value set by the electron density and temperature. We demonstrate experimentally that the postquench dynamics are universal in κ over a factor of 30 in density and an order of magnitude in temperature. Results are compared with molecular-dynamics simulations. We also demonstrate that features of the postquench kinetic energy evolution, such as disorder-induced heating and kinetic-energy oscillations, can be used to determine the plasma density and the electron temperature.

  11. Dynamics of Disagreement: Large-Scale Temporal Network Analysis Reveals Negative Interactions in Online Collaboration

    Science.gov (United States)

    Tsvetkova, Milena; García-Gavilanes, Ruth; Yasseri, Taha

    2016-11-01

    Disagreement and conflict are a fact of social life. However, negative interactions are rarely explicitly declared and recorded and this makes them hard for scientists to study. In an attempt to understand the structural and temporal features of negative interactions in the community, we use complex network methods to analyze patterns in the timing and configuration of reverts of article edits to Wikipedia. We investigate how often and how fast pairs of reverts occur compared to a null model in order to control for patterns that are natural to the content production or are due to the internal rules of Wikipedia. Our results suggest that Wikipedia editors systematically revert the same person, revert back their reverter, and come to defend a reverted editor. We further relate these interactions to the status of the involved editors. Even though the individual reverts might not necessarily be negative social interactions, our analysis points to the existence of certain patterns of negative social dynamics within the community of editors. Some of these patterns have not been previously explored and carry implications for the knowledge collection practice conducted on Wikipedia. Our method can be applied to other large-scale temporal collaboration networks to identify the existence of negative social interactions and other social processes.

  12. Interaction of Tenebrio Molitor Antifreeze Protein with Ice Crystal: Insights from Molecular Dynamics Simulations.

    Science.gov (United States)

    Ramya, L; Ramakrishnan, Vigneshwar

    2016-07-01

    Antifreeze proteins (AFP) observed in cold-adapting organisms bind to ice crystals and prevent further ice growth. However, the molecular mechanism of AFP-ice binding and AFP-inhibited ice growth remains unclear. Here we report the interaction of the insect antifreeze protein (Tenebrio molitor, TmAFP) with ice crystal by molecular dynamics simulation studies. Two sets of simulations were carried out at 263 K by placing the protein near the primary prism plane (PP) and basal plane (BL) of the ice crystal. To delineate the effect of temperatures, both the PP and BL simulations were carried out at 253 K as well. The analyses revealed that the protein interacts strongly with the ice crystal in BL simulation than in PP simulation both at 263 K and 253 K. Further, it was observed that the interactions are primarily mediated through the interface waters. We also observed that as the temperature decreases, the interaction between the protein and the ice increases which can be attributed to the decreased flexibility and the increased structuring of the protein at low temperature. In essence, our study has shed light on the interaction mechanism between the TmAFP antifreeze protein and the ice crystal. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Dynamics of a trapped 1D Bose gas for finite interaction strength

    Science.gov (United States)

    Muth, Dominik; Mering, Alexander; Fleischhauer, Michael

    2008-05-01

    We investigate the dynamics of a 1D Bose gas in a harmonic trap with point like interactions, recently studied experimentally in [1]. Starting from a discretisation of this model we calculate the groundstate properties and time evolution in the resulting Bose-Hubbard model using the time-evolving block decimation algorithm, TEBD. Both the case of vanishing interaction strength corresponding to the trivial case of free bosons, and the quasi integrable hard core case are well understood [2]. Furthermore recently exact solutions have been found in the absence of a trap potential and few particles [3]. We are focusing on the dynamics in the region with finite repulsive interaction and in a trap. Forall cases, using TEBD, we are able to calculate the propagation in both momentum and real space. [1] T. Kinoshita, T. Wenger, D. Weiss, Nature 440, 900 (2006) [2] M. Rigol, V. Dunjko, V. Yurovsky, M. Olshanii, Phys. Rev. Lett. 98, 050405 (2007) [3] H. Buljan, R. Pezer and T. Gasenzer, arXiv:0709.1444 (2007)

  14. Biomolecular interactions modulate macromolecular structure and dynamics in atomistic model of a bacterial cytoplasm

    Science.gov (United States)

    Yu, Isseki; Mori, Takaharu; Ando, Tadashi; Harada, Ryuhei; Jung, Jaewoon; Sugita, Yuji; Feig, Michael

    2016-01-01

    Biological macromolecules function in highly crowded cellular environments. The structure and dynamics of proteins and nucleic acids are well characterized in vitro, but in vivo crowding effects remain unclear. Using molecular dynamics simulations of a comprehensive atomistic model cytoplasm we found that protein-protein interactions may destabilize native protein structures, whereas metabolite interactions may induce more compact states due to electrostatic screening. Protein-protein interactions also resulted in significant variations in reduced macromolecular diffusion under crowded conditions, while metabolites exhibited significant two-dimensional surface diffusion and altered protein-ligand binding that may reduce the effective concentration of metabolites and ligands in vivo. Metabolic enzymes showed weak non-specific association in cellular environments attributed to solvation and entropic effects. These effects are expected to have broad implications for the in vivo functioning of biomolecules. This work is a first step towards physically realistic in silico whole-cell models that connect molecular with cellular biology. DOI: http://dx.doi.org/10.7554/eLife.19274.001 PMID:27801646

  15. Moisture-temperature interactions in soil carbon fluxes as a result of substrate dynamics

    Science.gov (United States)

    Moyano, Fernando; Vasilyeva, Nadezda; Menichetti, Lorenzo

    2017-04-01

    Soil carbon fluxes are complex and often non-linear with respect to their drivers. Mechanistic soil carbon models have the capacity to simulate such non-linear responses, but identifying optimal model structures and parameterizations remains a challenge. In this study we focus on the combined effects of temperature and moisture on two soils contrasting in carbon content. We applied a data driven modelling approach to study the interactive effects of temperature and moisture on soil microbial CO2 production. Using a process-based model we found that substrate and enzyme dynamics create interactive effects that occurring in both directions. The observed interactions emerge in model simulations that combine diffusion with non-linear reaction kinetics. Diffusion limitations lead to a decoupling of respiration and decomposition fluxes and to differences in the response to temperature that occurs at all moisture levels but are more pronounced under drier, colder and generally low substrate conditions. Our model also demonstrates the time-dependent nature of temperature and moisture responses, a result that has implications for predictions at different time scales. The findings highlight the importance of moisture for understanding and predicting both short and long term soil carbon dynamics.

  16. Dynamic Characterization and Interaction Control of the CBM-Motus Robot for Upper-Limb Rehabilitation

    Directory of Open Access Journals (Sweden)

    Loredana Zollo

    2013-10-01

    Full Text Available This paper presents dynamic characterization and control of an upper-limb rehabilitation machine aimed at improving robot performance in the interaction with the patient. An integrated approach between mechanics and control is the key issue of the paper for the development of a robotic machine with desirable dynamic properties. Robot inertial and acceleration properties are studied in the workspace via a graphical representation based on ellipses. Robot friction is experimentally retrieved by means of a parametric identification procedure. A current-based impedance control is developed in order to compensate for friction and enhance control performance in the interaction with the patient by means of force feedback, without increasing system inertia. To this end, servo-amplifier motor currents are monitored to provide force feedback in the interaction, thus avoiding the need for force sensors mounted at the robot end-effector. Current-based impedance control is implemented on the robot; experimental results in free space as well as in constrained space are provided.

  17. Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

    Science.gov (United States)

    Ciota, Alexander T.; Kramer, Laura D.

    2013-01-01

    West Nile virus (WNV; Flavivirus; Flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. Mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. The concept of vectorial capacity integrates these factors to address interactions of the virus with the arthropod host, leading to a clearer understanding of their complex interrelationships, how they affect transmission of vector-borne disease, and how they impact human health. Vertebrate factors including host competence, population dynamics, and immune status also affect transmission dynamics. The complexity of these interactions are further exacerbated by the fact that not only can divergent hosts differentially alter the virus, but the virus also can affect both vertebrate and invertebrate hosts in ways that significantly alter patterns of virus transmission. This chapter concentrates on selected components of the virus-vector-vertebrate interrelationship, focusing specifically on how interactions between vector, virus, and environment shape the patterns and intensity of WNV transmission. PMID:24351794

  18. Molecular dynamics simulations on interaction between bacterial proteins: Implication on pathogenic activities.

    Science.gov (United States)

    Mondal, Manas; Chakrabarti, Jaydeb; Ghosh, Mahua

    2017-12-18

    We perform molecular dynamics simulation studies on interaction between bacterial proteins: an outer-membrane protein STY3179 and a yfdX protein STY3178 of Salmonella Typhi. STY3179 has been found to be involved in bacterial adhesion and invasion. STY3178 is recently biophysically characterized. It is a soluble protein having antibiotic binding and chaperon activity capabilities. These two proteins co-occur and are from neighboring gene in Salmonella Typhi-occurrence of homologs of both STY3178 and STY3179 are identified in many Gram-negative bacteria. We show using homology modeling, docking followed by molecular dynamics simulation that they can form a stable complex. STY3178 belongs to aqueous phase, while the beta barrel portion of STY3179 remains buried in DPPC bilayer with extra-cellular loops exposed to water. To understand the molecular basis of interaction between STY3178 and STY3179, we compute the conformational thermodynamics which indicate that these two proteins interact through polar and acidic residues belonging to their interfacial region. Conformational thermodynamics results further reveal instability of certain residues in extra-cellular loops of STY3179 upon complexation with STY3178 which is an indication for binding with host cell protein laminin. © 2017 Wiley Periodicals, Inc.

  19. Electronic dynamics due to exchange interaction with holes in GaAs

    Science.gov (United States)

    Schneider, Hans Christian; Krauß, Michael

    2010-02-01

    We present an investigation of electron-spin dynamics in p-doped bulk GaAs due to the electron-hole exchange interaction, aka the Bir-Aronov-Pikus mechanism. We discuss under which conditions a spin relaxation times for this mechanism is, in principle, accessible to experimental techniques, in particular to 2-photon photoemission, but also Faraday/Kerr effect measurements. We give numerical results for the spin relaxation time for a range of p-doping densities and temperatures. We then go beyond the relaxation time approximation and calculate numerically the spin-dependent electron dynamics by including the spin-flip electron-hole exchange scattering and spin-conserving carrier Coulomb scattering at the level of Boltzmann scattering integrals. We show that the electronic dynamics deviates from the simple spin-relaxation dynamics for electrons excited at high energies where the thermalization does not take place faster than the spin relaxation time. We also present a derivation of the influence of screening on the electron-hole exchange scattering and conclude that it can be neglected for the case of GaAs, but may become important for narrow-gap semiconductors.

  20. Dynamics of person-to-person interactions from distributed RFID sensor networks.

    Science.gov (United States)

    Cattuto, Ciro; Van den Broeck, Wouter; Barrat, Alain; Colizza, Vittoria; Pinton, Jean-François; Vespignani, Alessandro

    2010-07-15

    Digital networks, mobile devices, and the possibility of mining the ever-increasing amount of digital traces that we leave behind in our daily activities are changing the way we can approach the study of human and social interactions. Large-scale datasets, however, are mostly available for collective and statistical behaviors, at coarse granularities, while high-resolution data on person-to-person interactions are generally limited to relatively small groups of individuals. Here we present a scalable experimental framework for gathering real-time data resolving face-to-face social interactions with tunable spatial and temporal granularities. We use active Radio Frequency Identification (RFID) devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We analyze the dynamics of person-to-person interaction networks obtained in three high-resolution experiments carried out at different orders of magnitude in community size. The data sets exhibit common statistical properties and lack of a characteristic time scale from 20 seconds to several hours. The association between the number of connections and their duration shows an interesting super-linear behavior, which indicates the possibility of defining super-connectors both in the number and intensity of connections. Taking advantage of scalability and resolution, this experimental framework allows the monitoring of social interactions, uncovering similarities in the way individuals interact in different contexts, and identifying patterns of super-connector behavior in the community. These results could impact our understanding of all phenomena driven by face-to-face interactions, such as the spreading of transmissible infectious diseases and information.

  1. Dynamics of person-to-person interactions from distributed RFID sensor networks.

    Directory of Open Access Journals (Sweden)

    Ciro Cattuto

    Full Text Available BACKGROUND: Digital networks, mobile devices, and the possibility of mining the ever-increasing amount of digital traces that we leave behind in our daily activities are changing the way we can approach the study of human and social interactions. Large-scale datasets, however, are mostly available for collective and statistical behaviors, at coarse granularities, while high-resolution data on person-to-person interactions are generally limited to relatively small groups of individuals. Here we present a scalable experimental framework for gathering real-time data resolving face-to-face social interactions with tunable spatial and temporal granularities. METHODS AND FINDINGS: We use active Radio Frequency Identification (RFID devices that assess mutual proximity in a distributed fashion by exchanging low-power radio packets. We analyze the dynamics of person-to-person interaction networks obtained in three high-resolution experiments carried out at different orders of magnitude in community size. The data sets exhibit common statistical properties and lack of a characteristic time scale from 20 seconds to several hours. The association between the number of connections and their duration shows an interesting super-linear behavior, which indicates the possibility of defining super-connectors both in the number and intensity of connections. CONCLUSIONS: Taking advantage of scalability and resolution, this experimental framework allows the monitoring of social interactions, uncovering similarities in the way individuals interact in different contexts, and identifying patterns of super-connector behavior in the community. These results could impact our understanding of all phenomena driven by face-to-face interactions, such as the spreading of transmissible infectious diseases and information.

  2. Stiffness Characteristics of High-Speed Railway Turnout and the Effect on the Dynamic Train-Turnout Interaction

    National Research Council Canada - National Science Library

    Jingmang Xu; Ping Wang; Xiaochuan Ma; Yuan Gao; Rong Chen

    2016-01-01

      Track stiffness in railway turnouts is variable due to differences in structural composition along the longitudinal direction, which will lead to severe dynamic interaction between train and turnout...

  3. Interaction learning for dynamic movement primitives used in cooperative robotic tasks

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Biehl, Martin; Aein, Mohamad Javad

    2013-01-01

    Abstract Since several years dynamic movement primitives (DMPs) are more and more getting into the center of interest for flexible movement control in robotics. In this study we introduce sensory feedback together with a predictive learning mechanism which allows tightly coupled dual-agent system...... to cooperate. Simulations as well as real-robot experiments are shown. Interestingly, all these mechanisms are entirely based on low level interactions without any planning or cognitive component.......Abstract Since several years dynamic movement primitives (DMPs) are more and more getting into the center of interest for flexible movement control in robotics. In this study we introduce sensory feedback together with a predictive learning mechanism which allows tightly coupled dual-agent systems...

  4. GOING NOT STAYING: CONCEPTS OF “TVORCHESTVO” AND “KREATIVNOST” IN DYNAMIC INTERACTION

    Directory of Open Access Journals (Sweden)

    Nataliya M. Azarova

    2016-01-01

    Full Text Available The article considers the concepts of tvorchestvo and kreativ (kreativnost’, elicits their distinctive features, and analyses the functions of the words tvorchestvo, kreativ and their derivatives in various discourse practices. The paper analyzes the usage and the ways to avoid the words tvorchestvo and kreativ and their derivatives in the right-wing liberal and stateoriented publications. Interaction of the concepts tvorchestvo and kreativ in the beginning of the 21st century manifests a certain dynamics: progressive substitution of tvorchestvo by kreativ in various discourses, at the first stage, and, inversely, diminishing of the use of kreativ, its shift towards terminological usage, and partial restitution of tvorchestvo, at a later stage. The social dynamics of usage of the concepts tvorchestvo and kreativ (kreativnost’ shows - in connection the crisis, when kreativ not involving systemic reasoning disappears from the public rhetoric - that we should expect a somewhat return of the concept and the word tvorchestvo in a broad discursive practice. 

  5. Some aspects of the interaction between chemical and dynamic processes relating to the Antarctic ozone hole

    Science.gov (United States)

    Eckman, R. S.; Turner, R. E.; Blackshear, W. T.; Fairlie, T. D. A.; Grose, W. L.

    1993-01-01

    Observational and modeling studies have been conducted to examine the interaction between the chemical and dynamical processes that occur during springtime in the lower stratosphere of the Southern Hemisphere. The temporal evolution of the ozone distribution and the circulation during 1987 is contrasted with that for 1988 as an illustrative example of how dynamical processes and the resulting meteorological conditions modulate the ozone depletion. Concurrently with the observational analysis, an effort was initiated to simulate the ozone depletion during austral spring using a 3D chemical/transport model. The model includes a parameterized representation of the heterogeneous processes thought to be important in this region. The simulation indicates that the inclusion of this additional chemistry, which results in the release of free chlorine and the redistribution of odd nitrogen into reservoir species, reproduces many aspects of the observations.

  6. Dynamic soil-pile-interaction effects on eigenfrequency and damping of slender structures

    DEFF Research Database (Denmark)

    Zania, Varvara

    2014-01-01

    of the dynamic soil-pile-interaction on the natural vibration characteristics of the flexibly supported structure. For this purpose a two-step iterative procedure has been developed based on two analytical solutions. The frequency dependent dynamic stiffness and damping coefficients are taken into consideration......-conservative overestimation of the eigenfrequency and underestimation of damping especially for small slenderness ratios and high flexibility factor of the soil – pile system (short, rigid piles). The observed trends become even more prominent as the height of the slender structure increases. The effect of the monopile...... foundation properties on the natural vibration characteristics was also examined. The influence of the frequency dependent impedances was proven significant, since the modified SSI eigenfrequency decreased substantially, when the structural eigenfrequency was set between the first and the second...

  7. DNA-controlled dynamic colloidal nanoparticle systems for mediating cellular interaction

    Science.gov (United States)

    Ohta, Seiichi; Glancy, Dylan; Chan, Warren C. W.

    2016-02-01

    Precise control of biosystems requires development of materials that can dynamically change physicochemical properties. Inspired by the ability of proteins to alter their conformation to mediate function, we explored the use of DNA as molecular keys to assemble and transform colloidal nanoparticle systems. The systems consist of a core nanoparticle surrounded by small satellites, the conformation of which can be transformed in response to DNA via a toe-hold displacement mechanism. The conformational changes can alter the optical properties and biological interactions of the assembled nanosystem. Photoluminescent signal is altered by changes in fluorophore-modified particle distance, whereas cellular targeting efficiency is increased 2.5 times by changing the surface display of targeting ligands. These concepts provide strategies for engineering dynamic nanotechnology systems for navigating complex biological environments.

  8. Out-of-equilibrium dynamics in superspin glass state of strongly interacting magnetic nanoparticle assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Nakamae, Sawako, E-mail: Sawako.nakamae@cea.fr

    2014-04-15

    Interacting magnetic nanoparticles display a wide variety of magnetic behaviors ranging from modified superparamagnetism, superspin glass to possibly, superferromagnetism. The superspin glass state is described by its slow and out-of-equilibrium magnetic behaviors akin to those found in atomic spin glasses. In this article, recent experimental findings on superspin correlation length growth and the violation of the fluctuation-dissipation theorem obtained in concentrated frozen ferrofluids are presented to illustrate certain out-of-equilibrium dynamics behavior in superspin glasses. - Highlights: • Recent experimental findings on superspin glass dynamics in magnetic nanoparticle systems. • Advantages of magnetic nanoparticles for the study of spin glass physics. • Open questions and future directions in superspin glass research.

  9. Dynamics of interacting bosons using the Herman-Kluk semiclassical initial value representation

    Science.gov (United States)

    Ray, Shouryya; Ostmann, Paula; Simon, Lena; Grossmann, Frank; Strunz, Walter T.

    2016-04-01

    Recent experimental progress in monitoring the dynamics of ultracold gases in optical lattices necessitates a quantitative theoretical description for a significant number of bosons. In the present paper, we investigate if time-dependent semiclassical initial value methodology, with propagators expressed as integrals over phase space and using classical trajectories, is suitable to describe interacting bosons, concentrating on a single mode. Despite the nonlinear contribution from the self-interaction, the corresponding classical dynamics allows for a largely analytical treatment of the semiclassical propagator. We find that application of the Herman-Kluk (HK) propagator conserves unitarity in the semiclassical limit, but a decay of the norm is seen for low particle numbers n. The frozen Gaussian approximation (FGA) (HK with unit prefactor) is explicitly shown to violate unitarity in the present system for non-vanishing interaction strength, even in the semiclassical limit. Furthermore, we show by evaluating the phase space integral in steepest descent approximation, that the HK propagator reproduces the exact spectrum correctly in the semiclassical limit (n\\to ∞ ). An error is, however, incurred in next-to-next-to-leading order (small parameter 1/n), as seen upon numerical evaluation of the integral and confirmed analytically by considering finite n corrections to the steepest descent calculations. The FGA, in contrast, is only accurate to lowest order, and an erroneous next-to-leading order term in the energy spectrum was found analytically. Finally, as an example application, we study the dynamics of wave packets by computing the time evolution of the Wigner function. While the often-used truncated Wigner approximation cannot capture any interferences present in the exact quantum mechanical solution (known analytically), we find that the HK approach, despite also using classical information only, reproduces the salient features of the exact solution correctly.

  10. Multi-scale interactions of geological processes during mineralization: cascade dynamics model and multifractal simulation

    Directory of Open Access Journals (Sweden)

    L. Yao

    2011-03-01

    Full Text Available Relations between mineralization and certain geological processes are established mostly by geologist's knowledge of field observations. However, these relations are descriptive and a quantitative model of how certain geological processes strengthen or hinder mineralization is not clear, that is to say, the mechanism of the interactions between mineralization and the geological framework has not been thoroughly studied. The dynamics behind these interactions are key in the understanding of fractal or multifractal formations caused by mineralization, among which singularities arise due to anomalous concentration of metals in narrow space. From a statistical point of view, we think that cascade dynamics play an important role in mineralization and studying them can reveal the nature of the various interactions throughout the process. We have constructed a multiplicative cascade model to simulate these dynamics. The probabilities of mineral deposit occurrences are used to represent direct results of mineralization. Multifractal simulation of probabilities of mineral potential based on our model is exemplified by a case study dealing with hydrothermal gold deposits in southern Nova Scotia, Canada. The extent of the impacts of certain geological processes on gold mineralization is related to the scale of the cascade process, especially to the maximum cascade division number nmax. Our research helps to understand how the singularity occurs during mineralization, which remains unanswered up to now, and the simulation may provide a more accurate distribution of mineral deposit occurrences that can be used to improve the results of the weights of evidence model in mapping mineral potential.

  11. Speeding Up Exact Solutions of Interactive Dynamic Influence Diagrams Using Action Equivalence

    DEFF Research Database (Denmark)

    Zeng, Yifeng; Prashant, Doshi

    2009-01-01

    Interactive dynamic influence diagrams (I-DIDs) are graphical models for sequential decision making in partially observable settings shared by other agents. Algorithms for solving I-DIDs face the challenge of an exponentially growing space of candidate models ascribed to other agents, over time. ...... at a single time step. We show how to update these augmented classes and prove that our method is exact. The new approach enables us to bound the aggregated model space by the cardinality of other agents' actions. We evaluate its performance and provide empirical results in support....

  12. The ‘hit’ phenomenon: a mathematical model of human dynamics interactions as a stochastic process

    Science.gov (United States)

    Ishii, Akira; Arakaki, Hisashi; Matsuda, Naoya; Umemura, Sanae; Urushidani, Tamiko; Yamagata, Naoya; Yoshida, Narihiko

    2012-06-01

    A mathematical model for the ‘hit’ phenomenon in entertainment within a society is presented as a stochastic process of human dynamics interactions. The model uses only the advertisement budget time distribution as an input, and word-of-mouth (WOM), represented by posts on social network systems, is used as data to make a comparison with the calculated results. The unit of time is days. The WOM distribution in time is found to be very close to the revenue distribution in time. Calculations for the Japanese motion picture market based on the mathematical model agree well with the actual revenue distribution in time.

  13. Quantum corrected Langevin dynamics for adsorbates on metal surfaces interacting with hot electrons

    DEFF Research Database (Denmark)

    Olsen, Thomas; Schiøtz, Jakob

    2010-01-01

    We investigate the importance of including quantized initial conditions in Langevin dynamics for adsorbates interacting with a thermal reservoir of electrons. For quadratic potentials the time evolution is exactly described by a classical Langevin equation and it is shown how to rigorously obtain...... mechanical master equation approach. With CO on Cu(100) as an example, we demonstrate the effect for a system with ab initio frictional tensor and potential energy surfaces and show that quantizing the initial conditions can have a large impact on both the desorption probability and the distribution...

  14. Interaction sorting method for molecular dynamics on multi-core SIMD CPU architecture.

    Science.gov (United States)

    Matvienko, Sergey; Alemasov, Nikolay; Fomin, Eduard

    2015-02-01

    Molecular dynamics (MD) is widely used in computational biology for studying binding mechanisms of molecules, molecular transport, conformational transitions, protein folding, etc. The method is computationally expensive; thus, the demand for the development of novel, much more efficient algorithms is still high. Therefore, the new algorithm designed in 2007 and called interaction sorting (IS) clearly attracted interest, as it outperformed the most efficient MD algorithms. In this work, a new IS modification is proposed which allows the algorithm to utilize SIMD processor instructions. This paper shows that the improvement provides an additional gain in performance, 9% to 45% in comparison to the original IS method.

  15. From Brain-Environment Connections to Temporal Dynamics and Social Interaction: Principles of Human Brain Function.

    Science.gov (United States)

    Hari, Riitta

    2017-06-07

    Experimental data about brain function accumulate faster than does our understanding of how the brain works. To tackle some general principles at the grain level of behavior, I start from the omnipresent brain-environment connection that forces regularities of the physical world to shape the brain. Based on top-down processing, added by sparse sensory information, people are able to form individual "caricature worlds," which are similar enough to be shared among other people and which allow quick and purposeful reactions to abrupt changes. Temporal dynamics and social interaction in natural environments serve as further essential organizing principles of human brain function. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Hvad bruger vi tiden til?

    DEFF Research Database (Denmark)

    Brichet, Nathalia Sofie; Hastrup, Frida

    2016-01-01

    I denne artikel kaster vi et antropologisk blik på samtidsarkæologi ved at diskutere måder, hvorpå antropologiske analyser kan adressere tid, fortidige hændelser og historiske processer. Vi argumenterer for, at en radikal nutidsorientering er en afgørende kvalitet ved det antropologiske feltarbej...... komplicerer en ide om fortidige (gamle eller nyere) objekter som nogle, der kan udgraves......., hvis sigte det er løbende at generere sit materiale nu og her med henblik på at skabe nye forståelser, historier og forslag til mangeartede sammenhænge. En implikation af dette er, at uanset hvor ’historisk’ et antropologisk materiale end måtte være, må det altid ses som samtidigt og ufærdigt, hvilket...

  17. A Wicked Problem: Early Childhood Safety in the Dynamic, Interactive Environment of Home

    Directory of Open Access Journals (Sweden)

    Jean Simpson

    2013-04-01

    Full Text Available Young children being injured at home is a perennial problem. When parents of young children and family workers discussed what influenced parents’ perceptions and responses to child injury risk at home, both “upstream” and “downstream” causal factors were identified. Among the former, complex and interactive facets of society and contemporary living emerged as potentially critical features. The “wicked problems” model arose from the need to find resolutions for complex problems in multidimensional environments and it proved a useful analogy for child injury. Designing dynamic strategies to provide resolutions to childhood injury, may address our over-dependence on ‘tame solutions’ that only deal with physical cause-and-effect relationships and which cannot address the complex interactive contexts in which young children are often injured.

  18. A wicked problem: early childhood safety in the dynamic, interactive environment of home.

    Science.gov (United States)

    Simpson, Jean; Fougere, Geoff; McGee, Rob

    2013-04-24

    Young children being injured at home is a perennial problem. When parents of young children and family workers discussed what influenced parents' perceptions and responses to child injury risk at home, both "upstream" and "downstream" causal factors were identified. Among the former, complex and interactive facets of society and contemporary living emerged as potentially critical features. The "wicked problems" model arose from the need to find resolutions for complex problems in multidimensional environments and it proved a useful analogy for child injury. Designing dynamic strategies to provide resolutions to childhood injury, may address our over-dependence on 'tame solutions' that only deal with physical cause-and-effect relationships and which cannot address the complex interactive contexts in which young children are often injured.

  19. Dissimilar interaction of CB1/CB2 with lipid bilayers as revealed by molecular dynamics simulation.

    Science.gov (United States)

    Ramos, Javier; Cruz, Víctor L; Martínez-Salazar, Javier; Campillo, Nuria E; Páez, Juan A

    2011-03-07

    Cannabinoid receptors CB1 and CB2 are a striking class of transmembrane proteins involved in a high number of important biological processes. In spite of the inherent similarity (40% in aminoacid sequence) these receptors are found in different cell environments. In addition to this, CB1 activity has been intimately associated with lipid rafts whereas CB2 has not. In this work we have performed a 50 nanosecond molecular dynamics simulation of the inactive conformations of both receptors inserted in a POPC lipid bilayer. Although in both cases the overall protein structure is maintained along the entire simulation we have found important differences in the protein-lipid interaction. While CB1 tends to distort the lipid bilayer regularity, especially in the extracellular moiety, CB2 has a minor influence on the lipid distribution along the plane of the bilayer. This observation is consistent with some experimental facts observed in these cannabinoid receptors with regard to lipid/protein interaction.

  20. Middle Atmosphere Dynamics with Gravity Wave Interactions in the Numerical Spectral Model: Tides and Planetary Waves

    Science.gov (United States)

    Mayr, Hans G.; Mengel, J. G.; Chan, K. L.; Huang, F. T.

    2010-01-01

    As Lindzen (1981) had shown, small-scale gravity waves (GW) produce the observed reversals of the zonal-mean circulation and temperature variations in the upper mesosphere. The waves also play a major role in modulating and amplifying the diurnal tides (DT) (e.g., Waltersheid, 1981; Fritts and Vincent, 1987; Fritts, 1995a). We summarize here the modeling studies with the mechanistic numerical spectral model (NSM) with Doppler spread parameterization for GW (Hines, 1997a, b), which describes in the middle atmosphere: (a) migrating and non-migrating DT, (b) planetary waves (PW), and (c) global-scale inertio gravity waves. Numerical experiments are discussed that illuminate the influence of GW filtering and nonlinear interactions between DT, PW, and zonal mean variations. Keywords: Theoretical modeling, Middle atmosphere dynamics, Gravity wave interactions, Migrating and non-migrating tides, Planetary waves, Global-scale inertio gravity waves.

  1. Integrative avenues for exploring the dynamics and evolution of protein interaction networks.

    Science.gov (United States)

    Diss, Guillaume; Filteau, Marie; Freschi, Luca; Leducq, Jean-Baptiste; Rochette, Samuel; Torres-Quiroz, Francisco; Landry, Christian R

    2013-08-01

    Over the past decade, the study of protein interaction networks (PINs) has shed light on the organizing principles of living cells. However, PINs have been mostly mapped in one single condition. We outline three of the most promising avenues of investigation in this field, namely the study of first, how PINs are rewired by mutations and environmental perturbations; secondly, how inter-species interactions affect PIN achitectures; thirdly, what mechanisms and forces drive PIN evolution. These investigations will unravel the dynamics and condition dependence of PINs and will thus lead to a better functional annotation of network architecture. One major challenge to reach these goals is the integration of PINs with other cellular regulatory networks in the context of complex cellular phenotypes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Analysis of Dynamic Interactions between Different Drivetrain Components with a Detailed Wind Turbine Model

    Science.gov (United States)

    Bartschat, A.; Morisse, M.; Mertens, A.; Wenske, J.

    2016-09-01

    The presented work describes a detailed analysis of the dynamic interactions among mechanical and electrical drivetrain components of a modern wind turbine under the influence of parameter variations, different control mechanisms and transient excitations. For this study, a detailed model of a 2MW wind turbine with a gearbox, a permanent magnet synchronous generator and a full power converter has been developed which considers all relevant characteristics of the mechanical and electrical subsystems. This model includes an accurate representation of the aerodynamics and the mechanical properties of the rotor and the complete mechanical drivetrain. Furthermore, a detailed electrical modelling of the generator, the full scale power converter with discrete switching devices, its filters, the transformer and the grid as well as the control structure is considered. The analysis shows that, considering control measures based on active torsional damping, interactions between mechanical and electrical subsystems can significantly affect the loads and thus the individual lifetime of the components.

  3. Event heap: a coordination infrastructure for dynamic heterogeneous application interactions in ubiquitous computing environments

    Science.gov (United States)

    Johanson, Bradley E.; Fox, Armando; Winograd, Terry A.; Hanrahan, Patrick M.

    2010-04-20

    An efficient and adaptive middleware infrastructure called the Event Heap system dynamically coordinates application interactions and communications in a ubiquitous computing environment, e.g., an interactive workspace, having heterogeneous software applications running on various machines and devices across different platforms. Applications exchange events via the Event Heap. Each event is characterized by a set of unordered, named fields. Events are routed by matching certain attributes in the fields. The source and target versions of each field are automatically set when an event is posted or used as a template. The Event Heap system implements a unique combination of features, both intrinsic to tuplespaces and specific to the Event Heap, including content based addressing, support for routing patterns, standard routing fields, limited data persistence, query persistence/registration, transparent communication, self-description, flexible typing, logical/physical centralization, portable client API, at most once per source first-in-first-out ordering, and modular restartability.

  4. Interaction between viruses and clays in static and dynamic batch systems

    Science.gov (United States)

    Syngouna, V. I.; Chrysikopoulos, C. V.

    2009-04-01

    The transport and fate of viruses in subsurface formations are mainly governed by virus attachment onto the solid matrix and inactivation. Furthermore, virus attachment onto clay colloids is primarily controlled by electrostatic interactions between surfaces. Consequently, bacteriophage MS2 and ΦX174 were used as surrogates for human viruses in order to investigate the interaction between viruses and clay particles. The selected phyllosilicate clays were kaolinite and bentonite. Numerous reactor vessels were filled with 0.5 g of clay and 50 mL of sterile phosphate buffered saline solution (1.2 mM sodium chloride, 0.027 mM potassium chloride, and 0.1 mM phosphate buffer salts) and adjusted to a pH of 7. A series of static and dynamic experiments for various bacteriophage concentrations were conducted at two different temperatures. Half of the reactor vessels were placed in a refrigerator at 4

  5. Weak antibody-cyclodextrin interactions determined by quartz crystal microbalance and dynamic/static light scattering.

    Science.gov (United States)

    Härtl, Elisabeth; Dixit, Nitin; Besheer, Ahmed; Kalonia, Devendra; Winter, Gerhard

    2013-11-01

    In a quest to elucidate the mechanism by which hydroxypropyl β-cyclodextrin (HPβCD) stabilizes antibodies against shaking stress, two heavily debated hypotheses exist, namely that stabilization is due to HPβCD's surface activity, or due to specific interactions with proteins. In a previous study by Serno et al. (Pharm. Res. 30 (2013) 117), we could refute the first hypothesis by proving that, although HPβCD is slightly surface active, it does not displace the antibody at the air-water interface, and accordingly, its surface activity is not the underlying stabilizing mechanism. In the present study, we investigated the possibility of interactions between HPβCD and monoclonal antibodies as the potential stabilization mechanism using quartz crystal microbalance (QCM) and static as well as dynamic light scattering. In the presence of HPβCD, the adsorption of IgG antibodies in the native state (IgG A) and the unfolded state (IgG A and IgG B) on gold-coated quartz crystals was studied by QCM. Results show that HPβCD causes a reduction in protein adsorption in both the folded and the unfolded states, probably due to an interaction between the protein and the cyclodextrin, leading to a reduced hydrophobicity of the protein and consequently a lower extent of adsorption. These results were supported by investigation of the interaction between the native protein and HPβCD using static and dynamic light scattering experiments, which provide the protein-protein interaction parameters, B22 and kD, respectively. Both B22 and kD showed an increase in magnitude with increasing HPβCD-concentrations, indicating a rise in net repulsive forces between the protein molecules. This is further evidence for the presence of interactions between HPβCD and the studied antibodies, since an association of HPβCD on the protein surface leads to a change in the intermolecular forces between the protein molecules. In conclusion, this study provides evidence that the previously observed

  6. Interaction of additive noise and nonlinear dynamics in the double-gyre wind-driven ocean circulation

    NARCIS (Netherlands)

    Sapsis, T.; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467

    2013-01-01

    In this paper the authors study the interactions of additive noise and nonlinear dynamics in a quasi-geostrophicmodel of the double-gyre wind-driven ocean circulation. The recently developed framework of dynamically orthogonal field theory is used to determine the statistics of the flows that arise

  7. The Ability of Benzoic Acid to Reduce Cr(VI Heavy Metal Content in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Anugrah Windy Mustikarini

    2015-12-01

    Full Text Available Chromium (VI is an ionic heavy metal which has to be handled properly when dissolved in water due to its toxicity, corosive, carsinogenic activity.. According to the State Minister for Population and Environment’s regulation, the quality standards of waste water, which is allowed to be discharge on surface water contains Cr(VI is 0.05-1 mg/L. This research used benzoic acid which is a kind of organic acid to reduce Cr(VI content in water. Benzoic acid has an active carboxyl group which interact this metal. This paper, the elimination of Cr(VI using benzoic acid is undertaken through pH adjustment by regulating with phosphoric acid. The result showed the best condition to reducing Cr(VI content 41.99% when 400 ppm of benzoic acid and pH 7 was applied, respectively.

  8. A Dynamic Bayesian Model for Characterizing Cross-Neuronal Interactions During Decision-Making.

    Science.gov (United States)

    Zhou, Bo; Moorman, David E; Behseta, Sam; Ombao, Hernando; Shahbaba, Babak

    2016-01-01

    The goal of this paper is to develop a novel statistical model for studying cross-neuronal spike train interactions during decision making. For an individual to successfully complete the task of decision-making, a number of temporally-organized events must occur: stimuli must be detected, potential outcomes must be evaluated, behaviors must be executed or inhibited, and outcomes (such as reward or no-reward) must be experienced. Due to the complexity of this process, it is likely the case that decision-making is encoded by the temporally-precise interactions between large populations of neurons. Most existing statistical models, however, are inadequate for analyzing such a phenomenon because they provide only an aggregated measure of interactions over time. To address this considerable limitation, we propose a dynamic Bayesian model which captures the time-varying nature of neuronal activity (such as the time-varying strength of the interactions between neurons). The proposed method yielded results that reveal new insight into the dynamic nature of population coding in the prefrontal cortex during decision making. In our analysis, we note that while some neurons in the prefrontal cortex do not synchronize their firing activity until the presence of a reward, a different set of neurons synchronize their activity shortly after stimulus onset. These differentially synchronizing sub-populations of neurons suggests a continuum of population representation of the reward-seeking task. Secondly, our analyses also suggest that the degree of synchronization differs between the rewarded and non-rewarded conditions. Moreover, the proposed model is scalable to handle data on many simultaneously-recorded neurons and is applicable to analyzing other types of multivariate time series data with latent structure. Supplementary materials (including computer codes) for our paper are available online.

  9. Effects of Acoustic and Fluid Dynamic Interactions in Resonators: Applications in Thermoacoustic Refrigeration

    Science.gov (United States)

    Antao, Dion Savio

    Thermoacoustic refrigeration systems have gained increased importance in cryogenic cooling technologies and improvements are needed to increase the efficiency and effectiveness of the current cryogenic refrigeration devices. These improvements in performance require a re-examination of the fundamental acoustic and fluid dynamic interactions in the acoustic resonators that comprise a thermoacoustic refrigerator. A comprehensive research program of the pulse tube thermoacoustic refrigerator (PTR) and arbitrarily shaped, circular cross-section acoustic resonators was undertaken to develop robust computational models to design and predict the transport processes in these systems. This effort was divided into three main focus areas: (a) studying the acoustic and fluid dynamic interactions in consonant and dissonant acoustic resonators, (b) experimentally investigating thermoacoustic refrigeration systems attaining cryogenic levels and (c) computationally studying the transport processes and energy conversion through fluid-solid interactions in thermoacoustic pulse tube refrigeration devices. To investigate acoustic-fluid dynamic interactions in resonators, a high fidelity computational fluid dynamic model was developed and used to simulate the flow, pressure and temperature fields generated in consonant cylindrical and dissonant conical resonators. Excitation of the acoustic resonators produced high-amplitude standing waves in the conical resonator. The generated peak acoustic overpressures exceeded the initial undisturbed pressure by two to three times. The harmonic response in the conical resonator system was observed to be dependent on the piston amplitude. The resultant strong acoustic streaming structures in the cone resonator highlighted its potential over a cylindrical resonator as an efficient mixer. Two pulse tube cryogenic refrigeration (PTR) devices driven by a linear motor (a pressure wave generator) were designed, fabricated and tested. The characterization

  10. Dynamic Interaction between Machine, Tool, and Substrate in Bobbin Friction Stir Welding

    Directory of Open Access Journals (Sweden)

    Mohammad K. Sued

    2016-01-01

    Full Text Available The bobbin friction stir welding (BFSW process has benefits for welding aluminium alloy 6082-T6 in the boat-building industry. However this alloy is difficult to weld in the thin state. There are a large number of process variables and covert situational factors that affect weld quality. This paper investigates how tool holder and machine-type affect BFSW weld quality of 4 mm Al6082-T6. The variables were tool features (three types, machine-controller type (two types, and tool holder (fixed versus floating. Fourier analysis was performed on motor spindle current to determine the frequency response of the machine. An interaction was found between the computer numerical control (CNC, the degrees of freedom of the tool holder, and the substrate (workpiece. The conventional idea that the welding tool has a semisteady interaction with the substrate is not supported. Instead the interaction is highly dynamic, and this materially affects the weld quality. Specific vibrational interactions are associated with poor welding. The CNC machine-type also emerges as a neglected variable that needs to be given attention in the selection of process parameters. Although compliance in the tool holder might seem useful, it is shown to have negative consequences as it introduces tool positioning problems.

  11. Examining dynamic interactions among experimental factors influencing hydrologic data assimilation with the ensemble Kalman filter

    Science.gov (United States)

    Wang, S.; Huang, G. H.; Baetz, B. W.; Cai, X. M.; Ancell, B. C.; Fan, Y. R.

    2017-11-01

    The ensemble Kalman filter (EnKF) is recognized as a powerful data assimilation technique that generates an ensemble of model variables through stochastic perturbations of forcing data and observations. However, relatively little guidance exists with regard to the proper specification of the magnitude of the perturbation and the ensemble size, posing a significant challenge in optimally implementing the EnKF. This paper presents a robust data assimilation system (RDAS), in which a multi-factorial design of the EnKF experiments is first proposed for hydrologic ensemble predictions. A multi-way analysis of variance is then used to examine potential interactions among factors affecting the EnKF experiments, achieving optimality of the RDAS with maximized performance of hydrologic predictions. The RDAS is applied to the Xiangxi River watershed which is the most representative watershed in China's Three Gorges Reservoir region to demonstrate its validity and applicability. Results reveal that the pairwise interaction between perturbed precipitation and streamflow observations has the most significant impact on the performance of the EnKF system, and their interactions vary dynamically across different settings of the ensemble size and the evapotranspiration perturbation. In addition, the interactions among experimental factors vary greatly in magnitude and direction depending on different statistical metrics for model evaluation including the Nash-Sutcliffe efficiency and the Box-Cox transformed root-mean-square error. It is thus necessary to test various evaluation metrics in order to enhance the robustness of hydrologic prediction systems.

  12. Infant's action skill dynamically modulates parental action demonstration in the dyadic interaction.

    Science.gov (United States)

    Fukuyama, Hiroshi; Qin, Shibo; Kanakogi, Yasuhiro; Nagai, Yukie; Asada, Minoru; Myowa-Yamakoshi, Masako

    2015-11-01

    When interacting with infants, human adults modify their behaviours in an exaggerated manner. Previous studies have demonstrated that infant-directed modification affects the infant's behaviour. However, little is known about how infant-directed modification is elicited during infant-parent interaction. We investigated whether and how the infant's behaviour affects the mother's action during an interaction. We recorded three-dimensional information of cup movements while mothers demonstrated a cup-nesting task during interaction with their infants aged 11 to 13 months. Analyses revealed that spatial characteristics of the mother's task demonstration clearly changed depending on the infant's object manipulation. In particular, the variance in the distance that the cup was moved decreased after the infant's cup nesting and increased after the infant's task-irrelevant manipulation (e.g. cup banging). This pattern was not observed for mothers with 6- to 8-month-olds, who do not have the fine motor skill to perform the action. These results indicate that the infant's action skill dynamically affects the infant-directed action and suggest that the mother is sensitive to the infant's potential to learn a novel action. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=VNS2IHwLIhg&feature=youtu.be. © 2014 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

  13. Dynamic imaging of interaction between protein 14-3-3 and Bid in living cells

    Science.gov (United States)

    Chen, Tongsheng; Xing, Da; Wang, Jinjun

    2006-02-01

    The 14-3-3 proteins are known to sequester certain pro-apoptotic members of this family. BH3- interacting domain death agonist (Bid) may contribute to tumor necrosis factor α(TNF-α)-induced neuronal death, although regulation by 14-3-3 has not been reported. In this study we examined whether 14-3-3 proteins interact with Bid/tBid during TNF-α-induced cell death. The TNF-αtriggered Bid cleavage and tBid translocated to mitochondria. Human lung adenocarcinoma cells were co-transfected with both CFP-Bid and 14-3-3-YFP plasmids, and the dynamical interaction between the Bid/tBid and 14-3-3 were performed on laser confocal fluorescence microscope in single living cell during TNF-α-induced cell apoptosis. The Bid distribute equally only in the cytoplasm of healthy cells, and the 14-3-3 protein distribute not only in the cytoplasm but also in the nucleus of healthy cells. Our data showed that the tBid aggregate, but the 14-3-3 protein does not aggregate as the tBid, and the 14-3-3 protein separate from the aggregated tBid, implying that the 14-3-3 proteins do not interact with the aggregated tBid after TNF-αtreatment.

  14. Temporal dynamics of neurogenomic plasticity in response to social interactions in male threespined sticklebacks.

    Directory of Open Access Journals (Sweden)

    Syed Abbas Bukhari

    2017-07-01

    Full Text Available Animals exhibit dramatic immediate behavioral plasticity in response to social interactions, and brief social interactions can shape the future social landscape. However, the molecular mechanisms contributing to behavioral plasticity are unclear. Here, we show that the genome dynamically responds to social interactions with multiple waves of transcription associated with distinct molecular functions in the brain of male threespined sticklebacks, a species famous for its behavioral repertoire and evolution. Some biological functions (e.g., hormone activity peaked soon after a brief territorial challenge and then declined, while others (e.g., immune response peaked hours afterwards. We identify transcription factors that are predicted to coordinate waves of transcription associated with different components of behavioral plasticity. Next, using H3K27Ac as a marker of chromatin accessibility, we show that a brief territorial intrusion was sufficient to cause rapid and dramatic changes in the epigenome. Finally, we integrate the time course brain gene expression data with a transcriptional regulatory network, and link gene expression to changes in chromatin accessibility. This study reveals rapid and dramatic epigenomic plasticity in response to a brief, highly consequential social interaction.

  15. Colloidal particles at fluid interfaces: Effective interactions, dynamics and a gravitation-like instability

    Science.gov (United States)

    Bleibel, J.; Domínguez, A.; Oettel, M.

    2013-11-01

    Colloidal particles of micrometer size usually become irreversibly trapped at fluid interfaces if they are partially wetted by one phase. This opens the chance to create two-dimensional model systems where the effective interactions between the particles are possibly influenced by the presence of the interface to a great extent. We will review recent developments in the quantitive understanding of these effective interactions with a special emphasis on electrostatics and capillarity. Charged colloids of micrometer size at an interface form effective dipoles whose strength sensitively depends on the double layer structure. We discuss the success of modified Poisson-Boltzmann equations with regard to measured colloidal dipole moments. On the other hand, for somewhat larger particles capillary interactions arise which are long-ranged and analogous to two-dimensional screened Newtonian gravity with the capillary length λ as the screening length. For colloidal diameters of around 10 micrometer, the collective effect of these long-ranged capillary interactions will dominate thermal motion and residual, short-ranged repulsions, and results in an instability towards a collapsed state for a finite patch of particles. Such long-ranged interactions with the associated instability are also of interest in other branches of physics, such as self-gravitating fluids in cosmology, two-dimensional vortex flow in hydrodynamics, and bacterial chemotaxis in biology. Starting from the colloidal case we develop and discuss a dynamical "phase diagram" in the temperature and interaction range variables which appears to be of more general scope and applicable also to other systems.

  16. Parental and Infant Gender Factors in Parent–Infant Interaction: State-Space Dynamic Analysis

    Directory of Open Access Journals (Sweden)

    M. Angeles Cerezo

    2017-10-01

    Full Text Available This study aimed to investigate the influence of parental gender on their interaction with their infants, considering, as well, the role of the infant’s gender. The State Space Grid (SSG method, a graphical tool based on the non-linear dynamic system (NDS approach was used to analyze the interaction, in Free-Play setting, of 52 infants, aged 6 to 10 months, divided into two groups: half of the infants interacted with their fathers and half with their mothers. There were 50% boys in each group. MANOVA results showed no differential parenting of boys and girls. Additionally, mothers and fathers showed no differences in the Diversity of behavioral dyadic states nor in Predictability. However, differences associated with parent’s gender were found in that the paternal dyads were more “active” than the maternal dyads: they were faster in the rates per second of behavioral events and transitions or change of state. In contrast, maternal dyads were more repetitive because, once they visited a certain dyadic state, they tend to be involved in more events. Results showed a significant discriminant function on the parental groups, fathers and mothers. Specifically, the content analyses carried out for the three NDS variables, that previously showed differences between groups, showed particular dyadic behavioral states associated with the rate of Transitions and the Events per Visit ratio. Thus, the transitions involving ‘in–out’ of ‘Child Social Approach neutral – Sensitive Approach neutral’ state and the repetitions of events in the dyadic state ‘Child Play-Sensitive Approach neutral’ distinguished fathers from mothers. The classification of dyads (with fathers and mothers based on this discriminant function identified 73.10% (19/26 of the father–infant dyads and 88.5% (23/26 of the mother–infant dyads. The study of father-infant interaction using the SSG approach offers interesting possibilities because it characterizes and

  17. Information Dynamics in the Interaction between a Prey and a Predator Fish

    Directory of Open Access Journals (Sweden)

    Feng Hu

    2015-10-01

    Full Text Available Accessing information efficiently is vital for animals to make the optimal decisions, and it is particularly important when they are facing predators. Yet until now, very few quantitative conclusions have been drawn about the information dynamics in the interaction between animals due to the lack of appropriate theoretic measures. Here, we employ transfer entropy (TE, a new information-theoretic and model-free measure, to explore the information dynamics in the interaction between a predator and a prey fish. We conduct experiments in which a predator and a prey fish are confined in separate parts of an arena, but can communicate with each other visually and tactilely. TE is calculated on the pair’s coarse-grained state of the trajectories. We find that the prey’s TE is generally significantly bigger than the predator’s during trials, which indicates that the dominant information is transmitted from predator to prey. We then demonstrate that the direction of information flow is irrelevant to the parameters used in the coarse-grained procedures. We further calculate the prey’s TE at different distances between it and the predator. The resulted figure shows that there is a high plateau in the mid-range of the distance and that drops quickly at both the near and the far ends. This result reflects that there is a sensitive space zone where the prey is highly vigilant of the predator’s position.

  18. Vortices determine the dynamics of biodiversity in cyclical interactions with protection spillovers

    Science.gov (United States)

    Szolnoki, Attila; Perc, Matjaž

    2015-11-01

    If rock beats scissors and scissors beat paper, one might assume that rock beats paper too. But this is not the case for intransitive relationships that make up the famous rock-paper-scissors game. However, the sole presence of paper might prevent rock from beating scissors, simply because paper beats rock. This is the blueprint for the rock-paper-scissors game with protection spillovers, which has recently been introduced as a new paradigm for biodiversity in well-mixed microbial populations. Here we study the game in structured populations, demonstrating that protection spillovers give rise to spatial patterns that are impossible to observe in the classical rock-paper-scissors game. We show that the spatiotemporal dynamics of the system is determined by the density of stable vortices, which may ultimately transform to frozen states, to propagating waves, or to target waves with reversed propagation direction, depending further on the degree and type of randomness in the interactions among the species. If vortices are rare, the fixation to waves and complex oscillatory solutions is likelier. Moreover, annealed randomness in interactions favors the emergence of target waves, while quenched randomness favors collective synchronization. Our results demonstrate that protection spillovers may fundamentally change the dynamics of cyclic dominance in structured populations, and they outline the possibility of programming pattern formation in microbial populations.

  19. Molecular Dynamics Study of the Interactions Between Minerals and Gas Hydrate Species

    Science.gov (United States)

    Kvamme, B.; Leirvik, K. N.; Olsen, R.; Kuznetsova, T.

    2014-12-01

    The need for knowledge on gas hydrate "host" and "guest" interactions with reservoir rocks comes from the two folded exploitation of gas hydrates. On one hand natural gas hydrates represent an immense energy source, on the other hand carbon sequestration in the form of CO2 hydrates represents a long-term storage of carbon dioxide. Whether one's goal is to extract methane from natural gas hydrates or store carbon dioxide in the form of hydrates, it requires an understanding of the complex phenomena involving coupled dynamics of hydrates and hydrate stability in porous media. Hydrates can never attach directly to solid mineral surfaces because of the incompatibility of charges between the mineral surfaces and the hydrates. However, adsorption of water and carbon dioxide on mineral surfaces may favor heterogeneous nucleation of hydrate in the immediate vicinity. Different surfaces have their own specific adsorption preferences and corresponding adsorption thermodynamics. We have selected calcite, a common mineral found in porous media. Using molecular dynamics we have initially focused on the water interface in order to evaluate the "host" interactions towards the surface. We also aimed at evaluating the model before including guest molecules.

  20. Wolbachia-Host Interactions: Host Mating Patterns Affect Wolbachia Density Dynamics.

    Directory of Open Access Journals (Sweden)

    Dong-Xiao Zhao

    Full Text Available Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and cause an array of effects on host reproduction, fitness and mating behavior. Although our understanding of the Wolbachia-associated effects on hosts is rapidly expanding, our knowledge of the host factors that mediate Wolbachia dynamics is rudimentary. Here, we explore the interactions between Wolbachia and its host, the two-spotted spider mite Tetranychus urticae Koch. Our results indicate that Wolbachia induces strong cytoplasmic incompatibility (CI, increases host fecundity, but has no effects on the longevity of females and the mating competitiveness of males in T. urticae. Most importantly, host mating pattern was found to affect Wolbachia density dynamics during host aging. Mating of an uninfected mite of either sex with an infected mite attenuates the Wolbachia density in the infected mite. According to the results of Wolbachia localization, this finding may be associated with the tropism of Wolbachia for the reproductive tissue in adult spider mites. Our findings describe a new interaction between Wolbachia and their hosts.

  1. Design sensitivity analysis of dynamic responses for a BLDC motor with mechanical and electromagnetic interactions

    Science.gov (United States)

    Im, Hyungbin; Bae, Dae Sung; Chung, Jintai

    2012-04-01

    This paper presents a design sensitivity analysis of dynamic responses of a BLDC motor with mechanical and electromagnetic interactions. Based on the equations of motion which consider mechanical and electromagnetic interactions of the motor, the sensitivity equations for the dynamic responses were derived by applying the direct differential method. From the sensitivity equation along with the equations of motion, the time responses for the sensitivity analysis were obtained by using the Newmark time integration method. The sensitivities of the motor performances such as the electromagnetic torque, rotating speed, and vibration level were analyzed for the six design parameters of rotor mass, shaft/bearing stiffness, rotor eccentricity, winding resistance, coil turn number, and residual magnetic flux density. Furthermore, to achieve a higher torque, higher speed, and lower vibration level, a new BLDC motor was designed by applying the multi-objective function method. It was found that all three performances are sensitive to the design parameters in the order of the coil turn number, magnetic flux density, rotor mass, winding resistance, rotor eccentricity, and stiffness. It was also found that the torque and vibration level are more sensitive to the parameters than the rotating speed. Finally, by applying the sensitivity analysis results, a new optimized design of the motor resulted in better performances. The newly designed motor showed an improved torque, rotating speed, and vibration level.

  2. Modeling the nonlinear dynamic interactions of afferent pathways in the dentate gyrus of the hippocampus.

    Science.gov (United States)

    Dimoka, Angelika; Courellis, Spiros H; Marmarelis, Vasilis Z; Berger, Theodore W

    2008-05-01

    The dentate gyrus is the first region of the hippocampus that receives and integrates sensory information (e.g., visual, auditory, and olfactory) via the perforant path, which is composed of two distinct neuronal pathways: the Lateral Perforant Path (LPP) and the Medial Perforant Path (MPP). This paper examines the nonlinear dynamic interactions among arbitrary stimulation patterns at these two afferent pathways and their combined effect on the resulting response of the granule cells at the dentate gyrus. We employ non-parametric Poisson-Volterra models that serve as canonical quantitative descriptors of the nonlinear dynamic transformations of the neuronal signals propagating through these two neuronal pathways. These Poisson-Volterra models are estimated in the so-called "reduced form" with experimental data from in vitro hippocampal slices and provide excellent predictions of the electrophysiological activity of the granule cells in response to arbitrary stimulation patterns. The data are acquired through a custom-made multi-electrode-array system, which stimulated simultaneously the two pathways with random impulse trains and recorded the neuronal postsynaptic activity at the granule cell layer. The results of this study show that significant nonlinear interactions exist between the LPP and the MPP that may be critical for the integration of sensory information performed by the dentate gyrus of the hippocampus.

  3. On the Relation of Wave-Particle Interactions, Particle Dynamics, and Suprathermal Particle Distributions

    Science.gov (United States)

    Kucharek, Harald; Galvin, Antoinette; Farrugia, Charles; Klecker, Berndt; Pogorelov, Nikolai

    2016-04-01

    Wave-particle interactions, ion acceleration, and magnetic turbulence are closely interlinked and the physical processes may occur on different scales. These scales range from the kinetic scale to the macro-scale (MHD-scale). These processes are likely universal and the same basic processes occur at the Earth's environment, at the Earth's bow shock, the solar wind, and around the heliosphere. Undoubtedly, the Earth's environment as well as the close interplanetary space are the best plasma environments to study these processes using satellite measurements. Recently, ACE, STEREO, IBEX and Voyager observations clearly showed that turbulence and wave-particle interactions and turbulence are extremely important in interplanetary space and in the heliosphere. Using data from STEREO, Wind, we have investigated the spectral properties of suprathermal ion distributions. The results show that spectral slopes are very variable and depend on the plasma properties. We have also performed 3D hybrid simulations and studied particle dynamics. These simulations show that the particle dynamics in the turbulent magnetic wave field is Levy-Flight like which leads to a kappa distribution, which is often found in various space environments. This result is very significant of future mission such as THOR and IMAP and current operating missions such as STEREO, IBEX, and MMS.

  4. The Effect of Exogenous Inputs and Defiant Agents on Opinion Dynamics with Local and Global Interactions

    CERN Document Server

    Fotouhi, Babak

    2012-01-01

    Most of the conventional models for opinion dynamics mainly account for a fully local influence, where myopic agents decide their actions after they interact with other agents that are adjacent to them. For example, in the case of social interactions, this includes family, friends, and other strong social ties. The model proposed in this contribution, embodies a global influence as well where, by global, we mean that each node also observes a sample of the average behavior of the entire population (in the social example, people observe other people on the streets, subway, and other social venues). We consider a case where nodes have dichotomous states (examples include elections with two major parties, whether or not to adopt a new technology or product, and any yes/no opinion such as in voting on a referendum). The dynamics of states on a network with arbitrary degree distribution are studied. For a given initial condition, we find the probability to reach consensus on each state and the expected time reach ...

  5. Bacteriophage-prokaryote dynamics and interaction within anaerobic digestion processes across time and space.

    Science.gov (United States)

    Zhang, Junyu; Gao, Qun; Zhang, Qiuting; Wang, Tengxu; Yue, Haowei; Wu, Linwei; Shi, Jason; Qin, Ziyan; Zhou, Jizhong; Zuo, Jiane; Yang, Yunfeng

    2017-05-31

    Bacteriophage-prokaryote dynamics and interaction are believed to be important in governing microbiome composition and ecosystem functions, yet our limited knowledge of the spatial and temporal variation in phage and prokaryotic community compositions precludes accurate assessment of their roles and impacts. Anaerobic digesters are ideal model systems to examine phage-host interaction, owing to easy access, stable operation, nutrient-rich environment, and consequently enormous numbers of phages and prokaryotic cells. Equipped with high-throughput, cutting-edge environmental genomics techniques, we examined phage and prokaryotic community composition of four anaerobic digesters in full-scale wastewater treatment plants across China. Despite the relatively stable process performance in biogas production, phage and prokaryotic groups fluctuated monthly over a year of study period, showing significant correlations between those two groups at the α- and β-diversity levels. Strikingly, phages explained 40.6% of total variations of the prokaryotic community composition, much higher than the explanatory power by abiotic factors (14.5%). Consequently, phages were significantly (P small viral clades. Those results collectively demonstrate phages as a major biotic factor in controlling prokaryotic composition and process performance. Therefore, phages may play a larger role in shaping prokaryotic community dynamics and process performance of anaerobic digesters than currently appreciated.

  6. Simulation of Quantum Many-Body Dynamics for Generic Strongly-Interacting Systems

    Science.gov (United States)

    Meyer, Gregory; Machado, Francisco; Yao, Norman

    2017-04-01

    Recent experimental advances have enabled the bottom-up assembly of complex, strongly interacting quantum many-body systems from individual atoms, ions, molecules and photons. These advances open the door to studying dynamics in isolated quantum systems as well as the possibility of realizing novel out-of-equilibrium phases of matter. Numerical studies provide insight into these systems; however, computational time and memory usage limit common numerical methods such as exact diagonalization to relatively small Hilbert spaces of dimension 215 . Here we present progress toward a new software package for dynamical time evolution of large generic quantum systems on massively parallel computing architectures. By projecting large sparse Hamiltonians into a much smaller Krylov subspace, we are able to compute the evolution of strongly interacting systems with Hilbert space dimension nearing 230. We discuss and benchmark different design implementations, such as matrix-free methods and GPU based calculations, using both pre-thermal time crystals and the Sachdev-Ye-Kitaev model as examples. We also include a simple symbolic language to describe generic Hamiltonians, allowing simulation of diverse quantum systems without any modification of the underlying C and Fortran code.

  7. The dynamics of the monomeric restriction endonuclease BcnI during its interaction with DNA.

    Science.gov (United States)

    Kostiuk, Georgij; Dikic, Jasmina; Schwarz, Friedrich W; Sasnauskas, Giedrius; Seidel, Ralf; Siksnys, Virginijus

    2017-06-02

    Endonucleases that generate DNA double strand breaks often employ two independent subunits such that the active site from each subunit cuts either DNA strand. Restriction enzyme BcnI is a remarkable exception. It binds to the 5΄-CC/SGG-3΄ (where S = C or G, '/' designates the cleavage position) target as a monomer forming an asymmetric complex, where a single catalytic center approaches the scissile phosphodiester bond in one of DNA strands. Bulk kinetic measurements have previously shown that the same BcnI molecule cuts both DNA strands at the target site without dissociation from the DNA. Here, we analyse the BcnI DNA binding and target recognition steps at the single molecule level. We find, using FRET, that BcnI adopts either 'open' or 'closed' conformation in solution. Next, we directly demonstrate that BcnI slides over long distances on DNA using 1D diffusion and show that sliding is accompanied by occasional jumping events, where the enzyme leaves the DNA and rebinds immediately at a distant site. Furthermore, we quantify the dynamics of the BcnI interactions with cognate and non-cognate DNA, and determine the preferred binding orientation of BcnI to the target site. These results provide new insights into the intricate dynamics of BcnI-DNA interactions. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  8. Dynamic and interactive web-based radiology teaching file using layer and javascript

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Ho; Han, Joon Koo; Lee, Kyoung Ho [Seoul National Univ. College of Medicine and the Institute of Radiation Medicine, SNUMRC, Seoul (Korea, Republic of)] [and others

    1999-03-01

    To improve the Web-based radiology teaching file by means of a dynamic and interactive interface using Layer and JavaScript. The radiology teaching file for medical students at the author's medical school was used. By mean of a digital camera, films were digitized and compressed to Joint Photographic Expert Group (JPEG) format. Layers which had arrows or lines pointing out lesions and anatomical structures were converted to transparent CompuServe Graphics Interchange Format (GIF). Basically, HyperText Mark-up Language (HTML) was used for each Web page. Using JavaScript, Layers were made to be overlapped with radiologic images at the user's request. Each case page consisted of radiologic images and texts for additional information and explanation. By moving the cursor or clicking onto key words, indicators pointing out corresponding lesions and anatomical structures were automatically shown on radiologic images. Although not compatible with some Web-browsers, a dynamic and interactive interface using Layer and JavaScript has little effect on the time needed for data transfer through a network, and is therefore an effective method of accessing radiologic images using the World-Wide Web and using these for teaching and learning.

  9. Dynamics of tactical behaviour in association football when manipulating players' space of interaction.

    Directory of Open Access Journals (Sweden)

    Angel Ric

    Full Text Available The analysis of positional data in association football allows the spatial distribution of players during matches to be described in order to improve the understanding of tactical-related constraints on the behavioural dynamics of players. The aim of this study was to identify how players' spatial restrictions affected the exploratory tactical behaviour and constrained the perceptual-motor workspace of players in possession of the ball, as well as inter-player passing interactions. Nineteen professional outfield male players were divided into two teams of 10 and 9 players, respectively. The game was played under three spatial constraints: a players were not allowed to move out of their allocated zones, except for the player in possession of the ball; b players were allowed to move to an adjacent zone, and; c non-specific spatial constraints. Positional data was captured using a 5 Hz interpolated GPS tracking system and used to define the configuration states of players for each second in time. The configuration state comprised 37 categories derived from tactical actions, distance from the nearest opponent, distance from the target and movement speed. Notational analysis of players in possession of the ball allowed the mean time of ball possession and the probabilities of passing the ball between players to be calculated. The results revealed that the players' long-term exploratory behaviour decreased and their short-term exploration increased when restricting their space of interaction. Relaxing players' positional constraints seemed to increase the speed of ball flow dynamics. Allowing players to move to an adjacent sub-area increased the probabilities of interaction with the full-back during play build-up. The instability of the coordinative state defined by being free from opponents when players had the ball possession was an invariant feature under all three task constraints. By allowing players to move to adjacent sub-areas, the

  10. Dynamics of tactical behaviour in association football when manipulating players' space of interaction.

    Science.gov (United States)

    Ric, Angel; Torrents, Carlota; Gonçalves, Bruno; Torres-Ronda, Lorena; Sampaio, Jaime; Hristovski, Robert

    2017-01-01

    The analysis of positional data in association football allows the spatial distribution of players during matches to be described in order to improve the understanding of tactical-related constraints on the behavioural dynamics of players. The aim of this study was to identify how players' spatial restrictions affected the exploratory tactical behaviour and constrained the perceptual-motor workspace of players in possession of the ball, as well as inter-player passing interactions. Nineteen professional outfield male players were divided into two teams of 10 and 9 players, respectively. The game was played under three spatial constraints: a) players were not allowed to move out of their allocated zones, except for the player in possession of the ball; b) players were allowed to move to an adjacent zone, and; c) non-specific spatial constraints. Positional data was captured using a 5 Hz interpolated GPS tracking system and used to define the configuration states of players for each second in time. The configuration state comprised 37 categories derived from tactical actions, distance from the nearest opponent, distance from the target and movement speed. Notational analysis of players in possession of the ball allowed the mean time of ball possession and the probabilities of passing the ball between players to be calculated. The results revealed that the players' long-term exploratory behaviour decreased and their short-term exploration increased when restricting their space of interaction. Relaxing players' positional constraints seemed to increase the speed of ball flow dynamics. Allowing players to move to an adjacent sub-area increased the probabilities of interaction with the full-back during play build-up. The instability of the coordinative state defined by being free from opponents when players had the ball possession was an invariant feature under all three task constraints. By allowing players to move to adjacent sub-areas, the coordinative state became

  11. Dynamics of fermionic Hubbard models after interaction quenches in one and two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Hamerla, Simone Anke

    2013-10-15

    calculation up to second order in the interaction. Then the dynamics of the one-dimensional model is discussed with a focus on the relation of the results derived by the iterated equations of motion approach to results obtained by bosonization theory, the behavior for strong interactions and the dynamical transition from the weak to the strong quench regime. Furthermore, the Hubbard model is studied on a two-dimensional square lattice. This model is fundamentally different from the one-dimensional model: In contrast to the one-dimensional model the two-dimensional model is not integrable allowing a true relaxation of the system. For this system a calculation up to second order in the interaction is performed and compared to the results of the iterated equation of motion approach. Besides, the time evolution of the momentum distribution and the influence of doping on the dynamics is studied. Moreover, a first estimate for relaxation times is provided without relying on the assumption of a mixed state.

  12. Elucidating the Solvation Structure and Dynamics of Lithium Polysulfides Resulting from Competitive Salt and Solvent Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Rajput, Nav Nidhi; Murugesan, Vijayakumar; Shin, Yongwoo; Han, Kee Sung; Lau, Kah Chun; Chen, Junzheng; Liu, Jun; Curtiss, Larry A.; Mueller, Karl T.; Persson, Kristin A.

    2017-04-10

    Fundamental molecular level understanding of functional properties of liquid solutions provides an important basis for designing optimized electrolytes for numerous applica-tions. In particular, exhaustive knowledge of solvation structure, stability and transport properties is critical for developing stable electrolytes for fast charging and high energy density next-generation energy storage systems. Here we report the correlation between solubility, solvation structure and translational dynamics of a lithium salt (Li-TFSI) and polysulfides species using well-benchmarked classical molecular dynamics simulations combined with nuclear magnetic resonance (NMR). It is observed that the polysulfide chain length has a significant effect on the ion-ion and ion-solvent interaction as well as on the diffusion coefficient of the ionic species in solution. In particular, extensive cluster formation is observed in lower order poly-sulfides (Sx2-; x≤4), whereas the longer polysulfides (Sx2-; x>4) show high solubility and slow dynamics in the solu-tion. It is observed that optimal solvent/salt ratio is essen-tial to control the solubility and conductivity as the addi-tion of Li salt increases the solubility but decreases the mo-bility of the ionic species. This work provides a coupled theoretical and experimental study of bulk solvation struc-ture and transport properties of multi-component electro-lyte systems, yielding design metrics for developing optimal electrolytes with improved stability and solubility.

  13. Dynamical Models of Interactions between Herds Forage and Water Resources in Sahelian Region

    Directory of Open Access Journals (Sweden)

    Jean Jules Tewa

    2014-01-01

    Full Text Available Optimal foraging is one of the capital topics nowadays in Sahelian region. The vast majority of feed consumed by ruminants in Sahelian region is still formed by natural pastures. Pastoral constraints are the high variability of available forage and drinking water in space and especially in time (highly seasonal, interannual variability and the scarcity of water resources. The mobility is the main functional and opportunistic adaptation to these constraints. Our goal in this paper is to formalize two dynamical models for interactions between a herd of domesticate animals, forage resources, and water resources inside a given Sahelian area, in order to confirm, explain, and predict by mathematical models some observations about pastoralism in Sahelian region. These models in some contexts can be similar to predator-prey models as forage and water resources can be considered as preys and herd’s animals as predators. These models exhibit very rich dynamics, since it predicts abrupt changes in consumer behaviour and disponibility of forage or water resources. The dynamics exhibits a possible coexistence between herd, resources, and water with alternative peaks in their trajectories.

  14. Stellar disc destruction by dynamical interactions in the Orion Trapezium star cluster

    Science.gov (United States)

    Portegies Zwart, Simon F.

    2016-03-01

    We compare the observed size distribution of circumstellar discs in the Orion Trapezium cluster with the results of N-body simulations in which we incorporated an heuristic prescription for the evolution of these discs. In our simulations, the sizes of stellar discs are affected by close encounters with other stars (with discs). We find that the observed distribution of disc sizes in the Orion Trapezium cluster is excellently reproduced by truncation due to dynamical encounters alone. The observed distribution appears to be a sensitive measure of the past dynamical history of the cluster, and therewith on the conditions of the cluster at birth. The best comparison between the observed disc-size distribution and the simulated distribution is realized with a cluster of N = 2500 ± 500 stars with a half-mass radius of about 0.5 pc in virial equilibrium (with a virial ratio of Q = 0.5, or somewhat colder Q ≃ 0.3), and with a density structure according to a fractal dimension of F ≃ 1.6. Simulations with these parameters reproduce the observed distribution of circumstellar discs in about 0.2-0.5 Myr. We conclude that the distribution of disk sizes in the Orion Trapezium cluster is the result of dynamical interactions in the early evolution of the cluster.

  15. Dynamic analysis of a 5-MW tripod offshore wind turbine by considering fluid-structure interaction

    Science.gov (United States)

    Zhang, Li-wei; Li, Xin

    2017-10-01

    Fixed offshore wind turbines usually have large underwater supporting structures. The fluid influences the dynamic characteristics of the structure system. The dynamic model of a 5-MW tripod offshore wind turbine considering the pile-soil system and fluid structure interaction (FSI) is established, and the structural modes in air and in water are obtained by use of ANSYS. By comparing low-order natural frequencies and mode shapes, the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed. On basis of the above work, seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method. The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water. The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater.

  16. Degradable hybrid materials based on cationic acylhydrazone dynamic covalent polymers promote DNA complexation through multivalent interactions.

    Science.gov (United States)

    Bouillon, Camille; Paolantoni, Delphine; Rote, Jennifer C; Bessin, Yannick; Peterson, Larryn W; Dumy, Pascal; Ulrich, Sébastien

    2014-11-03

    The design of smart nonviral vectors for gene delivery is of prime importance for the successful implementation of gene therapies. In particular, degradable analogues of macromolecules represent promising targets as they would combine the multivalent presentation of multiple binding units that is necessary for achieving effective complexation of therapeutic oligonucleotides with the controlled degradation of the vector that would in turn trigger drug release. Toward this end, we have designed and synthesized hybrid polyacylhydrazone-based dynamic materials that combine bis-functionalized cationic monomers with ethylene oxide containing monomers. Polymer formation was characterized by (1) H and DOSY NMR spectroscopy and was found to take place at high concentration, whereas macrocycles were predominantly formed at low concentration. HPLC monitoring of solutions of these materials in aqueous buffers at pH values ranging from 5.0 to 7.0 revealed their acid-catalyzed degradation. An ethidium bromide displacement assay and gel electrophoresis clearly demonstrated that, despite being dynamic, these materials are capable of effectively complexing dsDNA in aqueous buffer and biological serum at N/P ratios comparable to polyethyleneimine polymers. The self-assembly of dynamic covalent polymers through the incorporation of a reversible covalent bond within their main chain is therefore a promising strategy for generating degradable materials that are capable of establishing multivalent interactions and effectively complexing dsDNA in biological media. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Interactive iterative relative fuzzy connectedness lung segmentation on thoracic 4D dynamic MR images

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Wu, Caiyun; Zhao, Yue; McDonough, Joseph M.; Capraro, Anthony; Torigian, Drew A.; Campbell, Robert M.

    2017-03-01

    Lung delineation via dynamic 4D thoracic magnetic resonance imaging (MRI) is necessary for quantitative image analysis for studying pediatric respiratory diseases such as thoracic insufficiency syndrome (TIS). This task is very challenging because of the often-extreme malformations of the thorax in TIS, lack of signal from bone and connective tissues resulting in inadequate image quality, abnormal thoracic dynamics, and the inability of the patients to cooperate with the protocol needed to get good quality images. We propose an interactive fuzzy connectedness approach as a potential practical solution to this difficult problem. Manual segmentation is too labor intensive especially due to the 4D nature of the data and can lead to low repeatability of the segmentation results. Registration-based approaches are somewhat inefficient and may produce inaccurate results due to accumulated registration errors and inadequate boundary information. The proposed approach works in a manner resembling the Iterative Livewire tool but uses iterative relative fuzzy connectedness (IRFC) as the delineation engine. Seeds needed by IRFC are set manually and are propagated from slice-to-slice, decreasing the needed human labor, and then a fuzzy connectedness map is automatically calculated almost instantaneously. If the segmentation is acceptable, the user selects "next" slice. Otherwise, the seeds are refined and the process continues. Although human interaction is needed, an advantage of the method is the high level of efficient user-control on the process and non-necessity to refine the results. Dynamic MRI sequences from 5 pediatric TIS patients involving 39 3D spatial volumes are used to evaluate the proposed approach. The method is compared to two other IRFC strategies with a higher level of automation. The proposed method yields an overall true positive and false positive volume fraction of 0.91 and 0.03, respectively, and Hausdorff boundary distance of 2 mm.

  18. Dynamic interaction between retinal and extraretinal signals in motion integration for smooth pursuit.

    Science.gov (United States)

    Bogadhi, Amarender R; Montagnini, Anna; Masson, Guillaume S

    2013-11-04

    Due to the aperture problem, the initial direction of tracking responses to a translating bar is biased towards the direction orthogonal to the bar. This observation offers a powerful way to explore the interactions between retinal and extraretinal signals in controlling our actions. We conducted two experiments to probe these interactions by briefly (200 and 400 ms) blanking the moving target (45° or 135° tilted bar) during steady state (Experiment 1) and at different moments during the early phase of pursuit (Experiment 2). In Experiment 1, we found a marginal but statistically significant directional bias on target reappearance for all subjects in at least one blank condition (200 or 400 ms). In Experiment 2, no systematic significant directional bias was observed at target reappearance after a blank. These results suggest that the weighting of retinal and extraretinal signals is dynamically modulated during the different phases of pursuit. Based on our previous theoretical work on motion integration, we propose a new closed-loop two-stage recurrent Bayesian model where retinal and extraretinal signals are dynamically weighted based on their respective reliabilities and combined to compute the visuomotor drive. With a single free parameter, the model reproduces many aspects of smooth pursuit observed across subjects during and immediately after target blanking. It provides a new theoretical framework to understand how different signals are dynamically combined based on their relative reliability to adaptively control our actions. Overall, the model and behavioral results suggest that human subjects rely more strongly on prediction during the early phase than in the steady state phase of pursuit.

  19. Successional changes in trophic interactions support a mechanistic model of post-fire population dynamics.

    Science.gov (United States)

    Smith, Annabel L

    2017-11-22

    Models based on functional traits have limited power in predicting how animal populations respond to disturbance because they do not capture the range of demographic and biological factors that drive population dynamics, including variation in trophic interactions. I tested the hypothesis that successional changes in vegetation structure, which affected invertebrate abundance, would influence growth rates and body condition in the early-successional, insectivorous gecko Nephrurus stellatus. I captured geckos at 17 woodland sites spanning a succession gradient from 2 to 48 years post-fire. Body condition and growth rates were analysed as a function of the best-fitting fire-related predictor (invertebrate abundance or time since fire) with different combinations of the co-variates age, sex and location. Body condition in the whole population was positively affected by increasing invertebrate abundance and, in the adult population, this effect was most pronounced for females. There was strong support for a decline in growth rates in weight with time since fire. The results suggest that increased early-successional invertebrate abundance has filtered through to a higher trophic level with physiological benefits for insectivorous geckos. I integrated the new findings about trophic interactions into a general conceptual model of mechanisms underlying post-fire population dynamics based on a long-term research programme. The model highlights how greater food availability during early succession could drive rapid population growth by contributing to previously reported enhanced reproduction and dispersal. This study provides a framework to understand links between ecological and physiological traits underlying post-fire population dynamics.

  20. Dynamic Distribution and Interaction of the Arabidopsis SRSF1 Subfamily Splicing Factors.

    Science.gov (United States)

    Stankovic, Nancy; Schloesser, Marie; Joris, Marine; Sauvage, Eric; Hanikenne, Marc; Motte, Patrick

    2016-02-01

    Ser/Arg-rich (SR) proteins are essential nucleus-localized splicing factors. Our prior studies showed that Arabidopsis (Arabidopsis thaliana) RSZ22, a homolog of the human SRSF7 SR factor, exits the nucleus through two pathways, either dependent or independent on the XPO1 receptor. Here, we examined the expression profiles and shuttling dynamics of the Arabidopsis SRSF1 subfamily (SR30, SR34, SR34a, and SR34b) under control of their endogenous promoter in Arabidopsis and in transient expression assay. Due to its rapid nucleocytoplasmic shuttling and high expression level in transient assay, we analyzed the multiple determinants that regulate the localization and shuttling dynamics of SR34. By site-directed mutagenesis of SR34 RNA-binding sequences and Arg/Ser-rich (RS) domain, we further show that functional RRM1 or RRM2 are dispensable for the exclusive protein nuclear localization and speckle-like distribution. However, mutations of both RRMs induced aggregation of the protein whereas mutation in the RS domain decreased the stability of the protein and suppressed its nuclear accumulation. Furthermore, the RNA-binding motif mutants are defective for their export through the XPO1 (CRM1/Exportin-1) receptor pathway, but retain nucleocytoplasmic mobility. We performed a yeast two hybrid screen with SR34 as bait and discovered SR45 as a new interactor. SR45 is an unusual SR splicing factor bearing two RS domains. These interactions were confirmed in planta by FLIM-FRET and BiFC and the roles of SR34 domains in protein-protein interactions were further studied. Altogether, our report extends our understanding of shuttling dynamics of Arabidopsis SR splicing factors. © 2016 American Society of Plant Biologists. All Rights Reserved.