Science.gov

Sample records for interactive influence diagrams

  1. CADDIS Volume 5. Causal Databases: Interactive Conceptual Diagrams (ICDs)

    EPA Pesticide Factsheets

    In Interactive Conceptual Diagram (ICD) section of CADDIS allows users to create conceptual model diagrams, search a literature-based evidence database, and then attach that evidence to their diagrams.

  2. Influence diagrams as oil spill decision science tools

    EPA Science Inventory

    Making inferences on risks to ecosystem services (ES) from ecological crises can be more reliably handled using decision science tools. Influence diagrams (IDs) are probabilistic networks that explicitly represent the decisions related to a problem and evidence of their influence...

  3. Influence Diagram Use With Respect to Technology Planning and Investment

    NASA Technical Reports Server (NTRS)

    Levack, Daniel J. H.; DeHoff, Bryan; Rhodes, Russel E.

    2009-01-01

    Influence diagrams are relatively simple, but powerful, tools for assessing the impact of choices or resource allocations on goals or requirements. They are very general and can be used on a wide range of problems. They can be used for any problem that has defined goals, a set of factors that influence the goals or the other factors, and a set of inputs. Influence diagrams show the relationship among a set of results and the attributes that influence them and the inputs that influence the attributes. If the results are goals or requirements of a program, then the influence diagram can be used to examine how the requirements are affected by changes to technology investment. This paper uses an example to show how to construct and interpret influence diagrams, how to assign weights to the inputs and attributes, how to assign weights to the transfer functions (influences), and how to calculate the resulting influences of the inputs on the results. A study is also presented as an example of how using influence diagrams can help in technology planning and investment. The Space Propulsion Synergy Team (SPST) used this technique to examine the impact of R&D spending on the Life Cycle Cost (LCC) of a space transportation system. The question addressed was the effect on the recurring and the non-recurring portions of LCC of the proportion of R&D resources spent to impact technology objectives versus the proportion spent to impact operational dependability objectives. The goals, attributes, and the inputs were established. All of the linkages (influences) were determined. The weighting of each of the attributes and each of the linkages was determined. Finally the inputs were varied and the impacts on the LCC determined and are presented. The paper discusses how each of these was accomplished both for credibility and as an example for future studies using influence diagrams for technology planning and investment planning.

  4. Phase diagram of two interacting helical states

    NASA Astrophysics Data System (ADS)

    Santos, Raul A.; Gutman, D. B.; Carr, Sam T.

    2016-06-01

    We consider two coupled time-reversal-invariant helical edge modes of the same helicity, such as would occur on two stacked quantum spin Hall insulators. In the presence of interaction, the low-energy physics is described by two collective modes, one corresponding to the total current flowing around the edge and the other one describing relative fluctuations between the two edges. We find that quite generically, the relative mode becomes gapped at low temperatures, but only when tunneling between the two helical modes is nonzero. There are two distinct possibilities for the gapped state depending on the relative size of different interactions. If the intraedge interaction is stronger than the interedge interaction, the state is characterized as a spin-nematic phase. However, in the opposite limit, when the interaction between the helical edge modes is strong compared to the interaction within each mode, a spin-density wave forms, with emergent topological properties. First, the gap protects the conducting phase against localization by weak nonmagnetic impurities; second, the protected phase hosts localized zero modes on the ends of the edge that may be created by sufficiently strong nonmagnetic impurities.

  5. Phase diagrams of hard spheres with algebraic attractive interactions.

    PubMed

    Camp, Philip J

    2003-01-01

    The phase diagrams of systems made up of hard spheres interacting with attractive potentials of the form -1/r(3+sigma) are calculated using Monte Carlo simulations, second-order thermodynamic perturbation theory, and an augmented van der Waals theory. In simulations of the systems with sigma=0.1, 1, and 3, fluid-solid coexistence results are obtained using the Gibbs-Duhem integration technique; simulation data for the vapor-liquid coexistence envelopes and critical points are taken from previously published work [P. J. Camp and G. N. Patey, J. Chem. Phys. 114, 399 (2001)]. It is shown that the agreement between the theoretical and simulated phase diagrams improves as the range of the potential is increased, reflecting the decreasing role of short-range correlations in determining the bulk thermodynamics. In the extreme case of sigma=0.1 both theories are in excellent agreement with simulations. Phase diagrams for systems with sigma=4, 5, and 6 are computed using second-order thermodynamic perturbation theory. The results indicate that the vapor-liquid transition becomes metastable with respect to freezing when sigma > or approximately equal to 5, in broad agreement with results for the hard-sphere attractive Yukawa system which is commonly used to model colloidal particles, globular proteins, and nanoparticles.

  6. Phase diagram and entanglement of two interacting topological Kitaev chains

    NASA Astrophysics Data System (ADS)

    Herviou, Loïc; Mora, Christophe; Le Hur, Karyn

    2016-04-01

    A superconducting wire described by a p -wave pairing and a Kitaev Hamiltonian exhibits Majorana fermions at its edges and is topologically protected by symmetry. We consider two Kitaev wires (chains) coupled by a Coulomb-type interaction and study the complete phase diagram using analytical and numerical techniques. A topological superconducting phase with four Majorana fermions occurs until moderate interactions between chains. For large interactions, both repulsive and attractive, by analogy with the Hubbard model, we identify Mott phases with Ising-type magnetic order. For repulsive interactions, the Ising antiferromagnetic order favors the occurrence of orbital currents spontaneously breaking time-reversal symmetry. By strongly varying the chemical potentials of the two chains, quantum phase transitions towards fully polarized (empty or full) fermionic chains occur. In the Kitaev model, the quantum critical point separating the topological superconducting phase and the polarized phase belongs to the universality class of the critical Ising model in two dimensions. When increasing the Coulomb interaction between chains, then we identify an additional phase corresponding to two critical Ising theories (or two chains of Majorana fermions). We confirm the existence of such a phase from exact mappings and from the concept of bipartite fluctuations. We show the existence of negative logarithmic corrections in the bipartite fluctuations, as a reminiscence of the quantum critical point in the Kitaev model. Other entanglement probes such as bipartite entropy and entanglement spectrum are also used to characterize the phase diagram. The limit of large interactions can be reached in an equivalent setup of ultracold atoms and Josephson junctions.

  7. Using Bayesian influence diagrams to assess organizational performance in 4 California county health departments, April-July 2009.

    PubMed

    Comfort, Louise K; Scheinert, Steve; Yeo, Jungwon; Schuh, Russell; Duran, Luis; Potter, Margaret A

    2013-01-01

    A Bayesian influence diagram is used to analyze interactions among operational units of county health departments. This diagram, developed using Bayesian network analysis, represents a novel method of analyzing the internal performance of county health departments that were operating under the simultaneous constraints of budget cuts and increased demand for services during the H1N1 threat in California, April-July 2009. This analysis reveals the interactions among internal organizational units that degrade performance under stress or, conversely, enable a county health department to manage heavy demands effectively.

  8. Phase diagram and thermal properties of strong-interaction matter

    NASA Astrophysics Data System (ADS)

    Gao, Fei; Chen, Jing; Liu, Yu-Xin; Qin, Si-Xue; Roberts, Craig D.; Schmidt, Sebastian M.

    2016-05-01

    We introduce a novel method for computing the (μ , T )-dependent pressure in continuum QCD, from which we obtain a complex phase diagram and predictions for thermal properties of the dressed-quark component of the system, providing the in-medium behavior of the related trace anomaly, speed of sound, latent heat, and heat capacity.

  9. Phase diagram and thermal properties of strong-interaction matter

    SciTech Connect

    Gao, Fei; Chen, Jing; Liu, Yu-Xin; Qin, Si-Xue; Roberts, Craig D.; Schmidt, Sebastian M.

    2016-05-20

    We introduce a novel method for computing the (μ, T)-dependent pressure in continuum QCD, from which we obtain a complex phase diagram and predictions for thermal properties of the dressed-quark component of the system, providing the in-medium behavior of the related trace anomaly, speed of sound, latent heat, and heat capacity.

  10. Influence Diagrams as Decision-Making Tools for Pesticide Risk Management

    EPA Science Inventory

    The pesticide policy arena is filled with discussion of probabilistic approaches to assess ecological risk, however, similar discussions about implementing formal probabilistic methods in pesticide risk decision making are less common. An influence diagram approach is proposed f...

  11. Water Mediated Interactions and the Protein Folding Phase Diagram in the Temperature-Pressure Plane.

    PubMed

    Sirovetz, Brian J; Schafer, Nicholas P; Wolynes, Peter G

    2015-08-27

    The temperature-pressure behavior of two proteins, ubiquitin and λ-repressor, is explored using a realistically coarse-grained physicochemical model, the associative memory, water mediated, structure and energy model (AWSEM). The phase diagram across the temperature-pressure plane is obtained by perturbing the water mediated interactions in the Hamiltonian systematically. The phase diagrams calculated with direct simulations along with an extended bridge sampling estimator show the main features found experimentally, including both cold- and pressure-denaturation. The denatured ensembles in different parts of the phase diagram are characterized and found to be structurally distinct. The protein energy landscape is found to be funneled throughout the phase diagram, but modest changes in the entropy and free energy of the water are found to drive both cold and pressure induced denaturation.

  12. Minimizing risks from spilled oil to ecosystem services using influence diagrams: The Deepwater Horizon spill response

    EPA Science Inventory

    Making inferences on risks to ecosystem services (ES) from ecological crises may be improved using decision science tools. Influence diagrams (IDs) are probabilistic networks that explicitly represent the decisions related to a problem and evidence of their influence on desired o...

  13. Low-momentum NN interactions and all-order summation of ring diagrams of symmetric nuclear matter

    NASA Astrophysics Data System (ADS)

    Siu, L.-W.; Holt, J. W.; Kuo, T. T. S.; Brown, G. E.

    2009-05-01

    We study the equation of state for symmetric nuclear matter using a ring-diagram approach in which the particle-particle hole-hole (pphh) ring diagrams within a momentum model space of decimation scale Λ are summed to all orders. The calculation is carried out using the renormalized low-momentum nucleon-nucleon (NN) interaction Vlow-k, which is obtained from a bare NN potential by integrating out the high-momentum components beyond Λ. The bare NN potentials of CD-Bonn, Nijmegen, and Idaho have been employed. The choice of Λ and its influence on the single particle spectrum are discussed. Ring-diagram correlations at intermediate momenta (k≃2fm-1) are found to be particularly important for nuclear saturation, suggesting the necessity of using a sufficiently large decimation scale so that the above momentum region is not integrated out. Using Vlow-k with Λ~3fm-1, we perform a ring-diagram computation with the above potentials, which all yield saturation energies E/A and Fermi momenta kF(0) considerably larger than the empirical values. On the other hand, similar computations with the medium-dependent Brown-Rho scaled NN potentials give satisfactory results of E/A≃-15 MeV and kF(0)≃1.4fm-1. The effect of this medium dependence is well reproduced by an empirical three-body force of the Skyrme type.

  14. Phase diagram of interacting spinless fermions on the honeycomb lattice.

    PubMed

    Capponi, Sylvain

    2017-02-01

    Fermions hopping on a hexagonal lattice represent one of the most active research fields in condensed matter since the discovery of graphene in 2004 and its numerous applications. Another exciting aspect of the interplay between geometry and quantum mechanical effects is given by the Haldane model (Haldane 1988 Phys. Rev. Lett. 61 2015), where spinless fermions experiencing a certain flux pattern on the honeycomb lattice leads to the stabilization of a topological phase of matter, distinct from a Mott insulator and nowadays dubbed Chern insulator. In this context, it is crucial to understand the role of interactions and this review will describe recent results that have been obtained for a minimal model, namely spinless fermions with nearest and next-nearest neighbour density-density interactions on the honeycomb lattice at half-filling. Topics addressed include an introduction of the minimal model and a discussion of the possible instabilities of the Dirac semimetal, a presentation of various theoretical and numerical approaches, and a summary of the results with a particular emphasis on the stability or not of some exotic quantum phases such as charge ordered ones (similar to Wigner crystals) and spontaneous Chern insulator phases.

  15. Phase diagram of interacting spinless fermions on the honeycomb lattice

    NASA Astrophysics Data System (ADS)

    Capponi, Sylvain

    2017-02-01

    Fermions hopping on a hexagonal lattice represent one of the most active research fields in condensed matter since the discovery of graphene in 2004 and its numerous applications. Another exciting aspect of the interplay between geometry and quantum mechanical effects is given by the Haldane model (Haldane 1988 Phys. Rev. Lett. 61 2015), where spinless fermions experiencing a certain flux pattern on the honeycomb lattice leads to the stabilization of a topological phase of matter, distinct from a Mott insulator and nowadays dubbed Chern insulator. In this context, it is crucial to understand the role of interactions and this review will describe recent results that have been obtained for a minimal model, namely spinless fermions with nearest and next-nearest neighbour density-density interactions on the honeycomb lattice at half-filling. Topics addressed include an introduction of the minimal model and a discussion of the possible instabilities of the Dirac semimetal, a presentation of various theoretical and numerical approaches, and a summary of the results with a particular emphasis on the stability or not of some exotic quantum phases such as charge ordered ones (similar to Wigner crystals) and spontaneous Chern insulator phases.

  16. Minimizing risks from spilled oil to ecosystem services using influence diagrams: the Deepwater Horizon spill response.

    PubMed

    Carriger, John F; Barron, Mace G

    2011-09-15

    Decision science tools can be used in evaluating response options and making inferences on risks to ecosystem services (ES) from ecological disasters. Influence diagrams (IDs) are probabilistic networks that explicitly represent the decisions related to a problem and their influence on desired or undesired outcomes. To examine how IDs might be useful in probabilistic risk management for spill response efforts, an ID was constructed to display the potential interactions between exposure events and the trade-offs between costs and ES impacts from spilled oil and response decisions in the DWH spill event. Quantitative knowledge was not formally incorporated but an ID platform for doing this was examined. Probabilities were assigned for conditional relationships in the ID and scenarios examining the impact of different response actions on components of spilled oil were investigated in hypothetical scenarios. Given the structure of the ID, potential knowledge gaps included understanding of the movement of oil, the ecological risk of different spill-related stressors to key receptors (e.g., endangered species, fisheries), and the need for stakeholder valuation of the ES benefits that could be impacted by a spill. Framing the Deepwater Horizon problem domain in an ID conceptualized important variables and relationships that could be optimally accounted for in preparing and managing responses in future spills. These features of the developed IDs may assist in better investigating the uncertainty, costs, and the trade-offs if large-scale, deep ocean spills were to occur again.

  17. Three body interaction effects on the phase diagram of spinor bosons

    NASA Astrophysics Data System (ADS)

    Nabi, Sk Noor; Basu, Saurabh

    2016-10-01

    We include a three body density interaction in the Bose Hubbard model and study its effects on the phase diagram for spinor (S = 1) bosons on an optical lattice via a mean field theory. The Mott insulating (MI) phases are noted to stabilize, in the sense that the MI phases extend to larger values of the system parameters alongwith widening of the particle-hole excitation spectrum as the three body interaction term is included for both the polar (spin dependent interaction being positive) and the ferromagnetic (spin dependent interaction being negative) cases. Another remarkable feature emerges as the phase diagram corresponding to the ferromagnetic case becomes distinct from that of its spinless variant, which in the absence of the three body term is indistinguishable from that of the scalar particles. A strong coupling perturbation theory is employed to provide analytical support to the above results.

  18. AZTECA, a y-y diagram oriented interactive computer program for optical system design and optimization

    NASA Astrophysics Data System (ADS)

    Flores-Hernandez, Ricardo

    1995-09-01

    The Centro de Investigaciones en Optica is developing the AZTECA optical design program to exploit the full synthesis capabilities intrinsic to Delano's y-y method. Both the y- y diagram and its dual the (omega) -(omega) diagram, are manipulated in real time to introduce changes at any point or line in those diagrams. These changes result in altered new versions of the optical system by means of a specialized subroutine that incorporates the fundamental synthesis equations for those diagrams. To display results on the computer's screen as the optimization process progress, AZTECA makes wide use of the fact that the y-y and the (omega) -(omega) diagrams display graphically all the first order attributes of an optical system. This program adjoins to these features the calculation of Buchdahl's 3rd, 5th, and 7th order aberration coefficients to the output. This results in a real time display of the system's paraxial and aberrational behavior. Efficient graphic displays, the program's modular structure and an interactive mode of operation, also contribute to make the AZTECA a versatile platform. It will be further developed as a new tool for efficient optical system design.

  19. A global genetic interaction network maps a wiring diagram of cellular function.

    PubMed

    Costanzo, Michael; VanderSluis, Benjamin; Koch, Elizabeth N; Baryshnikova, Anastasia; Pons, Carles; Tan, Guihong; Wang, Wen; Usaj, Matej; Hanchard, Julia; Lee, Susan D; Pelechano, Vicent; Styles, Erin B; Billmann, Maximilian; van Leeuwen, Jolanda; van Dyk, Nydia; Lin, Zhen-Yuan; Kuzmin, Elena; Nelson, Justin; Piotrowski, Jeff S; Srikumar, Tharan; Bahr, Sondra; Chen, Yiqun; Deshpande, Raamesh; Kurat, Christoph F; Li, Sheena C; Li, Zhijian; Usaj, Mojca Mattiazzi; Okada, Hiroki; Pascoe, Natasha; San Luis, Bryan-Joseph; Sharifpoor, Sara; Shuteriqi, Emira; Simpkins, Scott W; Snider, Jamie; Suresh, Harsha Garadi; Tan, Yizhao; Zhu, Hongwei; Malod-Dognin, Noel; Janjic, Vuk; Przulj, Natasa; Troyanskaya, Olga G; Stagljar, Igor; Xia, Tian; Ohya, Yoshikazu; Gingras, Anne-Claude; Raught, Brian; Boutros, Michael; Steinmetz, Lars M; Moore, Claire L; Rosebrock, Adam P; Caudy, Amy A; Myers, Chad L; Andrews, Brenda; Boone, Charles

    2016-09-23

    We generated a global genetic interaction network for Saccharomyces cerevisiae, constructing more than 23 million double mutants, identifying about 550,000 negative and about 350,000 positive genetic interactions. This comprehensive network maps genetic interactions for essential gene pairs, highlighting essential genes as densely connected hubs. Genetic interaction profiles enabled assembly of a hierarchical model of cell function, including modules corresponding to protein complexes and pathways, biological processes, and cellular compartments. Negative interactions connected functionally related genes, mapped core bioprocesses, and identified pleiotropic genes, whereas positive interactions often mapped general regulatory connections among gene pairs, rather than shared functionality. The global network illustrates how coherent sets of genetic interactions connect protein complex and pathway modules to map a functional wiring diagram of the cell.

  20. Phase diagrams of vortex matter with multi-scale inter-vortex interactions in layered superconductors

    NASA Astrophysics Data System (ADS)

    Meng, Qingyou; Varney, Christopher N.; Fangohr, Hans; Babaev, Egor

    2017-01-01

    It was recently proposed to use the stray magnetic fields of superconducting vortex lattices to trap ultracold atoms for building quantum emulators. This calls for new methods for engineering and manipulating of the vortex states. One of the possible routes utilizes type-1.5 superconducting layered systems with multi-scale inter-vortex interactions. In order to explore the possible vortex states that can be engineered, we present two phase diagrams of phenomenological vortex matter models with multi-scale inter-vortex interactions featuring several attractive and repulsive length scales. The phase diagrams exhibit a plethora of phases, including conventional 2D lattice phases, five stripe phases, dimer, trimer, and tetramer phases, void phases, and stable low-temperature disordered phases. The transitions between these states can be controlled by the value of an applied external field.

  1. Phase diagrams of vortex matter with multi-scale inter-vortex interactions in layered superconductors.

    PubMed

    Meng, Qingyou; Varney, Christopher N; Fangohr, Hans; Babaev, Egor

    2017-01-25

    It was recently proposed to use the stray magnetic fields of superconducting vortex lattices to trap ultracold atoms for building quantum emulators. This calls for new methods for engineering and manipulating of the vortex states. One of the possible routes utilizes type-1.5 superconducting layered systems with multi-scale inter-vortex interactions. In order to explore the possible vortex states that can be engineered, we present two phase diagrams of phenomenological vortex matter models with multi-scale inter-vortex interactions featuring several attractive and repulsive length scales. The phase diagrams exhibit a plethora of phases, including conventional 2D lattice phases, five stripe phases, dimer, trimer, and tetramer phases, void phases, and stable low-temperature disordered phases. The transitions between these states can be controlled by the value of an applied external field.

  2. Tuning the phase diagram of colloid-polymer mixtures via Yukawa interactions

    NASA Astrophysics Data System (ADS)

    González García, Álvaro; Tuinier, Remco

    2016-12-01

    Theory that predicts the phase behavior of interacting Yukawa spheres in a solution containing nonadsorbing polymer is presented. Our approach accounts for multiple overlap of depletion zones. It is found that additional Yukawa interactions beyond hard core interactions strongly affect the location and presence of coexistence regions and phase states. The theoretical phase diagrams are compared with Monte Carlo simulations. The agreement between the two approaches supports the validity of the theoretical approximations made and confirms that, by choosing the parameters of the interaction potentials, tuning of the binodals is possible. The critical end point characterizes the phase diagram topology. It is demonstrated how an additional Yukawa interaction shifts this point with respect to the hard sphere case. Provided a certain depletant-to-colloid size ratio for which a stable colloidal gas-liquid phase coexistence takes place for hard spheres, added direct interactions turn this into a metastable gas-liquid equilibrium. The opposite case, the induction of a stable gas-liquid coexistence where only fluid-solid was present for hard spheres, is also reported.

  3. Influence of finite volume and magnetic field effects on the QCD phase diagram

    NASA Astrophysics Data System (ADS)

    Magdy, Niseem; Csanád, M.; Lacey, Roy A.

    2017-02-01

    The 2 + 1 SU(3) Polyakov linear sigma model is used to investigate the respective influence of a finite volume and a magnetic field on the quark-hadron phase boundary in the plane of baryon chemical potential ({μ }B) versus temperature (T) of the quantum chromodynamics (QCD) phase diagram. The calculated results indicate sizable shifts of the quark-hadron phase boundary to lower values of ({μ }B {and} T) for increasing magnetic field strength, and an opposite shift to higher values of ({μ }B {and} T) for decreasing system volume. Such shifts could have important implications for the extraction of the thermodynamic properties of the QCD phase diagram from heavy ion data.

  4. Folded diagrams and 1s-Od effective interactions derived from Reid and Paris nucleon-nucleon potentials

    NASA Astrophysics Data System (ADS)

    Shurpin, J.; Kuo, T. T. S.; Strottman, D.

    1983-10-01

    The sd-shell effective-interaction matrix elements are derived from the Paris and Reid potentials using a microscopic folded-diagram effective-interaction theory. A comparison of these matrix elements is carried out by calculating spectra and energy centroids for nuclei of mass 18 to 24. The folded diagrams were included by both solving for the energy-dependent effective interaction self-consistently and by including the folded diagrams explicitly. In the latter case the folded diagrams were grouped either according to the number of folds or as prescribed by the Lee and Suzuki iteration technique; the Lee-Suzuki method was found to converge better and yield the more reliable results. Special attention was given to the proper treatment of one-body connected diagrams in the calculation of the two-body effective interaction. We first calculate the (energy-dependent) G-matrix appropriate for the sd-shell for both potentials using a momentum-space matrix-inversion method which treats the Pauli exclusion operator essentially exactly. This G-matrix interaction is then used to calculate the irreducible and non- folded diagrams contained in the Q̂- box. The effective-interaction matrix elements are obtained by evaluating a Q̂- box folded diagram series. We considered four approximations for the basic Q̂- box. These were (C1) the inclusion of diagrams up to 2nd order in G, (C2) 2nd order plus hole-hole phonons, (C3) 2nd order plus (bare TDA) particle-hole phonons, and (C4) 2nd order plus both hole-hole and particle-hole phonons. The contribution of the folded diagrams was found to be quite large, typically about 30%, and to weaken the interaction. Also, due to the greater energy dependence of higher-order diagrams, the effect of folded diagrams was much greater in higher orders. That is, the contribution from higher-order diagrams for most cases was greatly reduced by the folded diagrams. The convergence of the folded-diagram series deteriorates with the inclusion of

  5. Predicting the phase diagram of two-dimensional colloidal systems with long-range interactions.

    PubMed

    Mejía-Rosales, Sergio J; Gil-Villegas, Alejandro; Ivlev, Boris I; Ruiz-García, Jaime

    2006-11-09

    The phase diagram of a two-dimensional model system for colloidal particles at the air-water interface was determined using Monte Carlo computer simulations in the isothermic-isobaric ensemble. The micrometer-range binary colloidal interaction has been modeled by hard disklike particles interacting via a secondary minimum followed by a weaker longer-range repulsive maximum, both of the order of kBT. The repulsive part of the potential drives the clustering of particles at low densities and low temperatures. Pinned voids are formed at higher densities and intermediate values of the surface pressure. The analysis of isotherms, translational and orientational correlation functions as well as structure factor gives clear evidence of the presence of a melting first-order transition. However, the melting process can be also followed by a metastable route through a hexatic phase at low surface pressures and low temperatures, before crystalization occurs at higher surface pressure.

  6. Use of Influence Diagrams and Fuzzy Theory to Develop Assessment Method of Organizational Influences on Component Maintenance

    SciTech Connect

    Yoonik Kim; Kwang-Won Ahn; Chang-Hyun Chung; Kil Yoo Kim; Joon-Eon Yang

    2002-07-01

    Organization can make influences on all the systems. Especially in case of nuclear power plants in which safety is established to be one of the most important operating goals, there have been a lot of research efforts for the hardware advancement. However in recent years, it has been widely recognized that organizational factors in nuclear power plants have an important influence on the safety attitudes and the safe behavior of individuals. Until now, any means to include assessments of organizational structure in probabilistic risk assessments have not been universally accepted. The objective of this work is to develop a method to assess organizational influences on component maintenance. Influence diagrams are introduced in this method as a decision making tool and fuzzy theory is used to reflect the vagueness in considering relevance of human activities in maintenance tasks. Introducing fuzzy theory to assess the organizational factors is deemed to a somewhat new trial, which makes it possible to convert linguistic vague descriptions into mathematical ones. Fuzzy linguistic descriptions offer an alternative and often complementary language to conventional, i.e., analytic approaches to modeling systems. Among the existing methodologies to assess organizational factors, the concept of the {omega}-factor model is utilized and the mechanism that organizational factors have influences on component maintenance is evaluated through composing influence diagrams. These influences go to failure rates and eventually affect component unavailability. Further study will make it possible that the influences of organizational factors on human error probabilities are incorporated into human reliability analysis and furthermore probabilistic safety assessment. (authors)

  7. [Comparison of film-screen combination in a contrast detail diagram and with interactive image analysis. 1: Contrast detail diagram].

    PubMed

    Hagemann, G; Eichbaum, G

    1997-07-01

    The following three film-screen combinations were compared: a) a combination of anticrossover film and UV-light emitting screens, b) a combination of blue-light emitting screens and film, and c) a conventional green fluorescing screen film combination. Radiographs of a specially designed plexiglass phantom (0.2 x 0.2 x 0.12 m3) were obtained that contained bar patterns of lead and plaster (calcium sulfate) to test high and intermediate contrast resolution and bar patterns of air to test low contrast resolution, respectively. An aluminum step wedge was integrated to evaluate dose-density curves of the radiographs. The dose values for the various step thicknesses were measured as percentage of the dose value in air for 60, 81, and 117 kV. Exposure conditions were the following: 12 pulse generator, 0.6 mm focus size, 4.7 mm aluminum prefilter, a grid with 40 lines/cm (12:1), and a focus-detector distance of 1.15 m. The thresholds of visible bars of the various pattern materials were assessed by seven radiologists, one technician, and the authors. The resulting contrast detail diagram could not prove any significant differences between the three tested screen film combinations. The pairwise comparison, however, found 8 of the 18 paired differences to be statistically significant between the conventional and the two new screen-film combinations. The authors concluded that subjective visual assessment of the threshold in a contrast detail study alone is of only limited value to grade image quality if no well-defined criteria are used (BIR report 20 [1989] 137-139). The statistical approach of paired differences of the estimated means appeared to be more appropriate.

  8. Two-dimensional Ising model with competing interactions: Phase diagram and low-temperature remanent disorder

    NASA Astrophysics Data System (ADS)

    O'Hare, A.; Kusmartsev, F. V.; Kugel, K. I.

    2009-01-01

    The two-dimensional Ising model with competing nearest-neighbor and diagonal interactions on the square lattice is studied by the transfer-matrix technique and by the Monte Carlo simulations. The phase diagram of this model is constructed with a special emphasis to the analysis of a glassy state arising as an order to disorder transition at low temperatures. Evidence of the glassy state (based, in particular, on the calculation of the average length of domain walls and on the Edwards-Anderson order parameter) and its characteristics are presented. It was shown that, in the frustrated Ising model, the domain-wall length correlates to the onset of the glassy state, that is, it may play the role of the order parameter for the Ising glass or for glasslike states in other frustrated magnetic systems.

  9. Using Student Interactions to Foster Rule-Diagram Mapping during Problem Solving in an Intelligent Tutoring System

    ERIC Educational Resources Information Center

    Butcher, Kirsten R.; Aleven, Vincent

    2013-01-01

    In many domains, problem solving involves the application of general domain principles to specific problem representations. In 3 classroom studies with an intelligent tutoring system, we examined the impact of (learner-generated) interactions and (tutor-provided) visual cues designed to facilitate rule-diagram mapping (where students connect…

  10. Influence of V-Diagrams on 10th Grade Turkish Students' Achievement in the Subject of Mechanical Waves

    ERIC Educational Resources Information Center

    Tekes, Hanife; Gonen, Selahattin

    2012-01-01

    The purpose of the present study was to examine how the use of V-diagrams one of the learning techniques used in laboratory studies in experiments conducted regarding the 10th grade lesson unit of "waves" influenced students' achievements. In the study, a quasi-experimental design with a pretest and posttest control group was used. The…

  11. Interaction of yttrium with nickel and phosphorus: Phase diagram and structural chemistry

    SciTech Connect

    Zhak, Olga; Stoyko, Stanislav; Babizhetskyy, Volodymyr; Shved, Olena; Oryshchyn, Stepan; Hoch, Constantin

    2013-11-15

    The interaction between the components of the ternary Y–Ni–P system has been investigated by means of electron probe microanalysis, X-ray phase and structure analyses, and the isothermal section of the phase diagram at 1070 K has been constructed for the first time. Existence of the earlier reported eight ternary phosphides of yttrium and nickel was confirmed, among them seven ternaries are daltonide compounds: YNi{sub 4}P{sub 2} (ZrFe{sub 4}Si{sub 2}-type structure), Y{sub 2}Ni{sub 12}P{sub 7} (Zr{sub 2}Fe{sub 12}P{sub 7}-type structure), Y{sub 6}Ni{sub 20}P{sub 13} (Zr{sub 6}Ni{sub 20}P{sub 13}-type structure), Y{sub 6}Ni{sub 14.9}P{sub 10.18} (own structure type), Y{sub 20}Ni{sub 42}P{sub 30.34} (Sm{sub 20}Ni{sub 41.6}P{sub 30}-type structure), Y{sub 15}Ni{sub 28}P{sub 21} (Tb{sub 15}Ni{sub 28}P{sub 21}-type structure), and YNiP (Tb{sub 1−x}NiP-type structure), whereas YNi{sub 1.66−1.78}P{sub 2} (ThCr{sub 2}Si{sub 2}-type structure) is a berthollide compound with small homogeneity range. The crystal structures of the some ternary phosphides have been determined by X-ray powder diffraction (YNi{sub 4}P{sub 2} and YNi{sub 1.66−1.78}P{sub 2}) and single crystal diffraction (Y{sub 2}Ni{sub 12}P{sub 7}) techniques. - Graphical abstract: Structure block with the composition Ln{sub 10}M{sub 21}X{sub 15} of the homologous series of the compounds (Ln,M){sub ∼2}X. Display Omitted - Highlights: • The phase diagram of Y–Ni–P at 1070 K has been constructed. • Existence of the eight ternary phosphides of yttrium and nickel has been confirmed. • The crystal structures of YNi{sub 4}P{sub 2} and YNi{sub 1.66-1.78}P{sub 2} have been determined by powder X-ray diffraction. • The crystal structure of Y{sub 2}Ni{sub 12}P{sub 7} has been established by single crystal diffraction.

  12. Crystalline-amorphous interaction in relation to the phase diagrams of binary polymer blends containing a crystalline constituent.

    PubMed

    Rathi, Pankaj; Huang, Tsang-Min; Dayal, Pratyush; Kyu, Thein

    2008-05-22

    The present article describes an equilibrium theory for determining binary phase diagrams of various crystalline-amorphous polymer blends by taking into account the contributions from both liquid-liquid phase separation between the constituents and solid-liquid phase transition of the crystalline component. An analytical expression for determining a crystal-amorphous interaction parameter is deduced based on the solid-liquid transition, involving the solidus and liquidus lines in conjunction with the coexistence curve of an upper critical solution temperature type. Of particular importance is that the crystalline-amorphous interaction parameter can be determined directly from the melting point depression data. The present analysis is therefore different from the conventional Flory-Huggins interaction parameter, which is associated with the liquid-liquid phase separation. The validity of the present theory is tested with the experimental phase diagrams of blends of poly(ethylene oxide)/diacrylate and poly(vinyl alcohol)/cellulose.

  13. Phase diagram for the Nambu-Jona-Lasinio model with 't Hooft and eight-quark interactions

    NASA Astrophysics Data System (ADS)

    Hiller, B.; Moreira, J.; Osipov, A. A.; Blin, A. H.

    2010-06-01

    It is shown that the end point of the first-order transition line, which merges into a crossover regime in the phase diagram of the Nambu-Jona-Lasinio model, extended to include the six-quark ’t Hooft and eight-quark interaction Lagrangians, is pushed toward vanishing chemical potential and higher temperatures with increasing strength of the Okubo-Zweig-Iizuka-violating eight-quark interactions. We clarify the connection between the location of the end point in the phase diagram and the mechanism of chiral symmetry breaking at the quark level. We show how the 8q interactions affect the number of effective quark degrees of freedom. We are able to obtain the correct asymptotics for this number at large temperatures by using the Pauli-Villars regularization.

  14. The phase diagram of a directed polymer in random media with p-spin ferromagnetic interactions

    NASA Astrophysics Data System (ADS)

    Wedagedera, J. R.

    2011-01-01

    We consider a directed polymer model with an additive p-spin (p>2) ferromagnetic term in the Hamiltonian. We give a rigorous proof for the specific free energy and derive the phase diagram. This model was proposed previously, and a detailed proof was given in the case p = 2, while the main result was only stated for p > 2. We give a detailed proof of the main result and show the behavior of the model as p → ∞ by constructing the phase diagram also in this case. These results are important in many applications, for instance, in telecommunication and immunology. Our major finding is that in the phase diagram for p > 2, a new transition curve (absent for p = 2) emerges between the paramagnetic region and the so-called mixed region and that the ferromagnetic region diminishes as p → ∞.

  15. Teaching Electron--Positron--Photon Interactions with Hands-on Feynman Diagrams

    NASA Astrophysics Data System (ADS)

    Kontokostas, George; Kalkanis, George

    2013-04-01

    Feynman diagrams are introduced in many physics textbooks, such as those by Alonso and Finn 1 and Serway,2 and their use in physics education has been discussed by various authors.3-5 They have an appealing simplicity and can give insight into events in the microworld. Yet students often do not understand their significance and often cannot combine the basic units of interaction—points where the world lines of two fermions and one boson meet—to construct diagrams for observed processes.

  16. Teaching Electron--Positron--Photon Interactions with Hands-on Feynman Diagrams

    ERIC Educational Resources Information Center

    Kontokostas, George; Kalkanis, George

    2013-01-01

    Feynman diagrams are introduced in many physics textbooks, such as those by Alonso and Finn and Serway, and their use in physics education has been discussed by various authors. They have an appealing simplicity and can give insight into events in the microworld. Yet students often do not understand their significance and often cannot combine the…

  17. How Different Variants of Orbit Diagrams Influence Student Explanations of the Seasons

    ERIC Educational Resources Information Center

    Lee, Victor R.

    2010-01-01

    The cause of the seasons is often associated with a very particular alternative conception: That the earth's orbit around the sun is highly elongated, and the differences in distance result in variations in temperature. It has been suggested that the standard diagrams used to depict the earth's orbit may be in some way responsible for the initial…

  18. Cancer risk and the complexity of the interactions between environmental and host factors: HENVINET interactive diagrams as simple tools for exploring and understanding the scientific evidence

    PubMed Central

    2012-01-01

    Background Development of graphical/visual presentations of cancer etiology caused by environmental stressors is a process that requires combining the complex biological interactions between xenobiotics in living and occupational environment with genes (gene-environment interaction) and genomic and non-genomic based disease specific mechanisms in living organisms. Traditionally, presentation of causal relationships includes the statistical association between exposure to one xenobiotic and the disease corrected for the effect of potential confounders. Methods Within the FP6 project HENVINET, we aimed at considering together all known agents and mechanisms involved in development of selected cancer types. Selection of cancer types for causal diagrams was based on the corpus of available data and reported relative risk (RR). In constructing causal diagrams the complexity of the interactions between xenobiotics was considered a priority in the interpretation of cancer risk. Additionally, gene-environment interactions were incorporated such as polymorphisms in genes for repair and for phase I and II enzymes involved in metabolism of xenobiotics and their elimination. Information on possible age or gender susceptibility is also included. Diagrams are user friendly thanks to multistep access to information packages and the possibility of referring to related literature and a glossary of terms. Diagrams cover both chemical and physical agents (ionizing and non-ionizing radiation) and provide basic information on the strength of the association between type of exposure and cancer risk reported by human studies and supported by mechanistic studies. Causal diagrams developed within HENVINET project represent a valuable source of information for professionals working in the field of environmental health and epidemiology, and as educational material for students. Introduction Cancer risk results from a complex interaction of environmental exposures with inherited gene

  19. Interpersonal Influence in Cross-Cultural Interactions

    DTIC Science & Technology

    2010-10-01

    RTO-MP-HFM-202 7 - 1 Interpersonal Influence in Cross-Cultural Interactions D.A. van Hemert TNO Defence, Security and Safety Human...and the target audiences could have a negative impact upon influencing activities. To achieve effective interpersonal interactions in cross-cultural...military operations, insight is needed into determinants of successful interpersonal interactions. This paper discusses a generic theoretical

  20. Influence of thermophysical properties of working fluid on the design of cryogenic turboexpanders using nsds diagram

    NASA Astrophysics Data System (ADS)

    Sam, Ashish A.; Ghosh, Parthasarathi

    2015-12-01

    Cryogenic turboexpanders are an essential part of liquefaction and refrigeration plants. The thermodynamic efficiency of these plants depends upon the efficiency of the turboexpander, which is the main cold generating component of these plants, and therefore, they should be designed for high thermodynamic efficiencies. Balje's [1] nsdschart, which is a contour of isentropic efficiencies plotted against specific speed and specific diameter, is commonly used for the preliminary design of cryogenic turboexpanders. But, these charts were developed based on calculations for a specific heat ratio (γ) of 1.4, and studies show that care should be taken while implementing the same for gases which have a higher γ of 1.67. Hence there is a need to investigate the extent of applicability of nsds diagram in designing expansion turbines for higher specific heat ratios. In this paper, Computational Fluid Dynamics (CFD) analysis of cryogenic turboexpanders was carried out using Ansys CFX®. The turboexpanders were designed based on the methodologies prescribed by Kun and Sentz [2] following the nsds diagram of Balje and Hasselgruber's technique for generating blade profile. The computational results of the two cases were analysed to investigate the applicability of Balje's nsds diagram for the design of turboexpanders for refrigeration and liquefaction cycles.

  1. Generating functionals for harmonic expectation values of paths with fixed end points: Feynman diagrams for nonpolynomial interactions.

    PubMed

    Kleinert, H; Pelster, A; Bachmann, M

    1999-09-01

    We introduce a general class of generating functionals for the calculation of quantum-mechanical expectation values of arbitrary functionals of fluctuating paths with fixed end points in configuration or momentum space. The generating functionals are calculated explicitly for the harmonic oscillator with time-dependent frequency, and used to derive a smearing formula for correlation functions of polynomial and nonpolynomial functions of time-dependent positions and momenta. This formula summarizes the effect of quantum fluctuations, and serves to derive generalized Wick rules and Feynman diagrams for perturbation expansions of nonpolynomial interactions.

  2. Influence of trapping potentials on the phase diagram of bosonic atoms in optical lattices

    SciTech Connect

    Giampaolo, S.M.; Illuminati, F.; Mazzarella, G.; De Siena, S.

    2004-12-01

    We study the effect of external trapping potentials on the phase diagram of bosonic atoms in optical lattices. We introduce a generalized Bose-Hubbard Hamiltonian that includes the structure of the energy levels of the trapping potential, and show that these levels are in general populated both at finite and zero temperature. We characterize the properties of the superfluid transition for this situation and compare them with those of the standard Bose-Hubbard description. We briefly discuss similar behaviors for fermionic systems.

  3. MIDAS, prototype Multivariate Interactive Digital Analysis System, phase 1. Volume 3: Wiring diagrams

    NASA Technical Reports Server (NTRS)

    Kriegler, F. J.; Christenson, D.; Gordon, M.; Kistler, R.; Lampert, S.; Marshall, R.; Mclaughlin, R.

    1974-01-01

    The Midas System is a third-generation, fast, multispectral recognition system able to keep pace with the large quantity and high rates of data acquisition from present and projected sensors. A principal objective of the MIDAS Program is to provide a system well interfaced with the human operator and thus to obtain large overall reductions in turn-around time and significant gains in throughput. The hardware and software generated in Phase I of the overall program are described. The system contains a mini-computer to control the various high-speed processing elements in the data path and a classifier which implements an all-digital prototype multivariate-Gaussian maximum likelihood decision algorithm operating at 2 x 100,000 pixels/sec. Sufficient hardware was developed to perform signature extraction from computer-compatible tapes, compute classifier coefficients, control the classifier operation, and diagnose operation. The MIDAS construction and wiring diagrams are given.

  4. Use of an influence diagram and fuzzy probability for evaluating accident management in a boiling water reactor

    SciTech Connect

    Yu, D.; Kastenberg, W.E.; Okrent, D. . Mechanical, Aerospace, and Nuclear Engineering Dept.)

    1994-06-01

    A new approach is presented for evaluating the uncertainties inherent in severe accident management strategies. At first, this analysis considers accident management as a decision problem (i.e., applying a strategy compared with do nothing) and uses an influence diagram. To evaluate imprecise node probabilities in the influence diagram, the analysis introduces the concept of a fuzzy probability. When fuzzy logic is applied, fuzzy probabilities are easily propagated to obtain results. In addition, the results obtained provide not only information similar to the classical approach, which uses point-estimate values, but also additional information regarding the impact of using imprecise input data. As an illustrative example, the proposed methodology is applied to the evaluation of the drywell flooding strategy for a long-term station blackout sequence at the Peach Bottom nuclear power plant. The results show that the drywell flooding strategy is beneficial for preventing reactor vessel breach. It is also effective for reducing the probability of containment failure for both liner melt-through and late overpressurization. Even though uncertainty exists in the results, flooding is preferred to do nothing when evaluated in terms of two risk measures: early and late fatalities.

  5. Investigation of the distinction between van der Waals interaction and chemical bonding based on the PAEM-MO diagram.

    PubMed

    Zhao, Dong-Xia; Yang, Zhong-Zhi

    2014-05-15

    In recent years, the basic problem of understanding chemical bonding, nonbonded, and/or van der Waals interactions has been intensively debated in terms of various theoretical methods. We propose and construct the potential acting on one electron in a molecule-molecular orbital (PAEM-MO) diagram, which draws the PAEM inserted the MO energy levels with their major atomic orbital components. PAEM-MO diagram is able to show clear distinction of chemical bonding from nonbonded and/or vdW interactions. The rule for this is as follows. Along the line connecting two atoms in a molecule or a complex, the existence of chemical bonding between these two atoms needs to satisfy two conditions: (a) a critical point of PAEM exists and (b) PAEM barrier between the two atoms is lower in energy than the occupied major valence-shell bonding MO which contains in-phase atomic components (positive overlap) of the two considered atoms. In contrast to the chemical bonding, for a nonbonded interaction or van der Waals interaction between two atoms, both conditions (a) and (b) do not be satisfied at the same time. This is demonstrated and discussed by various typical cases, particularly those related to helium atom and H-H bonding in phenanthrene. There are helium bonds in HHeF and HeBeO molecules, whereas no H-H bonding in phenanthrene. The validity and limitation for this rule is demonstrated through the investigations of the curves of the PAEM barrier top and MO energies versus the internuclear distances for He2 , H2 , and He2 (+) systems.

  6. Particles, Feynman Diagrams and All That

    ERIC Educational Resources Information Center

    Daniel, Michael

    2006-01-01

    Quantum fields are introduced in order to give students an accurate qualitative understanding of the origin of Feynman diagrams as representations of particle interactions. Elementary diagrams are combined to produce diagrams representing the main features of the Standard Model.

  7. Study of grain interactions in perpendicular magnetic recording media using first order reversal curve diagrams

    NASA Astrophysics Data System (ADS)

    Papusoi, C.; Srinivasan, K.; Acharya, R.

    2011-10-01

    It is demonstrated that, for perpendicular magnetic recording (PMR) media, first order reversal curve analysis can independently measure the grain coercive field distribution (or switching field distribution) and the strength of grain interactions, i.e., the demagnetization (mean-field) factor and the dispersion of grain interaction fields around the mean-field. The coercive field distribution is used to determine the intrinsic anisotropy field distribution of PMR media. The temperature dependence of the demagnetization factor shows that the strength of inter-granular exchange coupling is increasing with increasing medium thickness and it is decreasing with increasing temperature.

  8. Interaction of tantalum, chromium, and phosphorus at 1070 K: Phase diagram and structural chemistry

    SciTech Connect

    Lomnytska, Ya.; Babizhetskyy, V.; Oliynyk, A.; Toma, O.; Dzevenko, M.; Mar, A.

    2016-03-15

    The phase diagram of Ta–Cr–P at 1070 K has been constructed. • New ternary compounds Ta{sub 0.92(2)}Cr{sub 0.08(2)}P{sub 2} and Ta{sub 0.93(3)}Ti{sub 0.07(3)}P{sub 2} were established. • Ta{sub 1.0−0.8}Cr{sub 1.0−1.2}P and Ta{sub 0.86+x}Ti{sub 0.15-x}P{sub 2}(x= 0−0.07) exhibit homogeneity ranges. • The binary compounds reveal homogeneity ranges by Ta/Cr and Cr/Ta substitutions.

  9. Ultracold bosons with cavity-mediated long-range interactions: A local mean-field analysis of the phase diagram

    NASA Astrophysics Data System (ADS)

    Niederle, Astrid E.; Morigi, Giovanna; Rieger, Heiko

    2016-09-01

    Ultracold bosonic atoms in optical lattices self-organize into a variety of structural and quantum phases when placed into a single-mode cavity and pumped by a laser. Cavity optomechanical effects induce an atom density modulation at the cavity-mode wavelength that competes with the optical lattice arrangement. Simultaneously short-range interactions via particle hopping promote superfluid order such that a variety of structural and quantum coherent phases can occur. We analyze the emerging phase diagram in two dimensions by means of an extended Bose-Hubbard model using a local mean-field approach combined with a superfluid cluster analysis. For commensurate ratios of the cavity and external lattice wavelengths, the Mott insulator-superfluid transition is modified by the appearance of charge density wave and supersolid phases, at which the atomic density supports the buildup of a cavity field. For incommensurate ratios, the optomechanical forces induce the formation of Bose-glass and superglass phases, namely, nonsuperfluid and superfluid phases, respectively, displaying quasiperiodic density modulations, which in addition can exhibit structural and superfluid stripe formation. The onset of such structures is constrained by the on-site interaction and is favorable at fractional densities. Experimental observables are identified and discussed.

  10. The Influence of the Diameter Ratio on the Characteristics Diagram of the Axial Compressor

    NASA Technical Reports Server (NTRS)

    Eckert, B.; Pflueger, F.; Weinig, F.

    1948-01-01

    With the further development of axial blowers into highly loaded flow machines, the influence of the diameter ratio upon air output and efficiency gains in significance. Clarification of this matter is important for single-stage axial compressors, and is of still greater importance for multistage ones, and particularly for aircraft power plants. Tests with a single-stage axial blower gave a decrease in the attainable maximum pressure coefficient and optimum efficiency as the diameter ratio increased. The decrease must be ascribed chiefly to the guide surface of the hub and housing between the blades increasing with the diameter ratio.

  11. Influence of Computer-Assisted Roundhouse Diagrams on High School 9th Grade Students' Understanding the Subjects of "Force and Motion"

    ERIC Educational Resources Information Center

    Kocakaya, F.; Gönen, S.

    2014-01-01

    Main aim of this study is to examine the influence of computer-assisted roundhouse diagrams on high school 9th grade students' academic achievements in the subjects of "Force and Motion". The study was carried out in a public high school in Diyarbakir the province in the Southeast of Turkey. In the study, the "pre-test-post-test…

  12. Interface-roughening phase diagram of the three-dimensional Ising model for all interaction anisotropies from hard-spin mean-field theory.

    PubMed

    Cağlar, Tolga; Berker, A Nihat

    2011-11-01

    The roughening phase diagram of the d=3 Ising model with uniaxially anisotropic interactions is calculated for the entire range of anisotropy, from decoupled planes to the isotropic model to the solid-on-solid model, using hard-spin mean-field theory. The phase diagram contains the line of ordering phase transitions and, at lower temperatures, the line of roughening phase transitions, where the interface between ordered domains roughens. Upon increasing the anisotropy, roughening transition temperatures settle after the isotropic case, whereas the ordering transition temperature increases to infinity. The calculation is repeated for the d=2 Ising model for the full range of anisotropy, yielding no roughening transition.

  13. Influence of intermolecular interactions on magnetic observables

    NASA Astrophysics Data System (ADS)

    Schnack, Jürgen

    2016-02-01

    Very often it is an implied paradigm of molecular magnetism that magnetic molecules in a crystal interact so weakly that measurements of dc magnetic observables reflect ensemble properties of single molecules. But the number of cases where the assumption of virtually noninteracting molecules does not hold grows steadily. A deviation from the noninteracting case can especially clearly be seen in clusters with antiferromagnetic couplings, where steps of the low-temperature magnetization curve are smeared out with increasing intermolecular interaction. In this investigation we demonstrate with examples in one, two, and three space dimensions how intermolecular interactions influence typical magnetic observables such as magnetization, susceptibility, and specific heat.

  14. Using Influence Diagrams.

    DTIC Science & Technology

    1987-01-01

    probability function. We can use Figure 2.2 again to illustrate these ideas. Suppose a crime has been committed and z denotes the blood type of a...blood stain found at the scene of the crime. A suspect is in hand. Let y be the suspect’s blood type . For convenience we consider only two blood types , say...type 1 and type. 2. Let p(y=l) = 0 where 0 is the frequency of blood type I in the generil population. Let I if the suspect is guilty 0 otherwise

  15. Hubble Diagram

    NASA Astrophysics Data System (ADS)

    Djorgovski, S.; Murdin, P.

    2000-11-01

    Initially introduced as a way to demonstrate the expansion of the universe, and subsequently to determine the expansion rate (the HUBBLE CONSTANT H0), the Hubble diagram is one of the classical cosmological tests. It is a plot of apparent fluxes (usually expressed as magnitudes) of some types of objects at cosmological distances, against their REDSHIFTS. It is used as a tool to measure the glob...

  16. Determination of protein phase diagrams by microbatch experiments: exploring the influence of precipitants and pH.

    PubMed

    Baumgartner, Kai; Galm, Lara; Nötzold, Juliane; Sigloch, Heike; Morgenstern, Josefine; Schleining, Kristina; Suhm, Susanna; Oelmeier, Stefan A; Hubbuch, Jürgen

    2015-02-01

    Knowledge of protein phase behavior is essential for downstream process design in the biopharmaceutical industry. Proteins can either be soluble, crystalline or precipitated. Additionally liquid-liquid phase separation, gelation and skin formation can occur. A method to generate phase diagrams in high throughput on an automated liquid handling station in microbatch scale was developed. For lysozyme from chicken egg white, human lysozyme, glucose oxidase and glucose isomerase phase diagrams were generated at four different pH values – pH 3, 5, 7 and 9. Sodium chloride, ammonium sulfate, polyethylene glycol 300 and polyethylene glycol 1000 were used as precipitants. Crystallizing conditions could be found for lysozyme from chicken egg white using sodium chloride, for human lysozyme using sodium chloride or ammonium sulfate and glucose isomerase using ammonium sulfate. PEG caused destabilization of human lysozyme and glucose oxidase solutions or a balance of stabilizing and destabilizing effects for glucose isomerase near the isoelectric point. This work presents a systematic generation and extensive study of phase diagrams of proteins. Thus, it adds to the general understanding of protein behavior in liquid formulation and presents a convenient methodology applicable to any protein solution.

  17. Extremely asymmetric phase diagram of homopolymer-monotethered nanoparticles: Competition between chain conformational entropy and particle steric interaction

    NASA Astrophysics Data System (ADS)

    Zhang, Tiancai; Fu, Chao; Yang, Yingzi; Qiu, Feng

    2017-02-01

    The phase behaviors of homopolymer-monotethered nanoparticles (HMNs) in melt are investigated via a theoretical method combining self-consistent field theory for polymers and density functional theory for hard spheres. An extremely asymmetric phase diagram is observed: (i) microphases are only possible for the volume fraction of the tethered polymer fA > 0.35; (ii) in addition to lamellar phase, the system can only self-assemble into various morphologies with a polymer-rich matrix, including gyroid phase, cylindrical phase, and spherical phase. In the frame of this theory, the critical point for HMNs' microphase separation is significantly lower than that of linear diblock copolymers. Furthermore, the characteristic length of microphase-separated structures of HMNs is much smaller than that of linear diblock copolymers with the same molecular weight. Our calculation results on morphologies and characteristic length agree well with recent simulations and experimental observations.

  18. Entropy, vortex interactions and the phase diagram of heavy-ion irradiated Bi 2Sr 2CaCu 2O 8+ δ

    NASA Astrophysics Data System (ADS)

    van der Beek, C. J.; Konczykowski, M.; Drost, R. J.; Kes, P. H.; Samoilov, A. V.; Chikumoto, N.; Bouffard, S.; Feigel'man, M. V.

    2000-05-01

    Using dynamic and thermodynamic magnetization measurements, we analyze the phase diagram of Bi 2Sr 2CaCu 2O 8+ δ single crystals containing amorphous columnar defects created by heavy-ion irradiation. Reversible magnetization experiments yield the respective magnitudes of the pinning energy and entropy contributions to the free energy of the vortex lattice. It appears that the entropy contribution in the London regime is relatively minor in both unirradiated and irradiated crystals, except in the case of high density of columns and inductions B that are smaller than the interaction field Hint≈ Bφ/6. The dependence of the entropy contribution on vortex and defect density correlates well with measurements of the irreversibility line (IRL) Hirr( T), which shows a sharp increase at Hint.

  19. Ion mixing and phase diagrams

    NASA Astrophysics Data System (ADS)

    Lau, S. S.; Liu, B. X.; Nicolet, M.-A.

    1983-05-01

    Interactions induced by ion irradiation are generally considered to be non-equilibrium processes, whereas phase diagrams are determined by phase equilibria. These two entities are seemingly unrelated. However, if one assumes that quasi-equilibrium conditions prevail after the prompt events, subsequent reactions are driven toward equilibrium by thermodynamical forces. Under this assumption, ion-induced reactions are related to equilibrium and therefore to phase diagrams. This relationship can be seen in the similarity that exists in thin films between reactions induced by ion irradiation and reactions induced by thermal annealing. In the latter case, phase diagrams have been used to predict the phase sequence of stable compound formation, notably so in cases of silicide formation. Ion-induced mixing not only can lead to stable compound formation, but also to metastable alloy formation. In some metal-metal systems, terminal solubilities can be greatly extended by ion mixing. In other cases, where the two constituents of the system have different crystal structures, extension of terminal solubility from both sides of the phase diagram eventually becomes structurally incompatible and a glassy (amorphous) mixture can form. The composition range where this bifurcation is likely to occur is in the two-phase regions of the phase diagram. These concepts are potentially useful guides in selecting metal pairs that from metallic glasses by ion mixing. In this report, phenomenological correlation between stable (and metastable) phase formation and phase diagram is discussed in terms of recent experimental data.

  20. Influence of radioactivity on surface interaction forces.

    PubMed

    Walker, M E; McFarlane, J; Glasgow, D C; Chung, E; Taboada-Serrano, P; Yiacoumi, S; Tsouris, C

    2010-10-15

    Although some differences have been observed, the transport behavior of radioactive aerosol particles has often been assumed to be analogous to the behavior of nonradioactive aerosols in dispersion models. However, radioactive particles can become electrostatically charged as a result of the decay process. Theories have been proposed to describe this self-charging phenomenon, which may have a significant effect on how these particles interact with one another and with charged surfaces in the environment. In this study, atomic force microscopy (AFM) was employed to quantify surface forces between a particle and a planar surface and to compare measurements with and without the involvement of radioactivity. The main objective of this work is to assess directly the effects of radioactivity on the surface interactions of radioactive aerosols via the measurement of the adhesion force. The adhesion force between a silicon nitride AFM tip and an activated gold substrate was measured so that any possible effects due to radioactivity could be observed. The adhesion force between the tip and the gold surface increased significantly when the gold substrate (25 mm(2) surface area) was activated to a level of approximately 0.6 mCi. The results of this investigation will prompt further work into the effects of radioactivity in particle-surface interactions.

  1. Anthocyanins influence tannin-cell wall interactions.

    PubMed

    Bautista-Ortín, Ana Belén; Martínez-Hernández, Alejandro; Ruiz-García, Yolanda; Gil-Muñoz, Rocío; Gómez-Plaza, Encarna

    2016-09-01

    The rate of tannin extraction was studied in a vinification of red grapes and the results compared with another vinification made with white grapes fermented as for typical red wine, in the presence of skins and seeds. Even though the grapes presented a quite similar skin and seed tannin content, the differences in tannin concentration between both vinifications was very large, despite the fact that the only apparent difference between the phenolic composition of both wines was the anthocyanin content. This suggests that anthocyanins play an important role in tannin extractability, perhaps because they affect the extent of the tannin-cell wall interaction, a factor that largely controls the resulting quantity of tannins in wines. To confirm this observation, the effect of anthocyanins on the tannin extractability from grape seeds and skin and on the interaction between tannins and grape cell walls suspended in model solutions were studied. The results indicated that anthocyanins favored skin and seed tannin extraction and that there is a competition for the adsorption sites between anthocyanins and tannins that increases the tannin content when anthocyanins are present.

  2. Caution: Venn Diagrams Ahead!

    ERIC Educational Resources Information Center

    Kimmins, Dovie L.; Winters, J. Jeremy

    2015-01-01

    Two perspectives of the term "Venn diagram" reflect the typical differences in the uses of Venn diagrams in the subject areas of mathematics and language arts. These differences are subtle; nevertheless, they can potentially be confusing. In language arts, the circles in a Venn diagram typically represent things that can be compared and…

  3. European Extremely Large Telescope (E-ELT) availability stochastic model: integrating failure mode and effect analysis (FMEA), influence diagram, and Bayesian network together

    NASA Astrophysics Data System (ADS)

    Verzichelli, Gianluca

    2016-08-01

    An Availability Stochastic Model for the E-ELT has been developed in GeNIE. The latter is a Graphical User Interface (GUI) for the Structural Modeling, Inference, and Learning Engine (SMILE), originally distributed by the Decision Systems Laboratory from the University of Pittsburgh, and now being a product of Bayes Fusion, LLC. The E-ELT will be the largest optical/near-infrared telescope in the world. Its design comprises an Alt-Azimuth mount reflecting telescope with a 39-metre-diameter segmented primary mirror, a 4-metre-diameter secondary mirror, a 3.75-metre-diameter tertiary mirror, adaptive optics and multiple instruments. This paper highlights how a Model has been developed for an earlier on assessment of the Telescope Avail- ability. It also describes the modular structure and the underlying assumptions that have been adopted for developing the model and demonstrates the integration of FMEA, Influence Diagram and Bayesian Network elements. These have been considered for a better characterization of the Model inputs and outputs and for taking into account Degraded-based Reliability (DBR). Lastly, it provides an overview of how the information and knowledge captured in the model may be used for an earlier on definition of the Failure, Detection, Isolation and Recovery (FDIR) Control Strategy and the Telescope Minimum Master Equipment List (T-MMEL).

  4. Phase Equilibria Diagrams Database

    National Institute of Standards and Technology Data Gateway

    SRD 31 NIST/ACerS Phase Equilibria Diagrams Database (PC database for purchase)   The Phase Equilibria Diagrams Database contains commentaries and more than 21,000 diagrams for non-organic systems, including those published in all 21 hard-copy volumes produced as part of the ACerS-NIST Phase Equilibria Diagrams Program (formerly titled Phase Diagrams for Ceramists): Volumes I through XIV (blue books); Annuals 91, 92, 93; High Tc Superconductors I & II; Zirconium & Zirconia Systems; and Electronic Ceramics I. Materials covered include oxides as well as non-oxide systems such as chalcogenides and pnictides, phosphates, salt systems, and mixed systems of these classes.

  5. The influence of nanostructured materials on biointerfacial interactions.

    PubMed

    Koegler, Peter; Clayton, Andrew; Thissen, Helmut; Santos, Gil Nonato C; Kingshott, Peter

    2012-12-01

    Control over biointerfacial interactions in vitro and in vivo is the key to many biomedical applications: from cell culture and diagnostic tools to drug delivery, biomaterials and regenerative medicine. The increasing use of nanostructured materials is placing a greater demand on improving our understanding of how these new materials influence biointerfacial interactions, including protein adsorption and subsequent cellular responses. A range of nanoscale material properties influence these interactions, and material toxicity. The ability to manipulate both material nanochemistry and nanotopography remains challenging in its own right, however, a more in-depth knowledge of the subsequent biological responses to these new materials must occur simultaneously if they are ever to be affective in the clinic. We highlight some of the key technologies used for fabrication of nanostructured materials, examine how nanostructured materials influence the behavior of proteins and cells at surfaces and provide details of important analytical techniques used in this context.

  6. Phase diagram and structures in mixtures of poly(styrenesulfonate anion) and alkyltrimethylammonium cations in water: significance of specific hydrophobic interaction.

    PubMed

    Sitar, Simona; Goderis, Bart; Hansson, Per; Kogej, Ksenija

    2012-04-19

    Mixtures of polyelectrolytes and oppositely charged surfactants show very rich phase behavior that is influenced by surfactant-ion and polyion properties and by water content. A general feature is associative phase separation as a result of strong electrostatic interactions, whereas the effect of eventual more specific interactions (e.g., hydrophobic) has not been thoroughly investigated. In this paper, we report a detailed study on phase behavior and structures in poly(styrenesulfonate anion) (PSS(-))-cetyltrimethylammonium cation (CTA(+))-water mixtures that are characterized by a hydrophobic interaction between the styrene groups of PSS(-) and the micelle interior. Structures of various phases were determined by small-angle X-ray scattering, and results indicated the presence of a disordered micellar and an ordered hexagonal phase; no cubic phase was found. The general conclusion is that the highlighted hydrophobic interaction promotes dissolution of CTAPSS when the polyion salt is added and provides further stabilization of the dense phase when the surfactant salt is added.

  7. Phase diagrams of pseudo-binary phospholipid systems. II. Selected calorimetric studies on the influence of branching on the mixing properties of phosphatidylcholines.

    PubMed

    Dörfler, H D; Miethe, P

    1990-04-01

    The miscibility properties of branched phosphatidylcholines in mixtures of aqueous dispersions were studied by means of differential scanning calorimetry. The phase diagrams of four pseudo-binary systems from mixing type unbranched phosphatidylcholine/branched phosphatidylcholine/water (50 wt. % water) were investigated and discussed. The unbranched dipalmitoylphosphatidylcholine acts as a reference component of the mixtures. The phase diagrams of these four pseudo-binary phosphatidylcholine systems showed some connections between chain structure of the branched phosphatidylcholines and miscibility of the components. A change of the phase diagram type has been observed according to the branching and/or chain length differences of the phosphatidylcholines: complete miscibility and peritectic mixing behaviour. Generally we observed complete miscibility in the high-temperature phase (La-phase) and demixing in the low-temperature phases (gel phase). This is dependent on the branching and chain length differences of the mixing components.

  8. Influence of vane sweep on rotor-stator interaction noise

    NASA Technical Reports Server (NTRS)

    Envia, Edmane; Kerschen, Edward J.

    1990-01-01

    The influence of vane sweep in rotor-stator interaction noise is investigated. In an analytical approach, the interaction of a convected gust representing the rotor viscous wake, with a cascade of cascade of finite span swept airfoils, representing the stator, is analyzed. The analysis is based on the solution of the exact linearized equations of motion. High frequency convected gusts for which noise generation is concentrated near the leading edge of airfoils is considered. In a preliminary study, the problem of an isolated finite span swept airfoil interacting with a convected gust is analyzed. Results indicate that sweep can substantially reduce the farfield noise levels for a single airfoil. Using the single airfoil model, an approximate solution to the problem of noise radiation from a cascade of finite span swept airfoils interacting with a convected gust is derived. A parametric study of noise generated by gust cascade interaction is carried out to assess the effectiveness of vane sweep in reducing rotor-stator interaction noise. The results show that sweep is beneficial in reducing noise levels. Rotor wake twist or circumferential lean substantially influences the effectiveness of vane sweep. The orientation of vane sweep must be chosen to enhance the natural phase lag caused by wake lean, in which case rather small sweep angles substantially reduce the noise levels.

  9. Influence of vane sweep on rotor-stator interaction noise

    NASA Astrophysics Data System (ADS)

    Envia, Edmane; Kerschen, Edward J.

    1990-12-01

    The influence of vane sweep in rotor-stator interaction noise is investigated. In an analytical approach, the interaction of a convected gust representing the rotor viscous wake, with a cascade of cascade of finite span swept airfoils, representing the stator, is analyzed. The analysis is based on the solution of the exact linearized equations of motion. High frequency convected gusts for which noise generation is concentrated near the leading edge of airfoils is considered. In a preliminary study, the problem of an isolated finite span swept airfoil interacting with a convected gust is analyzed. Results indicate that sweep can substantially reduce the farfield noise levels for a single airfoil. Using the single airfoil model, an approximate solution to the problem of noise radiation from a cascade of finite span swept airfoils interacting with a convected gust is derived. A parametric study of noise generated by gust cascade interaction is carried out to assess the effectiveness of vane sweep in reducing rotor-stator interaction noise. The results show that sweep is beneficial in reducing noise levels. Rotor wake twist or circumferential lean substantially influences the effectiveness of vane sweep. The orientation of vane sweep must be chosen to enhance the natural phase lag caused by wake lean, in which case rather small sweep angles substantially reduce the noise levels.

  10. Construction of drug-polymer thermodynamic phase diagrams using Flory-Huggins interaction theory: identifying the relevance of temperature and drug weight fraction to phase separation within solid dispersions.

    PubMed

    Tian, Yiwei; Booth, Jonathan; Meehan, Elizabeth; Jones, David S; Li, Shu; Andrews, Gavin P

    2013-01-07

    Amorphous drug-polymer solid dispersions have the potential to enhance the dissolution performance and thus bioavailability of BCS class II drug compounds. The principle drawback of this approach is the limited physical stability of amorphous drug within the dispersion. Accurate determination of the solubility and miscibility of drug in the polymer matrix is the key to the successful design and development of such systems. In this paper, we propose a novel method, based on Flory-Huggins theory, to predict and compare the solubility and miscibility of drug in polymeric systems. The systems chosen for this study are (1) hydroxypropyl methylcellulose acetate succinate HF grade (HPMCAS-HF)-felodipine (FD) and (2) Soluplus (a graft copolymer of polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol)-FD. Samples containing different drug compositions were mixed, ball milled, and then analyzed by differential scanning calorimetry (DSC). The value of the drug-polymer interaction parameter χ was calculated from the crystalline drug melting depression data and extrapolated to lower temperatures. The interaction parameter χ was also calculated at 25 °C for both systems using the van Krevelen solubility parameter method. The rank order of interaction parameters of the two systems obtained at this temperature was comparable. Diagrams of drug-polymer temperature-composition and free energy of mixing (ΔG(mix)) were constructed for both systems. The maximum crystalline drug solubility and amorphous drug miscibility may be predicted based on the phase diagrams. Hyper-DSC was used to assess the validity of constructed phase diagrams by annealing solid dispersions at specific drug loadings. Three different samples for each polymer were selected to represent different regions within the phase diagram.

  11. Hertzsprung-Russell Diagram

    NASA Astrophysics Data System (ADS)

    Chiosi, C.; Murdin, P.

    2000-11-01

    The Hertzsprung-Russell diagram (HR-diagram), pioneered independently by EJNAR HERTZSPRUNG and HENRY NORRIS RUSSELL, is a plot of the star luminosity versus the surface temperature. It stems from the basic relation for an object emitting thermal radiation as a black body: ...

  12. Massive basketball diagram for a thermal scalar field theory

    NASA Astrophysics Data System (ADS)

    Andersen, Jens O.; Braaten, Eric; Strickland, Michael

    2000-08-01

    The ``basketball diagram'' is a three-loop vacuum diagram for a scalar field theory that cannot be expressed in terms of one-loop diagrams. We calculate this diagram for a massive scalar field at nonzero temperature, reducing it to expressions involving three-dimensional integrals that can be easily evaluated numerically. We use this result to calculate the free energy for a massive scalar field with a φ4 interaction to three-loop order.

  13. Inductively generating Euler diagrams.

    PubMed

    Stapleton, Gem; Rodgers, Peter; Howse, John; Zhang, Leishi

    2011-01-01

    Euler diagrams have a wide variety of uses, from information visualization to logical reasoning. In all of their application areas, the ability to automatically layout Euler diagrams brings considerable benefits. In this paper, we present a novel approach to Euler diagram generation. We develop certain graphs associated with Euler diagrams in order to allow curves to be added by finding cycles in these graphs. This permits us to build Euler diagrams inductively, adding one curve at a time. Our technique is adaptable, allowing the easy specification, and enforcement, of sets of well-formedness conditions; we present a series of results that identify properties of cycles that correspond to the well-formedness conditions. This improves upon other contributions toward the automated generation of Euler diagrams which implicitly assume some fixed set of well-formedness conditions must hold. In addition, unlike most of these other generation methods, our technique allows any abstract description to be drawn as an Euler diagram. To establish the utility of the approach, a prototype implementation has been developed.

  14. Influence of dissipation on two-atom dispersion interactions

    NASA Astrophysics Data System (ADS)

    Barcellona, Pablo; Buhmann, Stefan Yoshi

    2015-03-01

    We consider the dispersion interaction between two neutral, ground-state atoms at zero and finite temperature by means of a dynamical approach. Our result differs from the previous ones obtained with time-independent perturbation theory because it correctly accounts for the influence of dissipation via the atomic decay rates. Modern measurements of Casimir force seem to suggest a suppressed influence of dissipation. Our new result shows similar features and can hence help resolve the Drude-plasma debate. We also consider the interaction between a ground-state atom and an excited atom. There are discordant results in the literature for the retarded potential: one oscillating and one monotonous. Our dynamical result uniquely leads to the oscillating result when taking into account the decay rates. This work was supported by the DFG (Grant BU 1803/3-1).

  15. Square Source Type Diagram

    NASA Astrophysics Data System (ADS)

    Aso, N.; Ohta, K.; Ide, S.

    2014-12-01

    Deformation in a small volume of earth interior is expressed by a symmetric moment tensor located on a point source. The tensor contains information of characteristic directions, source amplitude, and source types such as isotropic, double-couple, or compensated-linear-vector-dipole (CLVD). Although we often assume a double couple as the source type of an earthquake, significant non-double-couple component including isotropic component is often reported for induced earthquakes and volcanic earthquakes. For discussions on source types including double-couple and non-double-couple components, it is helpful to display them using some visual diagrams. Since the information of source type has two degrees of freedom, it can be displayed onto a two-dimensional flat plane. Although the diagram developed by Hudson et al. [1989] is popular, the trace corresponding to the mechanism combined by two mechanisms is not always a smooth line. To overcome this problem, Chapman and Leaney [2012] developed a new diagram. This diagram has an advantage that a straight line passing through the center corresponds to the mechanism obtained by a combination of an arbitrary mechanism and a double-couple [Tape and Tape, 2012], but this diagram has some difficulties in use. First, it is slightly difficult to produce the diagram because of its curved shape. Second, it is also difficult to read out the ratios among isotropic, double-couple, and CLVD components, which we want to obtain from the estimated moment tensors, because they do not appear directly on the horizontal or vertical axes. In the present study, we developed another new square diagram that overcomes the difficulties of previous diagrams. This diagram is an orthogonal system of isotropic and deviatoric axes, so it is easy to get the ratios among isotropic, double-couple, and CLVD components. Our diagram has another advantage that the probability density is obtained simply from the area within the diagram if the probability density

  16. The f-spin physics of rare-earth iron pnictides: influence of d-electron antiferromagnetic order on heavy fermion phase diagram

    SciTech Connect

    Zhu, Jian-xin; Dai, Jianhui; Si, Qimiao

    2009-01-01

    Some of the high {Tc} iron pnictides contain rare-earth elements, raising the question of how the existence and tunability of a d-electron antiferromagnetic order influences the heavy fermion behavior of the f-moments. With CeOFeP and CeOFeAs in mind as prototypes, we derive an extended Anderson lattice model appropriate for these quaternary systems. We show that the Kondo screening of the f-moments are efficiently suppressed by the d-electron ordering. We also argue that, inside the d-electron ordered state (as in CeOFeAs), the f-moments provide a rare realization of a quantum frustrated magnet with competing J{sub 1}-J{sub 2}-J{sub 3} interactions in an effective square lattice. Implications ofr the heavy fermion physics in broader contexts are also discussed.

  17. Influence of interstitial Fe to the phase diagram of Fe1+yTe1‑xSex single crystals

    NASA Astrophysics Data System (ADS)

    Sun, Yue; Yamada, Tatsuhiro; Pyon, Sunseng; Tamegai, Tsuyoshi

    2016-08-01

    Superconductivity (SC) with the suppression of long-range antiferromagnetic (AFM) order is observed in the parent compounds of both iron-based and cuprate superconductors. The AFM wave vectors are bicollinear (π, 0) in the parent compound FeTe different from the collinear AFM order (π, π) in most iron pnictides. Study of the phase diagram of Fe1+yTe1‑xSex is the most direct way to investigate the competition between bicollinear AFM and SC. However, presence of interstitial Fe affects both magnetism and SC of Fe1+yTe1‑xSex, which hinders the establishment of the real phase diagram. Here, we report the comparison of doping-temperature (x-T) phase diagrams for Fe1+yTe1‑xSex (0 ≤ x ≤ 0.43) single crystals before and after removing interstitial Fe. Without interstitial Fe, the AFM state survives only for x < 0.05, and bulk SC emerges from x = 0.05, and does not coexist with the AFM state. The previously reported spin glass state, and the coexistence of AFM and SC may be originated from the effect of the interstitial Fe. The phase diagram of Fe1+yTe1‑xSex is found to be similar to the case of the “1111” system such as LaFeAsO1‑xFx, and is different from that of the “122” system.

  18. Influence of interstitial Fe to the phase diagram of Fe1+yTe1−xSex single crystals

    PubMed Central

    Sun, Yue; Yamada, Tatsuhiro; Pyon, Sunseng; Tamegai, Tsuyoshi

    2016-01-01

    Superconductivity (SC) with the suppression of long-range antiferromagnetic (AFM) order is observed in the parent compounds of both iron-based and cuprate superconductors. The AFM wave vectors are bicollinear (π, 0) in the parent compound FeTe different from the collinear AFM order (π, π) in most iron pnictides. Study of the phase diagram of Fe1+yTe1−xSex is the most direct way to investigate the competition between bicollinear AFM and SC. However, presence of interstitial Fe affects both magnetism and SC of Fe1+yTe1−xSex, which hinders the establishment of the real phase diagram. Here, we report the comparison of doping-temperature (x-T) phase diagrams for Fe1+yTe1−xSex (0 ≤ x ≤ 0.43) single crystals before and after removing interstitial Fe. Without interstitial Fe, the AFM state survives only for x < 0.05, and bulk SC emerges from x = 0.05, and does not coexist with the AFM state. The previously reported spin glass state, and the coexistence of AFM and SC may be originated from the effect of the interstitial Fe. The phase diagram of Fe1+yTe1−xSex is found to be similar to the case of the “1111” system such as LaFeAsO1−xFx, and is different from that of the “122” system. PMID:27577047

  19. Phase Diagrams of Electric-Fduced Aggregation in Conducting Colloids

    NASA Technical Reports Server (NTRS)

    Khusid, B.; Acrivos, A.

    1999-01-01

    Under the application of a sufficiently strong electric field, a suspension may undergo reversible phase transitions from a homogeneous random arrangement of particles into a variety of ordered aggregation patterns. The surprising fact about electric-field driven phase transitions is that the aggregation patterns, that are observed in very diverse systems of colloids, display a number of common structural features and modes of evolution thereby implying that a universal mechanism may exist to account for these phenomena. It is now generally believed that this mechanism emanates from the presence of the long-range anisotropic interactions between colloidal particles due to their polarization in an applied field. But, in spite of numerous applications of the electric-field-driven phenomena in biotechnology, separation, materials engineering, chemical analysis, etc. our understanding of these phenomena is far from complete. Thus, it is the purpose of the proposed research to develop a theory and then test experimentally, under normal- and low-gravity conditions, the accuracy of the theoretical predictions regarding the effect of the synergism of the interparticle electric and hydrodynamic interactions on the phase diagram of a suspension. The main results from our theoretical studies performed to-date enable one to trace how the variations of the electrical properties of the constituent materials influence the topology of the suspension phase diagram and then, by using an appropriate phase diagram, to evaluate how the electric-field-induced transformations will depend on the frequency and the strength of the applied field.

  20. Influence of airfoil thickness on convected gust interaction noise

    NASA Technical Reports Server (NTRS)

    Kerschen, E. J.; Tsai, C. T.

    1989-01-01

    The case of a symmetric airfoil at zero angle of attack is considered in order to determine the influence of airfoil thickness on sound generated by interaction with convected gusts. The analysis is based on a linearization of the Euler equations about the subsonic mean flow past the airfoil. Primary sound generation is found to occur in a local region surrounding the leading edge, with the size of the local region scaling on the gust wavelength. For a parabolic leading edge, moderate leading edge thickness is shown to decrease the noise level in the low Mach number limit.

  1. Dynamic tactile diagram simplification on refreshable displays.

    PubMed

    Rastogi, Ravi; Pawluk, Dianne T V

    2013-01-01

    The increasing use of visual diagrams in educational and work environments, and even our daily lives, has created obstacles for individuals who are blind or visually impaired to independently access the information they represent. Although physical tactile pictures can be created to convey the visual information, it is typically a slow, cumbersome, and costly process. Refreshable haptic displays, which interact with computers, promise to make this access quicker, easier, and cheaper. One important aspect in converting visual to tactile diagrams is to simplify the diagram as otherwise it can be too difficult to interpret with touch. Enabling this to be under user control in an interactive environment, such as with refreshable displays, could allow users to avoid being overwhelmed by the diagrams at any instant in time while still retaining access to all information in "storage". Through this article the authors investigate whether two types of diagram simplification--boundary simplification and contextual simplification--showed potential utility in an interactive environment. Boundary simplification was found to be significantly helpful in answering general questions about borders on a geographic map, and contextual simplification was helpful in answering relational questions, as compared to using the original map unchanged.

  2. Influence of salt purity on Na+ and palmitic acid interactions.

    PubMed

    Huang, Zishuai; Hua, Wei; Verreault, Dominique; Allen, Heather C

    2013-12-19

    The influence of salt purity on the interactions between Na(+) ions and the carboxylate (COO(-)) head group of palmitic acid (PA) monolayers is studied in the COO(-) and OH stretching regions using broad-band vibrational sum frequency generation (VSFG) spectroscopy. Ultrapure (UP) and ACS grade NaCl salts are used for aqueous solution preparation after proper pretreatment. The time evolution of VSFG spectra of PA monolayers on solutions made from these two grades of salts is different, which reveals that the salt purity has a significant impact on the interactions between Na(+) ions and the COO(-) group of PA. The trace metal impurities in ACS grade salt, which are more abundant than those in UP grade salt, are responsible for this difference due to their stronger affinity for the carboxylate group relative to Na(+) and further affects the interfacial water structure. These results suggest that the alkali salt grade even after pretreatment is critical in the studies of alkali cation-carboxylate interactions and comparison of relative binding affinities of different cations.

  3. Discourse Genre and Linguistic Mode: Interpreter Influences in Visual and Tactile Interpreted Interaction

    ERIC Educational Resources Information Center

    Metzger, Melanie; Fleetwood, Earl; Collins, Steven D.

    2004-01-01

    In this article, the authors investigate visual and tactile ASL-English interpreters' influences on interactive discourse through an interactional sociolinguistic analysis of videotaped, interpreted interactions. They examine the participation framework of each of the interactions to determine whether the interpreters' utterances influence the…

  4. Influence of Expectation and Campus Racial Climate on Undergraduates' Interracial Interaction

    ERIC Educational Resources Information Center

    Tamam, Ezhar; Idris, Fazilah; Tien, Wendy Yee Mei; Ahmad, Mona Alkauthar

    2013-01-01

    In this study, the authors examine the influence of interracial interaction expectation and campus racial climate perception on attitudes toward interracial interaction which, in turn, influences the levels of interracial interaction among students at a multicultural university in Malaysia. Interaction across race is fundamental to students'…

  5. Impulse-Momentum Diagrams

    ERIC Educational Resources Information Center

    Rosengrant, David

    2011-01-01

    Multiple representations are a valuable tool to help students learn and understand physics concepts. Furthermore, representations help students learn how to think and act like real scientists. These representations include: pictures, free-body diagrams, energy bar charts, electrical circuits, and, more recently, computer simulations and…

  6. Elementary diagrams in nuclear and neutron matter

    SciTech Connect

    Wiringa, R.B.

    1995-08-01

    Variational calculations of nuclear and neutron matter are currently performed using a diagrammatic cluster expansion with the aid of nonlinear integral equations for evaluating expectation values. These are the Fermi hypernetted chain (FHNC) and single-operator chain (SOC) equations, which are a way of doing partial diagram summations to infinite order. A more complete summation can be made by adding elementary diagrams to the procedure. The simplest elementary diagrams appear at the four-body cluster level; there is one such E{sub 4} diagram in Bose systems, but 35 diagrams in Fermi systems, which gives a level of approximation called FHNC/4. We developed a novel technique for evaluating these diagrams, by computing and storing 6 three-point functions, S{sub xyz}(r{sub 12}, r{sub 13}, r{sub 23}), where xyz (= ccd, cce, ddd, dde, dee, or eee) denotes the exchange character at the vertices 1, 2, and 3. All 35 Fermi E{sub 4} diagrams can be constructed from these 6 functions and other two-point functions that are already calculated. The elementary diagrams are known to be important in some systems like liquid {sup 3}He. We expect them to be small in nuclear matter at normal density, but they might become significant at higher densities appropriate for neutron star calculations. This year we programmed the FHNC/4 contributions to the energy and tested them in a number of simple model cases, including liquid {sup 3}He and Bethe`s homework problem. We get reasonable, but not exact agreement with earlier published work. In nuclear and neutron matter with the Argonne v{sub 14} interaction these contributions are indeed small corrections at normal density and grow to only 5-10 MeV/nucleon at 5 times normal density.

  7. Time-temperature-transformation diagrams with more than one nose

    NASA Technical Reports Server (NTRS)

    Weinberg, Michael C.

    1992-01-01

    The structures of time-temperature-transformation diagrams of glasses which crystallize the combined homogeneous and heterogeneous crystallization mechanisms are examined. Considerations are given to the factors which might produce more than one extremum in such diagrams. Specific nucleation and growth models are used, and the influence of the parameters which appear in the nucleation and growth rate expressions upon the structure of the diagrams is evaluated.

  8. Bow-tie diagrams for risk management in anaesthesia.

    PubMed

    Culwick, M D; Merry, A F; Clarke, D M; Taraporewalla, K J; Gibbs, N M

    2016-11-01

    Bow-tie analysis is a risk analysis and management tool that has been readily adopted into routine practice in many high reliability industries such as engineering, aviation and emergency services. However, it has received little exposure so far in healthcare. Nevertheless, its simplicity, versatility, and pictorial display may have benefits for the analysis of a range of healthcare risks, including complex and multiple risks and their interactions. Bow-tie diagrams are a combination of a fault tree and an event tree, which when combined take the shape of a bow tie. Central to bow-tie methodology is the concept of an undesired or 'Top Event', which occurs if a hazard progresses past all prevention controls. Top Events may also occasionally occur idiosyncratically. Irrespective of the cause of a Top Event, mitigation and recovery controls may influence the outcome. Hence the relationship of hazard to outcome can be viewed in one diagram along with possible causal sequences or accident trajectories. Potential uses for bow-tie diagrams in anaesthesia risk management include improved understanding of anaesthesia hazards and risks, pre-emptive identification of absent or inadequate hazard controls, investigation of clinical incidents, teaching anaesthesia risk management, and demonstrating risk management strategies to third parties when required.

  9. Gene–environment interactions influence ecological consequences of transgenic animals

    PubMed Central

    Sundström, L. F.; Lõhmus, M.; Tymchuk, W. E.; Devlin, Robert H.

    2007-01-01

    Production of transgenic animals has raised concern regarding their potential ecological impact should they escape or be released to the natural environment. This concern has arisen mainly from research on laboratory-reared animals and theoretical modeling exercises. In this study, we used biocontained naturalized stream environments and conventional hatchery environments to show that differences in phenotype between transgenic and wild genotypes depend on rearing conditions and, critically, that such genotype-by-environment interactions may influence subsequent ecological effects in nature. Genetically wild and growth hormone transgenic coho salmon (Oncorhynchus kisutch) were reared from the fry stage under either standard hatchery conditions or under naturalized stream conditions. When reared under standard hatchery conditions, the transgenic fish grew almost three times longer than wild conspecifics and had (under simulated natural conditions) stronger predation effects on prey than wild genotypes (even after compensation for size differences). In contrast, when fish were reared under naturalized stream conditions, transgenic fish were only 20% longer than the wild fish, and the magnitude of difference in relative predation effects was much reduced. These data show that genotype-by-environment interactions can influence the relative phenotype of transgenic and wild-type organisms and that extrapolations of ecological consequences from phenotypes developed in the unnatural laboratory environment may lead to an overestimation or underestimation of ecological risk. Thus, for transgenic organisms that may not be released to nature, the establishment of a range of highly naturalized environments will be critical for acquiring reliable experimental data to be used in risk assessments. PMID:17360448

  10. Albumin's Influence on Carprofen Enantiomers-Hymecromone Interaction.

    PubMed

    Tang, Mingjie; Guo, Yanjie; Gao, Youshui; Tang, Chao; Dang, Xiaoqian; Zhou, Zubin; Sun, Yuqiang; Wang, Kunzheng

    2016-03-01

    Hymecromone is an important coumarin drug, and carprofen is one of the most important nonsteroidal antiinflammatory drugs (NSAIDs). The present study aims to determine the influence of bovine serum albumin (BSA) on the carprofen-hymecromone interaction. The inhibition of carprofen enantiomers on the UDP-glucuronosyltransferase (UGT) 2B7-catalyzed glucuronidation of hymecromone was investigated in the UGTs incubation system with and without BSA. The inhibition capability of increased by 20% (P < 0.001) of (R)-carprofen after the addition of 0.5% BSA in the incubation mixture. In contrast, no significant difference was observed for the inhibition of (S)-carprofen on UGT2B7 activity in the absence or presence of 0.5% BSA in the incubation system. The Lineweaver-Burk plot showed that the intersection point was located in the vertical axis, indicating the competitive inhibition of (R)-carprofen on UGT2B7 in the incubation system with BSA, which is consistent with the inhibition kinetic type of (R)-carprofen on UGT2B7 in the incubation system without BSA. Furthermore, the second plot using the slopes from the Lineweaver-Burk versus the concentrations of (R)-carprofen showed that the fitting equation was y=39.997x+50. Using this equation, the inhibition kinetic parameter was calculated to be 1.3 μM. For (S)-carprofen, the intersection point was located in the horizontal axis in the Lineweaver-Burk plot for the incubation system with BSA, indicating the noncompetitive inhibition of (S)-carprofen on the activity of UGT2B7. The fitting plot of the second plot was y=24.6x+180, and the inhibition kinetic parameter was 7.3 μM. In conclusion, the present study gives a short summary of BSA's influence on the carprofen enantiomers-hymecromone interaction, which will guide the clinical application of carprofen and hymecromone.

  11. Calcium interacts with temperature to influence Daphnia movement rates

    PubMed Central

    Roszell, Jordan; Heyland, Andreas; Fryxell, John M.

    2016-01-01

    Predicting the ecological responses to climate change is particularly challenging, because organisms might be affected simultaneously by the synergistic effects of multiple environmental stressors. Global warming is often accompanied by declining calcium concentration in many freshwater ecosystems. Although there is growing evidence that these changes in water chemistry and thermal conditions can influence ecosystem dynamics, little information is currently available about how these synergistic environmental stressors could influence the behaviour of aquatic organisms. Here, we tested whether the combined effects of calcium and temperature affect movement parameters (average speed, mean turning frequency and mean-squared displacement) of the planktonic Daphnia magna, using a full factorial design and exposing Daphnia individuals to a range of realistic levels of temperature and calcium concentration. We found that movement increased with both temperature and calcium concentration, but temperature effects became considerably weaker when individuals were exposed to calcium levels close to survival limits documented for several Daphnia species, signalling a strong interaction effect. These results support the notion that changes in water chemistry might have as strong an effect as projected changes in temperature on movement rates of Daphnia, suggesting that even sublethal levels of calcium decline could have a considerable impact on the dynamics of freshwater ecosystems. PMID:28083097

  12. TEP process flow diagram

    SciTech Connect

    Wilms, R Scott; Carlson, Bryan; Coons, James; Kubic, William

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  13. Prey type, vibrations and handling interactively influence spider silk expression.

    PubMed

    Blamires, S J; Chao, I-C; Tso, I-M

    2010-11-15

    The chemical and mechanical properties of spider major ampullate (MA) silks vary in response to different prey, mostly via differential expression of two genes - MaSp1 and MaSp2 - although the spinning process exerts additional influence over the mechanical properties of silk. The prey cues that initiate differential gene expression are unknown. Prey nutrients, vibratory stimuli and handling have been suggested to be influential. We performed experiments to decouple the vibratory stimuli and handling associated with high and low kinetic energy prey (crickets vs flies) from their prey nutrients to test the relative influence of each as inducers of silk protein expression in the orb web spider Nephila pilipes. We found that the MA silks from spiders feeding on live crickets had greater percentages of glutamine, serine, alanine and glycine than those from spiders feeding on live flies. Proline composition of the silks was unaffected by feeding treatment. Increases in alanine and glycine in the MA silks of the live-cricket-feeding spiders indicate a probable increase in MaSp1 gene expression. The amino acid compositions of N. pilipes feeding on crickets with fly stimuli and N. pilipes feeding on flies with cricket stimuli did not differ from each other or from pre-treatment responses, so these feeding treatments did not induce differential MaSp expression. Our results indicate that cricket vibratory stimuli and handling interact with nutrients to induce N. pilipes to adjust their gene expression to produce webs with mechanical properties appropriate for the retention of this prey. This shows that spiders can genetically alter their silk chemical compositions and, presumably, mechanical properties upon exposure to different prey types. The lack of any change in proline composition with feeding treatment in N. pilipes suggests that the MaSp model determined for Nephila clavipes is not universally applicable to all Nephila.

  14. Massive basketball diagram for a thermal scalar field theory

    SciTech Connect

    Andersen, Jens O.; Braaten, Eric; Strickland, Michael

    2000-08-15

    The ''basketball diagram'' is a three-loop vacuum diagram for a scalar field theory that cannot be expressed in terms of one-loop diagrams. We calculate this diagram for a massive scalar field at nonzero temperature, reducing it to expressions involving three-dimensional integrals that can be easily evaluated numerically. We use this result to calculate the free energy for a massive scalar field with a {phi}{sup 4} interaction to three-loop order. (c) 2000 The American Physical Society.

  15. J.L. Meijering's contribution to the calculation of phase diagrams — A personal perspective

    NASA Astrophysics Data System (ADS)

    Kaufman, Larry

    1981-01-01

    During the 1950s the present author had the benefit of studying with Wagner, Chipman, and Cohen, reading the work of Zener, Kubaschewski, Darken and Meijering, and having student colleagues such as Hillert, Hilliard and Cahn wiht whom one could argue and disagree. Notwithstanding the fact that all of these individuals contributed substantially to the author's appreciation of the interaction between thermochemistry and phase diagrams, none had a greater impact than J.L. Meijering. Although I did not meet him in person until 1967, I found that his 1950-1963 papers (listed below) and the extensive correspondence we conducted on lattice stability had the most profound influence on my own perception of the importance of phase diagram calculations. In this brief paper I hope to review Meijering's contribution to the development of our understanding of binary phase diagram characteristics, synthesis of ternary phase diagrams from the components binary diagrams, miscibility gap phenomena, magnetic contributions, and lattice stability. I will try to convince you of my own opinion that Meijering has been the most successful disciple of Van Laar in our time in enhancing the tradition of the Dutch school of thermodynamicists.

  16. Phase diagram of Hertzian spheres

    NASA Astrophysics Data System (ADS)

    Pàmies, Josep C.; Cacciuto, Angelo; Frenkel, Daan

    2009-07-01

    We report the phase diagram of interpenetrating Hertzian spheres. The Hertz potential is purely repulsive, bounded at zero separation, and decreases monotonically as a power law with exponent 5/2, vanishing at the overlapping threshold. This simple functional describes the elastic interaction of weakly deformable bodies and, therefore, it is a reliable physical model of soft macromolecules, like star polymers and globular micelles. Using thermodynamic integration and extensive Monte Carlo simulations, we computed accurate free energies of the fluid phase and a large number of crystal structures. For this, we defined a general primitive unit cell that allows for the simulation of any lattice. We found multiple re-entrant melting and first-order transitions between crystals with cubic, trigonal, tetragonal, and hexagonal symmetries.

  17. Situational influences on rhythmicity in speech, music, and their interaction

    PubMed Central

    Hawkins, Sarah

    2014-01-01

    Brain processes underlying the production and perception of rhythm indicate considerable flexibility in how physical signals are interpreted. This paper explores how that flexibility might play out in rhythmicity in speech and music. There is much in common across the two domains, but there are also significant differences. Interpretations are explored that reconcile some of the differences, particularly with respect to how functional properties modify the rhythmicity of speech, within limits imposed by its structural constraints. Functional and structural differences mean that music is typically more rhythmic than speech, and that speech will be more rhythmic when the emotions are more strongly engaged, or intended to be engaged. The influence of rhythmicity on attention is acknowledged, and it is suggested that local increases in rhythmicity occur at times when attention is required to coordinate joint action, whether in talking or music-making. Evidence is presented which suggests that while these short phases of heightened rhythmical behaviour are crucial to the success of transitions in communicative interaction, their modality is immaterial: they all function to enhance precise temporal prediction and hence tightly coordinated joint action. PMID:25385776

  18. Wilson Loop Diagrams and Positroids

    NASA Astrophysics Data System (ADS)

    Agarwala, Susama; Marin-Amat, Eloi

    2017-03-01

    In this paper, we study a new application of the positive Grassmannian to Wilson loop diagrams (or MHV diagrams) for scattering amplitudes in N= 4 Super Yang-Mill theory ( N = 4 SYM). There has been much interest in studying this theory via the positive Grassmannians using BCFW recursion. This is the first attempt to study MHV diagrams for planar Wilson loop calculations (or planar amplitudes) in terms of positive Grassmannians. We codify Wilson loop diagrams completely in terms of matroids. This allows us to apply the combinatorial tools in matroid theory used to identify positroids (non-negative Grassmannians) to Wilson loop diagrams. In doing so, we find that certain non-planar Wilson loop diagrams define positive Grassmannians. While non-planar diagrams do not have physical meaning, this finding suggests that they may have value as an algebraic tool, and deserve further investigation.

  19. Warped penguin diagrams

    SciTech Connect

    Csaki, Csaba; Grossman, Yuval; Tanedo, Philip; Tsai, Yuhsin

    2011-04-01

    We present an analysis of the loop-induced magnetic dipole operator in the Randall-Sundrum model of a warped extra dimension with anarchic bulk fermions and an IR brane-localized Higgs. These operators are finite at one-loop order and we explicitly calculate the branching ratio for {mu}{yields}e{gamma} using the mixed position/momentum space formalism. The particular bound on the anarchic Yukawa and Kaluza-Klein (KK) scales can depend on the flavor structure of the anarchic matrices. It is possible for a generic model to either be ruled out or unaffected by these bounds without any fine-tuning. We quantify how these models realize this surprising behavior. We also review tree-level lepton flavor bounds in these models and show that these are on the verge of tension with the {mu}{yields}e{gamma} bounds from typical models with a 3 TeV Kaluza-Klein scale. Further, we illuminate the nature of the one-loop finiteness of these diagrams and show how to accurately determine the degree of divergence of a five-dimensional loop diagram using both the five-dimensional and KK formalism. This power counting can be obfuscated in the four-dimensional Kaluza-Klein formalism and we explicitly point out subtleties that ensure that the two formalisms agree. Finally, we remark on the existence of a perturbative regime in which these one-loop results give the dominant contribution.

  20. Consumer trait variation influences tritrophic interactions in salt marsh communities.

    PubMed

    Hughes, Anne Randall; Hanley, Torrance C; Orozco, Nohelia P; Zerebecki, Robyn A

    2015-07-01

    The importance of intraspecific variation has emerged as a key question in community ecology, helping to bridge the gap between ecology and evolution. Although much of this work has focused on plant species, recent syntheses have highlighted the prevalence and potential importance of morphological, behavioral, and life history variation within animals for ecological and evolutionary processes. Many small-bodied consumers live on the plant that they consume, often resulting in host plant-associated trait variation within and across consumer species. Given the central position of consumer species within tritrophic food webs, such consumer trait variation may play a particularly important role in mediating trophic dynamics, including trophic cascades. In this study, we used a series of field surveys and laboratory experiments to document intraspecific trait variation in a key consumer species, the marsh periwinkle Littoraria irrorata, based on its host plant species (Spartina alterniflora or Juncus roemerianus) in a mixed species assemblage. We then conducted a 12-week mesocosm experiment to examine the effects of Littoraria trait variation on plant community structure and dynamics in a tritrophic salt marsh food web. Littoraria from different host plant species varied across a suite of morphological and behavioral traits. These consumer trait differences interacted with plant community composition and predator presence to affect overall plant stem height, as well as differentially alter the density and biomass of the two key plant species in this system. Whether due to genetic differences or phenotypic plasticity, trait differences between consumer types had significant ecological consequences for the tritrophic marsh food web over seasonal time scales. By altering the cascading effects of the top predator on plant community structure and dynamics, consumer differences may generate a feedback over longer time scales, which in turn influences the degree of trait

  1. Consumer trait variation influences tritrophic interactions in salt marsh communities

    PubMed Central

    Hughes, Anne Randall; Hanley, Torrance C; Orozco, Nohelia P; Zerebecki, Robyn A

    2015-01-01

    The importance of intraspecific variation has emerged as a key question in community ecology, helping to bridge the gap between ecology and evolution. Although much of this work has focused on plant species, recent syntheses have highlighted the prevalence and potential importance of morphological, behavioral, and life history variation within animals for ecological and evolutionary processes. Many small-bodied consumers live on the plant that they consume, often resulting in host plant-associated trait variation within and across consumer species. Given the central position of consumer species within tritrophic food webs, such consumer trait variation may play a particularly important role in mediating trophic dynamics, including trophic cascades. In this study, we used a series of field surveys and laboratory experiments to document intraspecific trait variation in a key consumer species, the marsh periwinkle Littoraria irrorata, based on its host plant species (Spartina alterniflora or Juncus roemerianus) in a mixed species assemblage. We then conducted a 12-week mesocosm experiment to examine the effects of Littoraria trait variation on plant community structure and dynamics in a tritrophic salt marsh food web. Littoraria from different host plant species varied across a suite of morphological and behavioral traits. These consumer trait differences interacted with plant community composition and predator presence to affect overall plant stem height, as well as differentially alter the density and biomass of the two key plant species in this system. Whether due to genetic differences or phenotypic plasticity, trait differences between consumer types had significant ecological consequences for the tritrophic marsh food web over seasonal time scales. By altering the cascading effects of the top predator on plant community structure and dynamics, consumer differences may generate a feedback over longer time scales, which in turn influences the degree of trait

  2. Program Synthesizes UML Sequence Diagrams

    NASA Technical Reports Server (NTRS)

    Barry, Matthew R.; Osborne, Richard N.

    2006-01-01

    A computer program called "Rational Sequence" generates Universal Modeling Language (UML) sequence diagrams of a target Java program running on a Java virtual machine (JVM). Rational Sequence thereby performs a reverse engineering function that aids in the design documentation of the target Java program. Whereas previously, the construction of sequence diagrams was a tedious manual process, Rational Sequence generates UML sequence diagrams automatically from the running Java code.

  3. The Factors Influencing Young Children's Social Interaction in Technology Integration

    ERIC Educational Resources Information Center

    Lim, Eun Mee

    2015-01-01

    When technology integration is accomplished successfully in early childhood education settings, children tend to interact more with one another and exchange information related to computer tasks as well as the overall classroom on-going curriculum themes. Therefore, to explore how young children are interacting in computer areas when using…

  4. Influence of dipolar interactions on hyperthermia properties of ferromagnetic particles

    NASA Astrophysics Data System (ADS)

    Serantes, D.; Baldomir, D.; Martinez-Boubeta, C.; Simeonidis, K.; Angelakeris, M.; Natividad, E.; Castro, M.; Mediano, A.; Chen, D.-X.; Sanchez, A.; Balcells, LI.; Martínez, B.

    2010-10-01

    We show both experimental evidences and Monte Carlo modeling of the effects of interparticle dipolar interactions on the hysteresis losses. Results indicate that an increase in the intensity of dipolar interactions produce a decrease in the magnetic susceptibility and hysteresis losses, thus diminishing the hyperthermia output. These findings may have important clinical implications for cancer treatment.

  5. Expert-Novice Interactions: Influence of Partner Status.

    ERIC Educational Resources Information Center

    Verba, Mina; Winnykamen, Fajda

    1992-01-01

    Presents study results showing that a range of modes of interactive organization coexist in expert-novice problem-solving activity and vary with the asymmetry of the relationships. Reports that by combining high achieving status with task-related expertise, the resulting interactive dynamic is guidance/tutoring. Argues for multidimensional…

  6. Influence of charge traps in carbon nanodots on gas interaction.

    PubMed

    Mukherjee, Anwesha; Reddy, Siva Kumar; Deka Boruah, Buddha; Misra, Abha

    2017-03-01

    The nonlinear electrical characteristic of carbon nanodots (CNDs) has revealed important physical phenomena of charge trapping playing a dominant role in surface interactions. Functional groups on the surface of CNDs attract ambient water molecules which in turn act as charge traps and give rise to electrical hysteresis that plays a dominant role in understanding charge transport in CNDs on surface interactions. Hysteresis in the current-voltage response is further utilized to study the interaction of the CNDs with nitrogen dioxide gas as an external stimuli. The hysteresis area is observed to be dependent on the time of gas interaction with the CNDs, therefore revealing the interaction mechanism of the CNDs with the gas.

  7. Framing matters: contextual influences on interracial interaction outcomes.

    PubMed

    Babbitt, Laura G; Sommers, Samuel R

    2011-09-01

    Previous studies indicate that interracial interactions frequently have negative outcomes but have typically focused on social contexts. The current studies examined the effect of manipulating interaction context. In Study 1, Black and White participants worked together with instructions that created either a social focus or a task focus. With a task focus, interracial pairs were more consistently synchronized, Black participants showed less executive function depletion, and White participants generally showed reduced implicit bias. Follow-up studies suggested that prejudice concerns help explain these findings: White participants reported fewer concerns about appearing prejudiced when they imagined an interracial interaction with a task focus rather than a social focus (Study 2a), and Black participants reported less vigilance against prejudice in an imagined interracial interaction with a task focus rather than a social focus (Study 2b). Taken together, these studies illustrate the importance of interaction context for the experiences of both Blacks and Whites.

  8. Influence of charge traps in carbon nanodots on gas interaction

    NASA Astrophysics Data System (ADS)

    Mukherjee, Anwesha; Reddy, Siva Kumar; Deka Boruah, Buddha; Misra, Abha

    2017-03-01

    The nonlinear electrical characteristic of carbon nanodots (CNDs) has revealed important physical phenomena of charge trapping playing a dominant role in surface interactions. Functional groups on the surface of CNDs attract ambient water molecules which in turn act as charge traps and give rise to electrical hysteresis that plays a dominant role in understanding charge transport in CNDs on surface interactions. Hysteresis in the current–voltage response is further utilized to study the interaction of the CNDs with nitrogen dioxide gas as an external stimuli. The hysteresis area is observed to be dependent on the time of gas interaction with the CNDs, therefore revealing the interaction mechanism of the CNDs with the gas.

  9. The influence of interspecific interactions on species range expansion rates

    USGS Publications Warehouse

    Svenning, Jens-Christian; Gravel, Dominique; Holt, Robert D.; Schurr, Frank M.; Thuiller, Wilfried; Münkemüller, Tamara; Schiffers, Katja H.; Dullinger, Stefan; Edwards, Thomas C.; Hickler, Thomas; Higgins, Steven I.; Nabel, Julia E.M.S.; Pagel, Jörn; Normand, Signe

    2014-01-01

    Ongoing and predicted global change makes understanding and predicting species’ range shifts an urgent scientific priority. Here, we provide a synthetic perspective on the so far poorly understood effects of interspecific interactions on range expansion rates. We present theoretical foundations for how interspecific interactions may modulate range expansion rates, consider examples from empirical studies of biological invasions and natural range expansions as well as process-based simulations, and discuss how interspecific interactions can be more broadly represented in process-based, spatiotemporally explicit range forecasts. Theory tells us that interspecific interactions affect expansion rates via alteration of local population growth rates and spatial displacement rates, but also via effects on other demographic parameters. The best empirical evidence for interspecific effects on expansion rates comes from studies of biological invasions. Notably, invasion studies indicate that competitive dominance and release from specialized enemies can enhance expansion rates. Studies of natural range expansions especially point to the potential for competition from resident species to reduce expansion rates. Overall, it is clear that interspecific interactions may have important consequences for range dynamics, but also that their effects have received too little attention to robustly generalize on their importance. We then discuss how interspecific interactions effects can be more widely incorporated in dynamic modeling of range expansions. Importantly, models must describe spatiotemporal variation in both local population dynamics and dispersal. Finally, we derive the following guidelines for when it is particularly important to explicitly represent interspecific interactions in dynamic range expansion forecasts: if most interacting species show correlated spatial or temporal trends in their effects on the target species, if the number of interacting species is low

  10. The influence of interspecific interactions on species range expansion rates

    PubMed Central

    Svenning, Jens-Christian; Gravel, Dominique; Holt, Robert D.; Schurr, Frank M.; Thuiller, Wilfried; Münkemüller, Tamara; Schiffers, Katja H.; Dullinger, Stefan; Edwards, Thomas C.; Hickler, Thomas; Higgins, Steven I.; Nabel, Julia E. M. S.; Pagel, Jörn; Normand, Signe

    2014-01-01

    Ongoing and predicted global change makes understanding and predicting species’ range shifts an urgent scientific priority. Here, we provide a synthetic perspective on the so far poorly understood effects of interspecific interactions on range expansion rates. We present theoretical foundations for how interspecific interactions may modulate range expansion rates, consider examples from empirical studies of biological invasions and natural range expansions as well as process-based simulations, and discuss how interspecific interactions can be more broadly represented in process-based, spatiotemporally explicit range forecasts. Theory tells us that interspecific interactions affect expansion rates via alteration of local population growth rates and spatial displacement rates, but also via effects on other demographic parameters. The best empirical evidence for interspecific effects on expansion rates comes from studies of biological invasions. Notably, invasion studies indicate that competitive dominance and release from specialized enemies can enhance expansion rates. Studies of natural range expansions especially point to the potential for competition from resident species to reduce expansion rates. Overall, it is clear that interspecific interactions may have important consequences for range dynamics, but also that their effects have received too little attention to robustly generalize on their importance. We then discuss how interspecific interactions effects can be more widely incorporated in dynamic modeling of range expansions. Importantly, models must describe spatiotemporal variation in both local population dynamics and dispersal. Finally, we derive the following guidelines for when it is particularly important to explicitly represent interspecific interactions in dynamic range expansion forecasts: if most interacting species show correlated spatial or temporal trends in their effects on the target species, if the number of interacting species is low

  11. Diagonal Slices of 3D Young Diagrams in the Approach of Maya Diagrams

    NASA Astrophysics Data System (ADS)

    Cai, Li-Qiang; Wang, Li-Fang; Wu, Ke; Yang, Jie

    2014-09-01

    According to the correspondence between 2D Young diagrams and Maya diagrams and the relation between 2D and 3D Young diagrams, we construct 3D Young diagrams in the approach of Maya diagrams. Moreover, we formulate the generating function of 3D Young diagrams, which is the MacMahon function in terms of Maya diagrams.

  12. On Public Influence on People's Interactions with Ordinary Biodiversity.

    PubMed

    Skandrani, Zina; Daniel, Lucie; Jacquelin, Lauriane; Leboucher, Gérard; Bovet, Dalila; Prévot, Anne-Caroline

    2015-01-01

    Besides direct impacts of urban biodiversity on local ecosystem services, the contact of city dwellers with urban nature in their everyday life could increase their awareness on conservation issues. In this paper, we focused on a particularly common animal urban species, the feral pigeon Columba livia. Through an observational approach, we examined behavioral interactions between city dwellers and this species in the Paris metropolis, France. We found that most people (mean: 81%) do not interact with pigeons. Further, interactions (either positive or negative) are context and age-dependent: children interact more than adults and the elderly, while people in tourist spots interact more than people in urban parks or in railway stations, a result that suggests that people interacting with pigeons are mostly tourists. We discuss these results in terms of public normative pressures on city dwellers' access to and reconnection with urban nature. We call for caution in how urban species are publically portrayed and managed, given the importance of interactions with ordinary biodiversity for the fate of nature conservation.

  13. Potential-pH Diagrams.

    ERIC Educational Resources Information Center

    Barnum, Dennis W.

    1982-01-01

    Potential-pH diagrams show the domains of redoxpotential and pH in which major species are most stable. Constructing such diagrams provides students with opportunities to decide what species must be considered, search literature for equilibrium constants and free energies of formation, and practice in using the Nernst equation. (Author/JN)

  14. Phase diagram of elastic spheres.

    PubMed

    Athanasopoulou, L; Ziherl, P

    2017-02-15

    Experiments show that polymeric nanoparticles often self-assemble into several non-close-packed lattices in addition to the face-centered cubic lattice. Here, we explore theoretically the possibility that the observed phase sequences may be associated with the softness of the particles, which are modeled as elastic spheres interacting upon contact. The spheres are described by two finite-deformation theories of elasticity, the modified Saint-Venant-Kirchhoff model and the neo-Hookean model. We determine the range of indentations where the repulsion between the spheres is pairwise additive and agrees with the Hertz theory. By computing the elastic energies of nine trial crystal lattices at densities far beyond the Hertzian range, we construct the phase diagram and find the face- and body-centered cubic lattices as well as the A15 lattice and the simple hexagonal lattice, with the last two being stable at large densities where the spheres are completely faceted. These results are qualitatively consistent with observations, suggesting that deformability may indeed be viewed as a generic property that determines the phase behavior in nanocolloidal suspensions.

  15. Failure Assessment Diagram for Titanium Brazed Joints

    NASA Technical Reports Server (NTRS)

    Flom, Yury; Jones, Justin S.; Powell, Mollie M.; Puckett, David F.

    2011-01-01

    The interaction equation was used to predict failure in Ti-4V-6Al joints brazed with Al 1100 filler metal. The joints used in this study were geometrically similar to the joints in the brazed beryllium metering structure considered for the ATLAS telescope. This study confirmed that the interaction equation R(sub sigma) + R(sub Tau) = 1, where R(sub sigma) and R(sub Tau)are normal and shear stress ratios, can be used as conservative lower bound estimate of the failure criterion in ATLAS brazed joints as well as for construction of the Failure Assessment Diagram (FAD).

  16. Penguin-like diagrams from the standard model

    SciTech Connect

    Ping, Chia Swee

    2015-04-24

    The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the ‘tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to the flavor changing processes estimated.

  17. Penguin-like diagrams from the standard model

    NASA Astrophysics Data System (ADS)

    Ping, Chia Swee

    2015-04-01

    The Standard Model is highly successful in describing the interactions of leptons and quarks. There are, however, rare processes that involve higher order effects in electroweak interactions. One specific class of processes is the penguin-like diagram. Such class of diagrams involves the neutral change of quark flavours accompanied by the emission of a gluon (gluon penguin), a photon (photon penguin), a gluon and a photon (gluon-photon penguin), a Z-boson (Z penguin), or a Higgs-boson (Higgs penguin). Such diagrams do not arise at the tree level in the Standard Model. They are, however, induced by one-loop effects. In this paper, we present an exact calculation of the penguin diagram vertices in the `tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex functions for the penguin diagram vertices are obtained. The various penguin diagram vertex functions are related to one another via Ward-Takahashi identity. From these, a set of relations is obtained connecting the vertex form factors of various penguin diagrams. Explicit expressions for the gluon-photon penguin vertex form factors are obtained, and their contributions to the flavor changing processes estimated.

  18. Titanium Dioxide Nanoparticle-Biomolecule Interactions Influence Oral Absorption

    PubMed Central

    Jo, Mi-Rae; Yu, Jin; Kim, Hyoung-Jun; Song, Jae Ho; Kim, Kyoung-Min; Oh, Jae-Min; Choi, Soo-Jin

    2016-01-01

    Titanium dioxide (TiO2) nanoparticles (NPs) have been widely applied in various industrial fields, such as electronics, packaging, food, and cosmetics. Accordingly, concerns about the potential toxicity of TiO2 NPs have increased. In order to comprehend their in vivo behavior and potential toxicity, we must evaluate the interactions between TiO2 NPs and biomolecules, which can alter the physicochemical properties and the fate of NPs under physiological conditions. In the present study, in vivo solubility, oral absorption, tissue distribution, and excretion kinetics of food grade TiO2 (f-TiO2) NPs were evaluated following a single-dose oral administration to rats and were compared to those of general grade TiO2 (g-TiO2) NPs. The effect of the interactions between the TiO2 NPs and biomolecules, such as glucose and albumin, on oral absorption was also investigated, with the aim of determining the surface interactions between them. The intestinal transport pathway was also assessed using 3-dimensional culture systems. The results demonstrate that slightly higher oral absorption of f-TiO2 NPs compared to g-TiO2 NPs could be related to their intestinal transport mechanism by microfold (M) cells, however, most of the NPs were eliminated through the feces. Moreover, the biokinetics of f-TiO2 NPs was highly dependent on their interaction with biomolecules, and the dispersibility was affected by modified surface chemistry. PMID:28335354

  19. The Features of Interactive Whiteboards and Their Influence on Learning

    ERIC Educational Resources Information Center

    Kennewell, Steve; Beauchamp, Gary

    2007-01-01

    In a small-scale study of Information and Communication Technology (ICT)-rich primary school, interactive whiteboards (IWBs) were found to be the predominant ICT tools used by teachers. The study sought to identify how the teachers used features of ICT to enhance learning, based on a list of ICT's functions published for teacher education…

  20. Factors influencing flow steadiness in laminar boundary layer shock interactions

    NASA Astrophysics Data System (ADS)

    Tumuklu, Ozgur; Levin, Deborah A.; Gimelshein, Sergey F.; Austin, Joanna M.

    2016-11-01

    The Direct Simulation Monte Carlo method has been used to model laminar shock wave boundary interactions of hypersonic flow over a 30/55-deg double-wedge and "tick-shaped" model configurations studied in the Hypervelocity Expansion Tube facility and T-ADFA free-piston shock tunnel, respectively. The impact of thermochemical effects on these interactions by changing the chemical composition from nitrogen to air as well as argon for a stagnation enthalpy of 8.0 MJ/kg flow are investigated using the 2-D wedge model. The simulations are found to reproduce many of the classic features related to Edney Type V strong shock interactions that include the attached, oblique shock formed over the first wedge, the detached bow shock from the second wedge, the separation zone, and the separation and reattachment shocks that cause complex features such as the triple point for both cases. However, results of a reacting air flow case indicate that the size of the separation length, and the movement of the triple point toward to the leading edge is much less than the nitrogen case.

  1. Cyanogenic Pseudomonads Influence Multitrophic Interactions in the Rhizosphere

    PubMed Central

    Rudrappa, Thimmaraju; Splaine, Robert E.; Biedrzycki, Meredith L.; Bais, Harsh P.

    2008-01-01

    In the rhizosphere, plant roots cope with both pathogenic and beneficial bacterial interactions. The exometabolite production in certain bacterial species may regulate root growth and other root-microbe interactions in the rhizosphere. Here, we elucidated the role of cyanide production in pseudomonad virulence affecting plant root growth and other rhizospheric processes. Exposure of Arabidopsis thaliana Col-0 seedlings to both direct (with KCN) and indirect forms of cyanide from different pseudomonad strains caused significant inhibition of primary root growth. Further, we report that this growth inhibition was caused by the suppression of an auxin responsive gene, specifically at the root tip region by pseudomonad cyanogenesis. Additionally, pseudomonad cyanogenesis also affected other beneficial rhizospheric processes such as Bacillus subtilis colonization by biofilm formation on A. thaliana Col-0 roots. The effect of cyanogenesis on B. subtilis biofilm formation was further established by the down regulation of important B. subtilis biofilm operons epsA and yqxM. Our results show, the functional significance of pseudomonad cyanogenesis in regulating multitrophic rhizospheric interactions. PMID:18446201

  2. Pilot Automated Influence Diagram Decision Aid.

    DTIC Science & Technology

    1978-12-01

    1; 1, IN ONE LINE:’ CSZI NEW:NEWAVALS-U 126] ’ARE THESE VA-LIES3 COlRRECT? (Y OR N)’ 127!] -NEW IF Y’ 11121 128) MARAVALS ’-MtARA VJIhS, NE WA V.,AL.S...L/ 4 CA V AL tL GN ) l ]’V AL 1 3 3; C N OA COtiP/ DIM) (+/CONACOMP) p- I+CfNA[.COMP/CTRS1 122]3 MARAVAL4- MARAVALS [ ( -/ (±.ACAAN ITT’ ] CRS N𔃽N I

  3. Atemporal diagrams for quantum circuits

    SciTech Connect

    Griffiths, Robert B.; Wu Shengjun; Yu Li; Cohen, Scott M.

    2006-05-15

    A system of diagrams is introduced that allows the representation of various elements of a quantum circuit, including measurements, in a form which makes no reference to time (hence 'atemporal'). It can be used to relate quantum dynamical properties to those of entangled states (map-state duality), and suggests useful analogies, such as the inverse of an entangled ket. Diagrams clarify the role of channel kets, transition operators, dynamical operators (matrices), and Kraus rank for noisy quantum channels. Positive (semidefinite) operators are represented by diagrams with a symmetry that aids in understanding their connection with completely positive maps. The diagrams are used to analyze standard teleportation and dense coding, and for a careful study of unambiguous (conclusive) teleportation. A simple diagrammatic argument shows that a Kraus rank of 3 is impossible for a one-qubit channel modeled using a one-qubit environment in a mixed state.

  4. The Hertzsprung-Russell Diagram.

    ERIC Educational Resources Information Center

    Woodrow, Janice

    1991-01-01

    Describes a classroom use of the Hertzsprung-Russell diagram to infer not only the properties of a star but also the star's probable stage in evolution, life span, and age of the cluster in which it is located. (ZWH)

  5. Interpersonal Interaction in Online Learning: Experienced Online Instructors' Perceptions of Influencing Factors

    ERIC Educational Resources Information Center

    York, Cindy S.; Richardson, Jennifer C.

    2012-01-01

    A multitude of factors influence interpersonal interaction between students and instructors in an online course. This study examines perceptions of six experienced online instructors to determine factors they believe increase interaction among their students and between the students and instructor of online courses. The end result is an inventory…

  6. Characteristics of Interactive Oral and Computer-Mediated Peer Group Talk and Its Influence on Revision.

    ERIC Educational Resources Information Center

    Hewett, Beth L.

    2000-01-01

    Details a functional and qualitative study of interactive oral and computer-mediated communication (CMC)-generated (Norton "Connect") peer response group talk and its influence on revision. Finds the interactive peer groups in both environments talked primarily about their writing; however, the talk had different qualities when students used…

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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

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

    PubMed

    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.

  10. U-Mo/Al-Si interaction: Influence of Si concentration

    NASA Astrophysics Data System (ADS)

    Allenou, J.; Palancher, H.; Iltis, X.; Cornen, M.; Tougait, O.; Tucoulou, R.; Welcomme, E.; Martin, Ph.; Valot, C.; Charollais, F.; Anselmet, M. C.; Lemoine, P.

    2010-04-01

    Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 °C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2Al 20, when the other sub-layer (close to U-Mo) is silicon free and made of UAl 3 and U 6Mo 4Al 43. For Si weight concentrations above 5 wt.%, the Si-rich part becomes U 3(Si, Al) 5 + U(Al, Si) 3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2Al 20. On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

  11. Influence of Solvent in Controlling Peptide-Surface Interactions.

    PubMed

    Cannon, Daniel A; Ashkenasy, Nurit; Tuttle, Tell

    2015-10-01

    Protein binding to surfaces is an important phenomenon in biology and in modern technological applications. Extensive experimental and theoretical research has been focused in recent years on revealing the factors that govern binding affinity to surfaces. Theoretical studies mainly focus on examining the contribution of the individual amino acids or, alternatively, the binding potential energies of the full peptide, which are unable to capture entropic contributions and neglect the dynamic nature of the system. We present here a methodology that involves the combination of nonequilibrium dynamics simulations with strategic mutation of polar residues to reveal the different factors governing the binding free energy of a peptide to a surface. Using a gold-binding peptide as an example, we show that relative binding free energies are a consequence of the balance between strong interactions of the peptide with the surface and the ability for the bulk solvent to stabilize the peptide.

  12. Failure Assessment Diagram for Brazed 304 Stainless Steel Joints

    NASA Technical Reports Server (NTRS)

    Flom, Yory

    2011-01-01

    Interaction equations were proposed earlier to predict failure in Albemet 162 brazed joints. Present study demonstrates that the same interaction equations can be used for lower bound estimate of the failure criterion in 304 stainless steel joints brazed with silver-based filler metals as well as for construction of the Failure Assessment Diagrams (FAD).

  13. Factors in Client–Clinician Interaction That Influence Hearing Aid Adoption

    PubMed Central

    Jennings, Mary Beth; Shaw, Lynn; Meston, Christine N.; Cheesman, Margaret F.

    2011-01-01

    The influence of client–clinician interactions has not been emphasized in hearing health care, despite the extensive evidence of the impact of the provider–patient interaction on health outcomes. The purpose of this study was to identify factors in the client–clinician interaction that may influence hearing aid adoption. Thirteen adults who had received a hearing aid recommendation within the previous 3 months and 10 audiologists participated in a study to generate, sort, and rate the importance of factors in client–clinician interaction that may influence the hearing aid purchase decision. A concept mapping approach was used to define meaningful clusters of factors. Quantitative analysis and qualitative interpretation of the statements resulted in eight concepts. The concepts in order of their importance are (a) Ensuring client comfort, (b) Understanding and meeting client needs, (c) Client-centered traits and actions, (d) Acknowledging client as an individual, (e) Imposing undue pressure and discomfort, (f) Conveying device information by clinician, (g) Supporting choices and shared decision making, and (h) Factors in client readiness. Two overarching themes of client-centered interaction and client empowerment were identified. Results highlight the influence of the client–clinician interaction in hearing aid adoption and suggest the possibility of improving hearing aid adoption by empowering clients through a client-centered interaction. PMID:22155784

  14. Interaction between river water and groundwater: Geochemical and anthropogenic influence

    NASA Astrophysics Data System (ADS)

    Elango, L.; Karthikeyan, B.

    2011-12-01

    River water generally controls the quality and quantity of groundwater in its vicinity. Contribution by the rivers to groundwater is significant if there is over extraction. This is common in large cities where dependence on groundwater is high due to limited piped water supply. Chennai, India is one such large city where the river flowing is contaminated and the people in the near locality depend on groundwater for domestic use (Figure). The objective of this study is to understand the linkage between the river water and groundwater, and to assess the role played by the geochemical processes and anthropogenic influence. This study was carried out in and around Adyar River basin, Chennai by the collection of surface water and groundwater samples. Rainfall, lake water level and groundwater level from January 2005 to December 2009 was compared to understand their relationship. The concentration of major ion concentration vary widely in groundwater and surface water with respect to space and time. Na-Cl and Ca-Mg-Cl were the dominant groundwater and surface water type. Seawater intrusion may also be one of the reasons for Na-Cl dominant nature. In general, the ionic concentration of surface water increases towards the eastern part as in the case of groundwater. Evaporation and ion exchange were the major processes controlling groundwater chemistry in this area. Groundwater chemistry is similar to that of surface water. The surface water is contaminated due to discharge of industrial effluents and domestic sewage into the Adyar River by partly or untreated domestic sewage. Ecological restoration of Adyar River is planned and to be implemented shortly by the Government agencies which is expected to improve the river water quality. Systematic monitoring of water quality in this area will help to assess the improvement in surface water quality during the restoration process as well as its impact on groundwater.

  15. Automatically Assessing Graph-Based Diagrams

    ERIC Educational Resources Information Center

    Thomas, Pete; Smith, Neil; Waugh, Kevin

    2008-01-01

    To date there has been very little work on the machine understanding of imprecise diagrams, such as diagrams drawn by students in response to assessment questions. Imprecise diagrams exhibit faults such as missing, extraneous and incorrectly formed elements. The semantics of imprecise diagrams are difficult to determine. While there have been…

  16. The Influence of Social Interaction on Intuitions of Objectivity and Subjectivity.

    PubMed

    Fisher, Matthew; Knobe, Joshua; Strickland, Brent; Keil, Frank C

    2016-06-01

    We present experimental evidence that people's modes of social interaction influence their construal of truth. Participants who engaged in cooperative interactions were less inclined to agree that there was an objective truth about that topic than were those who engaged in a competitive interaction. Follow-up experiments ruled out alternative explanations and indicated that the changes in objectivity are explained by argumentative mindsets: When people are in cooperative arguments, they see the truth as more subjective. These findings can help inform research on moral objectivism and, more broadly, on the distinctive cognitive consequences of different types of social interaction.

  17. How will biotic interactions influence climate change-induced range shifts?

    PubMed

    HilleRisLambers, Janneke; Harsch, Melanie A; Ettinger, Ailene K; Ford, Kevin R; Theobald, Elinore J

    2013-09-01

    Biotic interactions present a challenge in determining whether species distributions will track climate change. Interactions with competitors, consumers, mutualists, and facilitators can strongly influence local species distributions, but few studies assess how and whether these interactions will impede or accelerate climate change-induced range shifts. In this paper, we explore how ecologists might move forward on this question. We first outline the conditions under which biotic interactions can result in range shifts that proceed faster or slower than climate velocity and result in ecological surprises. Next, we use our own work to demonstrate that experimental studies documenting the strength of biotic interactions across large environmental gradients are a critical first step for understanding whether they will influence climate change-induced range shifts. Further progress could be made by integrating results from these studies into modeling frameworks to predict how or generalize when biotic interactions mediate how changing climates influence range shifts. Finally, we argue that many more case studies like those described here are needed to explore the importance of biotic interactions during climate change-induced range shifts.

  18. Generic Phase Diagram of Binary Superlattices

    NASA Astrophysics Data System (ADS)

    Tkachenko, Alexei

    Emergence of a large variety of self-assembled superlattices is a dramatic recent trend in the fields of nanoparticle and colloidal sciences. Motivated by this development, we propose a model that combines simplicity with a remarkably rich phase behavior, applicable to a wide range of such self-assembled systems. Those include nanoparticle and colloidal assemblies driven by DNA-mediated interactions, electrostatics, and possibly, by controlled drying. In our model, a binary system of Large and Small hard sphere (L and S)interact via selective short-range (''sticky'') attraction. In its simplest version, this Binary Sticky Sphere model features attraction only between 'S' and 'L' particles, respectively. We demonstrate that in the limit when this attraction is sufficiently strong compared to kT, the problem becomes purely geometrical: the thermodynamically preferred state should maximize the number of S-L contacts. A general procedure for constructing the phase diagram as a function of system composition f, and particle size ratio r, is outlined. In this way, the global phase behavior can be calculated very efficiently, for a given set of plausible candidate phases. Furthermore, the geometric nature of the problem enables us to generate those candidate phases through a well defined and intuitive construction. We calculate the phase diagrams both for 2D and 3D systems, and compare the results with existing experiments. Most of the 3D superlattices observed to date are featured in our phase diagram, while several more are yet to be discovered. The research was carried out at the CFN, DOE Office of Science Facility, at BNL, under Contract No. DE-SC0012704.

  19. How abusive supervisors influence employees' voice and silence: the effects of interactional justice and organizational attribution.

    PubMed

    Wang, Rong; Jiang, Jiang

    2015-01-01

    In this research we investigated the influence of abusive supervision on employees' prosocial voice and silence, as well as clarified the roles of interactional justice (as a mediator) and organizational attribution (as a moderator). Moreover, we examined a mediated moderating model stipulating that interactional justice mediated the moderating effect of organizational attribution on the focal relationship. A scenario experiment was employed in Study 1, and after analyzing data from 196 employees, we found that abusive supervision influenced employees' prosocial voice and silence via interactional justice. In Study 2, data were collected from 379 employees in two waves separated by 1 week. The results not only replicated the findings of Study 1 but also indicated that organizational attribution buffered the abusive supervision-voice and silence relationship, and that interactional justice mediated this moderating effect.

  20. Sound generation and upstream influence due to instability waves interacting with non-uniform mean flows

    NASA Technical Reports Server (NTRS)

    Goldstein, M. E.

    1984-01-01

    Attention is given to the sound produced by artificially excited, spatially growing instability waves on subsonic shear layers. Real flows that always diverge in the downstream direction allow sound to be produced by the interaction of the instability waves with the resulting streamwise variations of the flow. The upstream influence, or feedback, can interact with the splitter plate lip to produce a downstream-propagating instability wave that may under certain conditions be the same instability wave that originally generated the upstream influence. The present treatment is restricted to very low Mach number flows, so that compressibility effects can only become important over large distances.

  1. Leader charisma and affective team climate: the moderating role of the leader's influence and interaction.

    PubMed

    Hernández Baeza, Ana; Araya Lao, Cristina; García Meneses, Juliana; González Romá, Vicente

    2009-11-01

    In this study, we evaluate the role of leader charisma in fostering positive affective team climate and preventing negative affective climate. The analysis of a longitudinal database of 137 bank branches by means of hierarchical moderated regression shows that leader charisma has a stronger effect on team optimism than on team tension. In addition, the leader's influence and the frequency of leader-team interaction moderate the relationship between charisma and affective climate. However, whereas the leader's influence enhances the relationship between leader charisma and positive affective climate, the frequency of interaction has counterproductive effects.

  2. Quantification of the Influence of Protein-Protein Interactions on Adsorbed Protein Structure and Bioactivity

    PubMed Central

    Wei, Yang; Thyparambil, Aby A.; Latour, Robert A.

    2013-01-01

    While protein-surface interactions have been widely studied, relatively little is understood at this time regarding how protein-surface interaction effects are influenced by protein-protein interactions and how these effects combine with the internal stability of a protein to influence its adsorbed-state structure and bioactivity. The objectives of this study were to develop a method to study these combined effects under widely varying protein-protein interaction conditions using hen egg-white lysozyme (HEWL) adsorbed on silica glass, poly(methyl methacrylate), and polyethylene as our model systems. In order to vary protein-protein interaction effects over a wide range, HEWL was first adsorbed to each surface type under widely varying protein solution concentrations for 2 h to saturate the surface, followed by immersion in pure buffer solution for 15 h to equilibrate the adsorbed protein layers in the absence of additionally adsorbing protein. Periodic measurements were made at selected time points of the areal density of the adsorbed protein layer as an indicator of the level of protein-protein interaction effects within the layer, and these values were then correlated with measurements of the adsorbed protein’s secondary structure and bioactivity. The results from these studies indicate that protein-protein interaction effects help stabilize the structure of HEWL adsorbed on silica glass, have little influence on the structural behavior of HEWL on HDPE, and actually serve to destabilize HEWL’s structure on PMMA. The bioactivity of HEWL on silica glass and HDPE was found to decrease in direct proportion to the degree of adsorption-induce protein unfolding. A direct correlation between bioactivity and the conformational state of adsorbed HEWL was less apparent on PMMA, thus suggesting that other factors influenced HEWL’s bioactivity on this surface, such as the accessibility of HEWL’s bioactive site being blocked by neighboring proteins or the surface

  3. Voronoi Diagrams and Spring Rain

    ERIC Educational Resources Information Center

    Perham, Arnold E.; Perham, Faustine L.

    2011-01-01

    The goal of this geometry project is to use Voronoi diagrams, a powerful modeling tool across disciplines, and the integration of technology to analyze spring rainfall from rain gauge data over a region. In their investigation, students use familiar equipment from their mathematical toolbox: triangles and other polygons, circumcenters and…

  4. Cues Matter: Learning Assistants Influence Introductory Biology Student Interactions during Clicker-Question Discussions

    PubMed Central

    Knight, Jennifer K.; Wise, Sarah B.; Rentsch, Jeremy; Furtak, Erin M.

    2015-01-01

    The cues undergraduate biology instructors provide to students before discussions of clicker questions have previously been shown to influence student discussion. We further explored how student discussions were influenced by interactions with learning assistants (LAs, or peer coaches). We recorded and transcribed 140 clicker-question discussions in an introductory molecular biology course and coded them for features such as the use of reasoning and types of questions asked. Students who did not interact with LAs had discussions that were similar in most ways to students who did interact with LAs. When students interacted with LAs, the only significant changes in their discussions were the use of more questioning and more time spent in discussion. However, when individual LA–student interactions were examined within discussions, different LA prompts were found to generate specific student responses: question prompts promoted student use of reasoning, while students usually stopped their discussions when LAs explained reasons for answers. These results demonstrate that LA prompts directly influence student interactions during in-class discussions. Because clicker discussions can encourage student articulation of reasoning, instructors and LAs should focus on how to effectively implement questioning techniques rather than providing explanations. PMID:26590204

  5. Cues Matter: Learning Assistants Influence Introductory Biology Student Interactions during Clicker-Question Discussions.

    PubMed

    Knight, Jennifer K; Wise, Sarah B; Rentsch, Jeremy; Furtak, Erin M

    2015-01-01

    The cues undergraduate biology instructors provide to students before discussions of clicker questions have previously been shown to influence student discussion. We further explored how student discussions were influenced by interactions with learning assistants (LAs, or peer coaches). We recorded and transcribed 140 clicker-question discussions in an introductory molecular biology course and coded them for features such as the use of reasoning and types of questions asked. Students who did not interact with LAs had discussions that were similar in most ways to students who did interact with LAs. When students interacted with LAs, the only significant changes in their discussions were the use of more questioning and more time spent in discussion. However, when individual LA-student interactions were examined within discussions, different LA prompts were found to generate specific student responses: question prompts promoted student use of reasoning, while students usually stopped their discussions when LAs explained reasons for answers. These results demonstrate that LA prompts directly influence student interactions during in-class discussions. Because clicker discussions can encourage student articulation of reasoning, instructors and LAs should focus on how to effectively implement questioning techniques rather than providing explanations.

  6. Shifting species interaction in soil microbial community and its influence on ecosystem functions modulating.

    PubMed

    Li, Hua; Colica, Giovanni; Wu, Pei-pei; Li, Dunhai; Rossi, Federico; De Philippis, Roberto; Liu, Yongding

    2013-04-01

    The supportive and negative evidence for the stress gradient hypothesis (SGH) led to an ongoing debate among ecologists and called for new empirical and theoretical work. In this study, we took various biological soil crust (BSCs) samples along a spatial gradient with four environmental stress levels to examine the fitness of SGH in microbial interactions and evaluate its influence on biodiversity-function relationships in BSCs. A new assessment method of species interactions within hard-cultured invisible soil community was employed, directly based on denaturing gradient gel electrophoresis fingerprint images. The results showed that biotic interactions in soil phototroph community dramatically shifted from facilitation to dominant competition with the improvement of microhabitats. It offered new evidence, which presented a different perspective on the hypothesis that the relative importance of facilitation and competition varies inversely along the gradient of abiotic stress. The path analysis indicated that influence of biotic interactions (r = 0.19, p < 0.05) on ecosystem functions is lower than other community properties (r = 0.62, p < 0.001), including soil moisture, crust coverage, and biodiversity. Furthermore, the correlation between species interactions and community properties was non-significant with low negative influence (r = -0.27, p > 0.05). We demonstrate that the inversion of biotic interaction as a response to the gradient of abiotic stresses existed not only in the visible plant community but also in the soil microbial community.

  7. Monte Carlo study of Dirac semimetals phase diagram

    NASA Astrophysics Data System (ADS)

    Braguta, V. V.; Katsnelson, M. I.; Kotov, A. Yu.; Nikolaev, A. A.

    2016-11-01

    In this paper the phase diagram of Dirac semimetals is studied within a lattice Monte Carlo simulation. In particular, we concentrate on the dynamical chiral symmetry breaking which results in a semimetal-insulator transition. Using numerical simulation, we determine the values of the critical coupling constant of the semimetal-insulator transition for different values of the anisotropy of the Fermi velocity. This measurement allows us to draw a tentative phase diagram for Dirac semimetals. It turns out that within the Dirac model with Coulomb interaction both Na3Bi and Cd3As2 , known experimentally to be Dirac semimetals, would lie deep in the insulating region of the phase diagram. This result probably shows a decisive role of screening of the interelectron interaction in real materials, similar to the situation in graphene.

  8. Influence of cooling intensity on shock wave boundary layer interaction region in turbine cascade

    NASA Astrophysics Data System (ADS)

    Kaczyński, P.; Szwaba, R.

    2016-10-01

    The shock wave boundary layer interaction on the suction side of a transonic turbine blade was one of the main objectives of the TFAST project. For this purpose a model of a turbine passage was designed, manufactured and assembled in a transonic wind tunnel. The paper presents the experimental investigations concerning the flow structure on the transonic turbine blade. A clean case (without a cooling system) with a normal shock wave interacting with a laminar boundary layer and also the influence of the blade cooling system with three different coolant blowing intensities on the laminar interaction region were investigated.

  9. Correlated and cooperative motions in segmental relaxation: Influence of constitutive unit weight and intermolecular interactions

    NASA Astrophysics Data System (ADS)

    Rijal, Bidur; Soto Puente, Jorge Arturo; Atawa, Bienvenu; Delbreilh, Laurent; Fatyeyeva, Kateryna; Saiter, Allisson; Dargent, Eric

    2016-12-01

    This work clarifies the notion of correlated and cooperative motions appearing during the α-relaxation process through the role of the molecular weight of the constitutive units and of the interchain dipolar interactions. By studying amorphous copolymers of poly(ethylene-co-vinyl acetate) with different vinyl acetate contents, we show that the correlated motions are not sensitive to the interchain dipolar interactions, in contrast to the cooperative motions, which increase with a strengthening of the intermolecular interactions for this sample family. Concerning the influence of the molecular weight m0, the notion of "correlated motions" seems to be equivalent to the notion of "cooperative motions" only for low m0 systems.

  10. Flow interaction based propagation model and bursty influence behavior analysis of Internet flows

    NASA Astrophysics Data System (ADS)

    Wu, Xiao-Yu; Gu, Ren-Tao; Ji, Yue-Feng

    2016-11-01

    QoS (quality of service) fluctuations caused by Internet bursty flows influence the user experience in the Internet, such as the increment of packet loss and transmission time. In this paper, we establish a mathematical model to study the influence propagation behavior of the bursty flow, which is helpful for developing a deep understanding of the network dynamics in the Internet complex system. To intuitively reflect the propagation process, a data flow interaction network with a hierarchical structure is constructed, where the neighbor order is proposed to indicate the neighborhood relationship between the bursty flow and other flows. The influence spreads from the bursty flow to each order of neighbors through flow interactions. As the influence spreads, the bursty flow has negative effects on the odd order neighbors and positive effects on the even order neighbors. The influence intensity of bursty flow decreases sharply between two adjacent orders and the decreasing degree can reach up to dozens of times in the experimental simulation. Moreover, the influence intensity increases significantly when network congestion situation becomes serious, especially for the 1st order neighbors. Network structural factors are considered to make a further study. Simulation results show that the physical network scale expansion can reduce the influence intensity of bursty flow by decreasing the flow distribution density. Furthermore, with the same network scale, the influence intensity in WS small-world networks is 38.18% and 18.40% lower than that in ER random networks and BA scale-free networks, respectively, due to a lower interaction probability between flows. These results indicate that the macro-structural changes such as network scales and styles will affect the inner propagation behaviors of the bursty flow.

  11. The Influence of Positive Mother-Child Verbal Interactions on Adolescent Mothers' Literacy

    ERIC Educational Resources Information Center

    Baron, Heather-Lee M.

    2010-01-01

    The purpose of this six-month qualitative microethnographic case study was to determine what influence a family literacy program based on positive mother-child verbal interactions would have on the participating adolescent mothers' literacy skills. The design of the program was founded on the Hart and Risley study (1995) and their findings…

  12. Using Tablet Computers in Preschool: How Does the Design of Applications Influence Participation, Interaction and Dialogues?

    ERIC Educational Resources Information Center

    Palmér, Hanna

    2015-01-01

    The results in this article explore whether and how the design of applications used on tablet computers influences the interaction and dialogues that occur between children and pedagogues, the participation of children in the activities and the mathematics that can be learned. While mathematics offered a lens to explore the use of tablet devices,…

  13. Influences of Family-Systems Intervention Practices on Parent-Child Interactions and Child Development

    ERIC Educational Resources Information Center

    Trivette, Carol M.; Dunst, Carl J.; Hamby, Deborah W.

    2010-01-01

    The extent to which the influences of family-systems intervention practices could be traced to variations in parent-child interactions and child development was investigated by meta-analytic structural equation modeling (MASEM). MASEM is a procedure for producing a weighted pooled correlation matrix and fitting a structural equation model to the…

  14. Support Services and Learning Styles Influencing Interaction in Asynchronous Online Discussions

    ERIC Educational Resources Information Center

    Kucuk, M.; Genc-Kumtepe, E.; Tasci, D.

    2010-01-01

    This paper reports a case of online classes from the English Language Teaching Programme at Anadolu University, Turkey. The study used an explanatory case oriented research design that assisted to examine relations between students' learning styles and factors influencing students' participation in asynchronous interactions in online courses. The…

  15. Interacting with a Computer-Simulated Pet: Factors Influencing Children's Humane Attitudes and Empathy

    ERIC Educational Resources Information Center

    Tsai, Yueh-Feng; Kaufman, David

    2014-01-01

    Previous research by Tsai and Kaufman (2010a, 2010b) has suggested that computer-simulated virtual pet dogs can be used as a potential medium to enhance children's development of empathy and humane attitudes toward animals. To gain a deeper understanding of how and why interacting with a virtual pet dog might influence children's social and…

  16. The Influence of Interactive Context on Prelinguistic Vocalizations and Maternal Responses

    ERIC Educational Resources Information Center

    Gros-Louis, Julie; West, Meredith J.; King, Andrew P.

    2016-01-01

    Many studies have documented influences of maternal responsiveness on cognitive and language development. Given the bidirectionality of interactions in caregiver-infant dyads, it is important to understand how infant behavior elicits variable responses. Prior studies have shown that mothers respond differentially to features of prelinguistic…

  17. Influence of supramolecular structures in crystals on parallel stacking interactions between pyridine molecules.

    PubMed

    Janjić, Goran V; Ninković, Dragan B; Zarić, Snezana D

    2013-08-01

    Parallel stacking interactions between pyridines in crystal structures and the influence of hydrogen bonding and supramolecular structures in crystals on the geometries of interactions were studied by analyzing data from the Cambridge Structural Database (CSD). In the CSD 66 contacts of pyridines have a parallel orientation of molecules and most of these pyridines simultaneously form hydrogen bonds (44 contacts). The geometries of stacked pyridines observed in crystal structures were compared with the geometries obtained by calculations and explained by supramolecular structures in crystals. The results show that the mean perpendicular distance (R) between pyridine rings with (3.48 Å) and without hydrogen bonds (3.62 Å) is larger than that calculated, because of the influence of supramolecular structures in crystals. The pyridines with hydrogen bonds show a pronounced preference for offsets of 1.25-1.75 Å, close to the position of the calculated minimum (1.80 Å). However, stacking interactions of pyridines without hydrogen bonds do not adopt values at or close to that of the calculated offset. This is because stacking interactions of pyridines without hydrogen bonds are less strong, and they are more susceptible to the influence of supramolecular structures in crystals. These results show that hydrogen bonding and supramolecular structures have an important influence on the geometries of stacked pyridines in crystals.

  18. TPH-2 Polymorphisms Interact with Early Life Stress to Influence Response to Treatment with Antidepressant Drugs

    PubMed Central

    Reynolds, Gavin P.; Yuan, Yonggui; Shi, Yanyan; Pu, Mengjia; Zhang, Zhijun

    2016-01-01

    Background: Variation in genes implicated in monoamine neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of single nucleotide polymorphisms in monoaminergic genes influence this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. An initial study of monoaminergic coding region single nucleotide polymorphisms identified significant associations of TPH2 and HTR1B single nucleotide polymorphisms with treatment response that showed interactions with childhood and recent life stress, respectively (Xu et al., 2012). Methods: A total of 47 further single nucleotide polymorphisms in 17 candidate monoaminergic genes were genotyped in 281 Chinese Han patients with major depressive disorder. Response to 6 weeks’ antidepressant treatment was determined by change in the 17-item Hamilton Depression Rating Scale score, and previous stressful events were evaluated by the Life Events Scale and Childhood Trauma Questionnaire-Short Form. Results: Three TPH2 single nucleotide polymorphisms (rs11178998, rs7963717, and rs2171363) were significantly associated with antidepressant response in this Chinese sample, as was a haplotype in TPH2 (rs2171363 and rs1487278). One of these, rs2171363, showed a significant interaction with childhood adversity in its association with antidepressant response. Conclusions: These findings provide further evidence that variation in TPH2 is associated with antidepressant response and may also interact with childhood trauma to influence outcome of antidepressant treatment. PMID:27521242

  19. How parental dietary behavior and food parenting practices affect children's dietary behavior. Interacting sources of influence?

    PubMed

    Larsen, Junilla K; Hermans, Roel C J; Sleddens, Ester F C; Engels, Rutger C M E; Fisher, Jennifer O; Kremers, Stef P J

    2015-06-01

    Until now, the literatures on the effects of food parenting practices and parents' own dietary behavior on children's dietary behavior have largely been independent from one another. Integrating findings across these areas could provide insight on simultaneous and interacting influences on children's food intake. In this narrative review, we provide a conceptual model that bridges the gap between both literatures and consists of three main hypotheses. First, parental dietary behavior and food parenting practices are important interactive sources of influence on children's dietary behavior and Body Mass Index (BMI). Second, parental influences are importantly mediated by changes in the child's home food environment. Third, parenting context (i.e., parenting styles and differential parental treatment) moderates effects of food parenting practices, whereas child characteristics (i.e., temperament and appetitive traits) mainly moderate effects of the home food environment. Future studies testing (parts of) this conceptual model are needed to inform effective parent-child overweight preventive interventions.

  20. Novel antagonistic interactions associated with plant polyploidization influence trait selection and habitat preference.

    PubMed

    Arvanitis, Leena; Wiklund, Christer; Münzbergova, Zuzana; Dahlgren, Johan P; Ehrlén, Johan

    2010-03-01

    Polyploidization is an important mechanism for sympatric speciation in plants. Still, we know little about whether plant polyploidization leads to insect host shifts, and if novel interactions influence habitat and trait selection in plants. We investigated herbivory by the flower bud gall-forming midge Dasineura cardaminis on tetraploids and octoploids of the herb Cardamine pratensis. Gall midges attacked only octoploid plant populations, and a transplantation experiment confirmed this preference. Attack rates were higher in populations that were shaded, highly connected or occurred along stream margins. Within populations, late-flowering individuals with many flowers were most attacked. Galling reduced seed production and significantly influenced phenotypic selection on flower number. Our results suggest that an increase in ploidy may lead to insect host shifts and that plant ploidy explains insect host use. In newly formed plant polyploids, novel interactions may alter habitat preferences and trait selection, and influence the further evolution of cytotypes.

  1. Analysing Collisions Using Minkowski Diagrams in Momentum Space

    ERIC Educational Resources Information Center

    Bokor, Nandor

    2011-01-01

    Momentum space and Minkowski diagrams are powerful tools for interpreting and analysing relativistic collisions in one or two spatial dimensions. All relevant quantities that characterize a collision, including the mass, velocity, momentum and energy of the interacting particles, both before and after collision, can be directly seen from a single…

  2. Introducing the Circular Flow Diagram to Business Students

    ERIC Educational Resources Information Center

    Daraban, Bogdan

    2010-01-01

    The circular flow of income diagram is a simplified representation of the functioning of a free-market economic system. It illustrates how businesses interact with the other economic participants within the key macroeconomic markets that coordinate the flow of income through the national economy. Therefore, it can provide students of business with…

  3. Hero's journey in bifurcation diagram

    NASA Astrophysics Data System (ADS)

    Monteiro, L. H. A.; Mustaro, P. N.

    2012-06-01

    The hero's journey is a narrative structure identified by several authors in comparative studies on folklore and mythology. This storytelling template presents the stages of inner metamorphosis undergone by the protagonist after being called to an adventure. In a simplified version, this journey is divided into three acts separated by two crucial moments. Here we propose a discrete-time dynamical system for representing the protagonist's evolution. The suffering along the journey is taken as the control parameter of this system. The bifurcation diagram exhibits stationary, periodic and chaotic behaviors. In this diagram, there are transition from fixed point to chaos and transition from limit cycle to fixed point. We found that the values of the control parameter corresponding to these two transitions are in quantitative agreement with the two critical moments of the three-act hero's journey identified in 10 movies appearing in the list of the 200 worldwide highest-grossing films.

  4. How does human-induced environmental change influence host-parasite interactions?

    PubMed

    Budria, Alexandre; Candolin, Ulrika

    2014-04-01

    Host-parasite interactions are an integral part of ecosystems that influence both ecological and evolutionary processes. Humans are currently altering environments the world over, often with drastic consequences for host-parasite interactions and the prevalence of parasites. The mechanisms behind the changes are, however, poorly known. Here, we explain how host-parasite interactions depend on two crucial steps--encounter rate and host-parasite compatibility--and how human activities are altering them and thereby host-parasite interactions. By drawing on examples from the literature, we show that changes in the two steps depend on the influence of human activities on a range of factors, such as the density and diversity of hosts and parasites, the search strategy of the parasite, and the avoidance strategy of the host. Thus, to unravel the mechanisms behind human-induced changes in host-parasite interactions, we have to consider the characteristics of all three parts of the interaction: the host, the parasite and the environment. More attention should now be directed to unfold these mechanisms, focusing on effects of environmental change on the factors that determine encounter rate and compatibility. We end with identifying several areas in urgent need of more investigations.

  5. Quantum Dimer Model: Phase Diagrams

    NASA Astrophysics Data System (ADS)

    Goldstein, Garry; Chamon, Claudio; Castelnovo, Claudio

    We present new theoretical analysis of the Quantum Dimer Model. We study dimer models on square, cubic and triangular lattices and we reproduce their phase diagrams (which were previously known only numerically). We show that there are several types of dimer liquids and solids. We present preliminary analysis of several other models including doped dimers and planar spin ice, and some results on the Kagome and hexagonal lattices.

  6. Phase diagram of crushed powders

    NASA Astrophysics Data System (ADS)

    Bodard, Sébastien; Jalbaud, Olivier; Saurel, Richard; Burtschell, Yves; Lapebie, Emmanuel

    2016-12-01

    Compression of monodisperse powder samples in quasistatic conditions is addressed in a pressure range such that particles fragmentation occurs while the solid remains incompressible (typical pressure range of 1-300 MPa for glass powders). For a granular bed made of particles of given size, the existence of three stages is observed during compression and crush up. First, classical compression occurs and the pressure of the granular bed increases along a characteristic curve as the volume decreases. Then, a critical pressure is reached for which fragmentation begins. During the fragmentation process, the granular pressure stays constant in a given volume range. At the end of this second stage, 20%-50% of initial grains are reduced to finer particles, depending on the initial size. Then the compression undergoes the third stage and the pressure increases along another characteristic curve, in the absence of extra fragmentation. The present paper analyses the analogies between the phase transition in liquid-vapour systems and powder compression with crush-up. Fragmentation diagram for a soda lime glass is determined by experimental means. The analogues of the saturation pressure and latent heat of phase change are determined. Two thermodynamic models are then examined to represent the crush-up diagram. The first one uses piecewise functions while the second one is of van der Waals type. Both equations of state relate granular pressure, solid volume fraction, and initial particle diameter. The piecewise functions approach provides reasonable representations of the phase diagram while the van der Waals one fails.

  7. Causal diagrams in systems epidemiology

    PubMed Central

    2012-01-01

    Methods of diagrammatic modelling have been greatly developed in the past two decades. Outside the context of infectious diseases, systematic use of diagrams in epidemiology has been mainly confined to the analysis of a single link: that between a disease outcome and its proximal determinant(s). Transmitted causes ("causes of causes") tend not to be systematically analysed. The infectious disease epidemiology modelling tradition models the human population in its environment, typically with the exposure-health relationship and the determinants of exposure being considered at individual and group/ecological levels, respectively. Some properties of the resulting systems are quite general, and are seen in unrelated contexts such as biochemical pathways. Confining analysis to a single link misses the opportunity to discover such properties. The structure of a causal diagram is derived from knowledge about how the world works, as well as from statistical evidence. A single diagram can be used to characterise a whole research area, not just a single analysis - although this depends on the degree of consistency of the causal relationships between different populations - and can therefore be used to integrate multiple datasets. Additional advantages of system-wide models include: the use of instrumental variables - now emerging as an important technique in epidemiology in the context of mendelian randomisation, but under-used in the exploitation of "natural experiments"; the explicit use of change models, which have advantages with respect to inferring causation; and in the detection and elucidation of feedback. PMID:22429606

  8. Scheil-Gulliver Constituent Diagrams

    NASA Astrophysics Data System (ADS)

    Pelton, Arthur D.; Eriksson, Gunnar; Bale, Christopher W.

    2017-03-01

    During solidification of alloys, conditions often approach those of Scheil-Gulliver cooling in which it is assumed that solid phases, once precipitated, remain unchanged. That is, they no longer react with the liquid or with each other. In the case of equilibrium solidification, equilibrium phase diagrams provide a valuable means of visualizing the effects of composition changes upon the final microstructure. In the present study, we propose for the first time the concept of Scheil-Gulliver constituent diagrams which play the same role as that in the case of Scheil-Gulliver cooling. It is shown how these diagrams can be calculated and plotted by the currently available thermodynamic database computing systems that combine Gibbs energy minimization software with large databases of optimized thermodynamic properties of solutions and compounds. Examples calculated using the FactSage system are presented for the Al-Li and Al-Mg-Zn systems, and for the Au-Bi-Sb-Pb system and its binary and ternary subsystems.

  9. Habitat context influences predator interference interactions and the strength of resource partitioning.

    PubMed

    Hughes, A Randall; Grabowski, Jonathan H

    2006-08-01

    Despite increasing evidence that habitat structure can shape predator-prey interactions, few studies have examined the impact of habitat context on interactions among multiple predators and the consequences for combined foraging rates. We investigated the individual and combined effects of stone crabs (Menippe mercenaria) and knobbed whelks (Busycon carica) when foraging on two common bivalves, the hard clam (Mercenaria mercenaria) and the ribbed mussel (Geukensia demissa) in oyster reef and sand flat habitats. Because these species co-occur across these and other estuarine habitats of varying physical complexity, this system is ideal for examining how habitat context influences foraging rates and the generality of predator interactions. Consistent with results from previous studies, consumption rates of each predator in isolation from the other were higher in the sand flat than in the more structurally complex oyster reef habitat. However, consumption by the two predators when combined surprisingly did not differ between the two habitats. This counterintuitive result probably stems from the influence of habitat structure on predator-predator interactions. In the sand-flat habitat, whelks significantly reduced their consumption of their less preferred prey when crabs were present. However, the structurally more complex oyster reef habitat appeared to reduce interference interactions among predators, such that consumption rates when the predators co-occurred did not differ from predation rates when alone. In addition, both habitat context and predator-predator interactions increased resource partitioning by strengthening predator dietary selectivity. Thus, an understanding of how habitat characteristics such as physical complexity influence interactions among predators may be critical to predicting the effects of modifying predator populations on their shared prey.

  10. The Importance of Design in Learning from Node-Link Diagrams

    ERIC Educational Resources Information Center

    van Amelsvoort, Marije; van der Meij, Jan; Anjewierden, Anjo; van der Meij, Hans

    2013-01-01

    Diagrams organize by location. They give spatial cues for finding and recognizing information and for making inferences. In education, diagrams are often used to help students understand and recall information. This study assessed the influence of perceptual cues on reading behavior and subsequent retention. Eighty-two participants were assigned…

  11. GPU based detection of topological changes in Voronoi diagrams

    NASA Astrophysics Data System (ADS)

    Bernaschi, M.; Lulli, M.; Sbragaglia, M.

    2017-04-01

    The Voronoi diagrams are an important tool having theoretical and practical applications in a large number of fields. We present a new procedure, implemented as a set of CUDA kernels, which detects, in a general and efficient way, topological changes in case of dynamic Voronoi diagrams whose generating points move in time. The solution that we provide has been originally developed to identify plastic events during simulations of soft-glassy materials based on a lattice Boltzmann model with frustrated-short range attractive and mid/long-range repulsive-interactions. Along with the description of our approach, we present also some preliminary physics results.

  12. The influence of interactions among phenolic compounds on the antiradical activity of chokeberries (Aronia melanocarpa).

    PubMed

    Jakobek, Lidija; Seruga, Marijan; Krivak, Petra

    2011-06-01

    In the present work, interactions between phenolic compounds from chokeberries and their influence on the antiradical activity was studied. Three fractions were isolated from chokeberries containing different classes of phenolic compounds. The first fraction contained a major part of phenolic acids and flavonols, the second anthocyanins, and the third insoluble phenols and proanthocyanidins. The phenolic compound content was determined using high-performance liquid chromatography, and the antiradical activity using the DPPH test. In order to evaluate the effects of interactions between phenolic compounds on the antiradical activity, the antiradical activity of individual phenolic fractions was compared with that obtained by mixing phenolic fractions. Phenolic mixtures showed the decrease in the antiradical activity in comparison with the individual phenolic fractions. These results suggest the existence of complex interactions among phenolic compounds that caused the decrease of the antiradical activity. Interactions among chokeberry phenols promoted a negative synergism.

  13. Predator cue and prey density interactively influence indirect effects on basal resources in intertidal oyster reefs.

    PubMed

    Hughes, A Randall; Rooker, Kelly; Murdock, Meagan; Kimbro, David L

    2012-01-01

    Predators can influence prey abundance and traits by direct consumption, as well as by non-consumptive effects of visual, olfactory, or tactile cues. The strength of these non-consumptive effects (NCEs) can be influenced by a variety of factors, including predator foraging mode, temporal variation in predator cues, and the density of competing prey. Testing the relative importance of these factors for determining NCEs is critical to our understanding of predator-prey interactions in a variety of settings. We addressed this knowledge gap by conducting two mesocosm experiments in a tri-trophic intertidal oyster reef food web. More specifically, we tested how a predatory fish (hardhead catfish, Ariopsis felis) directly influenced their prey (mud crabs, Panopeus spp.) and indirectly affected basal resources (juvenile oysters, Crassostrea virginica), as well as whether these direct and indirect effects changed across a density gradient of competing prey. Per capita crab foraging rates were inversely influenced by crab density, but they were not affected by water-borne predator cues. As a result, direct consumptive effects on prey foraging rates were stronger than non-consumptive effects. In contrast, predator cue and crab density interactively influenced indirect predator effects on oyster mortality in two experiments, with trait-mediated and density-mediated effects of similar magnitude operating to enhance oyster abundance. Consistent differences between a variable predator cue environment and other predator cue treatments (no cue and constant cue) suggests that an understanding of the natural risk environment experienced by prey is critical to testing and interpreting trait-mediated indirect interactions. Further, the prey response to the risk environment may be highly dependent on prey density, particularly in prey populations with strong intra-specific interactions.

  14. An Instructional Strategy to Introduce Pedagogical Content Knowledge Using Venn Diagrams

    ERIC Educational Resources Information Center

    Otto, Charlotte A.; Everett, Susan A.

    2013-01-01

    This paper describes the use of a three-circle Venn diagram as a vehicle for introducing pre-service elementary teachers to pedagogical content knowledge (PCK). Each circle of the diagram represents pedagogy, content and context individually. The overlap of any two circles represents the interaction between the circles. For example, the overlap of…

  15. The Effect of Social Network Diagrams on a Virtual Network of Practice: A Korean Case

    ERIC Educational Resources Information Center

    Jo, Il-Hyun

    2009-01-01

    This study investigates the effect of the presentation of social network diagrams on virtual team members' interaction behavior via e-mail. E-mail transaction data from 22 software developers in a Korean IT company was analyzed and depicted as diagrams by social network analysis (SNA), and presented to the members as an intervention. Results…

  16. Phase diagram of a model of the protein amelogenin

    NASA Astrophysics Data System (ADS)

    Haaga, Jason; Pemberton, Elizabeth; Gunton, J. D.; Rickman, J. M.

    2016-08-01

    There has been considerable recent interest in the self-assembly and phase behavior of models of colloidal and protein particles with anisotropic interactions. One example of particular interest is amelogenin, an important protein involved in the formation of dental enamel. Amelogenin is primarily hydrophobic with a 25-residue charged C-terminus tail. This protein undergoes a hierarchical assembly process that is crucial to mineral deposition, and experimental work has demonstrated that the deletion of the C-terminus tail prevents this self-assembly. A simplified model of amelogenin has been proposed in which the protein is treated as a hydrophobic sphere, interacting via the Asakura-Oosawa (AO) potential, with a tethered point charge on its surface. In this paper, we examine the effect of the Coulomb interaction between the point charges in altering the phase diagram of the AO model. For the parameter case specific to amelogenin, we find that the previous in vitro experimental and model conditions correspond to the system being near the low-density edge of the metastable region of the phase diagram. Our study illustrates more generally the importance of understanding the phase diagram for proteins, in that the kinetic pathway for self-assembly and the resulting aggregate morphology depends on the location of the initial state in the phase diagram.

  17. A Community Based Systems Diagram of Obesity Causes

    PubMed Central

    Allender, Steven; Owen, Brynle; Kuhlberg, Jill; Lowe, Janette; Nagorcka-Smith, Phoebe; Whelan, Jill; Bell, Colin

    2015-01-01

    Introduction Application of system thinking to the development, implementation and evaluation of childhood obesity prevention efforts represents the cutting edge of community-based prevention. We report on an approach to developing a system oriented community perspective on the causes of obesity. Methods Group model building sessions were conducted in a rural Australian community to address increasing childhood obesity. Stakeholders (n = 12) built a community model that progressed from connection circles to causal loop diagrams using scripts from the system dynamics literature. Participants began this work in identifying change over time in causes and effects of childhood obesity within their community. The initial causal loop diagram was then reviewed and elaborated by 50 community leaders over a full day session. Results The process created a causal loop diagram representing community perceptions of determinants and causes of obesity. The causal loop diagram can be broken down into four separate domains; social influences; fast food and junk food; participation in sport; and general physical activity. Discussion This causal loop diagram can provide the basis for community led planning of a prevention response that engages with multiple levels of existing settings and systems. PMID:26153893

  18. Interactions with grandparents and great-grandparents: a comparison of activities, influences, and relationships.

    PubMed

    Roberto, K A; Skoglund, R R

    1996-01-01

    This study explored the relationships between young adults and their grandparents and great-grandparents. A convenience sample of fifty-two college students, who had at least one living grandparent and great-grandparent, completed a questionnaire that assessed their interactions with their grandparents and great-grandparents. The respondents engaged in more frequent contact and activities with their grandparents than with their great-grandparents. They also perceived their grandparents as having a more defined role and being more influential in their lives than great-grandparents. Discussion centers on potential personal and demographic factors that may have influenced the respondents' perceptions of and interactions with their great-grandparents.

  19. Diagram, a Learning Environment for Initiation to Object-Oriented Modeling with UML Class Diagrams

    ERIC Educational Resources Information Center

    Py, Dominique; Auxepaules, Ludovic; Alonso, Mathilde

    2013-01-01

    This paper presents Diagram, a learning environment for object-oriented modelling (OOM) with UML class diagrams. Diagram an open environment, in which the teacher can add new exercises without constraints on the vocabulary or the size of the diagram. The interface includes methodological help, encourages self-correcting and self-monitoring, and…

  20. Phase diagrams of bosonic ABn chains

    NASA Astrophysics Data System (ADS)

    Cruz, G. J.; Franco, R.; Silva-Valencia, J.

    2016-04-01

    The A B N - 1 chain is a system that consists of repeating a unit cell with N sites where between the A and B sites there is an energy difference of λ. We considered bosons in these special lattices and took into account the kinetic energy, the local two-body interaction, and the inhomogenous local energy in the Hamiltonian. We found the charge density wave (CDW) and superfluid and Mott insulator phases, and constructed the phase diagram for N = 2 and 3 at the thermodynamic limit. The system exhibited insulator phases for densities ρ = α/ N, with α being an integer. We obtained that superfluid regions separate the insulator phases for densities larger than one. For any N value, we found that for integer densities ρ, the system exhibits ρ + 1 insulator phases, a Mott insulator phase, and ρ CDW phases. For non-integer densities larger than one, several CDW phases appear.

  1. Reentrant Phase Diagram of Network Fluids

    NASA Astrophysics Data System (ADS)

    Russo, J.; Tavares, J. M.; Teixeira, P. I. C.; Telo da Gama, M. M.; Sciortino, F.

    2011-02-01

    We introduce a microscopic model for particles with dissimilar patches which displays an unconventional “pinched” phase diagram, similar to the one predicted by Tlusty and Safran in the context of dipolar fluids [Science 290, 1328 (2000)SCIEAS0036-807510.1126/science.290.5495.1328]. The model—based on two types of patch interactions, which account, respectively, for chaining and branching of the self-assembled networks—is studied both numerically via Monte Carlo simulations and theoretically via first-order perturbation theory. The dense phase is rich in junctions, while the less-dense phase is rich in chain ends. The model provides a reference system for a deep understanding of the competition between condensation and self-assembly into equilibrium-polymer chains.

  2. Influences and interactions of inundation, peat, and snow on active layer thickness

    DOE PAGES

    Atchley, Adam L.; Coon, Ethan T.; Painter, Scott L.; ...

    2016-05-18

    The effect of three environmental conditions: 1) thickness of organic soil, 2) snow depth, and 3) soil moisture content or water table height above and below the soil surface, on active layer thickness (ALT) are investigated using an ensemble of 1D thermal hydrology models. Sensitivity analyses of the ensemble exposed the isolated influence of each environmental condition on ALT and their multivariate interactions. The primary and interactive influences are illustrated in the form of color maps of ALT change. Results show that organic layer acts as a strong insulator, and its thickness is the dominant control of ALT, but themore » strength of the effect of organic layer thickness is dependent on the saturation state. Snow depth, subsurface saturation, and ponded water depth are strongly codependent and positively correlated to ALT.« less

  3. Influences and interactions of inundation, peat, and snow on active layer thickness

    SciTech Connect

    Atchley, Adam L.; Coon, Ethan T.; Painter, Scott L.; Harp, Dylan R.; Wilson, Cathy J.

    2016-05-18

    The effect of three environmental conditions: 1) thickness of organic soil, 2) snow depth, and 3) soil moisture content or water table height above and below the soil surface, on active layer thickness (ALT) are investigated using an ensemble of 1D thermal hydrology models. Sensitivity analyses of the ensemble exposed the isolated influence of each environmental condition on ALT and their multivariate interactions. The primary and interactive influences are illustrated in the form of color maps of ALT change. Results show that organic layer acts as a strong insulator, and its thickness is the dominant control of ALT, but the strength of the effect of organic layer thickness is dependent on the saturation state. Snow depth, subsurface saturation, and ponded water depth are strongly codependent and positively correlated to ALT.

  4. Vulnerabilities, Influences and Interaction Paths: Failure Data for Integrated System Risk Analysis

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Fleming, Land

    2006-01-01

    We describe graph-based analysis methods for identifying and analyzing cross-subsystem interaction risks from subsystem connectivity information. By discovering external and remote influences that would be otherwise unexpected, these methods can support better communication among subsystem designers at points of potential conflict and to support design of more dependable and diagnosable systems. These methods identify hazard causes that can impact vulnerable functions or entities if propagated across interaction paths from the hazard source to the vulnerable target. The analysis can also assess combined impacts of And-Or trees of disabling influences. The analysis can use ratings of hazards and vulnerabilities to calculate cumulative measures of the severity and importance. Identification of cross-subsystem hazard-vulnerability pairs and propagation paths across subsystems will increase coverage of hazard and risk analysis and can indicate risk control and protection strategies.

  5. Expression of Superparamagnetic Particles on FORC Diagrams

    NASA Astrophysics Data System (ADS)

    Hirt, A. M.; Kumari, M.; Crippa, F.; Petri-Fink, A.

    2015-12-01

    Identification of superparamagnetic (SP) particles in natural materials provides information on processes that lead to the new formation or dissolution of iron oxides. SP particles express themselves on first-order reversal curve (FORC) diagrams as a distribution centered near the origin of the diagram. Pike et al. (2001, GJI, 145, 721) demonstrated that thermal relaxation produces an upward shift in the FORC distribution, and attributed this to a pause encountered at each reversal field. In this study we examine the relationship between this upward shift and particles size on two sets of synthetic iron oxide nanoparticles. One set of coated magnetite particles have well-constrained particles size with 9, 16 and 20 nm as their diameter. A second set from the FeraSpin™ Series, consisting of FeraSpinXS, M and XL, were evaluated. Rock magnetic experiments indicate that the first set of samples is exclusively magnetite, whereas the FeraSpin samples contain predominantly magnetite with some degree of oxidation. Samples from both sets show that the upward shift of the FORC distribution at the origin increases with decreasing particle size. The amount of shift in the FeraSpin series is less when compared to the samples from the first set. This is attributed to the effect of interaction that counteracts the effect of thermal relaxation behavior of the SP particles. The FeraSpin series also shows a broader FORC distribution on the vertical axis that appears to be related to non-saturation of the hysteresis curve at maximum applied field. This non-saturation behavior can be due to spins of very fine particles or oxidation to hematite. AC susceptibility at low temperature indicates that particle interaction may affect the effective magnetic particle size. Our results suggest that the FORC distribution in pure SP particle systems provides information on the particle size distribution or oxidation, which can be further evaluated with low temperature techniques.

  6. Phase diagrams of polyelectrolyte solutions

    NASA Astrophysics Data System (ADS)

    Mahdi, Khaled A.

    We study the phase diagram of polyelectrolyte solutions in salt and salt-free environments. We examine the phase behavior of polyelectrolyte solutions, in the semidilute regime, using different physical models, namely the Random Phase Approximation (RPA) and the cross-linked model. In the RPA, we calculate the electrostatic free energy by summing all the fluctuations of the chains and all present ionic species. Within this approximation, the phase diagrams of salt-free polyelectrolyte solutions show phase separation even without including short-range attractions or ion condensation. We find that the phase behavior of large chains resembles the phase diagram of polymer network solutions. That is, the equilibrium is established between a network phase and a chain-free phase. Upon the addition of salt, the dissociated ions increase the entropy of the system and overcome the energy from the electrostatic fluctuations. When the short-range attraction between monomers is included in the model, the free energy predicts phase segregation for all salt valences at high salt concentrations (1 mol/l and higher). The phenomenon is called salting-out and occurs simply because the addition of salt reduces the quality of the solvent and induces precipitation. However, phase segregation in the presence of multivalent ions in polyelectrolyte solutions occurs at low salt concentrations (less than 1 mol/l). We propose that this phase separation is due to polyions cross-linked by multivalent ions. We constructed a phenomenological two-state model to examine this phenomenon. The two phases coexisting in the solution are a network-like phase and a polymer-free phase. The polymer-free phase is modeled using Debye-Huckel theory. In the cross-linked phase, each condensed multivalent ion attracts an equal number of monomers creating a neutral cluster. The energy of the cluster is evaluated by a simple Coulombic energy. The bare monomer charges between the linkages are treated as line of

  7. Microbial endocrinology: Host-microbiota neuroendocrine interactions influencing brain and behavior.

    PubMed

    Lyte, Mark

    2014-01-01

    The ability of microorganisms, whether present as commensals within the microbiota or introduced as part of a therapeutic regimen, to influence behavior has been demonstrated by numerous laboratories over the last few years. Our understanding of the mechanisms that are responsible for microbiota-gut-brain interactions is, however, lacking. The complexity of the microbiota is, of course, a contributing factor. Nonetheless, while microbiologists approaching the issue of microbiota-gut-brain interactions in the behavior well recognize such complexity, what is often overlooked is the equal complexity of the host neurophysiological system, especially within the gut which is differentially innervated by the enteric nervous system. As such, in the search for common mechanisms by which the microbiota may influence behavior one may look for mechanisms which are shared by both host and microbiota. Such interkingdom signaling can be found in the shared production of neurochemical mediators that are found in both eukaryotes and prokaryotes. The study of the production and recognition of neurochemicals that are exactly the same in structure to those produced in the vertebrate organisms is known as microbial endocrinology. The examination of the microbiota from the vantage point of host-microbiota neuroendocrine interactions cannot only identify new microbial endocrinology-based mechanisms by which the microbiota can influence host behavior, but also lead to the design of interventions in which the composition of the microbiota may be modulated in order to achieve a specific microbial endocrinology-based profile beneficial to overall host behavior.

  8. Parents' Metacognitive Knowledge: Influences on Parent-Child Interactions in a Science Museum Setting

    NASA Astrophysics Data System (ADS)

    Thomas, Gregory P.; Anderson, David

    2013-06-01

    Despite science learning in settings such as science museums being recognized as important and given increasing attention in science education circles, the investigation of parents' and their children's metacognition in such settings is still in its infancy. This is despite an individual's metacognition being acknowledged as an important influence on their learning within and across contexts. This research investigated parents' metacognitive procedural and conditional knowledge, a key element of their metacognition, related to (a) what they knew about how they and their children thought and learned, and (b) whether this metacognitive knowledge influenced their interactions with their children during their interaction with a moderately complex simulation in a science museum. Parents reported metacognitive procedural and conditional knowledge regarding their own and their children's thinking and learning processes. Further, parents were aware that this metacognitive knowledge influenced their interactions with their children, seeing this as appropriate pedagogical action for them within the context of the particular exhibit and its task requirements at the science museum, and for the child involved. These findings have implications for exhibit and activity development within science museum settings.

  9. Evolutionary Influenced Interaction Pattern as Indicator for the Investigation of Natural Variants Causing Nephrogenic Diabetes Insipidus.

    PubMed

    Grunert, Steffen; Labudde, Dirk

    2015-01-01

    The importance of short membrane sequence motifs has been shown in many works and emphasizes the related sequence motif analysis. Together with specific transmembrane helix-helix interactions, the analysis of interacting sequence parts is helpful for understanding the process during membrane protein folding and in retaining the three-dimensional fold. Here we present a simple high-throughput analysis method for deriving mutational information of interacting sequence parts. Applied on aquaporin water channel proteins, our approach supports the analysis of mutational variants within different interacting subsequences and finally the investigation of natural variants which cause diseases like, for example, nephrogenic diabetes insipidus. In this work we demonstrate a simple method for massive membrane protein data analysis. As shown, the presented in silico analyses provide information about interacting sequence parts which are constrained by protein evolution. We present a simple graphical visualization medium for the representation of evolutionary influenced interaction pattern pairs (EIPPs) adapted to mutagen investigations of aquaporin-2, a protein whose mutants are involved in the rare endocrine disorder known as nephrogenic diabetes insipidus, and membrane proteins in general. Furthermore, we present a new method to derive new evolutionary variations within EIPPs which can be used for further mutagen laboratory investigations.

  10. Soil abiotic factors influence interactions between belowground herbivores and plant roots.

    PubMed

    Erb, Matthias; Lu, Jing

    2013-03-01

    Root herbivores are important ecosystem drivers and agricultural pests, and, possibly as a consequence, plants protect their roots using a variety of defensive strategies. One aspect that distinguishes belowground from aboveground plant-insect interactions is that roots are constantly exposed to a set of soil-specific abiotic factors. These factors can profoundly influence root resistance, and, consequently, the outcome of the interaction with belowground feeders. In this review, we synthesize the current literature on the impact of soil moisture, nutrients, and texture on root-herbivore interactions. We show that soil abiotic factors influence the interaction by modulating herbivore abundance and behaviour, root growth and resistance, beneficial microorganisms, as well as natural enemies of the herbivores. We suggest that abiotic heterogeneity may explain the high variability that is often encountered in root-herbivore systems. We also propose that under abiotic stress, the relative fitness value of the roots and the potential negative impact of herbivory increases, which may lead to a higher defensive investment and an increased recruitment of beneficial microorganisms by the plant. At the same time, both root-feeding herbivores and natural enemies are likely to decrease in abundance under extreme environmental conditions, leading to a context- and species-specific impact on plant fitness. Only by using tightly controlled experiments that include soil abiotic heterogeneity will it be possible to understand the impact of root feeders on an ecosystem scale and to develop predictive models for pest occurrence and impact.

  11. Influence of packing interactions on the average conformation of B-DNA in crystalline structures.

    PubMed

    Tereshko, V; Subirana, J A

    1999-04-01

    The molecular interactions in crystals of oligonucleotides in the B form have been analysed and in particular the end-to-end interactions. Phosphate-phosphate interactions in dodecamers are also reviewed. A strong influence of packing constraints on the average conformation of the double helix is found. There is a strong relationship between the space group, the end-to-end interactions and the average conformation of DNA. Dodecamers must have a B-form average conformation with 10 +/- 0.1 base pairs per turn in order to crystallize in the P212121 and related space groups usually found. Decamers show a wider range of conformational variation, with 9.7-10. 6 base pairs per turn, depending on the terminal sequence and the space group. The influence of the space group in decamers is quite striking and remains unexplained. Only small variations are allowed in each case. Thus, crystal packing is strongly related to the average DNA conformation in the crystals and deviations from the average are rather limited. The constraints imposed by the crystal lattice explain why the average twist of the DNA in solution (10.6 base pairs per turn) is seldom found in oligonucleotides crystallized in the B form.

  12. Polymer segregation under confinement: Influences of macromolecular crowding and the interaction between the polymer and crowders

    NASA Astrophysics Data System (ADS)

    Chen, Yuhao; Yu, Wancheng; Wang, Jiajun; Luo, Kaifu

    2015-10-01

    Entropy driven polymer segregation in confinements as a model for chromosome separation in bacteria has attracted wide attention; however, the effects of macromolecular crowding and the interaction between the binding protein and the newly replicated DNA on the segregation dynamics are not clear. Using Langevin dynamics simulations, we investigate the influences of crowders and the attractive interaction between the polymer and a small number of crowders on segregation of two overlapping polymers under a cylindrical confinement. We find that the segregation time increases with increasing the volume fraction of crowders due to the slower chain diffusion in crowded environments. For a fixed volume fraction of crowders, the segregation time decreases with increasing the size of crowders. Moreover, the attractive interaction between the polymer and a small number of crowders can significantly facilitate the chain segregation. These results are important for understanding the chromosome segregation in living cells.

  13. Influence of intramolecular f-f interactions on nuclear spin driven quantum tunneling of magnetizations in quadruple-decker phthalocyanine complexes containing two terbium or dysprosium magnetic centers.

    PubMed

    Fukuda, Takamitsu; Matsumura, Kazuya; Ishikawa, Naoto

    2013-10-10

    Nuclear spin driven quantum tunneling of magnetization (QTM) phenomena, which arise from admixture of more than two orthogonal electronic spin wave functions through the couplings with those of the nuclear spins, are one of the important magnetic relaxation processes in lanthanide single molecule magnets (SMMs) in the low temperature range. Although recent experimental studies have indicated that the presence of the intramolecular f-f interactions affects their magnetic relaxation processes, little attention has been given to their mechanisms and, to the best of our knowledge, no rational theoretical models have been proposed for the interpretations of how the nuclear spin driven QTMs are influenced by the f-f interactions. Since quadruple-decker phthalocyanine complexes with two terbium or dysprosium ions as the magnetic centers show moderate f-f interactions, these are appropriate to investigate the influence of the f-f interactions on the dynamic magnetic relaxation processes. In the present paper, a theoretical model including ligand field (LF) potentials, hyperfine, nuclear quadrupole, magnetic dipolar, and the Zeeman interactions has been constructed to understand the roles of the nuclear spins for the QTM processes, and the resultant Zeeman plots are obtained. The ac susceptibility measurements of the magnetically diluted quadruple-decker monoterbium and diterbium phthalocyanine complexes, [Tb-Y] and [Tb-Tb], have indicated that the presence of the f-f interactions suppresses the QTMs in the absence of the external magnetic field (H(dc)) being consistent with previous reports. On the contrary, the faster magnetic relaxation processes are observed for [Tb-Tb] than [Tb-Y] at H(dc) = 1000 Oe, clearly demonstrating that the QTMs are rather enhanced in the presence of the external magnetic field. Based on the calculated Zeeman diagrams, these observations can be attributed to the enhanced nuclear spin driven QTMs for [Tb-Tb]. At the H(dc) higher than 2000 Oe, the

  14. Phase diagrams for sonoluminescing bubbles

    NASA Astrophysics Data System (ADS)

    Hilgenfeldt, Sascha; Lohse, Detlef; Brenner, Michael P.

    1996-11-01

    Sound driven gas bubbles in water can emit light pulses. This phenomenon is called sonoluminescence (SL). Two different phases of single bubble SL have been proposed: diffusively stable and diffusively unstable SL. We present phase diagrams in the gas concentration versus forcing pressure state space and also in the ambient radius versus gas concentration and versus forcing pressure state spaces. These phase diagrams are based on the thresholds for energy focusing in the bubble and two kinds of instabilities, namely (i) shape instabilities and (ii) diffusive instabilities. Stable SL only occurs in a tiny parameter window of large forcing pressure amplitude Pa˜1.2-1.5 atm and low gas concentration of less than 0.4% of the saturation. The upper concentration threshold becomes smaller with increased forcing. Our results quantitatively agree with experimental results of Putterman's UCLA group on argon, but not on air. However, air bubbles and other gas mixtures can also successfully be treated in this approach if in addition (iii) chemical instabilities are considered. All statements are based on the Rayleigh-Plesset ODE approximation of the bubble dynamics, extended in an adiabatic approximation to include mass diffusion effects. This approximation is the only way to explore considerable portions of parameter space, as solving the full PDEs is numerically too expensive. Therefore, we checked the adiabatic approximation by comparison with the full numerical solution of the advection diffusion PDE and find good agreement.

  15. Asteroseismology Across the HR Diagram

    NASA Astrophysics Data System (ADS)

    Thompson, M. J.; Cunha, M. S.; Monteiro, M. J. P. F. G.

    2003-05-01

    Ground-based observations have detected solar-like oscillations on Sun-like stars, and diagnostics similar to those used in helioseismology are now being used to test and constrain the physics and evolutionary state of these stars. Multi-mode oscillations are being observed in an abundance of other stars, including slowly pulsating B stars (SPB stars), delta-Scuti stars, Ap stars and the pulsating white dwarfs. New classes of pulsators continue to be discovered across the Herzsprung-Russell diagram. Yet the chances still to be faced to make asteroseismology across the HR diagram a reality are formidable. Observation, data analysis and theory all pose hard problems to be overcome. This book, reflecting the goal of the meeting, aims to facilitate a cross-fertilisation of ideas and approaches between fields covering different pulsators and with different areas of expertise. The book successfully covers most known types of pulsators, reflecting a highly productive and far reaching interchange of ideas which we believe is conveyed by the papers and posters published, making it a reference for researchers and postgraduate students working on stellar structure and evolution. Link: http://www.wkap.nl/prod/b/1-4020-1173-3

  16. Phase Diagrams of Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Caplan, Matthew; Horowitz, Chuck; Berry, Don; da Silva Schneider, Andre

    2016-03-01

    In the inner crust of neutrons stars, where matter is near the saturation density, protons and neutrons arrange themselves into complex structures called nuclear pasta. Early theoretical work predicted a simple graduated hierarchy of pasta phases, consisting of spheres, cylinders, slabs, and uniform matter with voids. Previous work has simulated these phases with a simple classical model and has shown that the formation of these structures is dependent on the temperature, density, and proton fraction. However, previous work only studied a limited range of these parameters due to computational limitations. Thanks to recent advances in computing it is now possible to survey the structure of nuclear pasta for a larger range of parameters. By simulating nuclear pasta with constant temperature and proton fraction in an expanding simulation volume we are able to study the phase transitions in nuclear pasta, and thus produce a set of phase diagrams. We report on these phase diagrams as well as newly identified phases of nuclear pasta and discuss their implications for neutron star observables.

  17. Influence of substrate interaction and confinement on electric-field-induced transition in symmetric block-copolymer thin films

    NASA Astrophysics Data System (ADS)

    Mukherjee, Arnab; Mukherjee, Rajdip; Ankit, Kumar; Bhattacharya, Avisor; Nestler, Britta

    2016-03-01

    In the present work, we study morphologies arising due to competing substrate interaction, electric field, and confinement effects on a symmetric diblock copolymer. We employ a coarse-grained nonlocal Cahn-Hilliard phenomenological model taking into account the appropriate contributions of substrate interaction and electrostatic field. The proposed model couples the Ohta-Kawasaki functional with Maxwell equation of electrostatics, thus alleviating the need for any approximate solution used in previous studies. We calculate the phase diagram in electric-field-substrate strength space for different film thicknesses. In addition to identifying the presence of parallel, perpendicular, and mixed lamellae phases similar to analytical calculations, we also find a region in the phase diagram where hybrid morphologies (combination of two phases) coexist. These hybrid morphologies arise either solely due to substrate affinity and confinement or are induced due to the applied electric field. The dependence of the critical fields for transition between the various phases on substrate strength, film thickness, and dielectric contrast is discussed. Some preliminary 3D results are also presented to corroborate the presence of hybrid morphologies.

  18. Cascading processes and interactions in torrent catchments and their influence on the damage pattern

    NASA Astrophysics Data System (ADS)

    Keiler, Margreth; Gebbers, David

    2014-05-01

    Research on single geomorphological processes during damaging events has a long history; however, comprehensive documentations and analyses of the events have been conducted not until the late 1980s. Thus, for highly damaging events insights about triggering, the evolution and the impacts of processes during an event and the resulting damage were produced. Though, in the majority of cases the processes were studied in a well-defined procedure of one disciplinary focus. These focused studies neglect mutable influences which may alter the sequence of the process or the event. During damaging events multiple geomorphological processes are active which leads to the assumption that they have a certain impact on each other and the course of damaging effect. Consequently, for a comprehensive hazard and risk analysis all processes of a catchment have to be analysed and evaluated quantitatively and qualitatively (MARZOCCHI, 2007). Although the demand for a sophisticated risk management is increasing, the research on interactions as well as on physical vulnerability to multiple hazards, including the different processes impact effects, is still very limited (KAPPES et al., 2010, 2011). The challenges in this field are the quantity of data needed, and furthermore to conduct this kind of analysis is very complex and complicated (KAPPES et al. 2012). Yet, knowledge about possible interactions and resulting impact effects could significantly contribute to the reduction of risk in a region. The objective of this study is to analyse, i) how geomorphological processes interact with each other and with other factors of the surrounding during a damaging event, ii) what influences those interactions have on the resulting damage of the event and iii) whether or not different events are comparable in terms of those interactions and their impacts. To meet these objectives, 15 damaging torrent events, which occurred between 2000 and 2011 in the Bernese Oberland and the Pennine Alps

  19. Experimental Tests of Normative Group Influence and Representation Effects in Computer-Mediated Communication: When Interacting Via Computers Differs from Interacting With Computers.

    ERIC Educational Resources Information Center

    Lee, Eun-Ju; Nass, Clifford

    2002-01-01

    Presents two experiments to address the questions of if and how normative social influence operates in anonymous computer-mediated communication and human-computer interaction. Finds that the perception of interaction partner (human vs. computer) moderated the group conformity effect such that the undergraduate student subjects expressed greater…

  20. The Influence of Hydrogen Bonding on Sphingomyelin/Colipid Interactions in Bilayer Membranes

    PubMed Central

    Yasuda, Tomokazu; Al Sazzad, Md. Abdullah; Jäntti, Niklas Z.; Pentikäinen, Olli T.; Slotte, J. Peter

    2016-01-01

    The phospholipid acyl chain composition and order, the hydrogen bonding, and properties of the phospholipid headgroup all influence cholesterol/phospholipid interactions in hydrated bilayers. In this study, we examined the influence of hydrogen bonding on sphingomyelin (SM) colipid interactions in fluid uni- and multilamellar vesicles. We have compared the properties of oleoyl or palmitoyl SM with comparable dihydro-SMs, because the hydrogen bonding properties of SM and dihydro-SM differ. The association of cholestatrienol, a fluorescent cholesterol analog, with oleoyl sphingomyelin (OSM) was significantly stronger than its association with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, in bilayers with equal acyl chain order. The association of cholestatrienol with dihydro-OSM, which lacks a trans double bond in the sphingoid base, was even stronger than the association with OSM, suggesting an important role for hydrogen bonding in stabilizing sterol/SM interactions. Furthermore, with saturated SM in the presence of 15 mol % cholesterol, cholesterol association with fluid dihydro-palmitoyl SM bilayers was stronger than seen with palmitoyl SM under similar conditions. The different hydrogen bonding properties in OSM and dihydro-OSM bilayers also influenced the segregation of palmitoyl ceramide and dipalmitoylglycerol into an ordered phase. The ordered, palmitoyl ceramide-rich phase started to form above 2 mol % in the dihydro-OSM bilayers but only above 6 mol % in the OSM bilayers. The lateral segregation of dipalmitoylglycerol was also much more pronounced in dihydro-OSM bilayers than in OSM bilayers. The results show that hydrogen bonding is important for sterol/SM and ceramide/SM interactions, as well as for the lateral segregation of a diglyceride. A possible molecular explanation for the different hydrogen bonding in SM and dihydro-SM bilayers is presented and discussed. PMID:26789766

  1. Sandwichlike strain glass phase diagram of Ti49Ni51 -xPdx

    NASA Astrophysics Data System (ADS)

    Ren, Shuai; Zhou, Chao; Xue, Dezhen; Wang, Dong; Zhang, Jian; Ding, Xiangdong; Otsuka, Kazuhiro; Ren, Xiaobing

    2016-12-01

    Two kinds of phase diagrams can be observed in doped ferroic materials. A glass phase diagram is formed by doping a nontransforming end into a ferroic matrix, while doping a transforming end forms phase diagrams with a phase boundary separating two different ferroic phases. Here we report a phase diagram in which a strain glass state is sandwiched between two distinct ferroelastic phases. This type of phase diagram in doped ferroelastic materials bridges the one with a glass state and the one with a phase boundary. We thus establish a 3D phase diagram of Ti50 -yNi50 +y -xPdx ternary alloys, in which the evolution of these different kinds of phase diagrams can be observed. An understanding from the Landau free energy landscape suggests that the transforming doping end plays three roles in influencing the ferroic matrix: (1) to destabilize the ferroic matrix phase, (2) to stabilize another ferroic phase different from the matrix one, and (3) to create random local fields. The competition between these effects determines various phase diagrams in doped ferroic materials. Thus our work may provide an experimental foundation for a unified mechanism to all three kinds of phase diagrams.

  2. Influence of the number of topologically interacting neighbors on swarm dynamics

    PubMed Central

    Shang, Yilun; Bouffanais, Roland

    2014-01-01

    Recent empirical and theoretical works on collective behaviors based on a topological interaction are beginning to offer some explanations as for the physical reasons behind the selection of a particular number of nearest neighbors locally affecting each individual's dynamics. Recently, flocking starlings have been shown to topologically interact with a very specific number of neighbors, between six to eight, while metric-free interactions were found to govern human crowd dynamics. Here, we use network- and graph-theoretic approaches combined with a dynamical model of locally interacting self-propelled particles to study how the consensus reaching process and its dynamics are influenced by the number k of topological neighbors. Specifically, we prove exactly that, in the absence of noise, consensus is always attained with a speed to consensus strictly increasing with k. The analysis of both speed and time to consensus reveals that, irrespective of the swarm size, a value of k ~ 10 speeds up the rate of convergence to consensus to levels close to the one of the optimal all-to-all interaction signaling. Furthermore, this effect is found to be more pronounced in the presence of environmental noise. PMID:24567077

  3. Influence of metoprolol dosage release formulation on the pharmacokinetic drug interaction with paroxetine.

    PubMed

    Stout, Stephen M; Nielsen, Jace; Welage, Lynda S; Shea, Michael; Brook, Robert; Kerber, Kevin; Bleske, Barry E

    2011-03-01

    Studies have demonstrated an influence of dosage release formulations on drug interactions and enantiomeric plasma concentrations. Metoprolol is a commonly used beta-adrenergic antagonist metabolized by CYP2D6. The CYP2D6 inhibitor paroxetine has previously been shown to interact with metoprolol tartrate. This open-label, randomized, 4-phase crossover study assessed the potential differential effects of paroxetine on stereoselective pharmacokinetics of immediate-release (IR) tartrate and extended-release (ER) succinate metoprolol formulations. Ten healthy participants received metoprolol IR (50 mg) and ER (100 mg) with and without paroxetine coadministration. Blood samples were collected over 24 hours for determination of metoprolol plasma enantiomer concentrations. Paroxetine coadministration significantly increased S and R metoprolol area under the plasma concentration-time curve from time 0 to the 24-hour blood draw (AUC(0-24h)) by 4- and 5-fold, respectively for IR, and 3- and 4-fold, respectively, for ER. S/R AUC ratios significantly decreased. These results demonstrate a pharmacokinetic interaction between paroxetine and both formulations of metoprolol. The interaction is greater with R metoprolol, and stereoselective metabolism is lost. This could theoretically result in greater beta-blockade and lost cardioselectivity. The magnitude of the interaction was similar between metoprolol formulations, which may be attributable to low doses/drug input rates employed.

  4. Early adversity and combat exposure interact to influence anterior cingulate cortex volume in combat veterans☆

    PubMed Central

    Woodward, Steven H.; Kuo, Janice R.; Schaer, Marie; Kaloupek, Danny G.; Eliez, Stephan

    2013-01-01

    Objective Childhood and combat trauma have been observed to interact to influence amygdala volume in a sample of U.S. military veterans with and without PTSD. This interaction was assessed in a second, functionally-related fear system component, the pregenual and dorsal anterior cingulate cortex, using the same sample and modeling approach. Method Anterior cingulate cortical tissues (gray + white matter) were manually-delineated in 1.5 T MR images in 87 U.S. military veterans of the Vietnam and Persian Gulf wars. Hierarchical multiple regression modeling was used to assess associations between anterior cingulate volume and the following predictors, trauma prior to age 13, combat exposure, the interaction of early trauma and combat exposure, and PTSD diagnosis. Results As previously observed in the amygdala, unique variance in anterior cingulate cortical volume was associated with both the diagnosis of PTSD and with the interaction of childhood and combat trauma. The pattern of the latter interaction indicated that veterans with childhood trauma exhibited a significant inverse linear relationship between combat trauma and anterior cingulate volume while those without childhood trauma did not. Such associations were not observed in hippocampal or total cerebral tissue volumes. Conclusions In the dorsal anterior cingulate cortex, as in the amygdala, early trauma may confer excess sensitivity to later combat trauma. PMID:24179818

  5. The surprising influence of late charged current weak interactions on Big Bang Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Grohs, E.; Fuller, George M.

    2016-10-01

    The weak interaction charged current processes (νe + n ↔ p +e-; νbare + p ↔ n +e+; n ↔ p +e- +νbare) interconvert neutrons and protons in the early universe and have significant influence on Big Bang Nucleosynthesis (BBN) light-element abundance yields, particularly that for 4He. We demonstrate that the influence of these processes is still significant even when they operate well below temperatures T ∼ 0.7 MeV usually invoked for "weak freeze-out," and in fact down nearly into the alpha-particle formation epoch (T ≈ 0.1 MeV). This physics is correctly captured in commonly used BBN codes, though this late-time, low-temperature persistent effect of the isospin-changing weak processes, and the sensitivity of the associated rates to lepton energy distribution functions and blocking factors are not widely appreciated. We quantify this late-time influence by analyzing weak interaction rate dependence on the neutron lifetime, lepton energy distribution functions, entropy, the proton-neutron mass difference, and Hubble expansion rate. The effects we point out here render BBN a keen probe of any beyond-standard-model physics that alters lepton number/energy distributions, even subtly, in epochs of the early universe all the way down to near T = 100 keV.

  6. Continuation of point clouds via persistence diagrams

    NASA Astrophysics Data System (ADS)

    Gameiro, Marcio; Hiraoka, Yasuaki; Obayashi, Ippei

    2016-11-01

    In this paper, we present a mathematical and algorithmic framework for the continuation of point clouds by persistence diagrams. A key property used in the method is that the persistence map, which assigns a persistence diagram to a point cloud, is differentiable. This allows us to apply the Newton-Raphson continuation method in this setting. Given an original point cloud P, its persistence diagram D, and a target persistence diagram D‧, we gradually move from D to D‧, by successively computing intermediate point clouds until we finally find a point cloud P‧ having D‧ as its persistence diagram. Our method can be applied to a wide variety of situations in topological data analysis where it is necessary to solve an inverse problem, from persistence diagrams to point cloud data.

  7. Phase diagrams for high Tc superconductors

    SciTech Connect

    Whitler, J.D.; Roth, R.S. NIST, Gaithersburg, MD )

    1991-01-01

    The phase diagrams of ternary and quaternary systems containing superconducting phases are presented, as are the phase diagrams of the associated binary systems. The diagrams are divided into two large groups: (1) alkaline earth-rare earth-copper-oxygen diagrams, and (2) alkaline earth-bismuth/lead-copper-oxygen diagrams. The first group includes BaO-REO-CuO systems followed by SrO-REO-CuO or Nd2O3-CeO-CuO systems. The second group includes systems related to the AE-Bi2O3-CuO and AE-PbO-CuO systems. The phase diagrams are accompanied by notes relating procedures used in the studies, results obtained, and comparisons with the results in the literature for the same system.

  8. Sexual Interactions Influence the Molecular Oscillations in DN1 Pacemaker Neurons in Drosophila melanogaster

    PubMed Central

    Hanafusa, Shiho; Kawaguchi, Tomoaki; Umezaki, Yujiro; Tomioka, Kenji; Yoshii, Taishi

    2013-01-01

    Circadian rhythms can synchronize to environmental time cues, such as light, temperature, humidity, and food availability. Previous studies have suggested that these rhythms can also be entrained by social interactions. Here, we used Drosophila melanogaster as a model to study the influence of socio-sexual interactions on the circadian clock in behavior and pacemaker neurons. If two flies of opposite sex were paired and kept in a small space, the daily activity patterns of the two flies were clearly different from the sum of the activity of single male and female flies. Compared with single flies, paired flies were more active in the night and morning, were more active during females’ active phase, and were less active during males’ active phase. These behavioral phenotypes are related to courtship behavior, but not to the circadian clock. Nevertheless, in male-female pairs of flies with clocks at different speeds (wild-type and perS flies), clock protein cycling in the DN1 pacemaker neurons in the male brain were slightly influenced by their partners. These results suggest that sexual interactions between male-female couples can serve as a weak zeitgeber for the DN1 pacemaker neurons, but the effect is not sufficient to alter rhythms of behavioral activity. PMID:24367668

  9. Hubble's diagram and cosmic expansion

    PubMed Central

    Kirshner, Robert P.

    2004-01-01

    Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168–173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today's burgeoning field of cosmology. PMID:14695886

  10. Gravity on-shell diagrams

    NASA Astrophysics Data System (ADS)

    Herrmann, Enrico; Trnka, Jaroslav

    2016-11-01

    We study on-shell diagrams for gravity theories with any number of super-symmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only d log-factors, in gravity there is a non-trivial numerator as well as higher degree poles in the edge variables. Based on the structure of the Grassmannian formula for {N}=8 supergravity we conjecture that gravity loop amplitudes also possess similar properties. In particular, we find that there are only logarithmic singularities on cuts with finite loop momentum and that poles at infinity are present, in complete agreement with the conjecture presented in [1].

  11. Hubble's diagram and cosmic expansion.

    PubMed

    Kirshner, Robert P

    2004-01-06

    Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168-173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today's burgeoning field of cosmology.

  12. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, M.; Yoo, C. S.

    2014-05-01

    Ammonium Nitrate (AN) has often subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood -resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 17 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400 °C.

  13. Phase diagram of ammonium nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-01

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO-AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N2, N2O, and H2O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV' transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  14. Process Flow Diagrams for Training and Operations

    NASA Astrophysics Data System (ADS)

    Venter, Jacobus

    This paper focuses on the use of process flow diagrams for training first responders who execute search and seizure warrants at electronic crime scenes. A generic process flow framework is presented, and the design goals and layout characteristics of process flow diagrams are discussed. An evaluation of the process flow diagrams used in training courses indicates that they are beneficial to first responders performing searches and seizures, and they speed up investigations, including those conducted by experienced personnel.

  15. Origin and use of crystallization phase diagrams

    PubMed Central

    Rupp, Bernhard

    2015-01-01

    Crystallization phase diagrams are frequently used to conceptualize the phase relations and also the processes taking place during the crystallization of macromolecules. While a great deal of freedom is given in crystallization phase diagrams owing to a lack of specific knowledge about the actual phase boundaries and phase equilibria, crucial fundamental features of phase diagrams can be derived from thermodynamic first principles. Consequently, there are limits to what can be reasonably displayed in a phase diagram, and imagination may start to conflict with thermodynamic realities. Here, the commonly used ‘crystallization phase diagrams’ are derived from thermodynamic excess properties and their limitations and appropriate use is discussed. PMID:25760697

  16. Influence of compressibility on the Lagrangian statistics of vorticity-strain-rate interactions.

    PubMed

    Danish, Mohammad; Sinha, Sawan Suman; Srinivasan, Balaji

    2016-07-01

    The objective of this study is to investigate the influence of compressibility on Lagrangian statistics of vorticity and strain-rate interactions. The Lagrangian statistics are extracted from "almost" time-continuous data sets of direct numerical simulations of compressible decaying isotropic turbulence by employing a cubic spline-based Lagrangian particle tracker. We study the influence of compressibility on Lagrangian statistics of alignment in terms of compressibility parameters-turbulent Mach number, normalized dilatation-rate, and flow topology. In comparison to incompressible turbulence, we observe that the presence of compressibility in a flow field weakens the alignment tendency of vorticity toward the largest strain-rate eigenvector. Based on the Lagrangian statistics of alignment conditioned on dilatation and topology, we find that the weakened tendency of alignment observed in compressible turbulence is because of a special group of fluid particles that have an initially negligible dilatation-rate and are associated with stable-focus-stretching topology.

  17. Acculturation influences on AAPI adolescent-mother interactions and adolescents' sexual initiation.

    PubMed

    Kao, Tsui-Sui Annie; Loveland-Cherry, Carol; Guthrie, Barbara; Caldwell, Cleopatra H

    2011-08-01

    The purpose of this secondary analysis of data is to examine relationships among Asian American Pacific Islanders (AAPI) adolescents' level of acculturation, maternal influences, and age of sexual initiation. Selected predictive variables are based on the theoretical frameworks and literature review. The results indicate that for these adolescents speaking English at home was positively associated with maternal sexual discussion, mothers' perceptions of connectedness with their adolescents, adolescents' perceived maternal sexual expectations, and later sexual initiation at Wave 1. Adolescents' years of U.S. residency are positively associated with adolescents' level of perceived connectedness with their mothers and later sexual initiation at Wave 2. Adolescents' level of acculturation influence how they interacted with their mothers, perceived their mothers' sexual expectations, and when they decided to initiate sexual intercourse. Interventions to delay AAPI adolescents' sexual debut should consider factors related to AAPI adolescents' and their mothers' levels of acculturation.

  18. Interaction of Mean Temperature and Daily Fluctuation Influences Dengue Incidence in Dhaka, Bangladesh.

    PubMed

    Sharmin, Sifat; Glass, Kathryn; Viennet, Elvina; Harley, David

    2015-01-01

    Local weather influences the transmission of the dengue virus. Most studies analyzing the relationship between dengue and climate are based on relatively coarse aggregate measures such as mean temperature. Here, we include both mean temperature and daily fluctuations in temperature in modelling dengue transmission in Dhaka, the capital of Bangladesh. We used a negative binomial generalized linear model, adjusted for rainfall, anomalies in sea surface temperature (an index for El Niño-Southern Oscillation), population density, the number of dengue cases in the previous month, and the long term temporal trend in dengue incidence. In addition to the significant associations of mean temperature and temperature fluctuation with dengue incidence, we found interaction of mean and temperature fluctuation significantly influences disease transmission at a lag of one month. High mean temperature with low fluctuation increases dengue incidence one month later. Besides temperature, dengue incidence was also influenced by sea surface temperature anomalies in the current and previous month, presumably as a consequence of concomitant anomalies in the annual rainfall cycle. Population density exerted a significant positive influence on dengue incidence indicating increasing risk of dengue in over-populated Dhaka. Understanding these complex relationships between climate, population, and dengue incidence will help inform outbreak prediction and control.

  19. Non-local sub-characteristic zones of influence in unsteady interactive boundary-layers

    NASA Technical Reports Server (NTRS)

    Rothmayer, A. P.

    1992-01-01

    The properties of incompressible, unsteady, interactive, boundary layers are examined for a model hypersonic boundary layer and internal flow past humps or, equivalently, external flow past short-scaled humps. Using a linear high frequency analysis, it is shown that the domains of dependence within the viscous sublayer may be a strong function of position within the sublayer and may be strongly influenced by the pressure displacement interaction, or the prescribed displacement condition. Detailed calculations are presented for the hypersonic boundary layer. This effect is found to carry over directly to the fully viscous problem as well as the nonlinear problem. In the fully viscous problem, the non-local character of the domains of dependence manifests itself in the sub-characteristics. Potential implications of the domain of dependence structure on finite difference computations of unsteady boundary layers are briefly discussed.

  20. Electrophoresis of two spheres: Influence of double layer and van der Waals interactions.

    PubMed

    Tseng, Shiojenn; Huang, Chih-Hua; Hsu, Jyh-Ping

    2015-08-01

    Considering recent applications of electrophoresis conduced in nanoscaled devices, where particle-particle interaction can play a role, we studied for the first time the electrophoresis of two rigid spheres along their center line, taking account of the hydrodynamic, electric, and van der Waals interactions between them. Under the conditions of constant surface potential and surface charge density, the influences of the level of surface potential/charge density, the bulk salt concentration, and the particle-particle distance on their electrokinetic behaviors are examined. Numerical simulation reveals that these behaviors are much more complicated and interesting than those of isolated particles. In particular, we show that care must be taken in choosing an appropriate particle concentration in relevant experiment to avoid obtaining unreliable mobility data.

  1. Specific interaction of capsid protein and importin-{alpha}/{beta} influences West Nile virus production

    SciTech Connect

    Bhuvanakantham, Raghavan; Chong, Mun-Keat; Ng, Mah-Lee

    2009-11-06

    West Nile virus (WNV) capsid (C) protein has been shown to enter the nucleus of infected cells. However, the mechanism by which C protein enters the nucleus is unknown. In this study, we have unveiled for the first time that nuclear transport of WNV and Dengue virus C protein is mediated by their direct association with importin-{alpha}. This interplay is mediated by the consensus sequences of bipartite nuclear localization signal located between amino acid residues 85-101 together with amino acid residues 42 and 43 of C protein. Elucidation of biological significance of importin-{alpha}/C protein interaction demonstrated that the binding efficiency of this association influenced the nuclear entry of C protein and virus production. Collectively, this study illustrated the molecular mechanism by which the C protein of arthropod-borne flavivirus enters the nucleus and showed the importance of importin-{alpha}/C protein interaction in the context of flavivirus life-cycle.

  2. How does timing, duration and severity of heat stress influence pollen-pistil interactions in angiosperms?

    PubMed Central

    Oosterhuis, Derrick M

    2011-01-01

    Reproductive development in sexual plants is substantially more sensitive to high temperature stress than vegetative development, resulting in negative implications for food and fiber production under the moderate temperature increases projected to result from global climate change. High temperature exposure either during early pollen development or during the progamic phase of pollen development will negatively impact pollen performance and reproductive output; both phases of pollen development are considered exceptionally sensitive to moderate heat stress. However, moderately elevated temperatures either before or during the progamic phase can limit fertilization by negatively impacting important pollen pistil interactions required for successful pollen tube growth toward the ovules. This mini-review identifies the impacts of heat stress on pollen-pistil interactions and sexual reproduction in angiosperms. A special emphasis is placed on the biochemical response of the pistil to moderately high temperature and the resultant influence on in vivo pollen performance and fertilization. PMID:21628998

  3. Relaxation Process of Interacting Two-mode System Influenced by Markovian Thermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Ban, Masashi

    2016-11-01

    Two different models of a relaxation process are considered for a linearly interacting two-mode system under the influence of independent Markovian thermal reservoirs. One is to describe the relaxation process of bare particles and the other is to describe the one of quasi particles which are derived from bare particles by the Bogoliubov transformation. The difference is that the former does not includes the effect of the inter-mode interaction on the damping operator while the latter does. The equations of motion are solved algebraically by making use of non-equilibrium thermo field dynamics. The relaxation processes in the two models are investigated in detail. The results are applied for investigating a non-ideal beam splitter with photon loss and noise addition.

  4. Relaxation Process of Interacting Two-mode System Influenced by Markovian Thermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Ban, Masashi

    2017-02-01

    Two different models of a relaxation process are considered for a linearly interacting two-mode system under the influence of independent Markovian thermal reservoirs. One is to describe the relaxation process of bare particles and the other is to describe the one of quasi particles which are derived from bare particles by the Bogoliubov transformation. The difference is that the former does not includes the effect of the inter-mode interaction on the damping operator while the latter does. The equations of motion are solved algebraically by making use of non-equilibrium thermo field dynamics. The relaxation processes in the two models are investigated in detail. The results are applied for investigating a non-ideal beam splitter with photon loss and noise addition.

  5. Influence of interfacial Dzyaloshinskii-Moriya interaction on the parametric amplification of spin waves

    SciTech Connect

    Verba, Roman; Tiberkevich, Vasil; Slavin, Andrei

    2015-09-14

    The influence of the interfacial Dzyaloshinskii-Moriya interaction (IDMI) on the parametric amplification of spin waves propagating in ultrathin ferromagnetic film is considered theoretically. It is shown that the IDMI changes the relation between the group velocities of the signal and idler spin waves in a parametric amplifier, which may result in the complete vanishing of the reversed idler wave. In the optimized case, the idler spin wave does not propagate from the pumping region at all, which increases the efficiency of the amplification of the signal wave and suppresses the spurious impact of the idler waves on neighboring spin-wave processing devices.

  6. Influence of emitted electrons transiting between surfaces on plasma-surface interaction

    SciTech Connect

    Campanell, Michael; Wang, Hongyue

    2013-09-02

    Emitted electrons are accelerated back into the plasma by the sheath. If their mean free path is large, they can propagate directly to another surface without suffering collisions. We analyze the effects of “transit” on plasma-surface interaction. When transit occurs, surfaces exchanging electrons are intricately coupled. All surfaces float more negatively than they would if the emission collisionally remixed with the bulk plasma. Asymmetries of the system drive a net “transit current” between the surfaces, which influences their potential difference. The larger the initial energy spread of the emitted electrons, the larger the potential difference.

  7. Interactive effect of leaders' influence tactics and ethical leadership on work effort and helping behavior.

    PubMed

    Kacmar, K Michele; Carlson, Dawn S; Harris, Kenneth J

    2013-01-01

    The purpose of this study was to explore the interactive influence of a) leaders' exemplification and supplication efforts and b) followers' perceptions of the leaders' ethicality on followers' work efforts and helping behaviors. We surveyed 58 leaders and 175 followers who worked for a governmental agency in the United States. Results indicated that the expected positive (negative) relationship between leaders' usage of exemplification and work effort was evident when ethical leadership was high (low). The expected positive relationship between leaders' engagement in supplication and helping behaviors was not present when ethical leadership was high, but the predicted negative relationship was found between supplication and helping when perceptions of leaders' ethicality were low.

  8. Influence of counterions on the interaction of pyridinium salts with model membranes.

    PubMed

    Sarapuk, J; Kleszczyńska, H; Pernak, J; Kalewska, J; Rózycka-Roszak, B

    1999-11-01

    The interaction of pyridinium salts (PS) with red blood cells and planar lipid membranes was studied. The aim of the work was to find whether certain cationic surfactant counterion influence its possible biological activity. The counterions studied were Cl-, Br-, I-, ClO4-, BF4- and NO3-. The model membranes used were erythrocyte and planar lipid membranes (BLM). At high concentration the salts caused 100% erythrocyte hemolysis (C100) or broke BLMs (CC). Both parameters describe mechanical properties of model membranes. It was found that the efficiency of the surfactant to destabilize model membranes depended to some degree on its counterion. In both, erythrocyte and BLM experiments, the highest efficiency was observed for Br-, the lowest for NO3-. The influence of all other anions on surfactant efficiency changed between these two extremities; that of chloride and perchlorate ions was similar. Some differences were found in the case of BF4- ion. Its influence on hemolytic possibilities of PS was significant while BLM destruction required relatively high concentration of this anion. Apparently, the influence of various anions on the destructive action of PS on the model membrane used may be attributed to different mobilities and radii of hydrated ions and hence, to different possibilities of particular anions to modify the surface potential of model membranes. This can lead to a differentiated interaction of PS with modified bilayers. Moreover, the effect of anions on the water structure must be taken into account. It is important whether the anions can be classified as water ordering kosmotropes that hold the first hydration shell tightly or water disordering chaotropes that hold water molecules in that shell loosely.

  9. [Comparison of film-screen combinations in contrast-detail diagram and with interactive image analysis. 3: Trimodal histograms of gray scale distribution in bar groups of lead pattern images].

    PubMed

    Hagemann, G; Eichbaum, G; Stamm, G

    1998-05-01

    The following four screen film combinations were compared: a) a combination of anticrossover film and UV-light emitting screens, b) a combination of blue-light emitting screens and film and c) two conventional green fluorescing screen film combinations. Radiographs of a specially designed plexiglass phantom (0.2 x 0.2 x 0.12 m3) with bar patterns of lead and plaster and of air, respectively were obtained using the following parameters: 12 pulse generator, 0.6 mm focus size, 4.7 mm aluminum prefilter, a grid with 40 lines/cm (12:1) and a focus-detector distance of 1.15 m. Image analysis was performed using an Ibas system and a Zeiss Kontron computer. Display conditions were the following: display distance 0.12 m, a vario film objective 35/70 (Zeiss), a video camera tube with a PbO photocathode, 625 lines (Siemens Heimann), an Ibas image matrix of 512 x 512 pixels with a spatial resolution of ca. 7 cycles/mm, the projected matrix area was 5000 micron 2. Maxima in the histograms of a grouped bar pattern were estimated as mean values from the bar and gap regions ("mean value method"). They were used to calculate signal contrast, standard deviations of the means and scatter fraction. Comparing the histograms with respect to spatial resolution and kV setting a clear advantage of the UVR system becomes obvious. The quantitative analysis yielded a maximum spatial resolution of approx. 3 cycles/mm for the UVR system at 60 kV which decreased to half of this value at 117 kV caused by the increasing influence of scattered radiation. A ranking of screen-film systems with respect to image quality and dose requirement is presented. For its evaluation an interactive image analysis using the mean value method was found to be superior to signal/noise ratio measurements and visual analysis in respect to diagnostic relevance and saving of time.

  10. Influence of nonelectrostatic ion-ion interactions on double-layer capacitance

    NASA Astrophysics Data System (ADS)

    Zhao, Hui

    2012-11-01

    Recently a Poisson-Helmholtz-Boltzmann (PHB) model [Bohinc , Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.031130 85, 031130 (2012)] was developed by accounting for solvent-mediated nonelectrostatic ion-ion interactions. Nonelectrostatic interactions are described by a Yukawa-like pair potential. In the present work, we modify the PHB model by adding steric effects (finite ion size) into the free energy to derive governing equations. The modified PHB model is capable of capturing both ion specificity and ion crowding. This modified model is then employed to study the capacitance of the double layer. More specifically, we focus on the influence of nonelectrostatic ion-ion interactions on charging a double layer near a flat surface in the presence of steric effects. We numerically compute the differential capacitance as a function of the voltage under various conditions. At small voltages and low salt concentrations (dilute solution), we find out that the predictions from the modified PHB model are the same as those from the classical Poisson-Boltzmann theory, indicating that nonelectrostatic ion-ion interactions and steric effects are negligible. At moderate voltages, nonelectrostatic ion-ion interactions play an important role in determining the differential capacitance. Generally speaking, nonelectrostatic interactions decrease the capacitance because of additional nonelectrostatic repulsion among excess counterions inside the double layer. However, increasing the voltage gradually favors steric effects, which induce a condensed layer with crowding of counterions near the electrode. Accordingly, the predictions from the modified PHB model collapse onto those computed by the modified Poisson-Boltzmann theory considering steric effects alone. Finally, theoretical predictions are compared and favorably agree with experimental data, in particular, in concentrated solutions, leading one to conclude that the modified PHB model adequately predicts the diffuse

  11. Environmental influences on virus-host interactions in an Australian subtropical reservoir.

    PubMed

    Säwström, Christin; Pollard, Peter

    2012-02-01

    Viral and prokaryotic interactions in freshwaters have been investigated worldwide but there are few temporal studies in the tropics and none in the sub-tropics. In this 10-month study, we examined temporal changes in virus-host interactions and viral life cycles (lytic versus lysogenic) in relation to the prevailing environmental conditions in a subtropical water reservoir (Wivenhoe) in southeast Queensland, Australia. Heterotrophic prokaryotes and picocyanobacteria were positively correlated with concentrations of viruses throughout the study, indicating the presence of both bacteriophages and cyanophages in the reservoir. The percentage of heterotrophic prokaryotes and picocyanobacteria containing intracellular viruses (FVIC) ranged between 0.2% and 2.4% and did not vary significantly over the 10-month study, whereas lysogenic heterotrophic prokaryotes were only detected in the drier months of June and July. Spearman rank correlation analysis showed that the oxidative-reduction potential (ORP) of the water reservoir influenced the concentrations of viruses, heterotrophic prokaryotes and picocyanobacteria significantly, with low ORP offering a favourable environment for these components. There was a negative relationship between FVIC and rainfall suggesting the associated run-off altered virus-host interactions. Overall, our study provides novel information and inferences on how virus-host interactions in subtropical freshwaters might respond to changes in precipitation predicted to occur with global climate change.

  12. Influence of membrane lipid composition on flavonoid-membrane interactions: Implications on their biological activity.

    PubMed

    Selvaraj, Stalin; Krishnaswamy, Sridharan; Devashya, Venkappayya; Sethuraman, Swaminathan; Krishnan, Uma Maheswari

    2015-04-01

    The membrane interactions and localization of flavonoids play a vital role in altering membrane-mediated cell signaling cascades as well as influence the pharmacological activities such as anti-tumour, anti-microbial and anti-oxidant properties of flavonoids. Various techniques have been used to investigate the membrane interaction of flavonoids. These include partition coefficient, fluorescence anisotropy, differential scanning calorimetry, NMR spectroscopy, electrophysiological methods and molecular dynamics simulations. Each technique will provide specific information about either alteration of membrane fluidity or localization of flavonoids within the lipid bilayer. Apart from the diverse techniques employed, the concentrations of flavonoids and lipid membrane composition employed in various studies reported in literature also are different and together these variables contribute to diverse findings that sometimes contradict each other. This review highlights different techniques employed to investigate the membrane interaction of flavonoids with special emphasis on erythrocyte model membrane systems and their significance in understanding the nature and extent of flavonoid-membrane interactions. We also attempt to correlate the membrane localization and alteration in membrane fluidity with the biological activities of flavonoids such as anti-oxidant, anti-cancer and anti-microbial properties.

  13. Predominance zone diagrams and their application to solvent extraction techniques.

    PubMed

    Páez-Hernández, M E; Ramírez, M T; Rojas-Hernández, A

    2000-01-24

    Predominance zone diagrams have been useful tools in solving problems in analytical chemistry. They can be used to establish the best conditions for separation of mixtures or to optimize recovery procedures for a given species. The few reports on predominance zone diagrams for the participant species in liquid-liquid extraction systems, describe their construction as diagrams of the Pourbaix type (epsilon/pH). With the generalized species and equilibria method (GSEM) it is possible to elaborate Predominance zone diagrams for extraction (PZDE) in proper spaces and with parameters strictly related to these processes such as pH and the volume ratio, r. Therefore, using the GSEM, PZDE that allow us to determine the best conditions for the extraction of a given substance have been elaborated. The stoichiometry of the species been extracted can also be determined from the experimental conditions. It has been demonstrated that with the GSEM, PZDE can be constructed for systems of one and two components. In this work, we intend to demonstrate that the algorithm is valid for the elaboration of PZDE in systems of three and four components. Examples of analytical interest are presented such as lead (II) extraction with diphenyltiocarbazone (dithizone) and that for cadmium (II) with 8-hydroxyquinolein (oxine) in chloroform. The influence of a masking agent, the etilendiaminotetraacetic acid (EDTA) over the extraction of both metals was also assessed.

  14. Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

    NASA Astrophysics Data System (ADS)

    Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

    2015-12-01

    Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

  15. Influence of Mach Number and Incoming Boundary Layer on Shock Boundary Layer Interaction

    NASA Astrophysics Data System (ADS)

    Stab, Ilona; Threadgill, James; Little, Jesse

    2016-11-01

    Wall pressure fluctuations, schlieren imaging, oil flow visualization and PIV measurements have been performed on the shock boundary layer interaction (SBLI) formed by a 10° compression ramp. The incoming Mach number and boundary layer characteristics are varied to examine their influence on the SBLI. Focus is placed on understanding the effect of these parameters on the structure and unsteadiness of the resultant interaction. Lower Mach numbers M = 2 . 3 (δ0 = 1 . 7 mm , θ = 0 . 29 mm , Reθ = 3115 , H = 1 . 4) and M = 3 (δ0 = 1 . 3 mm , θ = 0 . 25 mm , Reθ = 1800 , H = 1 . 8) show a turbulent or transitional approach boundary layer with no apparent separation at the ramp. Mach 4 has a large separated region which is seemingly a result of a now laminar or transitional approach boundary layer. Pulsations in the separated region correspond to the expected low frequency SBLI dynamics showing a broad peak around a Strouhal number of St = fLint /U∞ = 0 . 27 which is lower than the characteristic frequency of the turbulent boundary layer. Additional results examining the influence of boundary layer modifications (e.g. sweep) and wind tunnel side-walls are also included. Supported by Raytheon Missile Systems.

  16. A heuristic model for potential geomorphic influences on trophic interactions in streams

    NASA Astrophysics Data System (ADS)

    Doyle, Martin W.

    2006-07-01

    Whereas certain linkages between stream channel morphology and stream ecology are fairly well-understood, how geomorphology influences trophic interactions remains largely unknown. As a first step, a simple, heuristic model is developed that couples reach-scale geomorphic morphology with trophic dynamics between vegetation, detritus, herbivores, and predators. Predation is assumed to increase with depth beyond a threshold depth, and herbivory is assumed to decrease with velocity beyond a threshold velocity. Results show that the modeled food chain is sensitive to channel geometry, particularly around the threshold conditions for predators and herbivores. Importantly, geomorphic influences are not isolated to a particular trophic level, but rather are transferred through the food chain via top-down and bottom-up effects. The modeled system is particularly sensitive to changes in the end-members of the food chain: vegetation and predators. Results illustrate that geomorphic disturbances, known to affect a single trophic level (e.g., fish), likely impact multiple trophic levels in the stream ecosystem via trophic interactions. Such impacts at the multiple trophic level are poorly understood. While limited by the lack of empirical long-term data for testing and calibration, this simple model provides a structure for generating hypotheses, collecting targeted data, and assessing the potential impacts of stream disturbance or restoration on entire stream ecosystems. Further, the model illustrates the potential for future coupled stream models to explore spatial and temporal linkages.

  17. Mucoadhesion on pig vesical mucosa: influence of polycarbophil/calcium interactions.

    PubMed

    Kerec, M; Bogataj, M; Mugerle, B; Gasperlin, M; Mrhar, A

    2002-07-08

    The influence of polycarbophil/calcium interactions on the mucoadhesive properties of polycarbophil has been examined. Polycarbophil dispersions and films with different concentrations of calcium or sodium ions were prepared and the following parameters were measured: detachment force on pig vesical mucosa, zeta potential, pH and viscosity. Polycarbophil detachment force decreased significantly in the presence of calcium but not sodium. Both ions decrease the pH of polycarbophil dispersions. On the other hand, altering the pH of hydrated polycarbophil films in the absence of added ions had an insignificant effect on detachment force. Both ions reduce the absolute values of polycarbophil zeta potential, calcium more efficiently than sodium. We could conclude that decreased mucoadhesion strength of polycarbophil in the presence of calcium is due to the chelation of polycarbophil carboxylic groups by calcium and crosslinking of polymer. The crosslinked polymer chains would be expected to be less flexible, and therefore, interpenetrate to a lesser extent with the glycosaminoglycans of mucus. Additionally, the interactions between functional groups of polycarbophil and mucus glycosaminoglycans are lowered due to the calcium, blocking the carboxylic groups. The mechanism of calcium influence on viscosity of polycarbophil dispersions appears to be different: repulsion between ionised carboxylic groups of polycarbophil prevails over the crosslinking of polycarbophil by calcium.

  18. Invasive earthworms interact with abiotic conditions to influence the invasion of common buckthorn (Rhamnus cathartica).

    PubMed

    Roth, Alexander M; Whitfeld, Timothy J S; Lodge, Alexandra G; Eisenhauer, Nico; Frelich, Lee E; Reich, Peter B

    2015-05-01

    Common buckthorn (Rhamnus cathartica L.) is one of the most abundant and ecologically harmful non-native plants in forests of the Upper Midwest United States. At the same time, European earthworms are invading previously glaciated areas in this region, with largely anecdotal evidence suggesting they compound the negative effects of buckthorn and influence the invasibility of these forests. Germination and seedling establishment are important control points for colonization by any species, and manipulation of the conditions influencing these life history stages may provide insight into why invasive species are successful in some environments and not others. Using a greenhouse microcosm experiment, we examined the effects of important biotic and abiotic factors on the germination and seedling establishment of common buckthorn. We manipulated light levels, leaf litter depth and earthworm presence to investigate the independent and interactive effects of these treatments on buckthorn establishment. We found that light and leaf litter depth were significant predictors of buckthorn germination but that the presence of earthworms was the most important factor; earthworms interacted with light and leaf litter to increase the number and biomass of buckthorn across all treatments. Path analysis suggested both direct and moisture-mediated indirect mechanisms controlled these processes. The results suggest that the action of earthworms may provide a pathway through which buckthorn invades forests of the Upper Midwest United States. Hence, researchers and managers should consider co-invasion of plants and earthworms when investigating invasibility and creating preemptive or post-invasion management plans.

  19. The effects of three-body dispersion interactions on liquid-liquid phase equilibrium

    NASA Astrophysics Data System (ADS)

    McMahon, P. D.

    1989-02-01

    Using perturbation theory, we show that three-body dispersion interactions influence the phase diagrams of partially miscible liquid mixtures. In our model mixtures, the argon-like particles interact through Maitland-Smith pair potentials and Axilrod-Teller three-body potentials. We find that ternary liquid-liquid coexistence curves are sensitive to vABC, the strength of the Axilrod-Teller interaction appearing for the first time in the ternary mixture. Effective pair potentials predict the ternary phase diagrams well if vABC satisfies Tang's rule.

  20. Vesicle deformation by microtubules: A phase diagram

    NASA Astrophysics Data System (ADS)

    Emsellem, Virginie; Cardoso, Olivier; Tabeling, Patrick

    1998-10-01

    The experimental investigation of vesicles deformed by the growth of encapsulated microtubules shows that the axisymmetric morphologies can be classified into ovals, lemons, φ, cherries, dumbbells, and pearls. A geometrical phase diagram is established. Numerical minimization of the elastic energy of the membrane reproduces satisfactorily well the observed morphologies and the corresponding phase diagram.

  1. Multilevel Modeling of Direct Effects and Interactions of Peers, Parents, School, and Community Influences on Adolescent Substance Use

    ERIC Educational Resources Information Center

    Mayberry, Megan L.; Espelage, Dorothy L.; Koenig, Brian

    2009-01-01

    This study tested a social-ecological model of adolescent substance use. Multilevel modeling was used to investigate how systems, such as parents, peers, schools, and communities, directly influence and interact together to influence adolescent substance use. Participants included 14,548 (50.3% female) middle school students who were 78.6% White,…

  2. The morphological diagram of spinels

    SciTech Connect

    Ziolkowski, J.

    1996-02-01

    Catalytic anisotropy in mild oxidation reactions results from the varying activity of different crystal faces. Here, spinels exposing (100), (110), and (111) faces have been considered and their Curie-Wulff plots have been drawn, admitting that the relative G(hkl) surface free energies may change in a wide range as a function of composition, inversion, and segregation degree. The normalized free surface energies are defined as A = G(100)/G(111), B = G(110)/G(111), and C = G(111)/G(111) = 1 = const. This made it possible to construct bidimensional morphological diagrams (morphology = f(A,B) at C = const) in the exposed-face-type, solid-type, and exposure-percentage versions. Eleven morphological habits of grains have been identified, including (100)-cube, (110)-dodecahedron, (111)-hexagons, 18-hedron, 20-hedron, and up to 26-hedra bordered with (i) 6 (100)-octagons, 12 (110)-rectangles, and 8 (111)-hexagons, (ii) 6 (100)-squares, 12 (110)-rectangles, and 8 (111)-triangles, or (iii) 6 (100)-squares, 12 (110)-octagons, and 8 (100)-triangles. The analysis is valid for all compounds crystallizing in the cubic system and preferentially exposing the three enumerated faces.

  3. Phase diagram of ammonium nitrate

    SciTech Connect

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-12-07

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ′} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  4. Phase Diagram of Ammonium Nitrate

    NASA Astrophysics Data System (ADS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-06-01

    Ammonium Nitrate (AN) has often been subjected to uses in improvised explosive devices, due to its wide availability as a fertilizer and its capability of becoming explosive with slight additions of organic and inorganic compounds. Yet, the origin of enhanced energetic properties of impure AN (or AN mixtures) is neither chemically unique nor well understood - resulting in rather catastrophic disasters in the past1 and thereby a significant burden on safety, in using ammonium nitrates even today. To remedy this situation, we have carried out an extensive study to investigate the phase stability of AN, in different chemical environments, at high pressure and temperature, using diamond anvil cells and micro-Raman spectroscopy. The present results confirm the recently proposed phase IV-to-IV' transition above 15 GPa2 and provide new constraints for the melting and phase diagram of AN to 40 GPa and 673 K. The present study has been supported by the U.S. DHS under Award Number 2008-ST-061-ED0001.

  5. Influence of molecular shape, conformability, net surface charge, and tissue interaction on transscleral macromolecular diffusion.

    PubMed

    Srikantha, Nishanthan; Mourad, Fatma; Suhling, Klaus; Elsaid, Naba; Levitt, James; Chung, Pei Hua; Somavarapu, Satyanarayana; Jackson, Timothy L

    2012-09-01

    The purpose of this study was to investigate the influence of molecular shape, conformability, net surface charge and tissue interaction on transscleral diffusion. Unfixed, porcine sclera was clamped in an Ussing chamber. Fluorophore-labelled neutral albumin, neutral dextran, or neutral ficoll were placed in one hemi-chamber and the rate of transscleral diffusion was measured over 24 h using a spectrophotometer. Experiments were repeated using dextrans and ficoll with positive or negative net surface charges. Fluorescence recovery after photobleaching (FRAP) was undertaken to compare transscleral diffusion with diffusion through a solution. All molecules were 70 kDa. With FRAP, the diffusion coefficient (D) of neutral molecules was highest for albumin, followed by ficoll, then dextran (p < 0.0001). Positive dextrans diffused fastest, followed by negative, then neutral dextrans (p = 0.0004). Neutral ficoll diffused the fastest, followed by positive then negative ficoll (p = 0.5865). For the neutral molecules, transscleral D was highest for albumin, followed by dextran, then ficoll (p < 0.0001). D was highest for negative ficoll, followed by neutral, then positive ficoll (p < 0.0001). By contrast, D was highest for positive dextran, followed by neutral, then negative dextran (p = 0.0021). In conclusion, diffusion in free solution does not predict transscleral diffusion and the molecular-tissue interaction is important. Molecular size, shape, and charge may all markedly influence transscleral diffusion, as may conformability to a lesser degree, but their effects may be diametrically opposed in different molecules, and their influence on diffusion is more complex than previously thought. Each variable cannot be considered in isolation, and the interplay of all these variables needs to be tested, when selecting or designing drugs for transscleral delivery.

  6. Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

    NASA Technical Reports Server (NTRS)

    McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

    2012-01-01

    The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

  7. Interaction of LL-37 with Model Membrane Systems of Different Complexity: Influence of the Lipid Matrix

    PubMed Central

    Sevcsik, E.; Pabst, G.; Richter, W.; Danner, S.; Amenitsch, H.; Lohner, K.

    2008-01-01

    As the main difference between bacterial and mammalian cell membranes is their net charge, the focal point of consideration in many model membrane experiments with antimicrobial peptides is lipid headgroup charge. We studied the interaction of the human multifunctional peptide LL-37 with single phospholipid monolayers, bilayers, and bilayers composed of binary mixtures of the four phospholipid species predominantly used in model membrane experiments (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylserine). We found that 1), the effects on single lipid monolayers are not comparable to those on the corresponding bilayers; 2), there are four different effects of LL-37 on bilayers of the four lipids; 3), the preference of LL-37 for the specific lipids is roughly inversely related to chain packing density; and 4), in the binary lipid mixtures, one lipid—and not necessarily the charged one—generally governs the mode of lipid/peptide interaction. Thus, our results show that lipid net charge is not the decisive factor determining the membrane-perturbing mechanism of LL-37, but only one of several parameters, among them packing density, the ability to form intermolecular H-bonds, and lipid molecular shape, which emphasizes how profoundly the choice of the model system can influence the outcome of a study of lipid/peptide interaction. PMID:18326643

  8. Legionella-protozoa-nematode interactions in aquatic biofilms and influence of Mip on Caenorhabditis elegans colonization.

    PubMed

    Rasch, Janine; Krüger, Stefanie; Fontvieille, Dominique; Ünal, Can M; Michel, Rolf; Labrosse, Aurélie; Steinert, Michael

    2016-09-01

    Legionella pneumophila, the causative agent of Legionnaireś disease, is naturally found in aquatic habitats. The intracellular life cycle within protozoa pre-adapted the "accidental" human pathogen to also infect human professional phagocytes like alveolar macrophages. Previous studies employing the model organism Caenorhabditis elegans suggest that also nematodes might serve as a natural host for L. pneumophila. Here, we report for the first time from a natural co-habitation of L. pneumophila and environmental nematode species within biofilms of a warm water spring. In addition, we identified the protozoan species Oxytricha bifaria, Stylonychia mytilus, Ciliophrya sp. which have never been described as potential interaction partners of L. pneumophila before. Modeling and dissection of the Legionella-protozoa-nematode interaction revealed that C. elegans ruptures Legionella-infected amoebal cells and by this means incorporate the pathogen. Further infection studies revealed that the macrophage infectivity potentiator (Mip) protein of L. pneumophila, which is known to bind collagen IV during human lung infection, promotes the colonization of the intestinal tract of L4 larvae of C. elegans and negatively influences the life span of the worms. The Mip-negative L. pneumophila mutant exhibited a 32-fold reduced colonization rate of the nematodes after 48h when compared to the wild-type strain. Taken together, these studies suggest that nematodes may serve as natural hosts for L. pneumophila, promote their persistence and dissemination in the environment, and co-evolutionarily pre-adapt the pathogen for interactions with extracellular constituents of human lung tissue.

  9. The influence of inelastic neutrino interactions with light clusters on core-collapse supernova simulations

    NASA Astrophysics Data System (ADS)

    Furusawa, Shun; Nagakura, Hiroki; Sumiyoshi, Kohsuke; Yamada, Shoichi

    2014-12-01

    We perform numerical experiments to investigate the influence of inelastic neutrino reactions with light clusters in hot nuclear matter on core-collapse supernova simulations. These interactions have been neglected in most hydrodynamical supernova simulations. The neutrino absorptions and inelastic interactions with deuterons, tritons, helions and alpha particles are taken into account in the hydrodynamical simulations in addition to the ordinary charged- current interactions with nucleons. Axial symmetry is assumed but no equatorial symmetry is imposed. The time evolutions of shock waves are calculated with a simple light-bulb approximation for the neutrino transport and a multi-nuclei equation of state. We show that the heating rates of deuterons reach as high as ~ 10% of those of nucleons around the bottom of the gain region. On the other hand, alpha particles heat the matter near the shock wave, which is important when the shock wave expands and density and temperature of matter become low. It is also found that the models with heating by light clusters have different evolutions from those without it in non-linear evolution phase. The matter in the gain region has various densities and temperatures and there appear regions that are locally rich in deuterons and alpha particles. These results indicate that the inelastic reactions of light clusters, especially deuterons, should be incorporated in the simulations of core-collapse supernovae.

  10. Interaction of triprolidine hydrochloride with serum albumins: thermodynamic and binding characteristics, and influence of site probes.

    PubMed

    Sandhya, B; Hegde, Ashwini H; Kalanur, Shankara S; Katrahalli, Umesha; Seetharamappa, J

    2011-04-05

    The interaction between triprolidine hydrochloride (TRP) to serum albumins viz. bovine serum albumin (BSA) and human serum albumin (HSA) has been studied by spectroscopic methods. The experimental results revealed the static quenching mechanism in the interaction of TRP with protein. The number of binding sites close to unity for both TRP-BSA and TRP-HSA indicated the presence of single class of binding site for the drug in protein. The binding constant values of TRP-BSA and TRP-HSA were observed to be 4.75 ± 0.018 × 10(3) and 2.42 ± 0.024 × 10(4)M(-1) at 294 K, respectively. Thermodynamic parameters indicated that the hydrogen bond and van der Waals forces played the major role in the binding of TRP to proteins. The distance of separation between the serum albumin and TRP was obtained from the Förster's theory of non-radioactive energy transfer. The metal ions viz., K(+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Mn(2+) and Zn(2+) were found to influence the binding of the drug to protein. Displacement experiments indicated the binding of TRP to Sudlow's site I on both BSA and HSA. The CD, 3D fluorescence spectra and FT-IR spectral results revealed the changes in the secondary structure of protein upon interaction with TRP.

  11. Interactions between acute lymphoblastic leukemia and bone marrow stromal cells influence response to therapy.

    PubMed

    Tesfai, Yordanos; Ford, Jette; Carter, Kim W; Firth, Martin J; O'Leary, Rebecca A; Gottardo, Nicholas G; Cole, Catherine; Kees, Ursula R

    2012-03-01

    The cure rate for pediatric patients with B precursor acute lymphoblastic leukemia (pre-B ALL) is steadily improving, however relapses do occur despite initial response to therapy. To identify links between drug resistance and gene deregulation we used oligonucleotide microarray technology and determined in 184 pre-B ALL specimen genes differentially expressed compared to normal CD34(+) specimens. We identified 20 signature genes including CTGF, BMP-2, CXCR4 and IL7R, documented to regulate interactions in the bone marrow. We recorded remarkably similar levels of expression in three independent patient cohorts, and found distinct patterns in cytogenetically defined subgroups of pre-B ALL. The canonical pathways that were affected are involved in inter- and intra-cellular communication, regulating signaling within the microenvironment. We tested experimentally whether interaction with stromal cells conferred protection to four drugs used in current ALL therapy, and demonstrated that bone marrow stromal cells significantly influenced resistance to vincristine and cytosine arabinoside. Compounds designed to block the identified cellular interactions within the bone marrow microenvironment are expected to mobilise the leukemic cells and make them more accessible to contemporary antileukemic agents. The data provide novel insight into the pathobiology of ALL and indicate new therapeutic targets for patients with ALL.

  12. State diagrams for harmonically trapped bosons in optical lattices

    SciTech Connect

    Rigol, Marcos; Batrouni, George G.; Rousseau, Valery G.; Scalettar, Richard T.

    2009-05-15

    We use quantum Monte Carlo simulations to obtain zero-temperature state diagrams for strongly correlated lattice bosons in one and two dimensions under the influence of a harmonic confining potential. Since harmonic traps generate a coexistence of superfluid and Mott insulating domains, we use local quantities such as the quantum fluctuations of the density and a local compressibility to identify the phases present in the inhomogeneous density profiles. We emphasize the use of the 'characteristic density' to produce a state diagram that is relevant to experimental optical lattice systems, regardless of the number of bosons or trap curvature and of the validity of the local-density approximation. We show that the critical value of U/t at which Mott insulating domains appear in the trap depends on the filling in the system, and it is in general greater than the value in the homogeneous system. Recent experimental results by Spielman et al. [Phys. Rev. Lett. 100, 120402 (2008)] are analyzed in the context of our two-dimensional state diagram, and shown to exhibit a value for the critical point in good agreement with simulations. We also study the effects of finite, but low (T{<=}t/2), temperatures. We find that in two dimensions they have little influence on our zero-temperature results, while their effect is more pronounced in one dimension.

  13. Mapping QTL main and interaction influences on milling quality in elite US rice germplasm.

    PubMed

    Nelson, J C; McClung, A M; Fjellstrom, R G; Moldenhauer, K A K; Boza, E; Jodari, F; Oard, J H; Linscombe, S; Scheffler, B E; Yeater, K M

    2011-02-01

    Rice (Oryza sativa L.) head-rice yield (HR) is a key export and domestic quality trait whose genetic control is poorly understood. With the goal of identifying genomic regions influencing HR, quantitative-trait-locus (QTL) mapping was carried out for quality-related traits in recombinant inbred lines (RILs) derived from crosses of common parent Cypress, a high-HR US japonica cultivar, with RT0034, a low-HR indica line (129 RILs) and LaGrue, a low-HR japonica cultivar (298 RILs), grown in two US locations in 2005-2007. Early heading increased HR in the Louisiana (LA) but not the Arkansas (AR) location. Fitting QTL-mapping models to separate QTL main and QTL × environment interaction (QEI) effects and identify epistatic interactions revealed six main-effect HR QTLs in the two crosses, at four of which Cypress contributed the increasing allele. Multi-QTL models accounted for 0.36 of genetic and 0.21 of genetic × environment interaction of HR in MY1, and corresponding proportions of 0.25 and 0.37 in MY2. The greater HR advantage of Cypress in LA than in AR corresponded to a genomewide pattern of opposition of HR-increasing QTL effects by AR-specific effects, suggesting a selection strategy for improving this cultivar for AR. Treating year-location combinations as independent environments resulted in underestimation of QEI effects, evidently owing to lower variation among years within location than between location. Identification of robust HR QTLs in elite long-grain germplasm is suggested to require more detailed attention to the interaction of plant and grain development parameters with environmental conditions than has been given to date.

  14. Disordering transitions in vortex matter: Peak effect and phase diagram

    SciTech Connect

    Olson, C.J.; Reichhardt, C.; Zimanyi, G.T.; Gronbech-Jensen, Niels

    2000-08-01

    Using numerical simulations of magnetically interacting vortices in disordered layered superconductors we obtain the static vortex phase diagram as a function of magnetic field and temperature. For increasing field or temperature, we find a transition from ordered straight vortices to disordered decoupled vortices. This transition is associated with a peak effect in the critical current as well as plastic flow of the vortices. For samples with increasing disorder strength the field at which the decoupling occurs decreases. Long range interactions in the c-axis are required to observe the effect.

  15. The Kohn-Luttinger mechanism and phase diagram of the superconducting state in the Shubin-Vonsovsky model

    SciTech Connect

    Kagan, M. Yu.; Val'kov, V. V.; Mitskan, V. A.; Korovuskin, M. M.

    2013-10-15

    Using the Shubin-Vonsovsky model in the weak-coupling regime W > U > V (W is the bandwidth, U is the Hubbard onsite repulsion, and V is the Coulomb interaction at neighboring sites) based on the Kohn-Luttinger mechanism, we determined the regions of the existence of the superconducting phases with the d{sub xy}, p, s, and d{sub x{sup 2}-y{sup 2}} symmetry types of the order parameter. It is shown that the effective interaction in the Cooper channel considerably depends not only on single-site but also on intersite Coulomb correlations. This is demonstrated by the example of the qualitative change and complication of the phase diagram of the superconducting state. The superconducting (SC) phase induction mechanism is determined taking into account polarization contributions in the second-order perturbation theory in the Coulomb interaction. The results obtained for the angular dependence of the superconducting gap in different channels are compared with angule-resolved photoemission spectroscopy (ARPES) results. The influence of long-range hops in the phase diagram and critical superconducting transition temperature in different channels is analyzed. The conditions for the appearance of the Kohn-Luttinger superconductivity with the d{sub x{sup 2}-y{sup 2}} symmetry and high critical temperatures T{sub c} {approx} 100 K near the half-filling are determined.

  16. Influence of hydroxylation and glycosylation in ring A of soybean isoflavones on interaction with BSA

    NASA Astrophysics Data System (ADS)

    Zhao, Jinyao; Ren, Fenglian

    2009-04-01

    In this paper, the influence of hydroxylation and glycosylation of soybean isoflavones in ring A on the interaction with BSA was investigated. Two soybean isoflavone aglycones (daidzein and genistein) and their glycosides (daidzin and genistin) were used to study their ability to bind BSA by quenching the BSA intrinsic fluorescence in solution. The hydroxylation and glycosylation of soybean isoflavones in ring A significantly affected the binding/quenching process; in general, the hydroxylation increases the binding affinity and the glycosylation decreased the binding affinity. For daidzein and daidzin, the binding constants for BSA were 5.2 × 10 4 and 5.58 × 10 3 L mol -1, respectively. For genistein and genistin, the binding constants were 8.40 × 10 5 and 1.44 × 10 5 L mol -1, respectively.

  17. The Influence of Railpad Stiffness on Wheelset/track Interaction and Corrugation Growth

    NASA Astrophysics Data System (ADS)

    ILIAS, H.

    1999-11-01

    The aim of the paper is to investigate the influence of the railpad stiffness on vehicle/track interaction and corrugation growth. For the structural dynamics of vehicle and track a time domain model is used which includes all relevant contact non-linearities. A simple war model enables profile development calculations to be undertaken in the time domain by closing the feedback loop between a short-term dynamical process (structural dynamics) and a long-term damaging process (wear). The initial profile is taken from measurements of a ground rail. It is found that stiffer railpads lead to higher corrugation growth. The parametric excitation from passing sleepers is found to be important. For the chosen operational values this wavelength-fixing mechanism dominates the so-called final profiles of profile development calculations.

  18. Influence of Alkylammonium Acetate Buffers on Protein-Ligand Noncovalent Interactions Using Native Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Zhuang, Xiaoyu; Gavriilidou, Agni F. M.; Zenobi, Renato

    2017-02-01

    We investigate the influence of three volatile alkylammonium acetate buffers on binding affinities for protein-ligand interactions determined by native electrospray ionization-mass spectrometry (ESI-MS). Four different types of proteins were chosen for this study. A charge-reduction effect was observed for all the cases studied, in comparison to the ions formed in ammonium acetate solution. When increasing the collision energy, the complexes of trypsin and the ligand were found to be more stable when sprayed from alkylammonium acetate buffers than from ammonium acetate. The determined dissociation constant (Kd) also exhibited a drop (up to 40%) when ammonium acetate was replaced by alkylammonium acetate buffers for the case of lysozyme and the ligand. The prospective uses of these ammonium acetate analogs in native ESI-MS are discussed in this paper as well.

  19. Phase diagrams of self-organizing maps

    NASA Astrophysics Data System (ADS)

    Bauer, H.-U.; Riesenhuber, M.; Geisel, T.

    1996-09-01

    We present a method which allows the analytic determination of phase diagrams in the self-organizing map, a model for the formation of topographic projection patterns in the brain and in signal processing applications. The method only requires an ansatz for the tesselation of the data space induced by the map, not for the explicit state of the map. We analytically obtain phase diagrams for various examples, including models for the development of orientation and ocular-dominance maps. The latter phase diagram exhibits transitions to broadening ocular-dominance patterns as observed in a recent experiment.

  20. Environmental conditions and biotic interactions influence ecosystem structure and function in a drying stream

    USGS Publications Warehouse

    Ludlam, J.P.; Magoulick, D.D.

    2010-01-01

    Benthic consumers influence stream ecosystem structure and function, but these interactions depend on environmental context. We experimentally quantified the effects of central stoneroller minnows (Campostoma anomalum (Rafinesque) and Meek's crayfish (Orconectes meeki meeki (Faxon)) on benthic communities using electric exclusion quadrats in Little Mulberry Creek before (June) and during (August) seasonal stream drying. Unglazed ceramic tiles were deployed in June and August to measure periphyton and invertebrate abundance, and leafpack decomposition and primary production were also measured in August. Relationships between stoneroller and crayfish density and the size of consumer effects were evaluated with multiple linear regression models. Average chlorophyll a abundance was greater on exposed than exclusion tiles in August, but not in June. Sediment dry mass, periphyton ash-free dry mass (AFDM), and chironomid densities on tiles did not differ among treatments in either period. Leaf packs decayed faster in exposed than exclusion treatments (kexposed = 0.038 ?? 0.013, kexclusion = 0.007 ?? 0.002), but consumer effects were stronger in some pools than others. Leafpack invertebrate biomass and abundance and tile primary productivity did not differ among treatments. Consumer effects on chlorophyll a were related to crayfish and stoneroller density, and effects on chironomid density were related to stoneroller density. These results contrast with a previous exclusion experiment in Little Mulberry Creek that demonstrated strong consumer effects. The influence of stream drying on consumer effects appears to have been reduced by strong spates, underscoring the importance of conducting multi-year studies to determine the magnitude of variability in ecological interactions. ?? US Government: USGS 2010.

  1. Managing uncertainty in collaborative robotics engineering projects: The influence of task structure and peer interaction

    NASA Astrophysics Data System (ADS)

    Jordan, Michelle

    Uncertainty is ubiquitous in life, and learning is an activity particularly likely to be fraught with uncertainty. Previous research suggests that students and teachers struggle in their attempts to manage the psychological experience of uncertainty and that students often fail to experience uncertainty when uncertainty may be warranted. Yet, few educational researchers have explicitly and systematically observed what students do, their behaviors and strategies, as they attempt to manage the uncertainty they experience during academic tasks. In this study I investigated how students in one fifth grade class managed uncertainty they experienced while engaged in collaborative robotics engineering projects, focusing particularly on how uncertainty management was influenced by task structure and students' interactions with their peer collaborators. The study was initiated at the beginning of instruction related to robotics engineering and preceded through the completion of several long-term collaborative robotics projects, one of which was a design project. I relied primarily on naturalistic observation of group sessions, semi-structured interviews, and collection of artifacts. My data analysis was inductive and interpretive, using qualitative discourse analysis techniques and methods of grounded theory. Three theoretical frameworks influenced the conception and design of this study: community of practice, distributed cognition, and complex adaptive systems theory. Uncertainty was a pervasive experience for the students collaborating in this instructional context. Students experienced uncertainty related to the project activity and uncertainty related to the social system as they collaborated to fulfill the requirements of their robotics engineering projects. They managed their uncertainty through a diverse set of tactics for reducing, ignoring, maintaining, and increasing uncertainty. Students experienced uncertainty from more different sources and used more and

  2. Influence of the interactions between tea (Camellia sinensis) extracts and ascorbic acid on their antioxidant activity: analysis with interaction indexes and isobolograms.

    PubMed

    Enko, Jolanta; Gliszczyńska-Świgło, Anna

    2015-01-01

    Products containing natural additives, including antioxidants, are usually perceived by consumers as safer than those with synthetic ones. Natural antioxidants, besides having a preservative activity, may exert beneficial health effects. Interactions between antioxidants may significantly change their antioxidant activity, thus in designing functional foods or food/cosmetic ingredients knowledge about the type of interactions could be useful. In the present study, the interactions between ascorbic acid (AA; vitamin C) and different black and green tea extracts and the influence on their antioxidant activities were investigated. The antioxidant activities of tea extracts and their mixtures with AA prepared in several different weight ratios were measured using the trolox equivalent antioxidant capacity (TEAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric-reducing antioxidant power (FRAP) methods. The type of interaction was determined by interaction indexes and isobolograms. It was found that the weight ratio of extracts to AA significantly influenced the antioxidant activity of a mixture and the type of interaction between these components. The weight ratio of tea extract to AA can cause the change of interaction, e.g. from antagonism to additivism or from additivism to synergism. The observed differences in the type of interactions were probably also a result of different extracts' polyphenol composition and content. The type of interaction may also be affected by the medium in which extracts and AA interact, especially its pH and the solvent used. To obtain the best antioxidant effect, all these factors should be taken into account during the design of a tea extract-AA mixture.

  3. Follow the heart or the head? The interactive influence model of emotion and cognition

    PubMed Central

    Luo, Jiayi; Yu, Rongjun

    2015-01-01

    The experience of emotion has a powerful influence on daily-life decision making. Following Plato’s description of emotion and reason as two horses pulling us in opposite directions, modern dual-system models of decision making endorse the antagonism between reason and emotion. Decision making is perceived as the competition between an emotion system that is automatic but prone to error and a reason system that is slow but rational. The reason system (in “the head”) reins in our impulses (from “the heart”) and overrides our snap judgments. However, from Darwin’s evolutionary perspective, emotion is adaptive, guiding us to make sound decisions in uncertainty. Here, drawing findings from behavioral economics and neuroeconomics, we provide a new model, labeled “The interactive influence model of emotion and cognition,” to elaborate the relationship of emotion and reason in decision making. Specifically, in our model, we identify factors that determine when emotions override reason and delineate the type of contexts in which emotions help or hurt decision making. We then illustrate how cognition modulates emotion and how they cooperate to affect decision making. PMID:25999889

  4. Influence of Cu(II) on the interaction of sulfite with DNA

    NASA Astrophysics Data System (ADS)

    Guo, Dong-Sheng; Yuan, Xiao-Ying; Liang, Jie-Qing

    2006-10-01

    The quantitative influence of Cu(II) on the interaction of eukaryotic DNA with sulfite (SO 32-), which is a derivative of sulfur dioxide in the human body, was studied using ultraviolet (UV) absorption spectrometry. The results showed that under physiological pH conditions, SO 32- reacted weakly with DNA at concentrations of up to 10 -1 M, at which point a rapid increase in the reaction constant and the reaction number of SO 32- with DNA was observed. The addition of Cu(II) at concentrations ranging from 6.67 × 10 -4 to 3.33 × 10 -3 M to DNA-SO 32- binary systems increased the reaction constant of SO 32- with DNA 41- to 115-fold at a low concentration of SO 32- (10 -3 M), and 4- to 84-fold at an intermediate concentration of SO 32- (10 -2 M), but had little influence on the reaction number of SO 32- with DNA compared with the absence of Cu(II). When the concentration of SO 32- reached 10 -1 M, the presence of Cu(II) reduced the reaction number but had no effect on the reaction constant of SO 32- with DNA. These results show that the efficiency of SO 32- is increased in the presence of Cu(II) at high concentrations of SO 32-.

  5. PATTERNS IN SOIL FERTILITY AND ROOT HERBIVORY INTERACT TO INFLUENCE FINE-ROOT DYNAMICS.

    SciTech Connect

    Stevens, Glen, N.; Jones, Robert, H.

    2006-03-01

    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8–9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (,1.0 mm diameter), which comprised well over half of all root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P , 0.0001), with maximum biomass found where the treatments were combined (interaction term significant, P , 0.001). These results suggest that root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.

  6. Cannibalism as an interacting phenotype: precannibalistic aggression is influenced by social partners in the endangered Socorro Isopod (Thermosphaeroma thermophilum).

    PubMed

    Bleakley, B H; Welter, S M; McCauley-Cole, K; Shuster, S M; Moore, A J

    2013-04-01

    Models for the evolution of cannibalism highlight the importance of asymmetries between individuals in initiating cannibalistic attacks. Studies may include measures of body size but typically group individuals into size/age classes or compare populations. Such broad comparisons may obscure the details of interactions that ultimately determine how socially contingent characteristics evolve. We propose that understanding cannibalism is facilitated by using an interacting phenotypes perspective that includes the influences of the phenotype of a social partner on the behaviour of a focal individual and focuses on variation in individual pairwise interactions. We investigated how relative body size, a composite trait between a focal individual and its social partner, and the sex of the partners influenced precannibalistic aggression in the endangered Socorro isopod, Thermosphaeroma thermophilum. We also investigated whether differences in mating interest among males and females influenced cannibalism in mixed sex pairs. We studied these questions in three populations that differ markedly in range of body size and opportunities for interactions among individuals. We found that relative body size influences the probability of and latency to attack. We observed differences in the likelihood of and latency to attack based on both an individual's sex and the sex of its partner but found no evidence of sexual conflict. The instigation of precannibalistic aggression in these isopods is therefore a property of both an individual and its social partner. Our results suggest that interacting phenotype models would be improved by incorporating a new conditional ψ, which describes the strength of a social partner's influence on focal behaviour.

  7. The influence of source-receiver interaction on the numerical prediction of railway induced vibrations

    NASA Astrophysics Data System (ADS)

    Coulier, P.; Lombaert, G.; Degrande, G.

    2014-06-01

    The numerical prediction of vibrations in buildings due to railway traffic is a complicated problem where wave propagation in the soil couples the source (railway tunnel or track) and the receiver (building). This through-soil coupling is often neglected in state-of-the-art numerical models in order to reduce the computational cost. In this paper, the effect of this simplifying assumption on the accuracy of numerical predictions is investigated. A coupled finite element-boundary element methodology is employed to analyze the interaction between a building and a railway tunnel at depth or a ballasted track at the surface of a homogeneous halfspace, respectively. Three different soil types are considered. It is demonstrated that the dynamic axle loads can be calculated with reasonable accuracy using an uncoupled strategy in which through-soil coupling is disregarded. If the transfer functions from source to receiver are considered, however, large local variations in terms of vibration insertion gain are induced by source-receiver interaction, reaching up to 10 dB and higher, although the overall wave field is only moderately affected. A global quantification of the significance of through-soil coupling is made, based on the mean vibrational energy entering a building. This approach allows assessing the common assumption in seismic engineering that source-receiver interaction can be neglected if the distance between source and receiver is sufficiently large compared to the wavelength of waves in the soil. It is observed that the interaction between a source at depth and a receiver mainly affects the power flow distribution if the distance between source and receiver is smaller than the dilatational wavelength in the soil. Interaction effects for a railway track at grade are observed if the source-receiver distance is smaller than six Rayleigh wavelengths. A similar trend is revealed if the passage of a freight train is considered. The overall influence of dynamic

  8. Influence of nuclear interactions in body tissues on tumor dose in carbon-ion radiotherapy

    SciTech Connect

    Inaniwa, T. Kanematsu, N.; Tsuji, H.; Kamada, T.

    2015-12-15

    Purpose: In carbon-ion radiotherapy treatment planning, the planar integrated dose (PID) measured in water is applied to the patient dose calculation with density scaling using the stopping power ratio. Since body tissues are chemically different from water, this dose calculation can be subject to errors, particularly due to differences in inelastic nuclear interactions. In recent studies, the authors proposed and validated a PID correction method for these errors. In the present study, the authors used this correction method to assess the influence of these nuclear interactions in body tissues on tumor dose in various clinical cases. Methods: Using 10–20 cases each of prostate, head and neck (HN), bone and soft tissue (BS), lung, liver, pancreas, and uterine neoplasms, the authors first used treatment plans for carbon-ion radiotherapy without nuclear interaction correction to derive uncorrected dose distributions. The authors then compared these distributions with recalculated distributions using the nuclear interaction correction (corrected dose distributions). Results: Median (25%/75% quartiles) differences between the target mean uncorrected doses and corrected doses were 0.2% (0.1%/0.2%), 0.0% (0.0%/0.0%), −0.3% (−0.4%/−0.2%), −0.1% (−0.2%/−0.1%), −0.1% (−0.2%/0.0%), −0.4% (−0.5%/−0.1%), and −0.3% (−0.4%/0.0%) for the prostate, HN, BS, lung, liver, pancreas, and uterine cases, respectively. The largest difference of −1.6% in target mean and −2.5% at maximum were observed in a uterine case. Conclusions: For most clinical cases, dose calculation errors due to the water nonequivalence of the tissues in nuclear interactions would be marginal compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response. In some extreme cases, however, these errors can be substantial. Accordingly, this correction method should be routinely applied to treatment planning in clinical practice.

  9. Virial expansion with Feynman diagrams

    SciTech Connect

    Leyronas, X.

    2011-11-15

    We present a field theoretic method for the calculation of the second and third virial coefficients b{sub 2} and b{sub 3} of two-species fermions interacting via a contact interaction. The method is mostly analytic. We find a closed expression for b{sub 3} in terms of the two- and three-body T matrices. We recover numerically, at unitarity, and also in the whole Bose-Einstein-condensate-BCS crossover, previous numerical results for the third virial coefficient b{sub 3}.

  10. Influence of wind and lake morphometry on the interaction between two rivers entering a stratified lake

    USGS Publications Warehouse

    Morillo, S.; Imberger, J.; Antenucci, J.P.; Woods, P.F.

    2008-01-01

    The interaction of two rivers flowing into Coeur d'Alene Lake (United States) was investigated with a field experiment and three-dimensional numerical simulations. The focus was on the influence of basin morphology, wind speed, and wind direction on the fate and transport of the inflowing water. Data from the field campaign showed that intrusions from the two rivers propagated into the lake at different depths, with the trace element polluted Coeur d'Alene River flowing into the lake above the trace element poor and nutrient rich St. Joe River inflow. The inflows initially intruded horizontally into the lake at their level of neutral buoyancy and later mixed vertically. Model results revealed that, as the intrusions entered the main lake basin, a forced horizontal mode-two basin-scale internal wave interacted with the intrusions to frequently siphon them into the lake proper and where rapid vertical mixing followed. The results serve to show how detailed transport and mixing patterns in a lake can have important consequences for the plankton ecology in the lake. ?? 2008 ASCE.

  11. Influence of interactions between genes and childhood trauma on refractoriness in psychiatric disorders.

    PubMed

    Kim, Ji Sun; Lee, Seung-Hwan

    2016-10-03

    Psychiatric disorders are excellent disease models in which gene-environmental interaction play a significant role in the pathogenesis. Childhood trauma has been known as a significant environmental factor in the progress of, and prognosis for psychiatric illness. Patients with refractory illness usually have more severe symptoms, greater disability, lower quality of life and are at greater risk of suicide than other psychiatric patients. Our literature review uncovered some important clinical factors which modulate response to treatment in psychiatric patients who have experienced childhood trauma. Childhood trauma seems to be a critical determinant of treatment refractoriness in psychotic disorder, bipolar disorder, major depressive disorder, and post-traumatic stress disorder. In patients with psychotic disorders, the relationship between childhood trauma and treatment-refractoriness appears to be mediated by cognitive impairment. In the case of bipolar disorder, the relationship appears to be mediated by greater affective disturbance and earlier onset, while in major depressive disorder the mediating factors are persistent, severe symptoms and frequent recurrence. In suicidal individuals, childhood maltreatment was associated with violent suicidal attempts. In the case of PTSD patients, it appears that childhood trauma makes the brain more vulnerable to subsequent trauma, thus resulting in more severe, refractory symptoms. Given that several studies have suggested that there are distinct subtypes of genetic vulnerability to childhood trauma, it is important to understand how gene-environment interactions influence the course of psychiatric illnesses in order to improve therapeutic strategies.

  12. Complex contextual influences on the communicative interactions of students with multiple and severe disabilities.

    PubMed

    De Bortoli, Tania; Arthur-Kelly, Michael; Foreman, Phil; Balandin, Susan; Mathisen, Bernice

    2011-10-01

    The aim of this study was to explore teachers' perceptions and experiences of supports and obstacles to engaging students with multiple and severe disabilities (MSD) in communicative interactions at school. Eleven teachers of students with MSD participated in two in-depth interviews. Interview transcripts were analysed for narrative structure and content themes. Inter-coder reliability for coding of content themes was 87.5%. Participants identified a broad range of factors, including: characteristics of individual students, attitudes, perceptions and beliefs of teachers and other staff, class structure, staffing, opportunities for collegiality, resources, funding, infrastructure, collaboration with speech-language pathologists, appropriate communication education for teachers, the role of government departments, and broader societal factors. The findings suggest that there are complex contextual influences on the communicative interactions of students with MSD. While inadequate systemic supports appear to contribute to low frequencies of communication, systemic factors can be structured so that students participate in activities and have opportunities for communication. Further research is required with teachers of students with MSD to substantiate these findings.

  13. Flavor release and perception in hard candy: influence of flavor compound-compound interactions.

    PubMed

    Schober, Amanda L; Peterson, Devin G

    2004-05-05

    The influence of flavor compound-compound interactions on flavor release properties and flavor perception in hard candy was investigated. Hard candies made with two different modes of binary flavor delivery, (1) L-menthol and 1,8-cineole added as a mixture and (2) L-menthol and 1,8-cineole added separate from one another, were analyzed via breath analysis and sensory time-intensity testing. Single-flavor candy containing only L-menthol or 1,8-cineole was also investigated via breath analysis for comparison. The release rates of both L-menthol and 1,8-cineole in the breath were more rapid and at a higher concentration when the compounds were added to hard candy separate from one another in comparison to their addition as a mixture (conventional protocol). Additionally, the time-intensity study indicated a significantly increased flavor intensity (measured as overall cooling) for hard candy made with separate addition of these flavor compounds. In conclusion, the flavor properties of hard candy can be controlled, at least in part, by flavor compound-compound interactions and may be altered by the method of flavor delivery.

  14. Influence of Mg 2+ and Cd 2+ on the interaction between sparfloxacin and calf thymus DNA

    NASA Astrophysics Data System (ADS)

    Yuan, Xiao-Ying; Guo, Dong-Sheng; Wang, Lin-Li

    2008-04-01

    Mg 2+ and Cd 2+ have different binding capacity to sparfloxacin, and have different combination modes with calf thymus DNA. Selecting these two different metal ions, the influence of them on the binding constants between SPFX and calf thymus DNA, as well as the related mechanism have been studied by using absorption and fluorescence spectroscopy. The result shows that Cd 2+ has weak binding capacity to SPFX in the SPFX-Cd 2+ binary system, but can decrease the binding between SPFX and DNA obviously in SPFX-DNA-Cd 2+ ternary system. Mg 2+ has strong binding capacity to SPFX. It can increase the binding between SPFX and DNA at concentrations <0.01 mM, and decrease the binding between them at concentrations >0.01 mM. Referring to the different modes of Mg 2+ and Cd 2+ binding to DNA, the mechanism of the influence of metal ions on the binding between SPFX and DNA has been proposed. SPFX can directly bind to DNA by chelating DNA base sites. If a metal ion at certain concentration mainly binds to DNA bases, it can decrease the binding constants between SPFX and DNA through competing with SPFX. While if a metal ion at certain concentration mainly binds to phosphate groups of DNA, it can increase the binding constants by building a bridge between SPFX and DNA. The influence direction of metal ions on the binding between quinolone and DNA relays on their binding ratio of affinity for bases to phosphate groups on DNA. Our result supports Palumbo's conclusion that the binding between SPFX and the phosphate groups is the precondition for the combination between SPFX and DNA, which is stabilized through stacking interactions between the condensed rings of SPFX and DNA bases.

  15. Composition of extrafloral nectar influences interactions between the myrmecophyte Humboldtia brunonis and its ant associates.

    PubMed

    Shenoy, Megha; Radhika, Venkatesan; Satish, Suma; Borges, Renee M

    2012-01-01

    Ant-plant interactions often are mediated by extrafloral nectar (EFN) composition that may influence plant visitation by ants. Over a 300 km range in the Indian Western Ghats, we investigated the correlation between the EFN composition of the myrmecophytic ant-plant Humboldtia brunonis (Fabaceae) and the number and species of ants visiting EFN. EFN composition varied among H. brunonis populations and between plant organs (floral bud vs. young leaf EFN). In general, EFN was rich in sugars with small quantities of amino acids, especially essential amino acids, and had moderate invertase activity. In experiments at the study sites with sugar and amino acid solutions and with leaf or floral bud EFN mimics, dominant EFN-feeding ants differentiated between solutions as well as between mimics. The castration parasite Crematogaster dohrni (northern study site) was the least selective and did not exhibit any clear feeding preferences, while the largely trophobiont-tending non-protective Myrmicaria brunnea (middle study site) preferred higher sucrose concentrations and certain essential/non-essential amino acid mixtures. The mutualistic Technomyrmex albipes (southern study site) preferred sucrose over glucose or fructose solutions and consumed the leaf EFN mimic to a greater extent than the floral bud EFN mimic. This young leaf EFN mimic had low sugar concentrations, the lowest viscosity and sugar:amino acid ratio, was rich in essential amino acids, and appeared ideally suited to the digestive physiology of T. albipes. This preference for young leaf EFN may explain the greater protection afforded to young leaves than to floral buds by T. albipes, and may also help to resolve ant-pollinator conflicts. The differential response of dominant ants to sugar, amino acids, or solution viscosity suggests that plants can fine-tune their interactions with local ants via EFN composition. Thus, EFN can mediate local partner-choice mechanisms in ant-plant interactions.

  16. Consequences of complex environments: Temperature and energy intake interact to influence growth and metabolic rate.

    PubMed

    Stahlschmidt, Zachary R; Jodrey, Alicia D; Luoma, Rachel L

    2015-09-01

    The field of comparative physiology has a rich history of elegantly examining the effects of individual environmental factors on performance traits linked to fitness (e.g., thermal performance curves for locomotion). However, animals live in complex environments wherein multiple environmental factors co-vary. Thus, we investigated the independent and interactive effects of temperature and energy intake on the growth and metabolic rate of juvenile corn snakes (Pantherophis guttatus) in the context of shifts in complex environments. Unlike previous studies that imposed constant or fluctuating temperature regimes, we manipulated the availability of preferred thermal microclimates (control vs. relatively warm regimes) for eight weeks and allowed snakes to behaviorally thermoregulate among microclimates. By also controlling for energy intake, we demonstrate an interactive effect of temperature and energy on growth-relevant temperature shifts had no effect on snakes' growth when energy intake was low and a positive effect on growth when energy intake was high. Thus, acclimation to relatively warm thermal options can result in increased rates of growth when food is abundant in a taxon in which body size confers fitness advantages. Temperature and energy also interactively influenced metabolic rate-snakes in the warmer temperature regime exhibited reduced metabolic rate (O2 consumption rate at 25 °C and 30 °C) if they had relatively high energy intake. Although we advocate for continued investigation into the effects of complex environments on other traits, our results indicate that warming may actually benefit important life history traits in some taxa and that metabolic shifts may underlie thermal acclimation.

  17. Caffeine/nutrition interaction in the rat brain: Influence on latent inhibition and cortical spreading depression.

    PubMed

    de Aguiar, Márlison José Lima; de Aguiar, Cilene Rejane Ramos Alves; Guedes, Rubem Carlos Araújo

    2011-01-10

    Caffeine, like malnutrition, can produce behavioral and electrophysiological alterations. However, the interaction of both factors remains unclear. Here this interaction has been studied in male Wistar rats previously malnourished during the lactation period by feeding their dams the "regional basic diet" of Northeast Brazil, containing about 8% protein, predominantly from vegetable sources (RBD(8)). At 70-75days of life, a subset of the pups was treated intraperitoneally with 30mg/kg caffeine for 4days while being tested according to the behavioral model of latent inhibition. Another group was subjected to an electrophysiological recording of the phenomenon known as cortical spreading depression, and the effects of caffeine injected during the recording session were evaluated. Caffeine did not affect cortical spreading depression, but antagonized latent inhibition in both the RBD(8)-malnourished rats and in the well-nourished control group fed a chow diet with 22% protein. This effect of caffeine was not seen in malnourished rats fed a protein-supplemented RBD (protein increased to 22% by increasing the proportion of foodstuffs from vegetable origin; RBD(22) group), suggesting that the amino acid imbalance of this diet may modulate the caffeine effects on latent inhibition. The results indicate a differential effect of caffeine in the latent inhibition behavioral model, as compared to the cortical spreading depression phenomenon, and this effect is influenced by the early nutritional status of the animal. We suggest that caffeine may modulate dopaminergic subcortical receptors participating in attention processes, but does not interact at the cortical level, in a way that would affect cortical spreading depression.

  18. Veitch diagram plotter simplifies Boolean functions

    NASA Technical Reports Server (NTRS)

    Rubin, D. K.

    1964-01-01

    This device for simplifying the plotting of a Veitch diagram consists of several overlays for blocking out the unwanted squares. This method of plotting the various input combinations to a computer is used in conjunction with the Boolean functions.

  19. Some Geometric Aspects of the Ternary Diagram.

    ERIC Educational Resources Information Center

    Philip, G. M.; Watson, D. F.

    1989-01-01

    Uses the process of normalization in the Cartesian coordinate system which entails radial projection onto a transect to compare different compositions of minerals. Warns that the ternary diagram should not be used as a framework for calculations. (MVL)

  20. An Improved Mnemonic Diagram for Thermodynamic Relationships.

    ERIC Educational Resources Information Center

    Rodriguez, Joaquin; Brainard, Alan J.

    1989-01-01

    Considers pressure, volume, entropy, temperature, Helmholtz free energy, Gibbs free energy, enthalpy, and internal energy. Suggests the mnemonic diagram is for use with simple systems that are defined as macroscopically homogeneous, isotropic, uncharged, and chemically inert. (MVL)

  1. Lattice and Phase Diagram in QCD

    SciTech Connect

    Lombardo, Maria Paola

    2008-10-13

    Model calculations have produced a number of very interesting expectations for the QCD Phase Diagram, and the task of a lattice calculations is to put these studies on a quantitative grounds. I will give an overview of the current status of the lattice analysis of the QCD phase diagram, from the quantitative results of mature calculations at zero and small baryochemical potential, to the exploratory studies of the colder, denser phase.

  2. [Factors influencing activity of oral anticoagulants. Interactions with drugs and food].

    PubMed

    Sawicka-Powierza, Jolanta; Rogowska-Szadkowska, Dorota; Ołtarzewska, Alicja Małgorzata; Chlabicz, Sławomir

    2008-05-01

    Oral anticoagulants (OAC) are commonly used as a life-long therapy in prevention of systemic embolism in patients with atrial fibrillation, valvular heart disease and prosthetic hart valves and in the primary and secondary prevention of venous thromboembolism. They are also used for the prevention of thromboembolic events in patients with acute myocardial infarction and with angina pectoris, in patients with biological hart valves and after some types of orthopaedics surgery. The International Normalized Ratio (INR) is used to evaluate the efficacy of anti-coagulant therapy. The risk of thromboembolic and haemorrhagic complications increases when the INR is out of the therapeutic range. The aim of this study was to present information about the factors influencing activity of oral anticoagulants and interactions between oral anticoagulants and drugs or food. The effect of oral anticoagulants is influenced by genetic and environmental factors such as: medicines, food, diseases and pre-existing conditions. A common mutation in the gene coding for the cytochrome P450 (CYP2C9), with one or more combinations of its polymorphisms, is responsible for the reduced warfarin requirements or for the resistance to warfarin. A mutation in the factor IX is responsible for the risk of bleeding during OAC therapy without excessive prolongation of the prothrombin time (PT). Drugs, herbs and multivitamin supplements can alter the absorption, pharmacokinetics or pharmakodynamics of OAC. Nonsteroid anti-inflammatory drugs and paracetamol in combination with OAC seem to be the most dangerous because they are available without prescription and are used without medical consultation. Patients on OAC therapy are sensitive to changing dietary intake of vitamin K, which is supplied from phylloquinones in plants or from vitamin K-containing medicines. The effect of OAC can be influenced by other existing factors like: fever, diarrhoea, alcohol abuse or physical hyperactivity. Some malignancies

  3. The influence of instructional interactions on students’ mental models about the quantization of physical observables: a modern physics course case

    NASA Astrophysics Data System (ADS)

    Didiş Körhasan, Nilüfer; Eryılmaz, Ali; Erkoç, Şakir

    2016-01-01

    Mental models are coherently organized knowledge structures used to explain phenomena. They interact with social environments and evolve with the interaction. Lacking daily experience with phenomena, the social interaction gains much more importance. In this part of our multiphase study, we investigate how instructional interactions influenced students’ mental models about the quantization of physical observables. Class observations and interviews were analysed by studying students’ mental models constructed in a modern physics course during an academic semester. The research revealed that students’ mental models were influenced by (1) the manner of teaching, including instructional methodologies and content specific techniques used by the instructor, (2) order of the topics and familiarity with concepts, and (3) peers.

  4. An analytical master curve for Goodman diagram data

    NASA Astrophysics Data System (ADS)

    Berkovits, A.; Fang, D.

    1993-05-01

    Estimation of the remaining safe life of structural parts which are not easily inspectable continues to be a problem. Even when load histories are available, laborious interpolation of Goodman diagram data is required in order to determine the remaining fatigue life of such parts. An analytical formulation of Goodman diagram data would expedite the life check. It is shown in this paper that, for many engineering materials at room temperature, the entire range of Goodman diagram data collapses on to a single master curve when presented as the ratio of lifetime with mean stress to lifetime at R = -1 for a given stress amplitude, as a function of a non-dimensional load parameter consisting of stress amplitude, mean stress, and material strength. The master curve is conveniently expressed in terms of two easily determined Weibull constants. Stress-concentration factor influences the value of the constants, as does the strain-rate sensitivity of some materials. By use of the master curve formula in an algorithm together with the Manson-Coffin life relation and Miner cumulative damage rule, computed fatigue lives lay within a factor of 2 of results obtained in tests under aircraft spectrum loads.

  5. The effective QCD phase diagram and the critical end point

    NASA Astrophysics Data System (ADS)

    Ayala, Alejandro; Bashir, Adnan; Cobos-Martínez, J. J.; Hernández-Ortiz, Saúl; Raya, Alfredo

    2015-08-01

    We study the QCD phase diagram on the temperature T and quark chemical potential μ plane, modeling the strong interactions with the linear sigma model coupled to quarks. The phase transition line is found from the effective potential at finite T and μ taking into account the plasma screening effects. We find the location of the critical end point (CEP) to be (μCEP /Tc, TCEP /Tc) ∼ (1.2, 0.8), where Tc is the (pseudo)critical temperature for the crossover phase transition at vanishing μ. This location lies within the region found by lattice inspired calculations. The results show that in the linear sigma model, the CEP's location in the phase diagram is expectedly determined solely through chiral symmetry breaking. The same is likely to be true for all other models which do not exhibit confinement, provided the proper treatment of the plasma infrared properties for the description of chiral symmetry restoration is implemented. Similarly, we also expect these corrections to be substantially relevant in the QCD phase diagram.

  6. Above–Belowground Herbivore Interactions in Mixed Plant Communities Are Influenced by Altered Precipitation Patterns

    PubMed Central

    Ryalls, James M. W.; Moore, Ben D.; Riegler, Markus; Johnson, Scott N.

    2016-01-01

    Root- and shoot-feeding herbivores have the capacity to influence one another by modifying the chemistry of the shared host plant. This can alter rates of nutrient mineralization and uptake by neighboring plants and influence plant–plant competition, particularly in mixtures combining grasses and legumes. Root herbivory-induced exudation of nitrogen (N) from legume roots, for example, may increase N acquisition by co-occurring grasses, with knock-on effects on grassland community composition. Little is known about how climate change may affect these interactions, but an important and timely question is how will grass–legume mixtures respond in a future with an increasing reliance on legume N mineralization in terrestrial ecosystems. Using a model grass–legume mixture, this study investigated how simultaneous attack on lucerne (Medicago sativa) by belowground weevils (Sitona discoideus) and aboveground aphids (Acyrthosiphon pisum) affected a neighboring grass (Phalaris aquatica) when subjected to drought, ambient, and elevated precipitation. Feeding on rhizobial nodules by weevil larvae enhanced soil water retention under ambient and elevated precipitation, but only when aphids were absent. While drought decreased nodulation and root N content in lucerne, grass root and shoot chemistry were unaffected by changes in precipitation. However, plant communities containing weevils but not aphids showed increased grass height and N concentrations, most likely associated with the transfer of N from weevil-attacked lucerne plants containing more nodules and higher root N concentrations compared with insect-free plants. Drought decreased aphid abundance by 54% but increased total and some specific amino acid concentrations (glycine, lysine, methionine, tyrosine, cysteine, histidine, arginine, aspartate, and glutamate), suggesting that aphid declines were being driven by other facets of drought (e.g., reduced phloem hydraulics). The presence of weevil larvae belowground

  7. Bidirectional psychoneuroimmune interactions in the early postpartum period influence risk of postpartum depression.

    PubMed

    Corwin, Elizabeth J; Pajer, Kathleen; Paul, Sudeshna; Lowe, Nancy; Weber, Mary; McCarthy, Donna O

    2015-10-01

    More than 500,000 U.S. women develop postpartum depression (PPD) annually. Although psychosocial risks are known, the underlying biology remains unclear. Dysregulation of the immune inflammatory response and the hypothalamic-pituitary-adrenal (HPA) axis are associated with depression in other populations. While significant research on the contribution of these systems to the development of PPD has been conducted, results have been inconclusive. This is partly because few studies have focused on whether disruption in the bidirectional and dynamic interaction between the inflammatory response and the HPA axis together influence PPD. In this study, we tested the hypothesis that disruption in the inflammatory-HPA axis bidirectional relationship would increase the risk of PPD. Plasma pro- and anti-inflammatory cytokines were measured in women during the 3rd trimester of pregnancy and on Days 7 and 14, and Months 1, 2, 3, and 6 after childbirth. Saliva was collected 5 times the day preceding blood draws for determination of cortisol area under the curve (AUC) and depressive symptoms were measured using the Edinburgh Postpartum Depression Survey (EPDS). Of the 152 women who completed the EPDS, 18% were depressed according to EDPS criteria within the 6months postpartum. Cortisol AUC was higher in symptomatic women on Day 14 (p=.017). To consider the combined effects of cytokines and cortisol on predicting symptoms of PPD, a multiple logistic regression model was developed that included predictors identified in bivariate analyses to have an effect on depressive symptoms. Results indicated that family history of depression, day 14 cortisol AUC, and the day 14 IL8/IL10 ratio were significant predictors of PPD symptoms. One unit increase each in the IL8/IL10 ratio and cortisol AUC resulted in 1.50 (p=0.06) and 2.16 (p=0.02) fold increases respectively in the development of PPD. Overall, this model correctly classified 84.2% of individuals in their respective groups. Findings

  8. Cognitive Workload and Sleep Restriction Interact to Influence Sleep Homeostatic Responses

    PubMed Central

    Goel, Namni; Abe, Takashi; Braun, Marcia E.; Dinges, David F.

    2014-01-01

    responses by increasing subjective fatigue and sleepiness, and producing a global sleep homeostatic response by reducing wake after sleep onset. When combined with sleep restriction, high workload increased local (occipital) sleep homeostasis, suggesting a use-dependent sleep response to visual work. We conclude that sleep restriction and cognitive workload interact to influence sleep homeostasis. Citation: Goel N, Abe T, Braun ME, Dinges DF. Cognitive workload and sleep restriction interact to influence sleep homeostatic responses. SLEEP 2014;37(11):1745-1756. PMID:25364070

  9. Relative Influences: Patterns of HPA Axis Concordance During Triadic Family Interaction

    PubMed Central

    Saxbe, Darby E.; Margolin, Gayla; Shapiro, Lauren Spies; Ramos, Michelle; Rodriguez, Aubrey; Iturralde, Esti

    2015-01-01

    Objective Within-family concordance in physiology may have implications for family system functioning and for individual health outcomes. Here, we examine patterns of association in cortisol within family triads. Methods A total of 103 adolescents and their parents sampled saliva at multiple timepoints before and after a conflict discussion task. We explored whether within-family associations existed and were moderated by stepparent presence and youth gender, and whether within-family patterns of influence correlated with individuals’ aggregate cortisol. Results Across the laboratory visit, the cortisol levels of fathers, mothers, and youth were positively associated. In time-lagged models, mothers’ cortisol predicted fathers’ cortisol levels sampled at the following timepoint, whereas fathers’ predicted youths’ and youths’ predicted mothers’ cortisol. These patterns appeared stronger in families not including stepparents. Youth gender moderated some associations: in the aggregate, youth were more strongly linked with their same-gender parent. In time-lagged models, girls were more closely linked to their mothers than boys, and both parents were more linked to girls. Youth showed higher aggregate cortisol output if they were more linked with their mothers, and lower output if more linked with their fathers; parents had higher output if they were more linked with their spouses and lower output if more linked with their children. Conclusions These results suggest that family members’ physiological activation may be linked during shared interaction, and that these patterns may be affected by family role and by youth gender. Our findings identify specific patterns of physiological influence within families that may inform family systems theories. PMID:23914815

  10. A study of the influence of forest gaps on fire-atmosphere interactions

    NASA Astrophysics Data System (ADS)

    Kiefer, Michael T.; Heilman, Warren E.; Zhong, Shiyuan; Charney, Joseph J.; Bian, Xindi

    2016-07-01

    Much uncertainty exists regarding the possible role that gaps in forest canopies play in modulating fire-atmosphere interactions in otherwise horizontally homogeneous forests. This study examines the influence of gaps in forest canopies on atmospheric perturbations induced by a low-intensity fire using the ARPS-CANOPY model, a version of the Advanced Regional Prediction System (ARPS) model with a canopy parameterization. A series of numerical experiments are conducted with a stationary low-intensity fire, represented in the model as a line of enhanced surface sensible heat flux. Experiments are conducted with and without forest gaps, and with gaps in different positions relative to the fire line. For each of the four cases considered, an additional simulation is performed without the fire to facilitate comparison of the fire-perturbed atmosphere and the background state. Analyses of both mean and instantaneous wind velocity, turbulent kinetic energy, air temperature, and turbulent mixing of heat are presented in order to examine the fire-perturbed atmosphere on multiple timescales. Results of the analyses indicate that the impact of the fire on the atmosphere is greatest in the case with the gap centered on the fire and weakest in the case with the gap upstream of the fire. It is shown that gaps in forest canopies have the potential to play a role in the vertical as well as horizontal transport of heat away from the fire. Results also suggest that, in order to understand how the fire will alter wind and turbulence in a heterogeneous forest, one needs to first understand how the forest heterogeneity itself influences the wind and turbulence fields without the fire.

  11. Influence of the Soil-Structure Interaction on the Design of Steel-Braced Building Foundation

    NASA Astrophysics Data System (ADS)

    Azarbakht, Alireza; Ashtiany, Mohsen Ghafory

    2008-07-01

    The modeling and analysis of the superstructure and the foundation for the seismic lateral loads are traditionally done separately. This assumption is an important issue in the design/rehabilitate procedures especially for the short period structures, i.e. steel braced or shear wall systems, which may result to a conservative design. By using more advance procedures, i.e. nonlinear static method, and the incorporation of the soil-structure interaction (SSI), the seismic demand in the lateral resisting system decreases and the design will become more economic. This paper includes an investigation about the influence of the SSI effect on the design of the steel-braced building foundation. The presented example is a three-bay three-storey steel braced frame. Three design methods based on the FEMA 356 guideline and the UBC 97 code are taken in to consideration. The three methods are: (1) linear static analysis based on the UBC 97 code assuming the fixed based condition; (2) linear static analysis based on the FEMA 356 guideline assuming the fixed based condition; and (3) nonlinear static analysis assuming both fixed and flexible based assumptions. The results show that the influence of the SSI on the input demand of the short period building foundations is significant and the foundation design based on the linear static method with the fixed base assumption is so conservative. A simple method is proposed to take the SSI effect in to consideration in the linear static procedure with the fixed base assumption, which is a common method for the engineers. The advantage of this proposed method is the simplicity and the applicability for the engineering purposes.

  12. Influence of the Soil-Structure Interaction on the Design of Steel-Braced Building Foundation

    SciTech Connect

    Azarbakht, Alireza; Ashtiany, Mohsen Ghafory

    2008-07-08

    The modeling and analysis of the superstructure and the foundation for the seismic lateral loads are traditionally done separately. This assumption is an important issue in the design/rehabilitate procedures especially for the short period structures, i.e. steel braced or shear wall systems, which may result to a conservative design. By using more advance procedures, i.e. nonlinear static method, and the incorporation of the soil-structure interaction (SSI), the seismic demand in the lateral resisting system decreases and the design will become more economic. This paper includes an investigation about the influence of the SSI effect on the design of the steel-braced building foundation. The presented example is a three-bay three-storey steel braced frame. Three design methods based on the FEMA 356 guideline and the UBC 97 code are taken in to consideration. The three methods are: (1) linear static analysis based on the UBC 97 code assuming the fixed based condition; (2) linear static analysis based on the FEMA 356 guideline assuming the fixed based condition; and (3) nonlinear static analysis assuming both fixed and flexible based assumptions. The results show that the influence of the SSI on the input demand of the short period building foundations is significant and the foundation design based on the linear static method with the fixed base assumption is so conservative. A simple method is proposed to take the SSI effect in to consideration in the linear static procedure with the fixed base assumption, which is a common method for the engineers. The advantage of this proposed method is the simplicity and the applicability for the engineering purposes.

  13. Host-guest interaction and structural ordering in polymeric nanoassemblies: Influence of molecular design.

    PubMed

    Antoniuk, Iurii; Plazzotta, Beatrice; Wintgens, Véronique; Volet, Gisèle; Nielsen, Thorbjørn T; Pedersen, Jan Skov; Amiel, Catherine

    2017-02-24

    Host-guest nanoassemblies made from spontaneous self-association of host and guest polymers in aqueous solutions have been studied. The specific motivation behind this work was to clarify the impact of the molecular design of the polymers on the interactions between them and on the inner structure of the resulting nanoassemblies. The polymers were composed of a dextran backbone, functionalized with either pendant β-cyclodextrin (CD) or adamantyl (Ada). Those groups were connected to the backbone either directly or with hydrophilic polyethylene glycol (PEG) spacers. To study the impact of those spacers we have proposed a synthetic pathway to new guest polymers. The latter relied on the use of thiol-substituted dextrans as a scaffold, which is subsequently transformed into PEG-Ada grafted guest polymers via nucleophile-mediated thiol-click reaction. Surface plasmon resonance (SPR) studies evidenced strong mutual affinities between the host and guest polymers and showed that the stoichiometry was close to the ideal one (CD/Ada = 1/1) when PEG spacers were introduced. The structure of the nanoassemblies was studied by a combination of dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). The nature of the individual host or guest polymers has a strong impact on the size and internal structure of the resulting nanoassemblies. The presence of PEG spacers in the polymers led to smaller and less compact nanoassemblies, as evidenced by their large correlation length values (4-20nm compared to 2nm without PEG spacers). At the same time, all types of nanoassemblies appear to have radial density distribution with denser cores and pending polymer chains at the periphery. This study, centered on the influence of the molecular design on the host-guest interactions and structural ordering in polymeric nanoassemblies, will help to tailor host-guest nanoassemblies with attractive drug delivery profiles.

  14. Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

    PubMed

    Greene, Ciara M; Flannery, Oliver; Soto, David

    2014-12-01

    The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

  15. Influence of olive oil phenolic compounds on headspace aroma release by interaction with whey proteins.

    PubMed

    Genovese, Alessandro; Caporaso, Nicola; De Luca, Lucia; Paduano, Antonello; Sacchi, Raffaele

    2015-04-22

    The release of volatile compounds in an oil-in-water model system obtained from olive oil-whey protein (WP) pairing was investigated by considering the effect of phenolic compounds. Human saliva was used to simulate mouth conditions by retronasal aroma simulator (RAS) analysis. Twelve aroma compounds were quantified in the dynamic headspace by SPME-GC/MS. The results showed significant influences of saliva on the aroma release of virgin olive oil (VOO) volatiles also in the presence of WP. The interaction between WP and saliva leads to lower headspace release of ethyl esters and hexanal. Salivary components caused lower decrease of the release of acetates and alcohols. A lower release of volatile compounds was found in the RAS essay in comparison to that in orthonasal simulation of only refined olive oil (without addition of saliva or WP), with the exception of hexanal and 1-penten-3-one, where a significantly higher release was found. Our results suggest that the extent of retronasal odor (green, pungent) of these two volatile compounds is higher than orthonasal odor. An extra VOO was used to verify the release in model systems, indicating that WP affected aroma release more than model systems, while saliva seems to exert an opposite trend. A significant increase in aroma release was found when phenolic compounds were added to the system, probably due to the contrasting effects of binding of volatile compounds caused by WP, for the polyphenol-protein interaction phenomenon. Our study could be applied to the formulation of new functional foods to enhance flavor release and modulate the presence and concentrations of phenolics and whey proteins in food emulsions/dispersions.

  16. Smelling is Telling: Human Olfactory Cues Influence Social Judgments in Semi-Realistic Interactions.

    PubMed

    Gaby, Jessica M; Zayas, Vivian

    2017-03-29

    How does a person's smell affect others' impressions of them? Most body odor research asks perceivers to make social judgments based on armpit sweat without perfume or deodorant, presented on t-shirts. Yet, in real life, perceivers encounter fragranced body odor, on whole bodies. Our "raters" wore blindfolds and earplugs and repeatedly smelled same-sex "donors" in live interactions. In one condition, donors wore their normal deodorant and perfume ("diplomatic" odor) while in the other condition, donors were asked to avoid all outside fragrance influences ("natural" odor). We assessed the reliability of social judgments based on such live interactions, and the relationships between live judgments and traditional t-shirt based judgments, and between natural- and diplomatic odor-based judgments. Raters' repeated live social judgments (e.g., friendliness, likeability) were highly consistent for both diplomatic and natural odor, and converged with judgments based on t-shirts. However, social judgments based on natural odor did not consistently predict social judgments based on diplomatic odor, suggesting that natural and diplomatic body odor may convey different types of social information. Our results provide evidence that individuals can perceive reliable, meaningful social olfactory signals from whole bodies, at social distances, regardless of the presence or absence of perfume. Importantly, however, the social value of these signals is modified by the addition of exogenous fragrances. Further, our focus on judgments in same-sex dyads suggests that these olfactory cues hold social value in non-mating contexts. We suggest that future research employ more ecologically relevant methods.

  17. MAOA uVNTR and Early Physical Discipline Interact to Influence Delinquent Behavior

    PubMed Central

    Edwards, Alexis C.; Dodge, Kenneth A.; Latendresse, Shawn J.; Lansford, Jennifer E.; Bates, John E.; Pettit, Gregory S.; Budde, John P.; Goate, Alison M.; Dick, Danielle M.

    2011-01-01

    Background A functional polymorphism in the promoter region of the monoamine oxidizing gene monoamine oxidase A (MAOA) has been associated with behavioral sensitivity to adverse environmental conditions in multiple studies (e.g., Caspi et al. 2002, Kim-Cohen et al. 2006). The present study investigates the effects of genotype and early physical discipline on externalizing behavior. We expand on the current literature in our assessment of externalizing, incorporating information across multiple reporters and over a broad developmental time period, and in our understanding of environmental risk. Method This study uses data from the Child Development Project, an ongoing longitudinal study following a community sample of children beginning at age 5. Physical discipline before age 6 was quantified using a subset of questions from the Conflict Tactics Scale (Straus 1979). Externalizing behavior was assessed in the male, European-American sub-sample (N=250) by parent, teacher, and self report using Achenbach’s Child Behavior Checklist, Teacher Report Form, and Youth Self-Report (Achenbach 1991), at 17 time points from ages 6 to 22. Regression analyses tested the influence of genotype, physical discipline, and their interaction on externalizing behavior, and its subscales, delinquency and aggression. Results We found a significant interaction effect between genotype and physical discipline on levels of delinquent behavior. Similar trends were observed for aggression and overall externalizing behavior, although these did not reach statistical significance. Main effects of physical discipline held for all outcome variables, and no main effects held for genotype. Conclusion The adverse consequences of physical discipline on forms of externalizing behavior are exacerbated by an underlying biological risk conferred by MAOA genotype. PMID:19951362

  18. Thermal fluctuations and phase diagrams of the phase-field crystal model with pinning.

    PubMed

    Ramos, J A P; Granato, E; Achim, C V; Ying, S C; Elder, K R; Ala-Nissila, T

    2008-09-01

    We study the influence of thermal fluctuations in the phase diagram of a recently introduced two-dimensional phase field crystal model with an external pinning potential. The model provides a continuum description of pinned lattice systems allowing for both elastic deformations and topological defects. We introduce a nonconserved version of the model and determine the ground-state phase diagram as a function of lattice mismatch and strength of the pinning potential. Monte Carlo simulations are used to determine the phase diagram as a function of temperature near commensurate phases. The results show a rich phase diagram with commensurate, incommensurate, and liquidlike phases with a topology strongly dependent on the type of ordered structure. A finite-size scaling analysis of the melting transition for the c(2x2) commensurate phase shows that the thermal correlation length exponent nu and specific heat behavior are consistent with the Ising universality class as expected from analytical arguments.

  19. Influence of mechanical stress and surface interaction on the aggregation of Aspergillus niger conidia.

    PubMed

    Grimm, L H; Kelly, S; Völkerding, I I; Krull, R; Hempel, D C

    2005-12-30

    Productivity of fungal cultures is closely linked with their morphologic development. Morphogenesis of coagulating filamentous fungi, like Aspergillus niger, starts with aggregation of conidia, also denominated as spores. Several parameters are presumed to control this event, but little is known about their mode of action. Rational process optimization requires models that mirror the underlying reaction mechanisms. An approach in this regard is suggested and supported by experimental data. Aggregation kinetics was examined for the first 15 h of cultivation under different cultivation conditions. Mechanical stress was considered as well as pH-dependent surface interaction. Deliberations were based on a two-step aggregation mechanism. The first aggregation step is only affected by the pH-value, not by the fluid dynamic conditions in the bioreactor. The second aggregation step, in contrast, depends on the pH-value as well as on agitation and aeration induced power input. For the given experimental set-up, agitation had much more influence than aeration. In addition, hyphal growth rate was determined to be the driving force for the second aggregation step.

  20. How do interactions between early caregiving environment and genes influence health and behavior?

    PubMed

    Letourneau, Nicole; Giesbrecht, Gerald F; Bernier, Francois P; Joschko, Justin

    2014-01-01

    To promote optimal health and behavioral outcomes in children, nurses have long supported parents in providing the best possible care and nurturance to their offspring. A growing body of neuroscience research argues convincingly for the combined influences of genes and early caregiving on producing an individual's unique health and behavioral phenotype. In this article, we systematically review studies that demonstrate the relationship between qualities of early caregiving and genetic propensity to health and behavioral outcomes. From an initial set of 255 articles, 24 articles met our inclusion criteria. The outcomes fall into four distinct groups: hypothalamic-pituitary-adrenal (HPA) response to stress, externalizing behavior, internalizing behavior, and disorganized attachment. In the articles, authors examined genes that code for the 5-hydroxy tryptamine (serotonin) transporter genes linked polymorphic region [5-HTTLPR] serotonin transporter promoter, D4 dopamine receptor, brain-derived neurotrophic factor, and monoamine oxidase A promoter. The reviewed studies suggest that the effect of the early rearing environment on gene expression relates mainly to HPA response to stress, whereas interactions between genes and caregiving mainly relate to behavior and attachment. Findings have implications for nurses focused on advocacy, prevention, and intervention to support the healthy development of children in families faced with adversity.

  1. Influence of biogeochemical interactions on metal bioleaching performance in contaminated marine sediment.

    PubMed

    Fonti, Viviana; Dell'Anno, Antonio; Beolchini, Francesca

    2013-09-15

    Bioleaching strategies are still far from finding real applications in sediment clean-up, although metabolic mechanisms governing bioleaching processes have been deeply studied and can be considered well established. In this study, we carried out bioleaching experiments, using autotrophic and heterotrophic acidophilic bacteria strains, and worked with marine sediments characterized by different geochemical properties and metal concentrations and speciations. The solubilization efficiency of the metals was highly variable, with the highest for Zn (40%-76%) and the lowest for Pb (0%-7%). Our data suggest that the role of autotrophic Fe/S oxidizing bacteria is mainly associated with the production and re-cycling of leaching chemical species, mainly as protons and ferric ions. Metal solubilization appears to be more related to establishing environmental conditions that allow each metal or semimetal to remain stable in the solution phase. Thus, the maintenance of acid and oxidative conditions, the chemical behavior in aqueous environment of each metal species and the geochemical characteristics of sediment interact intimately to influence metal solubilization in site-specific and metal-specific way.

  2. Interaction with a high-versus low-competence influence source in inductive reasoning.

    PubMed

    Butera, Fabrizio; Caverni, Jean-Paul; Rossi, Sandrine

    2005-04-01

    Literature on inductive reasoning shows that when testing hypotheses, people are biased toward the use of confirmatory strategies (P. C. Wason, 1960). In the present article, the authors presented 2 studies showing how people use confirmation and disconfirmation strategies during actual interaction in problem solving. Study 1 showed that participants were able to learn to use disconfirmation when confronted with a low-competence, nonthreatening partner. When the partner was high in competence (thereby threatening the participant's competence), participants used confirmation, even when the partner used disconfirmation. In Study 2, the authors aimed at generalizing the aforementioned results by exploring the hypothesis that disconfirmation stems from the possibility of diverging from norms. Participants who were confronted with the violation of a conversational norm used a high proportion of disconfirmation, whatever the source of influence. When there was no violation but there was a low-competence partner, the proportion of disconfirmation was high; when there was no violation but there was a high-competence partner, the proportion of disconfirmation was low. The authors discussed the interpersonal functions of confirmation and disconfirmation.

  3. Interaction of Tissue Engineering Substrates with Serum Proteins and Its Influence on Human Primary Endothelial Cells.

    PubMed

    Mohan, Tamilselvan; Niegelhell, Katrin; Nagaraj, Chandran; Reishofer, David; Spirk, Stefan; Olschewski, Andrea; Stana Kleinschek, Karin; Kargl, Rupert

    2017-02-13

    Polymer-based biomaterials particularly polycaprolactone (PCL) are one of the most promising substrates for tissue engineering. The surface chemistry of these materials plays a major role since it governs protein adsorption, cell adhesion, viability, degradation, and biocompatibility in the first place. This study correlates the interaction of the most abundant serum proteins (albumin, immunoglobulins, fibrinogen) with the surface properties of PCL and its influence on the morphology and metabolic activity of primary human arterial endothelial cells that are seeded on the materials. Prior to that, thin films of PCL are manufactured by spin-coating and characterized in detail. A quartz crystal microbalance with dissipation (QCM-D), a multiparameter surface plasmon resonance spectroscopy instrument (MP-SPR), wettability data, and atomic force microscopy are combined to elucidate the pH-dependent protein adsorption on the PCL substrates. Primary endothelial cells are cultured on the protein modified polymer, and conclusions are drawn on the significant impact of type and form of proteins coatings on cell morphology and metabolic activity.

  4. Influence of the composition of cement kiln dust on its interaction with fly ash and slag

    SciTech Connect

    Chaunsali, Piyush; Peethamparan, Sulapha

    2013-12-15

    Cement kiln dust (CKD), a by-product of the cement industry, contains significant amounts of alkali, free lime, chloride and sulfate. Wide variation reported in the chemical composition of CKDs limits their potential application as a sustainable binder component in concrete. In the current study, the performance of two different CKDs as components in a novel binder is evaluated. Several binders are developed by blending CKDs with fly ash or slag. Binders with 70% CKD were prepared at a water-to-binder ratio of 0.4, and heat-cured at 75 °C to accelerate the strength development. The hydration progress was monitored using X-ray diffraction, and morphological examination was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Ettringite and calcium aluminosilicate hydrate (C-A-S-H) were identified as the main hydration products in the hardened binder system. Strength development of CKD-based binder was found to be significantly influenced by its free lime and sulfate contents. -- Highlights: •Interaction of cement kiln dust with fly ash and slag was explored. •CKD with higher free lime and sulfate content increased the strength of binder. •C-S-H like reaction gel with fibrillar morphology is observed in CKD-based binders.

  5. Quality of interactions influences everyday life in psychiatric inpatient care—patients’ perspectives

    PubMed Central

    Molin, Jenny; Graneheim, Ulla H.; Lindgren, Britt-Marie

    2016-01-01

    Everyday life consists of daily activities that are taken for granted. It forms the foundation for human efforts and contains elements of both comfort and boredom. Because everyday life escapes no one, life in a psychiatric ward will become ordinary while staying there. This study aims to explore everyday life in psychiatric inpatient care based on patients’ experiences. We individually interviewed 16 participants with experiences of psychiatric inpatient care and analysed the data in accordance with the methods of grounded theory. Data collection and analysis continued in parallel in accordance with the method. Our results showed that everyday life is linked to the core category quality of interactions influences everyday life, and three constructed categories—staff makes the difference, looking for shelter in a stigmatizing environment, and facing a confusing care content—were related to the core category. Our results highlight the importance of ordinary relationships between staff and patients in psychiatric inpatient care. These results can be used to develop nursing interventions to improve psychiatric inpatient care and might also be used as a basis for reflective dialogues among staff. PMID:26806313

  6. Cholecystokinin and endogenous opioid peptides: interactive influence on pain, cognition, and emotion.

    PubMed

    Hebb, Andrea L O; Poulin, Jean-François; Roach, Sean P; Zacharko, Robert M; Drolet, Guy

    2005-12-01

    It is well documented that stressful life experiences contribute to the etiology of human mood disorders. Cholecystokinin (CCK) is a neuropeptide found in high concentrations throughout the central nervous system, where it is involved in numerous physiological functions. A role for CCK in the induction and persistence of anxiety and major depression appears to be conspicuous. While increased CCK has been associated with motivational loss, anxiety and panic attacks, an increase in mesocorticolimbic opioid availability has been associated with coping and mood elevation. The close neuroanatomical distribution of CCK with opioid peptides in the limbic system suggests that there may be an opioid-CCK link in the modulation and expression of anxiety or stressor-related behaviors. In effect, while CCK induces relatively protracted behavioral disturbances in both animal and human subjects following stressor applications, opioid receptor activation may change the course of psychopathology. The antagonistic interaction of CCK and opioid peptides is evident in psychological disturbances as well as stress-induced analgesia. There appears to be an intricate balance between the memory-enhancing and anxiety-provoking effects of CCK on one hand, and the amnesic and anxiolytic effects of opioid peptides on the other hand. Potential anxiogenic and mnemonic influences of site-specific mesocorticolimbic CCK and opioid peptide availability, the relative contributions of specific CCK and opioid receptors, as well as the time course underlying neuronal substrates of long-term behavioral disturbances as a result of stressor manipulations, are discussed.

  7. Family and school socioeconomic disadvantage: interactive influences on adolescent dating violence victimization.

    PubMed

    Spriggs, Aubrey L; Halpern, Carolyn Tucker; Herring, Amy H; Schoenbach, Victor J

    2009-06-01

    Although low socioeconomic status has been positively associated with adult partner violence, its relationship to adolescent dating violence remains unclear. Further, few studies have examined the relationship between contextual disadvantage and adolescent dating violence, or the interactive influences of family and contextual disadvantage. Guided by social disorganization theory, relative deprivation theory, and gendered resource theory, we analyzed data from the U.S. National Longitudinal Study of Adolescent Health (1994-1996) to explore how family and school disadvantage relate to dating violence victimization. Psychological and minor physical victimization were self-reported by adolescents in up to six heterosexual romantic or sexual relationships. Family and school disadvantage were based on a principal component analysis of socioeconomic indicators reported by adolescents and parents. In weighted multilevel random effects models, between-school variability in dating violence victimization was proportionately small but substantive: 10% for male victimization and 5% for female victimization. In bivariate analyses, family disadvantage was positively related to victimization for both males and females; however, school disadvantage was only related to males' physical victimization. In models adjusted for race/ethnicity, relative age within the school, and mean school age, neither family nor school disadvantage remained related to males' victimization. For females, family disadvantage remained significantly positively associated with victimization, but was modified by school disadvantage: family disadvantage was more strongly associated with dating violence victimization in more advantaged schools. Findings support gendered resource theory, and suggest that status differentials between females and their school context may increase their vulnerability to dating violence victimization.

  8. The influence of cholesterol on interactions and dynamics of ibuprofen in a lipid bilayer.

    PubMed

    Khajeh, Aboozar; Modarress, Hamid

    2014-10-01

    In this work, molecular dynamics (MD) simulations with atomistic details were performed to examine the influence of the cholesterol on the interactions and the partitioning of the hydrophobic drug ibuprofen in a fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayer. Analysis of MD simulations indicated that ibuprofen molecules prefer to be located in the hydrophobic acyl chain region of DMPC/cholesterol bilayers. This distribution decreases the lateral motion of lipid molecules. The presence of ibuprofen molecules in the bilayers with 0 and 25mol% cholesterol increases the ordering of hydrocarbon tails of lipids whereas for the bilayers with 50mol% cholesterol, ibuprofen molecules perturb the flexible chains of DMPC lipids which leads to the reduction of the acyl chain order parameter. The potential of the mean force (PMF) method was used to calculate the free energy profile for the transferring of an ibuprofen molecule from the bulk water into the DMPC/cholesterol membranes. The PMF studies indicated that the presence of 50mol% cholesterol in the bilayers increases the free energy barrier and slows down the permeation of the ibuprofen drug across the DMPC bilayer. This can be due to the condensing and ordering effects of the cholesterol on the bilayer.

  9. Influence of habitat manipulations on interactions between cutthroat trout and invertebrate drift. [Salmo clarki

    SciTech Connect

    Wilzbach, M.A.; Cummins, K.W.; Hall, J.D.

    1986-08-01

    The objectives of this study were to examine the interactions of the riparian setting (logged vs forested) and prey availability on the prey capture efficiency and growth of cutthroat trout, and to determine if the riparian setting influences the impact of trout predation on drift composition. Short-term relative growth rates of cutthroat trout, experimentally confined in stream pools, were greater in a logged than in a forested section of stream. Differences in growth rates were attributed to differences, among pools in invertebrate drift density, and to differences in trout foraging efficiency that were related to differences between the sections in the amount of overhead shading and substrate crevices. Mean percentages of introduced prey captured by trout were greater in logged control pools and pools of both sections whose bottoms were covered with fiberglass screening to eliminate substrate crevices than in forested control pools and logged pools that were artificially shaded. A logarithmic relationship was found between trout foraging efficiency and surface light of pools. Drift density significantly increased relative to controls in pools from which trout were removed in the logged reach, but not in the forested section. This may result from habitat features in the logged section that favor greater trout foraging success and the occurrence of behaviorally drifting prey taxa, which represent a predictable food supply for the trout.

  10. Predicting the influence of long-range molecular interactions on macroscopic-scale diffusion by homogenization of the Smoluchowski equation

    NASA Astrophysics Data System (ADS)

    Kekenes-Huskey, P. M.; Gillette, A. K.; McCammon, J. A.

    2014-05-01

    The macroscopic diffusion constant for a charged diffuser is in part dependent on (1) the volume excluded by solute "obstacles" and (2) long-range interactions between those obstacles and the diffuser. Increasing excluded volume reduces transport of the diffuser, while long-range interactions can either increase or decrease diffusivity, depending on the nature of the potential. We previously demonstrated [P. M. Kekenes-Huskey et al., Biophys. J. 105, 2130 (2013)] using homogenization theory that the configuration of molecular-scale obstacles can both hinder diffusion and induce diffusional anisotropy for small ions. As the density of molecular obstacles increases, van der Waals (vdW) and electrostatic interactions between obstacle and a diffuser become significant and can strongly influence the latter's diffusivity, which was neglected in our original model. Here, we extend this methodology to include a fixed (time-independent) potential of mean force, through homogenization of the Smoluchowski equation. We consider the diffusion of ions in crowded, hydrophilic environments at physiological ionic strengths and find that electrostatic and vdW interactions can enhance or depress effective diffusion rates for attractive or repulsive forces, respectively. Additionally, we show that the observed diffusion rate may be reduced independent of non-specific electrostatic and vdW interactions by treating obstacles that exhibit specific binding interactions as "buffers" that absorb free diffusers. Finally, we demonstrate that effective diffusion rates are sensitive to distribution of surface charge on a globular protein, Troponin C, suggesting that the use of molecular structures with atomistic-scale resolution can account for electrostatic influences on substrate transport. This approach offers new insight into the influence of molecular-scale, long-range interactions on transport of charged species, particularly for diffusion-influenced signaling events occurring in crowded

  11. Predicting the influence of long-range molecular interactions on macroscopic-scale diffusion by homogenization of the Smoluchowski equation

    SciTech Connect

    Kekenes-Huskey, P. M.; Gillette, A. K.; McCammon, J. A.

    2014-05-07

    The macroscopic diffusion constant for a charged diffuser is in part dependent on (1) the volume excluded by solute “obstacles” and (2) long-range interactions between those obstacles and the diffuser. Increasing excluded volume reduces transport of the diffuser, while long-range interactions can either increase or decrease diffusivity, depending on the nature of the potential. We previously demonstrated [P. M. Kekenes-Huskey et al., Biophys. J. 105, 2130 (2013)] using homogenization theory that the configuration of molecular-scale obstacles can both hinder diffusion and induce diffusional anisotropy for small ions. As the density of molecular obstacles increases, van der Waals (vdW) and electrostatic interactions between obstacle and a diffuser become significant and can strongly influence the latter's diffusivity, which was neglected in our original model. Here, we extend this methodology to include a fixed (time-independent) potential of mean force, through homogenization of the Smoluchowski equation. We consider the diffusion of ions in crowded, hydrophilic environments at physiological ionic strengths and find that electrostatic and vdW interactions can enhance or depress effective diffusion rates for attractive or repulsive forces, respectively. Additionally, we show that the observed diffusion rate may be reduced independent of non-specific electrostatic and vdW interactions by treating obstacles that exhibit specific binding interactions as “buffers” that absorb free diffusers. Finally, we demonstrate that effective diffusion rates are sensitive to distribution of surface charge on a globular protein, Troponin C, suggesting that the use of molecular structures with atomistic-scale resolution can account for electrostatic influences on substrate transport. This approach offers new insight into the influence of molecular-scale, long-range interactions on transport of charged species, particularly for diffusion-influenced signaling events occurring in

  12. Predicting the influence of long-range molecular interactions on macroscopic-scale diffusion by homogenization of the Smoluchowski equation.

    PubMed

    Kekenes-Huskey, P M; Gillette, A K; McCammon, J A

    2014-05-07

    The macroscopic diffusion constant for a charged diffuser is in part dependent on (1) the volume excluded by solute "obstacles" and (2) long-range interactions between those obstacles and the diffuser. Increasing excluded volume reduces transport of the diffuser, while long-range interactions can either increase or decrease diffusivity, depending on the nature of the potential. We previously demonstrated [P. M. Kekenes-Huskey et al., Biophys. J. 105, 2130 (2013)] using homogenization theory that the configuration of molecular-scale obstacles can both hinder diffusion and induce diffusional anisotropy for small ions. As the density of molecular obstacles increases, van der Waals (vdW) and electrostatic interactions between obstacle and a diffuser become significant and can strongly influence the latter's diffusivity, which was neglected in our original model. Here, we extend this methodology to include a fixed (time-independent) potential of mean force, through homogenization of the Smoluchowski equation. We consider the diffusion of ions in crowded, hydrophilic environments at physiological ionic strengths and find that electrostatic and vdW interactions can enhance or depress effective diffusion rates for attractive or repulsive forces, respectively. Additionally, we show that the observed diffusion rate may be reduced independent of non-specific electrostatic and vdW interactions by treating obstacles that exhibit specific binding interactions as "buffers" that absorb free diffusers. Finally, we demonstrate that effective diffusion rates are sensitive to distribution of surface charge on a globular protein, Troponin C, suggesting that the use of molecular structures with atomistic-scale resolution can account for electrostatic influences on substrate transport. This approach offers new insight into the influence of molecular-scale, long-range interactions on transport of charged species, particularly for diffusion-influenced signaling events occurring in crowded

  13. Structure diagram of binary Lennard-Jones clusters.

    PubMed

    Mravlak, Marko; Kister, Thomas; Kraus, Tobias; Schilling, Tanja

    2016-07-14

    We analyze the structure diagram for binary clusters of Lennard-Jones particles by means of a global optimization approach for a large range of cluster sizes, compositions, and interaction energies and present a publicly accessible database of 180 000 minimal energy structures (http://softmattertheory.lu/clusters.html). We identify a variety of structures such as core-shell clusters, Janus clusters, and clusters in which the minority species is located at the vertices of icosahedra. Such clusters can be synthesized from nanoparticles in agglomeration experiments and used as building blocks in colloidal molecules or crystals. We discuss the factors that determine the formation of clusters with specific structures.

  14. Structure diagram of binary Lennard-Jones clusters

    NASA Astrophysics Data System (ADS)

    Mravlak, Marko; Kister, Thomas; Kraus, Tobias; Schilling, Tanja

    2016-07-01

    We analyze the structure diagram for binary clusters of Lennard-Jones particles by means of a global optimization approach for a large range of cluster sizes, compositions, and interaction energies and present a publicly accessible database of 180 000 minimal energy structures (http://softmattertheory.lu/clusters.html). We identify a variety of structures such as core-shell clusters, Janus clusters, and clusters in which the minority species is located at the vertices of icosahedra. Such clusters can be synthesized from nanoparticles in agglomeration experiments and used as building blocks in colloidal molecules or crystals. We discuss the factors that determine the formation of clusters with specific structures.

  15. Fano stability diagram of a symmetric triple quantum dot

    NASA Astrophysics Data System (ADS)

    Niklas, Michael; Trottmann, Andreas; Donarini, Andrea; Grifoni, Milena

    2017-03-01

    The Fano factor stability diagram of a C3 v symmetric triangular quantum dot is analyzed for increasing electron fillings N . At low filling, conventional Poissonian and sub-Poissonian behavior is found. At larger filling, N ≥2 , a breaking of the electron-hole symmetry is manifested in super-Poissonian noise with a peculiar bias voltage dependence of the Fano factor at Coulomb and interference blockade. An analysis of the Fano map unravels a nontrivial electron-bunching mechanism arising from the presence of degenerate many-body states combined with orbital interference and Coulomb interactions. An expression for the associated dark states is provided for generic N .

  16. Introduction to causal diagrams for confounder selection.

    PubMed

    Williamson, Elizabeth J; Aitken, Zoe; Lawrie, Jock; Dharmage, Shyamali C; Burgess, John A; Forbes, Andrew B

    2014-04-01

    In respiratory health research, interest often lies in estimating the effect of an exposure on a health outcome. If randomization of the exposure of interest is not possible, estimating its effect is typically complicated by confounding bias. This can often be dealt with by controlling for the variables causing the confounding, if measured, in the statistical analysis. Common statistical methods used to achieve this include multivariable regression models adjusting for selected confounding variables or stratification on those variables. Therefore, a key question is which measured variables need to be controlled for in order to remove confounding. An approach to confounder-selection based on the use of causal diagrams (often called directed acyclic graphs) is discussed. A causal diagram is a visual representation of the causal relationships believed to exist between the variables of interest, including the exposure, outcome and potential confounding variables. After creating a causal diagram for the research question, an intuitive and easy-to-use set of rules can be applied, based on a foundation of rigorous mathematics, to decide which measured variables must be controlled for in the statistical analysis in order to remove confounding, to the extent that is possible using the available data. This approach is illustrated by constructing a causal diagram for the research question: 'Does personal smoking affect the risk of subsequent asthma?'. Using data taken from the Tasmanian Longitudinal Health Study, the statistical analysis suggested by the causal diagram approach was performed.

  17. Teacher-Student Interaction, Empathy and Their Influence on Learning in Swimming Lessons

    ERIC Educational Resources Information Center

    Lémonie, Yannick; Light, Richard; Sarremejane, Philippe

    2016-01-01

    The bulk of interest in the role that interaction plays in learning in sport and physical education (PE) has focused on peer interaction at the expense of teacher-student interaction. This article redresses this imbalance in the literature by reporting on a study that inquired into the nature of teacher-student interaction and its effect on…

  18. The CYBA gene A640G polymorphism influences predispositions to coronary artery disease through interactions with cigarette smoking and hypercholesterolemia.

    PubMed

    Niemiec, Pawel; Nowak, Tomasz; Balcerzyk, Anna; Krauze, Jolanta; Zak, Iwona

    2011-08-01

    The CYBA gene encodes the p22phox peptide, an essential subunit of vascular NADPH oxidases. The aim of the study was to analyze potential interactions between CYBA gene A640G polymorphism and traditional risk factors of atherosclerosis. We studied 320 subjects: 160 patients with coronary artery disease (CAD) and 160 controls. The results of interactions were interpreted on the basis of synergy index values (SI, SIM). The 640G allele interacted with cigarette smoking (SI = 2.02, SIM = 2.32). Even greater increase of the CAD risk was found whenever the 640G allele interacted with both smoking and hypercholesterolemia (SI = 2.70, SIM = 3.60). The results suggest that the A640G polymorphism may influence individual predispositions to CAD through interactions with smoking and hypercholesterolemia.

  19. The Semiotic Structure of Geometry Diagrams: How Textbook Diagrams Convey Meaning

    ERIC Educational Resources Information Center

    Dimmel, Justin K.; Herbst, Patricio G.

    2015-01-01

    Geometry diagrams use the visual features of specific drawn objects to convey meaning about generic mathematical entities. We examine the semiotic structure of these visual features in two parts. One, we conduct a semiotic inquiry to conceptualize geometry diagrams as mathematical texts that comprise choices from different semiotic systems. Two,…

  20. Students' Understanding of Diagrams for Solving Word Problems: A Framework for Assessing Diagram Proficiency

    ERIC Educational Resources Information Center

    Poch, Apryl L.; van Garderen, Delinda; Scheuermann, Amy M.

    2015-01-01

    A visual representation, such as a diagram, can be a powerful strategy for solving mathematical word problems. However, using a representation to solve mathematical word problems is not as simple as it seems! Many students with learning disabilities struggle to use a diagram effectively and efficiently. This article provides a framework for…

  1. Early Adverse Environments and Genetic Influences on Age at First Sex: Evidence for Gene × Environment Interaction

    ERIC Educational Resources Information Center

    Carlson, Marie D.; Mendle, Jane; Harden, K. Paige

    2014-01-01

    Youth who experience adverse environments in early life initiate sexual activity at a younger age, on average, than those from more advantaged circumstances. Evolutionary theorists have posited that ecological stress precipitates earlier reproductive and sexual onset, but it is unclear how stressful environments interact with genetic influences on…

  2. The Influence of Dating Anxiety on Normative Experiences of Dating, Sexual Interactions, and Alcohol Consumption among Canadian Middle Adolescents

    ERIC Educational Resources Information Center

    Boyle, Andrea M.; O'Sullivan, Lucia F.

    2013-01-01

    Adolescents tend to consume alcohol and find romantic and sexual partners in mixed-group settings that are unmonitored by adults. Relatively little is known about the influence that dating anxiety may have with these social interactions. A sample of 163 high school students (aged 14-17 years) completed online surveys assessing dating, sex, and…

  3. The Interaction of Principal and Teacher Instructional Influence as a Measure of Leadership as an Organizational Quality

    ERIC Educational Resources Information Center

    Jackson, Karen M.; Marriott, Christine

    2012-01-01

    Purpose: This article presents the design and test of a measure of school leadership as an organizational quality through the interaction of principal and teacher instructional influence. The Organizational Leadership Model hypothesizes four distinct conditions of school leadership, and the analysis investigates the relationship between teacher,…

  4. Glucokinase regulatory proten genetic variant interacts with omega-3 PUFA to influence insulin resistance and inflammation in metabolic syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucokinase Regulatory Protein (GCKR) plays a central role regulating both hepatic triglyceride and glucose metabolism. Fatty acids are key metabolic regulators, which interact with genetic factors and influence glucose metabolism and other metabolic traits. Omega-3 polyunsaturated fatty acids (n-3...

  5. 49 CFR 1152.10 - System diagram map.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 8 2013-10-01 2013-10-01 false System diagram map. 1152.10 Section 1152.10... TRANSPORTATION UNDER 49 U.S.C. 10903 System Diagram § 1152.10 System diagram map. (a) Each carrier shall prepare a diagram of its rail system on a map, designating all lines in its system by the...

  6. 49 CFR 1152.10 - System diagram map.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 8 2012-10-01 2012-10-01 false System diagram map. 1152.10 Section 1152.10... TRANSPORTATION UNDER 49 U.S.C. 10903 System Diagram § 1152.10 System diagram map. (a) Each carrier shall prepare a diagram of its rail system on a map, designating all lines in its system by the...

  7. Fishbone Diagrams: Organize Reading Content with a "Bare Bones" Strategy

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2010-01-01

    Fishbone diagrams, also known as Ishikawa diagrams or cause-and-effect diagrams, are one of the many problem-solving tools created by Dr. Kaoru Ishikawa, a University of Tokyo professor. Part of the brilliance of Ishikawa's idea resides in the simplicity and practicality of the diagram's basic model--a fish's skeleton. This article describes how…

  8. Use of Affinity Diagrams as Instructional Tools in Inclusive Classrooms.

    ERIC Educational Resources Information Center

    Haselden, Polly G.

    2003-01-01

    This article describes how the affinity diagram, a tool for gathering information and organizing it into natural groupings, can be used in inclusive classrooms. It discusses how students can be taught to use an affinity diagram, how affinity diagrams can be used to reflect many voices, and how affinity diagrams can be used to plan class projects.…

  9. The Butterfly diagram leopard skin pattern

    NASA Astrophysics Data System (ADS)

    Ternullo, Maurizio

    2011-08-01

    A time-latitude diagram where spotgroups are given proportional relevance to their area is presented. The diagram reveals that the spotted area distribution is higly dishomogeneous, most of it being concentrated in few, small portions (``knots'') of the Butterfly Diagram; because of this structure, the BD may be properly described as a cluster of knots. The description, assuming that spots scatter around the ``spot mean latitude'' steadily drifting equatorward, is challenged. Indeed, spots cluster around at as many latitudes as knots; a knot may appear at either lower or higher latitudes than previous ones, in a seemingly random way; accordingly, the spot mean latitude abruptly drifts equatorward or even poleward at any knot activation, in spite of any smoothing procedure. Preliminary analyses suggest that the activity splits, in any hemisphere, into two or more distinct ``activity waves'', drifting equatorward at a rate higher than the spot zone as a whole.

  10. State-selective influence of the Breit interaction on the angular distribution of emitted photons following dielectronic recombination

    NASA Astrophysics Data System (ADS)

    Amaro, Pedro; Shah, Chintan; Steinbrügge, Rene; Beilmann, Christian; Bernitt, Sven; López-Urrutia, José R. Crespo; Tashenov, Stanislav

    2017-02-01

    We report a measurement of K L L dielectronic recombination in charge states from Kr+34 through Kr+28 in order to investigate the contribution of the Breit interaction for a wide range of resonant states. Highly charged Kr ions were produced in an electron-beam ion trap, while the electron-ion collision energy was scanned over a range of dielectronic recombination resonances. The subsequent K α x rays were recorded both along and perpendicular to the electron-beam axis, which allowed the observation of the influence of the Breit interaction on the angular distribution of the x rays. Experimental results are in good agreement with distorted-wave calculations. We demonstrate, both theoretically and experimentally, that there is a strong state-selective influence of the Breit interaction that can be traced back to the angular and radial properties of the wave functions in the dielectronic capture.

  11. Magnetohydrodynamic Model of Europa's Interaction with Jupiter's Magnetosphere: Influence of Plumes in Europa's Atmosphere on the Plasma Environment

    NASA Astrophysics Data System (ADS)

    Bloecker, A.; Saur, J.; Roth, L.; Hartkorn, O. A.

    2014-12-01

    We develop a three-dimensional magnetohydrodynamic (MHD) model to study the influence of plumes in Europa's atmosphere on the interaction with Jupiter's magnetosphere and plasma environment. We consider the cases when Europa is located in, above and below the magnetospheric current sheet. Recently, Roth et al. (2014) discovered transient water vapor plumes near Europa's south pole. Here we provide a structured study of the influence of plumes in Europa's atmosphere on the local plasma interaction and the Alfvén wings. In our model we have included an asymmetric atmosphere of Europa, the electromagnetic induction in a subsurface water ocean, the plasma production and loss due to electron impact ionization and dissociative recombination. Additionally, our model takes into account different types of model plumes at the south pole. Our analysis suggests that the plume modifies the global plasma interaction of Europa. The strength of the modification depends on the physical properties of the plume.

  12. When do procedural fairness and outcome fairness interact to influence employees' work attitudes and behaviors? The moderating effect of uncertainty.

    PubMed

    De Cremer, David; Brockner, Joel; Fishman, Ariel; van Dijke, Marius; van Olffen, Woody; Mayer, David M

    2010-03-01

    Prior research has shown that procedural fairness interacts with outcome fairness to influence employees' work attitudes (e.g., organizational commitment) and behaviors (e.g., job performance, organizational citizenship behavior), such that employees' tendencies to respond more positively to higher procedural fairness are stronger when outcome fairness is relatively low. In the present studies, we posited that people's uncertainty about their standing as organizational members would have a moderating influence on this interactive relationship between procedural fairness and outcome fairness, in that the interactive relationship was expected to be more pronounced when uncertainty was high. Using different operationalizations of uncertainty of standing (i.e., length of tenure as a proxy, along with self-reports and coworkers' reports), we found support for this hypothesis in 4 field studies spanning 3 different countries.

  13. On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation

    PubMed Central

    Håkonsson, Dorthe D.; Obel, Børge; Eskildsen, Jacob K.; Burton, Richard M.

    2016-01-01

    Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions. PMID:27242605

  14. On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation.

    PubMed

    Håkonsson, Dorthe D; Obel, Børge; Eskildsen, Jacob K; Burton, Richard M

    2016-01-01

    Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions.

  15. The effects of using diagramming as a representational technique on high school students' achievement in solving math word problems

    NASA Astrophysics Data System (ADS)

    Banerjee, Banmali

    Methods and procedures for successfully solving math word problems have been, and continue to be a mystery to many U.S. high school students. Previous studies suggest that the contextual and mathematical understanding of a word problem, along with the development of schemas and their related external representations, positively contribute to students' accomplishments when solving word problems. Some studies have examined the effects of diagramming on students' abilities to solve word problems that only involved basic arithmetic operations. Other studies have investigated how instructional models that used technology influenced students' problem solving achievements. Still other studies have used schema-based instruction involving students with learning disabilities. No study has evaluated regular high school students' achievements in solving standard math word problems using a diagramming technique without technological aid. This study evaluated students' achievement in solving math word problems using a diagramming technique. Using a quasi-experimental experimental pretest-posttest research design, quantitative data were collected from 172 grade 11 Hispanic English language learners (ELLS) and African American learners whose first language is English (EFLLs) in 18 classes at an inner city high school in Northern New Jersey. There were 88 control and 84 experimental students. The pretest and posttest of each participating student and samples of the experimental students' class assignments provided the qualitative data for the study. The data from this study exhibited that the diagramming method of solving math word problems significantly improved student achievement in the experimental group (p<.01) compared to the control group. The study demonstrated that urban, high school, ELLs benefited from instruction that placed emphasis on the mathematical vocabulary and symbols used in word problems and that both ELLs and EFLLs improved their problem solving success

  16. Spatial ecology of predator-prey interactions: corridors and patch shape influence seed predation.

    SciTech Connect

    J. L . Orrock; B. J. Danielson; M. J. Burns; D. J. Levey

    2003-02-03

    J.L. Orrock, B.J. Danielson, M.J. Burns, and D.J. Levey. 2003. Spatial ecology of predator-prey interactions: corridors and patch shape influence seed predation. Ecology, 84(10):2589-2599. Abstract: Corridors that connect patches of disjunct habitat may be promising tools for mediating the negative impacts of habitat fragmentation, but little is known about how corridors affect ecological interactions. In eight 12-ha experimental landscapes, we examined how corridors affect the impact of invertebrate, rodent, and avian seed predators on pokeweed, Phytolacca americana. Over 13 months in 2000 and 2001, we quantified the effects of patch shape, connectivity, and predator type on the number of seeds germinating in the field (germinants), seed removal, and the viability of remaining seeds. Corridors did not affect the number of P. americana germinants in experimental exclosures or the viability of seeds remaining in exclosures. However, corridors affected the removal of seeds in a predator-specific manner: invertebrates removed more seeds in unconnected patches, whereas rodents removed more seeds in connected patches. Seed removal by birds was similar in connected and unconnected patches. Total seed removal by all seed predators was not affected by corridors, because invertebrates removed more seeds where rodents removed fewer seeds, and vice versa. Overall, seed predation signi®cantly reduced the number and viability of remaining seeds, and reduced the number of germinants in 2000 but not in 2001. The abundance of naturally occurring P. americana plants in our experimental patches in 2000 decreased with increasing seed removal from exclosures but was not related to viability or germinants in 2000, suggesting that seed removal may shape the distribution and abundance of this species. Complementary patterns of seed removal by rodents and invertebrates suggest that corridors alter the effects of these predator taxa by changing the relative amounts of edge and core

  17. Influence of humic substances on plant-microbes interactions in the rhizosphere

    NASA Astrophysics Data System (ADS)

    Puglisi, Edoardo; Pascazio, Silvia; Spaccini, Riccardo; Crecchio, Carmine; Trevisan, Marco; Piccolo, Alessandro

    2013-04-01

    Humic substances are known to play a wide range of effects on the physiology of plant and microbes. This is of particular relevance in the rhizosphere of terrestrial environments, where the reciprocal interactions between plants roots, soil constituents and microorganisms strongly influence the plants acquisition of nutrients. Chemical advances are constantly improving our knowledge on humic substances: their supra-molecular architecture, as well as the moltitude of their chemical constituents, many of which are biologically active. An approach for linking the structure of humic substances with their biological activity in the rhizosphere is the use of rhizoboxes, which allow applying a treatment (e.g., an amendment with humic substances) in an upper soil-plant compartment and take measurements in a lower isolated rhizosphere compartment that can be sampled at desired distances from the rhizoplane. This approach can be adopted to assess the effects of several humic substances, as well as composted materials, on maize plants rhizodeposition of carbon, and in turn on the structure and activity of rhizosphere microbial communities. In order to gain a complete understanding of processes occurring in the complex soil-plant-microorganisms tripartite system, rhizobox experiments can be coupled with bacterial biosensors for the detection and quantification of bioavailable nutrients, chemical analyses of main rhizodeposits constituents, advanced chemical characterizations of humic substances, DNA-fingerprinting of microbial communities, and multivariate statistical approaches to manage the dataset produced and to infer general conclusions. By such an approach it was found that humic substances are significantly affecting the amount of carbon deposited by plant roots. This induction effect is more evident for substances with more hydrophobic and complex structure, thus supporting the scientific hypothesis of the "microbial loop model", which assumes that plants feed

  18. Interactive influences of ethnicity, gender and parental hypertension on hemodynamic responses to behavioral challenge.

    PubMed

    Terrell, D F; Manuck, S B

    1996-01-01

    To determine the independent and interactive influences of ethnicity, gender and parental hypertension on the magnitude and patterning of hemodynamic responses to standardized laboratory stressors, 112 normotensive, young adult African-American and Caucasian subjects (56 women, 56 men) completed a four-task protocol: three psychological stressors (the Stroop Color Word task, mental arithmetic and mirror tracing) and the forehead cold pressor test. Blood pressure (BP), heart rate (HR) and impedance derived measures of cardiac pre-ejection period and stroke volume were measured at rest and during each task; calculated indices of cardiac output and total peripheral resistance were also computed. Women responded to the psychological stressors with significantly larger increases in HR and cardiac output, less change in total peripheral resistance and greater attenuation of cardiac pre-ejection period than did men; however, blood pressure responses did not vary by gender, ethnicity or parental history of hypertension. Across tasks, African Americans showed larger elevations in total peripheral resistance than did Caucasians; conversely Caucasian subjects showed a more pronounced cardiac responsivity to stress, as evidenced by an elevated cardiac output and concomitant decrease in cardiac pre-ejection period, compared to their African-American counterparts. The ethnic differences in reactivity to psychological stressors were more apparent among males, while the gender differences were generally more pronounced among African Americans. Finally, the cold pressor test elicited larger increases in systolic blood pressure (SBP) among Caucasian subjects with family history positive (FH+), relative to family history negative (FH-) subjects, and also caused a greater reduction in HR among males compared to females.

  19. Influence of soil moisture-carbon cycle interactions on the terrestrial carbon cycle over Europe

    NASA Astrophysics Data System (ADS)

    Mystakidis, Stefanos; Davin, Edouard L.; Gruber, Nicolas; Seneviratne, Sonia I.

    2016-04-01

    Water availability is a crucial limiting factor for terrestrial ecosystems, but relatively few studies have quantitatively assessed the influence of soil moisture variability on the terrestrial carbon cycle. Here, we investigate the role of soil moisture variability and state in the contemporary terrestrial carbon cycle over Europe. For this we use a Regional Earth System Model (RESM) based on the COSMO-CLM Regional Climate Model, coupled to the Community Land Model version 4.0 (CLM4.0) and its carbon-nitrogen module. The simulation setup consists of a control simulation over the period 1979-2010 in which soil moisture is interactive and three sensitivity simulations in which soil moisture is prescribed to a mean, a very dry or a very wet seasonal cycle without inter-annual variability. The cumulative net biome productivity varies markedly between the different experiments ranging from a strong sink of up to 6PgC in the wet experiment to a source of up to 1.2PgC in the dry experiment. Changes in the land carbon uptake are driven by a combination of two factors: the direct impact of soil moisture on plant's carbon uptake (essentially in southern Europe) and an indirect effect through changes in temperature affecting ecosystem respiration (mainly in central and northern Europe). We find that removing temporal variations in soil moisture dampens interannual variations in terrestrial carbon fluxes (Gross Primary Productivity, respiration, Net Biome Productivity) by more than 50% over most of Europe. Moreover, the analysis reveals that on annual scale about two-thirds of central Europe and about 70% of southern Europe display statistically significant effect of drying and/or wetting on the terrestrial carbon budget and its components. Our findings confirm the crucial role of soil moisture in determining the magnitude and the inter-annual variability in land CO2 uptake which is a key contributor to the year-to-year variations in atmospheric CO2 concentration.

  20. Influence of nuclear interactions in polyethylene range compensators for carbon-ion radiotherapy

    SciTech Connect

    Kanematsu, Nobuyuki Koba, Yusuke; Ogata, Risa; Himukai, Takeshi

    2014-07-15

    Purpose: A recent study revealed that polyethylene (PE) would cause extra carbon-ion attenuation per range shift by 0.45%/cm due to compositional differences in nuclear interactions. The present study aims to assess the influence of PE range compensators on tumor dose in carbon-ion radiotherapy. Methods: Carbon-ion radiation was modeled to be composed of primary carbon ions and secondary particles, for each of which the dose and the relative biological effectiveness (RBE) were estimated at a tumor depth in the middle of spread-out Bragg peak. Assuming exponential behavior for attenuation and yield of these components with depth, the PE effect on dose was calculated for clinical carbon-ion beams and was partly tested by experiment. The two-component model was integrated into a treatment-planning system and the PE effect was estimated in two clinical cases. Results: The attenuation per range shift by PE was 0.1%–0.3%/cm in dose and 0.2%–0.4%/cm in RBE-weighted dose, depending on energy and range-modulation width. This translates into reduction of RBE-weighted dose by up to 3% in extreme cases. In the treatment-planning study, however, the effect on RBE-weighted dose to tumor was typically within 1% reduction. Conclusions: The extra attenuation of primary carbon ions in PE was partly compensated by increased secondary particles for tumor dose. In practical situations, the PE range compensators would normally cause only marginal errors as compared to intrinsic uncertainties in treatment planning, patient setup, beam delivery, and clinical response.

  1. Influence of Cu(II) on the interaction between sulfite and horseradish peroxidase in vitro

    NASA Astrophysics Data System (ADS)

    Lan, Jie; Guo, Dong-Sheng; Yuan, Xiao-Ying

    2007-06-01

    This paper discussed the quantitative influence of Cu(II) on the interaction between horseradish peroxidase (HRP) and sulfite (SO 32-), which is a derivate of sulfite dioxide in human bodies, by using fluorescence spectrum and ultraviolet (UV) absorption spectrometry in vitro. The results show that under the conditions of physiological pH and room-temperature, Cu(II) can bind strongly with both the protein part and the ferroporphyrin part in HRP at a low concentration (10 -4 mol L -1), and the combination constants are 2.047 × 10 3 and 7.66 × 10 2 L mol -1, respectively. Under the same conditions, SO 32- at low concentrations (<0.15 mol L -1) has little quenching for the fluorescence of HRP at 330 nm, and the combination constant is 0.108 L mol -1. While the fluorescence intensity at 440 nm enhance gradually with the increased concentration of SO 32- (<0.1 mol L -1), and the combination constant is 8.219 L mol -1. These indicate that SO 32- at low concentration has little reaction with the enzyme protein part in HRP but obvious reaction with the ferroporphyrin part in HRP. After SO 32- at low concentrations is added into the HRP-Cu(II) binary system, the reaction constants between SO 32- and the enzyme protein part in HRP increase rapidly. Compared with the absence of Cu(II), the combination constant of SO 32- with the enzyme protein part in HRP increases nearly 70 times with a certain Cu(II) concentration (5.0 × 10 -4 mol L -1) in the system. However, the presence of Cu(II) in the system has little effect on the reaction constants between SO 32- and the ferroporphyrin part in HRP.

  2. Interactions between Thermal Acclimation, Growth Rate, and Phylogeny Influence Prochlorococcus Elemental Stoichiometry

    PubMed Central

    Ma, Lanying; Mouginot, Céline; Chandler, Jeremy W.; Zinser, Erik R.

    2016-01-01

    Variability in plankton elemental requirements can be important for global ocean biogeochemistry but we currently have a limited understanding of how ocean temperature influences the plankton C/N/P ratio. Multiple studies have put forward a ‘translation-compensation’ hypothesis to describe the positive relationship between temperature and plankton N/P or C/P as cells should have lower demand for P-rich ribosomes and associated depressed QP when growing at higher temperature. However, temperature affects many cellular processes beyond translation with unknown outcomes on cellular elemental composition. In addition, the impact of temperature on growth and elemental composition of phytoplankton is likely modulated by the life history and growth rate of the organism. To test the direct and indirect (via growth rate changes) effect of temperature, we here analyzed the elemental composition and ratios in six strains affiliated with the globally abundant marine Cyanobacteria Prochlorococcus. We found that temperature had a significant positive effect on the carbon and nitrogen cell quota, whereas no clear trend was observed for the phosphorus cell quota. The effect on N/P and C/P were marginally significantly positive across Prochlorococcus. The elemental composition and ratios of individual strains were also affected but we found complex interactions between the strain identity, temperature, and growth rate in controlling the individual elemental ratios in Prochlorococcus and no common trends emerged. Thus, the observations presented here does not support the ‘translation-compensation’ theory and instead suggest unique cellular elemental effects as a result of rising temperature among closely related phytoplankton lineages. Thus, the biodiversity context should be considered when predicting future elemental ratios and how cycles of carbon, nitrogen, and phosphorus may change in a future ocean. PMID:27936127

  3. Mycorrhizal Influences On Soil Biogeochemistry In Forests: Are There Biosphere Consequences Of Rhizosphere Interactions?

    NASA Astrophysics Data System (ADS)

    Phillips, R.; Rosling, A.

    2011-12-01

    Temperate forests have experienced dramatic changes in forest composition over the last several decades owing land use change, insect outbreaks, nitrogen deposition and climate change. Understanding the consequences of such changes for carbon (C) and nutrient retention is vital to accurately predict terrestrial feedbacks to global climate change. We sought to test the hypothesis that tree species that form associations with arbuscular mycorrhizal (AM) fungi influence soil biogeochemistry in ways that are fundamentally different from tree species that form associations with ectomycorrhizal (ECM) fungi. We examined tree-mycorrhizal interactions in the central hardwood forests of southern Indiana where a rich assemblage of AM (e.g. maples, ashes, tulip poplar, black cherry) and ECM (e.g. oaks, hickories, beech, pine) tree species co-occur on soils developed from similar parent materials. Across 35 plots along a "mycorrhizal gradient" (plots varying in the relative abundance of AM vs. ECM trees), we found striking differences in soil pH, carbon, (C), nitrogen (N) and phosphorus (P) cycling in upper surface soils. Soil pH varied by three pH units across the gradient, and was positively correlated with the relative abundance of tree species within each mycorrhizal type (r2 = 0.65; p < 0.0001). Similarly, indices of C, N, and P availability were strongly correlated with the abundance of trees within a mycorrhizal association (r2 = 0.73, p < 0.0001; r2 = 0.55, p < 0.0001; r2 = 0.16, p = 0.019; respectively). Collectively, our results suggest that AM- and ECM-dominated stands may differ in their effects on chemical weathering and denudation, with important consequences for C and nutrient retention, and feedbacks to global change.

  4. The Influence of Host Plant Extrafloral Nectaries on Multitrophic Interactions: An Experimental Investigation

    PubMed Central

    Koptur, Suzanne; Jones, Ian M.; Peña, Jorge E.

    2015-01-01

    A field experiment was conducted with outplantings of the native perennial shrub Senna mexicana var. chapmanii in a semi-natural area adjacent to native pine rockland habitat in southern Florida. The presence of ants and the availability of extrafloral nectar were manipulated in a stratified random design. Insect communities were monitored and recorded over a period of six months with a view to addressing three main questions. Do ants provide biotic defense against key herbivores on S. chapmanii? Is the presence of ants on S. chapmanii mediated by EFN? Finally, are there ecological costs associated with the presence of ants on S. chapmanii, such as a reduction in alternative predator or parasitoid numbers? Herbivores on S. chapmanii included immature stages of three pierid butterflies, and adult weevils. Eight species of ants were associated with the plants, and other predators included spiders, ladybugs, wasps, and hemipterans. Parasitic, haemolymph-sucking midges (Ceratopogonidae) and parasitoid flies were also associated with the caterpillar herbivores, and possibly the extrafloral nectaries of the plants. The presence of ants did not appear to influence oviposition by butterflies, as numbers of lepidopterans of all developmental stages did not differ among treatments. Significantly more late instar caterpillars, however, were observed on plants with ants excluded, indicating that ants remove small caterpillars from plants. Substantially more alternative predators (spiders, ladybugs, and wasps) were observed on plants with ants excluded. Rates of parasitization did not differ among the treatments, but there were substantially fewer caterpillars succumbing to virus among those collected from control plants. We provide a rare look at facultative ant-plant mutualisms in the context of the many other interactions with which they overlap. We conclude that ants provide some biotic defense against herbivores on S. chapmanii, and plants benefit overall from the presence

  5. The Influence of Host Plant Extrafloral Nectaries on Multitrophic Interactions: An Experimental Investigation.

    PubMed

    Koptur, Suzanne; Jones, Ian M; Peña, Jorge E

    2015-01-01

    A field experiment was conducted with outplantings of the native perennial shrub Senna mexicana var. chapmanii in a semi-natural area adjacent to native pine rockland habitat in southern Florida. The presence of ants and the availability of extrafloral nectar were manipulated in a stratified random design. Insect communities were monitored and recorded over a period of six months with a view to addressing three main questions. Do ants provide biotic defense against key herbivores on S. chapmanii? Is the presence of ants on S. chapmanii mediated by EFN? Finally, are there ecological costs associated with the presence of ants on S. chapmanii, such as a reduction in alternative predator or parasitoid numbers? Herbivores on S. chapmanii included immature stages of three pierid butterflies, and adult weevils. Eight species of ants were associated with the plants, and other predators included spiders, ladybugs, wasps, and hemipterans. Parasitic, haemolymph-sucking midges (Ceratopogonidae) and parasitoid flies were also associated with the caterpillar herbivores, and possibly the extrafloral nectaries of the plants. The presence of ants did not appear to influence oviposition by butterflies, as numbers of lepidopterans of all developmental stages did not differ among treatments. Significantly more late instar caterpillars, however, were observed on plants with ants excluded, indicating that ants remove small caterpillars from plants. Substantially more alternative predators (spiders, ladybugs, and wasps) were observed on plants with ants excluded. Rates of parasitization did not differ among the treatments, but there were substantially fewer caterpillars succumbing to virus among those collected from control plants. We provide a rare look at facultative ant-plant mutualisms in the context of the many other interactions with which they overlap. We conclude that ants provide some biotic defense against herbivores on S. chapmanii, and plants benefit overall from the presence

  6. Social interaction and sex differences influence rat temperature circadian rhythm under LD cycles and constant light.

    PubMed

    Cambras, T; Castejón, L; Díez-Noguera, A

    2011-06-01

    Circadian rhythms produce an efficient organization of animal behaviour over the 24h day. In some species, social cues have been found to have a role as synchronizers of these rhythms. Here, the influence of social interaction on rat circadian behaviour was investigated, addressing the question of whether cohabitation would produce a delay in the appearance of arrhythmicity under constant light conditions. To this end, the circadian rhythms of male and female rat body temperature were studied for 10days under light-dark conditions, followed by 33days under constant bright light. Half of the animals were maintained in individual cages, whilst the others were maintained in larger cages in groups of three rats of the same sex. Results showed that individual circadian rhythms under 24hour light-dark (LD) cycles were more stable and with higher amplitude in grouped than in isolated animals, and higher in males than in females. During the first days under constant light (LL), the stability of the rhythm was also higher in males than in females, but there were no differences according to the group. Moreover, we did not find significant differences in the time of circadian rhythm loss under LL, since high individual variability was found for this variable. On the other hand, female rats living in isolation showed a delayed acrophase in the circadian rhythm under LD conditions compared with those living in groups. These results suggest that cohabitation increases the internal coherence of circadian behaviour, and could be interpreted as indicating that living in isolation may induce a level of stress that disturbs manifestation of the circadian rhythm, especially in females, which are also more reactive than males to external signals.

  7. DETECTING INTERACTIONS BETWEEN ELLIPTIO WACCAMAWENSIS AND LEPTODEA OCHRACEA: THE INFLUENCE OF EXPERIMENTAL SCALE.

    EPA Science Inventory

    Manipulative field experiments are used in ecology to study biotic interactions in populations and communities. In benthic suspension-feeding organisms, these interactions can occur over multiple spatial scales, but this has rarely received experimental attention. A field experim...

  8. Effect of speed matching on fundamental diagram of pedestrian flow

    NASA Astrophysics Data System (ADS)

    Fu, Zhijian; Luo, Lin; Yang, Yue; Zhuang, Yifan; Zhang, Peitong; Yang, Lizhong; Yang, Hongtai; Ma, Jian; Zhu, Kongjin; Li, Yanlai

    2016-09-01

    Properties of pedestrian may change along their moving path, for example, as a result of fatigue or injury, which has never been properly investigated in the past research. The paper attempts to study the speed matching effect (a pedestrian adjusts his velocity constantly to the average velocity of his neighbors) and its influence on the density-velocity relationship (a pedestrian adjust his velocity to the surrounding density), known as the fundamental diagram of the pedestrian flow. By the means of the cellular automaton, the simulation results fit well with the empirical data, indicating the great advance of the discrete model for pedestrian dynamics. The results suggest that the system velocity and flow rate increase obviously under a big noise, i.e., a diverse composition of pedestrian crowd, especially in the region of middle or high density. Because of the temporary effect, the speed matching has little influence on the fundamental diagram. Along the entire density, the relationship between the step length and the average pedestrian velocity is a piecewise function combined two linear functions. The number of conflicts reaches the maximum with the pedestrian density of 2.5 m-2, while decreases by 5.1% with the speed matching.

  9. Influence and interactions of multi-factors on the bioavailability of PAHs in compost amended contaminated soils.

    PubMed

    Wu, Guozhong; Li, Xingang; Kechavarzi, Cédric; Sakrabani, Ruben; Sui, Hong; Coulon, Frédéric

    2014-07-01

    Compost amendment to contaminated soils is a potential approach for waste recycling and soil remediation. The relative importance and interactions of multiple factors on PAH bioavailability in soils were investigated using conjoint analysis and five-way analysis of variance. Results indicated that soil type and contact time were the two most significant factors influencing the PAH bioavailability in amended soils. The other two factors (compost type and ratio of compost addition) were less important but their interactions with other factors were significant. Specifically the 4-factor interactions showed that compost addition stimulated the degradation of high molecular PAHs at the initial stage (3 month) by enhancing the competitive sorption within PAH groups. Such findings suggest that a realistic decision-making towards hydrocarbon bioavailability assessment should consider interactions among various factors. Further to this, this study demonstrated that compost amendment can enhance the removal of recalcitrant hydrocarbons such as PAHs in contaminated soils.

  10. Seasonal resource value and male size influence male aggressive interactions in the leaf footed cactus bug, Narnia femorata.

    PubMed

    Nolen, Zachary J; Allen, Pablo E; Miller, Christine W

    2017-02-06

    In animal contests, resource value (the quality of a given resource) and resource holding potential (a male's absolute fighting ability) are two important factors determining the level of engagement and outcome of contests. Few studies have tested these factors simultaneously. Here, we investigated whether natural, seasonal differences in cactus phenology (fruit quality) influence interactions between males in the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae). We also considered whether males were more likely to interact when they were similar in size, as predicted by theory. Finally, we examined if male size relative to the size of an opponent predicted competitive success. We found that males have more interactions on cactus with high value ripe fruit, as we predicted. Further, we found that males that were closer in size were more likely to interact, and larger males were more likely to become dominant.

  11. Weight diagram construction of Lax operators

    SciTech Connect

    Carbon, S.L.; Piard, E.J.

    1991-10-01

    We review and expand methods introduced in our previous paper. It is proved that cyclic weight diagrams corresponding to representations of affine Lie algebras allow one to construct the associated Lax operator. The resultant Lax operator is in the Miura-like form and generates the modified KdV equations. The algorithm is extended to the super-symmetric case.

  12. Valid Structure Diagrams and Chemical Gibberish

    ERIC Educational Resources Information Center

    Tauber, Stephen J.; Rankin, Kirk

    1972-01-01

    Chemical structure diagrams are considered as utterances in a written language. Two types of grammars are considered for this language: topological grammars and geometric grammars. The hypothesis is presented that compact computer storage may become accessible via grammars. (15 references) (Author/NH)

  13. Image Attributes: A Study of Scientific Diagrams.

    ERIC Educational Resources Information Center

    Brunskill, Jeff; Jorgensen, Corinne

    2002-01-01

    Discusses advancements in imaging technology and increased user access to digital images, as well as efforts to develop adequate indexing and retrieval methods for image databases. Describes preliminary results of a study of undergraduates that explored the attributes naive subjects use to describe scientific diagrams. (Author/LRW)

  14. The Binary Temperature-Composition Phase Diagram

    ERIC Educational Resources Information Center

    Sanders, Philip C.; Reeves, James H.; Messina, Michael

    2006-01-01

    The equations for the liquid and gas lines in the binary temperature-composition phase diagram are derived by approximating that delta(H)[subscript vap] of the two liquids are equal. It is shown that within this approximation, the resulting equations are not too difficult to present in an undergraduate physical chemistry lecture.

  15. The Keynesian Diagram: A Cross to Bear?

    ERIC Educational Resources Information Center

    Fleck, Juergen

    In elementary economics courses students are often introduced to the basic concepts of macroeconomics through very simplified static models, and the concept of a macroeconomic equilibrium is generally explained with the help of an aggregate demand/aggregate supply (AD/AS) model and an income/expenditure model (via the Keynesian cross diagram).…

  16. Computer-Generated Diagrams for the Classroom.

    ERIC Educational Resources Information Center

    Carle, Mark A.; Greenslade, Thomas B., Jr.

    1986-01-01

    Describes 10 computer programs used to draw diagrams usually drawn on chalkboards, such as addition of three vectors, vector components, range of a projectile, lissajous figures, beats, isotherms, Snell's law, waves passing through a lens, magnetic field due to Helmholtz coils, and three curves. Several programming tips are included. (JN)

  17. Data Exploration: Transposition Operations in Dynamic Diagrams.

    ERIC Educational Resources Information Center

    Sivasankaran, Vijay K.; Owen, Charles L.

    1992-01-01

    Defines transposition operations (changing the way the display of the model proceeds) in diagrams within computer graphics. Describes transpositions that are spatial (moving the point of view or the point viewed), procedural (changing the flow of time), or organizational (arranging multiple simultaneous views and interjecting auxiliary measuring…

  18. Drawing conformal diagrams for a fractal landscape

    SciTech Connect

    Winitzki, Sergei

    2005-06-15

    Generic models of cosmological inflation and the recently proposed scenarios of a recycling universe and the string theory landscape predict spacetimes whose global geometry is a stochastic, self-similar fractal. To visualize the complicated causal structure of such a universe, one usually draws a conformal (Carter-Penrose) diagram. I develop a new method for drawing conformal diagrams, applicable to arbitrary 1+1-dimensional spacetimes. This method is based on a qualitative analysis of intersecting lightrays and thus avoids the need for explicit transformations of the spacetime metric. To demonstrate the power and simplicity of this method, I present derivations of diagrams for spacetimes of varying complication. I then apply the lightray method to three different models of an eternally inflating universe (scalar-field inflation, recycling universe, and string theory landscape) involving the nucleation of nested asymptotically flat, de Sitter and/or anti-de Sitter bubbles. I show that the resulting diagrams contain a characteristic fractal arrangement of lines.

  19. Fog Machines, Vapors, and Phase Diagrams

    ERIC Educational Resources Information Center

    Vitz, Ed

    2008-01-01

    A series of demonstrations is described that elucidate the operation of commercial fog machines by using common laboratory equipment and supplies. The formation of fogs, or "mixing clouds", is discussed in terms of the phase diagram for water and other chemical principles. The demonstrations can be adapted for presentation suitable for elementary…

  20. Dynamic Tactile Diagram Simplification on Refreshable Displays

    ERIC Educational Resources Information Center

    Rastogi, Ravi; Pawluk, Dianne T. V.

    2013-01-01

    The increasing use of visual diagrams in educational and work environments, and even our daily lives, has created obstacles for individuals who are blind or visually impaired to "independently" access the information they represent. Although physical tactile pictures can be created to convey the visual information, it is typically a slow,…

  1. Failure Diagram for Chemically Assisted Crack Growth

    NASA Astrophysics Data System (ADS)

    Sadananda, K.; Vasudevan, A. K.

    2011-02-01

    A failure diagram that combines the thresholds for failure of a smooth specimen to that of a fracture mechanics specimen, similar to the modified Kitagawa diagram in fatigue, is presented. For a given material/environment system, the diagram defines conditions under which a crack initiated at the threshold stress in a smooth specimen becomes a propagating crack, by satisfying the threshold stress intensity of a long crack. In analogy with fatigue, it is shown that internal stresses or local stress concentrations are required to provide the necessary mechanical crack tip driving forces, on one hand, and reaction/transportation kinetics to provide the chemical potential gradients, on the other. Together, they help in the initiation and propagation of the cracks. The chemical driving forces can be expressed as equivalent mechanical stresses using the failure diagram. Both internal stresses and their gradients, in conjunction with the chemical driving forces, have to meet the minimum magnitude and the minimum gradients to sustain the growth of a microcrack formed. Otherwise, nonpropagating conditions will prevail or a crack formed will remain dormant. It is shown that the processes underlying the crack nucleation in a smooth specimen and the crack growth of a fracture mechanics specimen are essentially the same. Both require building up of internal stresses by local plasticity. The process involves intermittent crack tip blunting and microcrack nucleation until the crack becomes unstable under the applied stress.

  2. Geometrical splitting and reduction of Feynman diagrams

    NASA Astrophysics Data System (ADS)

    Davydychev, Andrei I.

    2016-10-01

    A geometrical approach to the calculation of N-point Feynman diagrams is reviewed. It is shown that the geometrical splitting yields useful connections between Feynman integrals with different momenta and masses. It is demonstrated how these results can be used to reduce the number of variables in the occurring functions.

  3. Complexities of One-Component Phase Diagrams

    ERIC Educational Resources Information Center

    Ciccioli, Andrea; Glasser, Leslie

    2011-01-01

    For most materials, the solid at and near the triple-point temperature is denser than the liquid with which it is in equilibrium. However, for water and certain other materials, the densities of the phases are reversed, with the solid being less dense. The profound consequences for the appearance of the "pVT" diagram of one-component materials…

  4. Phase diagram of spiking neural networks

    PubMed Central

    Seyed-allaei, Hamed

    2015-01-01

    In computer simulations of spiking neural networks, often it is assumed that every two neurons of the network are connected by a probability of 2%, 20% of neurons are inhibitory and 80% are excitatory. These common values are based on experiments, observations, and trials and errors, but here, I take a different perspective, inspired by evolution, I systematically simulate many networks, each with a different set of parameters, and then I try to figure out what makes the common values desirable. I stimulate networks with pulses and then measure their: dynamic range, dominant frequency of population activities, total duration of activities, maximum rate of population and the occurrence time of maximum rate. The results are organized in phase diagram. This phase diagram gives an insight into the space of parameters – excitatory to inhibitory ratio, sparseness of connections and synaptic weights. This phase diagram can be used to decide the parameters of a model. The phase diagrams show that networks which are configured according to the common values, have a good dynamic range in response to an impulse and their dynamic range is robust in respect to synaptic weights, and for some synaptic weights they oscillates in α or β frequencies, independent of external stimuli. PMID:25788885

  5. On phase diagrams of magnetic reconnection

    SciTech Connect

    Cassak, P. A.; Drake, J. F.

    2013-06-15

    Recently, “phase diagrams” of magnetic reconnection were developed to graphically organize the present knowledge of what type, or phase, of reconnection is dominant in systems with given characteristic plasma parameters. Here, a number of considerations that require caution in using the diagrams are pointed out. First, two known properties of reconnection are omitted from the diagrams: the history dependence of reconnection and the absence of reconnection for small Lundquist number. Second, the phase diagrams mask a number of features. For one, the predicted transition to Hall reconnection should be thought of as an upper bound on the Lundquist number, and it may happen for considerably smaller values. Second, reconnection is never “slow,” it is always “fast” in the sense that the normalized reconnection rate is always at least 0.01. This has important implications for reconnection onset models. Finally, the definition of the relevant Lundquist number is nuanced and may differ greatly from the value based on characteristic scales. These considerations are important for applications of the phase diagrams. This is demonstrated by example for solar flares, where it is argued that it is unlikely that collisional reconnection can occur in the corona.

  6. Students' different understandings of class diagrams

    NASA Astrophysics Data System (ADS)

    Boustedt, Jonas

    2012-03-01

    The software industry needs well-trained software designers and one important aspect of software design is the ability to model software designs visually and understand what visual models represent. However, previous research indicates that software design is a difficult task to many students. This article reports empirical findings from a phenomenographic investigation on how students understand class diagrams, Unified Modeling Language (UML) symbols, and relations to object-oriented (OO) concepts. The informants were 20 Computer Science students from four different universities in Sweden. The results show qualitatively different ways to understand and describe UML class diagrams and the "diamond symbols" representing aggregation and composition. The purpose of class diagrams was understood in a varied way, from describing it as a documentation to a more advanced view related to communication. The descriptions of class diagrams varied from seeing them as a specification of classes to a more advanced view, where they were described to show hierarchic structures of classes and relations. The diamond symbols were seen as "relations" and a more advanced way was seeing the white and the black diamonds as different symbols for aggregation and composition. As a consequence of the results, it is recommended that UML should be adopted in courses. It is briefly indicated how the phenomenographic results in combination with variation theory can be used by teachers to enhance students' possibilities to reach advanced understanding of phenomena related to UML class diagrams. Moreover, it is recommended that teachers should put more effort in assessing skills in proper usage of the basic symbols and models and students should be provided with opportunities to practise collaborative design, e.g. using whiteboards.

  7. Using cellular network diagrams to interpret large-scale datasets: past progress and future challenges

    NASA Astrophysics Data System (ADS)

    Karp, Peter D.; Latendresse, Mario; Paley, Suzanne

    2011-03-01

    Cellular networks are graphs of molecular interactions within the cell. Thanks to the confluence of genome sequencing and bioinformatics, scientists are now able to reconstruct cellular network models for more than 1,000 organisms. A variety of bioinformatics tools have been developed to support the visualization and navigation of cellular network data. Another important application is the use of cellular network diagrams to visualize and interpret large-scale datasets, such as gene-expression data. We present the Cellular Overview, a network visualization tool developed at SRI International (SRI) to support visualization, navigation, and interpretation of large-scale datasets on metabolic networks. Different variations of the diagram have been generated algorithmically for more than 1,000 organisms. We discuss the graphical design of the diagram and its interactive capabilities.

  8. Ethanol Concentration Influences the Mechanisms of Wine Tannin Interactions with Poly(L-proline) in Model Wine.

    PubMed

    McRae, Jacqui M; Ziora, Zyta M; Kassara, Stella; Cooper, Matthew A; Smith, Paul A

    2015-05-06

    Changes in ethanol concentration influence red wine astringency, and yet the effect of ethanol on wine tannin-salivary protein interactions is not well understood. Isothermal titration calorimetry (ITC) was used to measure the binding strength between the model salivary protein, poly(L-proline) (PLP) and a range of wine tannins (tannin fractions from a 3- and a 7-year old Cabernet Sauvignon wine) across different ethanol concentrations (5, 10, 15, and 40% v/v). Tannin-PLP interactions were stronger at 5% ethanol than at 40% ethanol. The mechanism of interaction changed for most tannin samples across the wine-like ethanol range (10-15%) from a combination of hydrophobic and hydrogen binding at 10% ethanol to only hydrogen binding at 15% ethanol. These results indicate that ethanol concentration can influence the mechanisms of wine tannin-protein interactions and that the previously reported decrease in wine astringency with increasing alcohol may, in part, relate to a decrease tannin-protein interaction strength.

  9. Influence of perceived interactivity of a sexual health text message service on young people's attitudes, satisfaction and repeat use.

    PubMed

    Willoughby, Jessica Fitts; L'Engle, Kelly Ladin

    2015-12-01

    Sexual health text message services are becoming an increasingly popular way to reach young people with sexual health information. A variety of service types exist: some send automated messages on a set schedule; others provide personalized responses to individual questions. Young people's perceptions of interactivity, which is often based on system responsiveness, may vary. This study examines perceptions of interactivity for users of a two-way text message service that connects young people directly with a health educator and examines the relationship between perceived interactivity and attitudes toward the service, service satisfaction, and repeated service use. Data from 131 users in the southeastern U.S.A. were analysed. Perceived interactivity was associated with positive attitudes, user satisfaction and repeat use. Data suggest that for sexual health information seeking, young people may view a program as more useful if they perceive it is interactive. Services that provide a back-and-forth dialog between health educators and users may be perceived as interactive, and those perceptions of interactivity can influence attitudes toward the service as well as behaviors, such as using the service repeatedly. Since such services offer accurate and timely health information, repeated use allows for the additional exchange of health information and educational opportunities.

  10. Evaluating the phase diagram of superconductors with asymmetric spin populations

    SciTech Connect

    Mannarelli, Massimo; Nardulli, Giuseppe; Ruggieri, Marco

    2006-09-15

    The phase diagram of a nonrelativistic fermionic system with imbalanced state populations interacting via a short-range S-wave attractive interaction is analyzed in the mean-field approximation. We determine the energetically favored state for different values of the mismatch between the two Fermi spheres in the weak- and strong-coupling regimes considering both homogeneous and nonhomogeneous superconductive states. We find that the homogeneous superconductive phase persists for values of the population imbalance that increase with increasing coupling strength. In the strong-coupling regime and for large population differences the energetically stable homogeneous phase is characterized by one gapless mode. We also find that the inhomogeneous superconductive phase characterized by the condensate {delta}(x){approx}{delta} exp(iq{center_dot}x) is energetically favored in a range of values of the chemical-potential mismatch that shrinks to zero in the strong-coupling regime.

  11. Influence of shifting cultivation practices on soil-plant-beetle interactions.

    PubMed

    Ibrahim, Kalibulla Syed; Momin, Marcy D; Lalrotluanga, R; Rosangliana, David; Ghatak, Souvik; Zothansanga, R; Kumar, Nachimuthu Senthil; Gurusubramanian, Guruswami

    2016-08-01

    . The present study revealed the fact that shifting cultivation practice significantly affects the beetle species in terms of biodiversity pattern as well as evolutionary features. Spatiotemporal assessment of soil-plant-beetle interactions in shifting cultivation system and their influence in land degradation and ecology will be helpful in making biodiversity conservation decisions in the near future.

  12. Search the Foot and Ankle: Interactive Foot Diagram

    MedlinePlus

    ... foot and ankle surgeons. All Fellows of the College are board certified by the American Board of Foot and Ankle Surgery. Copyright © 2017 American College of Foot and Ankle Surgeons (ACFAS), All Rights ...

  13. A Meta-Analysis of Factors Influencing the Development of Trust in Automation: Implications for Human-Robot Interaction

    DTIC Science & Technology

    2014-07-01

    Consequences and Human Factors Issues. The International Journal of Medical Robotics and Computer Assisted Surgery 2009, 5 (3), 297–308. Marsh, S...Medical Robotics and Computer Assisted Surgery 2009, 5, 297–308. doi:10.1002/rcs.261 *Merritt, S. M.; Heimbaugh, H.; LaChapell, J.; Lee, D. I Trust...A Meta-Analysis of Factors Influencing the Development of Trust in Automation: Implications for Human- Robot Interaction by Kristin E

  14. Disc-protoplanet interaction. Influence of circumprimary radiative discs on self-gravitating protoplanetary bodies in binary star systems

    NASA Astrophysics Data System (ADS)

    Gyergyovits, M.; Eggl, S.; Pilat-Lohinger, E.; Theis, Ch.

    2014-06-01

    Context. More than 60 planets have been discovered so far in systems that harbour two stars, some of which have binary semi-major axes as small as 20 au. It is well known that the formation of planets in such systems is strongly influenced by the stellar components, since the protoplanetary disc and the particles within are exposed to the gravitational influence of the binary. However, the question on how self-gravitating protoplanetary bodies affect the evolution of a radiative, circumprimary disc is still open. Aims: We present our 2D hydrodynamical GPU-CPU code and study the interaction of several thousands of self-gravitating particles with a viscous and radiative circumprimary disc within a binary star system. To our knowledge this program is the only one at the moment that is capable to handle this many particles and to calculate their influence on each other and on the disc. Methods: We performed hydrodynamical simulations of a circumstellar disc assuming the binary system to be coplanar. Our grid-based staggered mesh code relies on ideas from ZEUS-2D, where we implemented the FARGO algorithm and an additional energy equation for the radiative cooling according to opacity tables. To treat particle motion we used a parallelised version of the precise Bulirsch - Stoer algorithm. Four models in total where computed taking into account (i) only N-body interaction; (ii) N-body and disc interaction; (iii) the influence of computational parameters (especially smoothing) on N-body interaction; and (iv) the influence of a quiet low-eccentricity disc while running model (ii). The impact velocities were measured at two different time intervals and were compared. Results: We show that the combination of disc- and N-body self-gravity can have a significant influence on the orbit evolution of roughly Moon sized protoplanets. Conclusions: Not only gas drag can alter the orbit of particles, but the gravitational influence of the disc can accomplish this as well. The results

  15. Drawing and Using Free Body Diagrams: Why It May Be Better Not to Decompose Forces

    ERIC Educational Resources Information Center

    Aviani, Ivica; Erceg, Nataša; Mešic, Vanes

    2015-01-01

    In this study we investigated how two different approaches to drawing free body diagrams influence the development of students' understanding of Newton's laws, including their ability to identify real forces. For this purpose we developed a 12-item two-tier multiple choice survey and conducted a quasiexperiment. This experiment included two groups…

  16. PROGRAPH Diagrams--A New Old System for Teaching Functional Modelling

    ERIC Educational Resources Information Center

    Siller, Hans-Stefan

    2009-01-01

    This paper shows the basic concept of Functional Modelling in mathematics education which has become more and more important in recent years. Hence it is necessary to think about suitable graphical methods to explain the fundamental idea of a function and its influence on values and other functions. PROGRAPH diagrams are a potentially good way to…

  17. Bridging interactions of proteins with silica nanoparticles: the influence of pH, ionic strength and protein concentration.

    PubMed

    Bharti, Bhuvnesh; Meissner, Jens; Klapp, Sabine H L; Findenegg, Gerhard H

    2014-02-07

    Charge-driven bridging of nanoparticles by macromolecules represents a promising route for engineering functional structures, but the strong electrostatic interactions involved when using conventional polyelectrolytes impart irreversible complexation and ill-defined structures. Recently it was found that the electrostatic interaction of silica nanoparticles with small globular proteins leads to aggregate structures that can be controlled by pH. Here we study the combined influence of pH and electrolyte concentration on the bridging aggregation of silica nanoparticles with lysozyme in dilute aqueous dispersions. We find that protein binding to the silica particles is determined by pH irrespective of the ionic strength. The hetero-aggregate structures formed by the silica particles with the protein were studied by small-angle X-ray scattering (SAXS) and the structure factor data were analyzed on the basis of a short-range square-well attractive pair potential (close to the sticky-hard-sphere limit). It is found that the electrolyte concentration has a strong influence on the stickiness near pH 5, where the weakly charged silica particles are bridged by the strongly charged protein. An even stronger influence of the electrolyte is found in the vicinity of the isoelectric point of the protein (pI = 10.7) and is attributed to shielding of the repulsion between the highly charged silica particles and hydrophobic interactions between the bridging protein molecules.

  18. Process-Based Species Pools Reveal the Hidden Signature of Biotic Interactions Amid the Influence of Temperature Filtering.

    PubMed

    Lessard, Jean-Philippe; Weinstein, Ben G; Borregaard, Michael K; Marske, Katharine A; Martin, Danny R; McGuire, Jimmy A; Parra, Juan L; Rahbek, Carsten; Graham, Catherine H

    2016-01-01

    A persistent challenge in ecology is to tease apart the influence of multiple processes acting simultaneously and interacting in complex ways to shape the structure of species assemblages. We implement a heuristic approach that relies on explicitly defining species pools and permits assessment of the relative influence of the main processes thought to shape assemblage structure: environmental filtering, dispersal limitations, and biotic interactions. We illustrate our approach using data on the assemblage composition and geographic distribution of hummingbirds, a comprehensive phylogeny and morphological traits. The implementation of several process-based species pool definitions in null models suggests that temperature-but not precipitation or dispersal limitation-acts as the main regional filter of assemblage structure. Incorporating this environmental filter directly into the definition of assemblage-specific species pools revealed an otherwise hidden pattern of phylogenetic evenness, indicating that biotic interactions might further influence hummingbird assemblage structure. Such hidden patterns of assemblage structure call for a reexamination of a multitude of phylogenetic- and trait-based studies that did not explicitly consider potentially important processes in their definition of the species pool. Our heuristic approach provides a transparent way to explore patterns and refine interpretations of the underlying causes of assemblage structure.

  19. Theoretical studies to elucidate the influence of magnetic dipolar interactions occurring in the magnetic nanoparticle systems, for biomedical applications

    NASA Astrophysics Data System (ADS)

    Osaci, M.; Cacciola, M.

    2016-02-01

    In recent years, the study of magnetic nanoparticles has been intensively developed not only for their fundamental theoretical interest, but also for their many technological applications, especially biomedical applications, ranging from contrast agents for magnetic resonance imaging to the deterioration of cancer cells via hyperthermia treatment. The theoretical and experimental research has shown until now that the magnetic dipolar interactions between nanoparticles can have a significant influence on the magnetic behaviour of the system. But, this influence is not well understood. It is clear that the magnetic dipolar interaction intensity is correlated with the nanoparticle concentration, volume fraction and magnetic moment orientations. In this paper, we try to understand the influence of magnetic dipolar interactions on the behaviour of magnetic nanoparticle systems, for biomedical applications. For the model, we considered spherical nanoparticles with uniaxial anisotropy and lognormal distribution of the sizes. The model involves a simulation stage of the spatial distribution and orientation of the nanoparticles and their easy axes of magnetic anisotropy, and an evaluation stage of the Néel relaxation time. To assess the Néel relaxation time, we are going to discretise and adapt, to the local magnetic field, the Coffey analytical solution for the equation Fokker-Planck describing the dynamics of magnetic moments of nanoparticles in oblique external magnetic field. There are three fundamental aspects of interest in our studies on the magnetic nanoparticles: their spatial & orientational distributions, concentrations and sizes.

  20. The Influence of Gene-Environment Interactions on Alcohol Consumption and Alcohol Use Disorders: A Comprehensive Review

    PubMed Central

    Young-Wolff, Kelly C.; Enoch, Mary-Anne; Prescott, Carol A.

    2011-01-01

    Since 2005, a rapidly expanding literature has evaluated whether environmental factors such as socio-cultural context and environmental adversity interact with genetic influences on drinking behaviors. This article critically reviews empirical research on alcohol-related genotype-environment interactions (GxE) and provides a contextual framework for understanding how genetic factors combine with (or are shaped by) environmental influences to influence the development of drinking behaviors and alcohol use disorders. Collectively, evidence from twin, adoption, and molecular genetic studies indicates that the degree of importance of genetic influences on risk for drinking outcomes can vary in different populations and under different environmental circumstances. However, methodological limitations and lack of consistent replications in this literature make it difficult to draw firm conclusions regarding the nature and effect size of alcohol-related GxE. On the basis of this review, we describe several methodological challenges as they relate to current research on GxE in drinking behaviors and provide recommendations to aid future research. PMID:21530476

  1. Influence of substituents on the nature of metal⋯π interaction and its cooperativity with halogen bond

    SciTech Connect

    Gao, Meng; Cheng, Jianbo E-mail: liqingzhong1990@sina.com; Yang, Xin; Li, Wenzuo; Xiao, Bo; Li, Qingzhong E-mail: liqingzhong1990@sina.com

    2015-08-07

    High-level quantum chemical calculations have been performed to investigate the influence of substituents on the metal—π interaction and its cooperative effect with halogen bond in C{sub 2}X{sub 4}⋯MCN⋯ClF (X = H, CN, CH{sub 3}; M = Cu, Ag, Au). The strong electron-withdrawing group CN weakens the metal—π covalent interaction, while the weak electron-withdrawing group CH{sub 3} strengthens it. The metal—π covalent interaction is dominated by electrostatic energy although the AuCN complex has approximately equal electrostatic and polarization contributions. However, the metal—π covalent interaction is governed by polarization energy due to the CN substitution. A cooperative effect is found for the halogen bond and metal—π interactions in C{sub 2}H{sub 4}⋯MCN⋯ClF, while a diminutive effect occurs in the triads by the CN substituent. Orbital interaction analysis indicates that the strong electron-withdrawing group CN causes the C=C group vary from a stronger donor orbital to a stronger acceptor orbital.

  2. Pair interactions in polyelectrolyte-nanoparticle systems: Influence of dielectric inhomogeneities and the partial dissociation of polymers and nanoparticles

    SciTech Connect

    Pryamitsyn, Victor; Ganesan, Venkat

    2015-10-28

    We study the effective pair interactions between two charged spherical particles in polyelectrolyte solutions using polymer self-consistent field theory. In a recent study [V. Pryamitsyn and V. Ganesan, Macromolecules 47, 6095 (2015)], we considered a model in which the particles possess fixed charge density, the polymers contain a prespecified amount of dissociated charges and, the dielectric constant of the solution was assumed to be homogeneous in space and independent of the polymer concentration. In this article, we present results extending our earlier model to study situations in which either or both the particle and the polymers possess partially dissociable groups. Additionally, we also consider the case when the dielectric constant of the solution depends on the local concentration of the polymers and when the particle’s dielectric constant is lower than that of the solvent. For each case, we quantify the polymer-mediated interactions between the particles as a function of the polymer concentrations and the degree of dissociation of the polymer and particles. Consistent with the results of our previous study, we observe that the polymer-mediated interparticle interactions consist of a short-range attraction and a long-range repulsion. The partial dissociablity of the polymer and particles was seen to have a strong influence on the strength of the repulsive portion of the interactions. Rendering the dielectric permittivity to be inhomogeneous has an even stronger effect on the repulsive interactions and results in changes to the qualitative nature of interactions in some parametric ranges.

  3. COMT Val158Met polymorphism interacts with stressful life events and parental warmth to influence decision making.

    PubMed

    He, Qinghua; Xue, Gui; Chen, Chuansheng; Lu, Zhong-Lin; Chen, Chunhui; Lei, Xuemei; Liu, Yuyun; Li, Jin; Zhu, Bi; Moyzis, Robert K; Dong, Qi; Bechara, Antoine

    2012-01-01

    Both genetic and environmental factors have been shown to influence decision making, but their relative contributions and interactions are not well understood. The present study aimed to reveal possible gene-environment interactions on decision making in a large healthy sample. Specifically, we examined how the frequently studied COMT Val(158)Met polymorphism interacted with an environmental risk factor (i.e., stressful life events) and a protective factor (i.e., parental warmth) to influence affective decision making as measured by the Iowa Gambling Task. We found that stressful life events acted as a risk factor for poor IGT performance (i.e., high reward sensitivity) among Met carriers, whereas parental warmth acted as a protective factor for good IGT performance (i.e., higher IGT score) among Val/Val homozygotes. These results shed some new light on gene-environment interactions in decision making, which could potentially help us understand the underlying etiology of several psychiatric disorders associated with decision making impairment.

  4. Interaction between 2 extracellular loops influences the activity of the cystic fibrosis transmembrane conductance regulator chloride channel.

    PubMed

    Broadbent, Steven D; Wang, Wuyang; Linsdell, Paul

    2014-10-01

    Activity of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is thought to be controlled by cytoplasmic factors. However, recent evidence has shown that overall channel activity is also influenced by extracellular anions that interact directly with the extracellular loops (ECLs) of the CFTR protein. Very little is known about the structure of the ECLs or how substances interacting with these ECLs might affect CFTR function. We used patch-clamp recording to investigate the accessibility of cysteine-reactive reagents to cysteines introduced throughout ECL1 and 2 key sites in ECL4. Furthermore, interactions between ECL1 and ECL4 were investigated by the formation of disulfide crosslinks between cysteines introduced into these 2 regions. Crosslinks could be formed between R899C (in ECL4) and a number of sites in ECL1 in a manner that was dependent on channel activity, suggesting that the relative orientation of these 2 loops changes on activation. Formation of these crosslinks inhibited channel function, suggesting that relative movement of these ECLs is important to normal channel function. Implications of these findings for the effects of mutations in the ECLs that are associated with cystic fibrosis and interactions with extracellular substances that influence channel activity are discussed.

  5. Application of Influence Diagrams in Identifying Soviet Satellite Missions

    DTIC Science & Technology

    1990-12-01

    ultimate goal of a manned landing and return to Earth. During 1988, the Soviets launched Mars probes Phobos 1 and Phobos 2. According to Krasnaya...Zvezda, as mentioned by Mr. Johnson, Phobos 1 was lost due to an attitude control failure. In orbit around Mars, Phobos 2 began rotating which degraded...return of samples from the Mars moon, Phobos , followed by a 1998 mission to conduct soil analyses of the planet through the use of rovers. 4.3.16 Launch

  6. Fetal bovine serum influences the stability and bioactivity of resveratrol analogues: A polyphenol-protein interaction approach.

    PubMed

    Tang, Fen; Xie, Yixi; Cao, Hui; Yang, Hua; Chen, Xiaoqing; Xiao, Jianbo

    2017-03-15

    Fetal bovine serum (FBS) is a universal growth supplement of cell and tissue culture media. Herein, the influences of FBS on the stability and antioxidant activity of 21 resveratrol analogues were investigated using a polyphenol-protein interaction approach. The structure-stability relationships of resveratrol analogues in FBS showed a clear decrease in the stability of hydroxylated resveratrol analogues in the order: resorcinol-type>pyrogallol-type>catechol-type. The glycosylation and methoxylation of resveratrol analogues enhanced their stability. A linear relationship between the stability of resveratrol analogues in FBS and the affinity of resveratrol analogues-FBS interaction was found. The oxidation process is not the only factor governing the stability of resveratrol analogues in FBS. These results facilitated the insightful investigation of the role of polyphenol-protein interactions in serum, thereby providing some fundamental clues for future clinical research and pharmacological studies on natural small molecules.

  7. An exploration of motivations for two screen viewing, social interaction behaviors, and factors that influence viewing intentions.

    PubMed

    Shim, Hongjin; Oh, Poong; Song, Hyunjin; Lee, Yeonkyung

    2015-03-01

    This study explores whether, and how, motivations for two screen viewing predicted social interaction behaviors and subsequent viewing intention of TV programs. A total of 453 respondents who responded that they use social networking sites (SNSs) via smartphones and actively watch entertainment programs completed an online survey questionnaire. In agreement with uses and gratifications assumptions, motivations for TSV predicted distinctive sets of social interaction behaviors, which mediated the influence of motivations on viewing intentions. Respondents' two screen viewing was meaningfully related with social interaction, engagement with programs, information seeking, and passing time. Results suggest that two screen viewing could provide shared experiences nourishing social capital and reintegrate TV audiences by social adhesive resulting from TV with SNSs.

  8. Tense and Aspect in Word Problems about Motion: Diagram, Gesture, and the Felt Experience of Time

    ERIC Educational Resources Information Center

    de Freitas, Elizabeth; Zolkower, Betina

    2015-01-01

    Word problems about motion contain various conjugated verb forms. As students and teachers grapple with such word problems, they jointly operationalize diagrams, gestures, and language. Drawing on findings from a 3-year research project examining the social semiotics of classroom interaction, we show how teachers and students use gesture and…

  9. Student Sensemaking with Science Diagrams in a Computer-Based Setting

    ERIC Educational Resources Information Center

    Furberg, Anniken; Kluge, Anders; Ludvigsen, Sten

    2013-01-01

    This paper reports on a study of students' conceptual sensemaking with science diagrams within a computer-based learning environment aimed at supporting collaborative learning. Through the microanalysis of students' interactions in a project about energy and heat transfer, we demonstrate "how" representations become productive social and cognitive…

  10. Finding and accessing diagrams in biomedical publications.

    PubMed

    Kuhn, Tobias; Luong, ThaiBinh; Krauthammer, Michael

    2012-01-01

    Complex relationships in biomedical publications are often communicated by diagrams such as bar and line charts, which are a very effective way of summarizing and communicating multi-faceted data sets. Given the ever-increasing amount of published data, we argue that the precise retrieval of such diagrams is of great value for answering specific and otherwise hard-to-meet information needs. To this end, we demonstrate the use of advanced image processing and classification for identifying bar and line charts by the shape and relative location of the different image elements that make up the charts. With recall and precisions of close to 90% for the detection of relevant figures, we discuss the use of this technology in an existing biomedical image search engine, and outline how it enables new forms of literature queries over biomedical relationships that are represented in these charts.

  11. Phase diagram of UCoGe

    NASA Astrophysics Data System (ADS)

    Mineev, V. P.

    2017-03-01

    The temperature-pressure phase diagram of ferromagnetic superconductor UCoGe includes four phase transitions. They are between the paramagnetic and the ferromagnetic states with the subsequent transition in the superconducting ferromagnetic state and between the normal and the superconducting states after which the transition to the superconducting ferromagnetic state has to occur. Here we have developed the Landau theory description of the phase diagram and established the specific ordering arising at each type of transition. The phase transitions to the ferromagnetic superconducting state are inevitably accompanied by the emergence of screening currents. The corresponding magnetostatics considerations allow for establishing the significant difference between the transition from the ferromagnetic to the ferromagnetic superconducting state and the transition from the superconducting to the ferromagnetic superconducting state.

  12. Flamelet Regime Diagram for Turbulent Combustion Simulations

    NASA Astrophysics Data System (ADS)

    Chan, Wai Lee; Ihme, Matthias; Kolla, Hemanth; Chen, Jacqueline

    2016-11-01

    The flamelet model has been widely used in numerical combustion investigations, particularly for the closure of large-eddy simulations (LES) of turbulent reacting flows. In most cases, the simulation results demonstrated good agreements with their experimental counterparts. However, a systematic analysis of the flamelet model's applicability, as well as its potential limitations, is seldom conducted, and the model performance is usually based only on a-posteriori comparisons. The objective of this work is to derive a metric that can formally quantify the suitability of the flamelet model in different flame configurations. For this purpose, a flamelet regime diagram has been developed and studied in the context of direct numerical simulations (DNS) of a turbulent lifted jet flame. The implementation of the regime diagram in LES has been investigated through explicit filtering of the DNS results.

  13. Diagrams of stability of circumbinary planetary systems

    NASA Astrophysics Data System (ADS)

    Popova, Elena

    2014-07-01

    The stability diagrams in the ``pericentric distance - eccentricity'' plane of initial data are built and analyzed for Kepler-38, Kepler-47, and Kepler-64 (PH1). This completes a survey of stability of the known up to now circumbinary planetary systems, initiated by Popova & Shevchenko (2013), where the analysis was performed for Kepler-16, 34, and 35. In the diagrams, the planets appear to be ``embedded'' in the fractal chaos border; however, I make an attempt to measure the ``distance'' to the chaos border in a physically consistent way. The obtained distances are compared to those given by the widely used numerical-experimental criterion by Holman & Wiegert (1999), who employed smooth polynomial approximations to describe the border. I identify the resonance cells, hosting the planets.

  14. Phase diagram of a single lane roundabout

    NASA Astrophysics Data System (ADS)

    Echab, H.; Lakouari, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2016-03-01

    Using the cellular automata model, we numerically study the traffic dynamic in a single lane roundabout system of four entry/exit points. The boundaries are controlled by the injecting rates α1, α2 and the extracting rate β. Both the system with and without Splitter Islands of width Lsp are considered. The phase diagram in the (α1 , β) space and its variation with the roundabout size, Pagg (i.e. the probability of aggressive entry), and Pexit (i.e. the probability of preferential exit) are constructed. The results show that the phase diagram in both cases consists of three phases: free flow, congested and jammed. However, as Lsp increases the free flow phase enlarges while the congested and jammed ones shrink. On the other hand, the short sized roundabout shows better performance in the free flow phase while the large one is more optimal in the congested phase. The density profiles are also investigated.

  15. Modeling the Round Earth through Diagrams

    NASA Astrophysics Data System (ADS)

    Padalkar, Shamin; Ramadas, Jayashree

    Earlier studies have found that students, including adults, have problems understanding the scientifically accepted model of the Sun-Earth-Moon system and explaining day-to-day astronomical phenomena based on it. We have been examining such problems in the context of recent research on visual-spatial reasoning. Working with middle school students in India, we have developed a pedagogical sequence to build the mental model of the Earth and tried it in three schools for socially and educationally disadvantaged students. This pedagogy was developed on the basis of (1) a reading of current research in imagery and visual-spatial reasoning and (2) students' difficulties identified during the course of pretests and interviews. Visual-spatial tools such as concrete (physical) models, gestures, and diagrams are used extensively in the teaching sequence. The building of a mental model is continually integrated with drawing inferences to understand and explain everyday phenomena. The focus of this article is inferences drawn with diagrams.

  16. Prediction of boron carbon nitrogen phase diagram

    NASA Astrophysics Data System (ADS)

    Yao, Sanxi; Zhang, Hantao; Widom, Michael

    We studied the phase diagram of boron, carbon and nitrogen, including the boron-carbon and boron-nitrogen binaries and the boron-carbon-nitrogen ternary. Based on the idea of electron counting and using a technique of mixing similar primitive cells, we constructed many ''electron precise'' structures. First principles calculation is performed on these structures, with either zero or high pressures. For the BN binary, our calculation confirms that a rhmobohedral phase can be stablized at high pressure, consistent with some experimental results. For the BCN ternary, a new ground state structure is discovered and an Ising-like phase transition is suggested. Moreover, we modeled BCN ternary phase diagram and show continuous solubility from boron carbide to the boron subnitride phase.

  17. Penguin diagrams for improved staggered fermions

    SciTech Connect

    Lee, Weonjong

    2005-01-01

    We calculate, at the one-loop level, penguin diagrams for improved staggered fermion operators constructed using various fat links. The main result is that diagonal mixing coefficients with penguin operators are identical between the unimproved operators and the improved operators using such fat links as Fat7, Fat7+Lepage, Fat7, HYP (I) and HYP (II). In addition, it turns out that the off-diagonal mixing vanishes for those constructed using fat links of Fat7, Fat7 and HYP (II). This is a consequence of the fact that the improvement by various fat links changes only the mixing with higher dimension operators and off-diagonal operators. The results of this paper, combined with those for current-current diagrams, provide complete matching at the one-loop level with all corrections of O(g{sup 2}) included.

  18. Phase diagram of silica from computer simulation

    NASA Astrophysics Data System (ADS)

    Saika-Voivod, Ivan; Sciortino, Francesco; Grande, Tor; Poole, Peter H.

    2004-12-01

    We evaluate the phase diagram of the “BKS” potential [van Beest, Kramer, and van Santen, Phys. Rev. Lett. 64, 1955 (1990)], a model of silica widely used in molecular dynamics (MD) simulations. We conduct MD simulations of the liquid, and three crystals ( β -quartz, coesite, and stishovite) over wide ranges of temperature and density, and evaluate the total Gibbs free energy of each phase. The phase boundaries are determined by the intersection of these free energy surfaces. Not unexpectedly for a classical pair potential, our results reveal quantitative discrepancies between the locations of the BKS and real silica phase boundaries. At the same time, we find that the topology of the real phase diagram is reproduced, confirming that the BKS model provides a satisfactory qualitative description of a silicalike material. We also compare the phase boundaries with the locations of liquid-state thermodynamic anomalies identified in previous studies of the BKS model.

  19. Finding and Accessing Diagrams in Biomedical Publications

    PubMed Central

    Kuhn, Tobias; Luong, ThaiBinh; Krauthammer, Michael

    2012-01-01

    Complex relationships in biomedical publications are often communicated by diagrams such as bar and line charts, which are a very effective way of summarizing and communicating multi-faceted data sets. Given the ever-increasing amount of published data, we argue that the precise retrieval of such diagrams is of great value for answering specific and otherwise hard-to-meet information needs. To this end, we demonstrate the use of advanced image processing and classification for identifying bar and line charts by the shape and relative location of the different image elements that make up the charts. With recall and precisions of close to 90% for the detection of relevant figures, we discuss the use of this technology in an existing biomedical image search engine, and outline how it enables new forms of literature queries over biomedical relationships that are represented in these charts. PMID:23304318

  20. On Public Influence on People’s Interactions with Ordinary Biodiversity

    PubMed Central

    Skandrani, Zina; Daniel, Lucie; Jacquelin, Lauriane; Leboucher, Gérard; Bovet, Dalila; Prévot, Anne-Caroline

    2015-01-01

    Besides direct impacts of urban biodiversity on local ecosystem services, the contact of city dwellers with urban nature in their everyday life could increase their awareness on conservation issues. In this paper, we focused on a particularly common animal urban species, the feral pigeon Columba livia. Through an observational approach, we examined behavioral interactions between city dwellers and this species in the Paris metropolis, France. We found that most people (mean: 81%) do not interact with pigeons. Further, interactions (either positive or negative) are context and age-dependent: children interact more than adults and the elderly, while people in tourist spots interact more than people in urban parks or in railway stations, a result that suggests that people interacting with pigeons are mostly tourists. We discuss these results in terms of public normative pressures on city dwellers’ access to and reconnection with urban nature. We call for caution in how urban species are publically portrayed and managed, given the importance of interactions with ordinary biodiversity for the fate of nature conservation. PMID:26154622

  1. Correlations and symmetry of interactions influence collective dynamics of molecular motors

    NASA Astrophysics Data System (ADS)

    Celis-Garza, Daniel; Teimouri, Hamid; Kolomeisky, Anatoly B.

    2015-04-01

    Enzymatic molecules that actively support many cellular processes, including transport, cell division and cell motility, are known as motor proteins or molecular motors. Experimental studies indicate that they interact with each other and they frequently work together in large groups. To understand the mechanisms of collective behavior of motor proteins we study the effect of interactions in the transport of molecular motors along linear filaments. It is done by analyzing a recently introduced class of totally asymmetric exclusion processes that takes into account the intermolecular interactions via thermodynamically consistent approach. We develop a new theoretical method that allows us to compute analytically all dynamic properties of the system. Our analysis shows that correlations play important role in dynamics of interacting molecular motors. Surprisingly, we find that the correlations for repulsive interactions are weaker and more short-range than the correlations for the attractive interactions. In addition, it is shown that symmetry of interactions affect dynamic properties of molecular motors. The implications of these findings for motor proteins transport are discussed. Our theoretical predictions are tested by extensive Monte Carlo computer simulations.

  2. Influence of membrane surface roughness on interfacial interactions with sludge flocs in a submerged membrane bioreactor.

    PubMed

    Zhao, Leihong; Shen, Liguo; He, Yiming; Hong, Huachang; Lin, Hongjun

    2015-05-15

    In this study, the interfacial interactions between sludge flocs and a rough membrane surface in a submerged membrane bioreactor were investigated. Models describing these interfacial interactions were firstly proposed based on the surface element integration (SEI) method. Surface properties of sludge flocs and membrane were experimentally determined to simulate the models through composite Simpson's rule. It was found that, roughness on membrane surface significantly decreased interaction strength, which enabled the sludge flocs to more easily attach on and detach from the rough membrane surface. Further analysis showed that the value of total interaction energy increased with asperity radius, while the strength of total interaction energy decreased with asperity height. Results also demonstrated that increase in floc size would significantly decrease the attractive specific total interaction with rough membrane surface. It was revealed that there existed a critical asperity radius above which the total interaction energy in certain separation distance coverage was continuously repulsive, facilitating membrane fouling control in MBRs. This study demonstrated the possibility to mitigate membrane fouling by "tailoring" membrane surface roughness.

  3. Displaying multimedia environmental partitioning by triangular diagrams

    SciTech Connect

    Lee, S.C.; Mackay, D.

    1995-11-01

    It is suggested that equilateral triangular diagrams are a useful method of depicting the equilibrium partitioning of organic chemicals among the three primary environmental media of the atmosphere, the hydrosphere, and the organosphere (natural organic matter and biotic lipids and waxes). The technique is useful for grouping chemicals into classes according to their partitioning tendencies, for depicting the incremental effects of substituents such as alkyl groups and chlorine, and for showing how partitioning changes in response to changes in temperature.

  4. Phase diagram of a traffic roundabout

    NASA Astrophysics Data System (ADS)

    Huang, Ding-wei

    2007-09-01

    We propose a simple cellular automaton model to study the traffic dynamics in a roundabout. Both numerical and analytical results are presented. We are able to obtain exact solutions in the full parameter space. Exact phase diagrams are derived. When the traffic from two directions mixed, there are only five distinct phases. Some of the combinations from naive intuition are strictly forbidden. We also compare the results to a signaled intersection.

  5. Sketching for Military Courses of Action Diagrams

    DTIC Science & Technology

    2003-01-01

    Course-of- Action Diagrams. Proceedings of the 14th International Workshop on Qualitative Reasoning. Morelia, Mexico . June, 2000. 10. Forbus, K...computational model of sketching. IUI’01, January 14-17, 2001, Santa Fe, New Mexico 15. Forbus, K., Gentner, D. and Law, K. 1995. MAC/FAC: A...Operations 2002. pp. 85- 90. 22. Landay, J. and Myers, B. 1996. Sketching storyboards to illustrate interface behaviors. CHI’96 Conference Companion

  6. Mixed wasted integrated program: Logic diagram

    SciTech Connect

    Mayberry, J.; Stelle, S.; O`Brien, M.; Rudin, M.; Ferguson, J.; McFee, J.

    1994-11-30

    The Mixed Waste Integrated Program Logic Diagram was developed to provide technical alternative for mixed wastes projects for the Office of Technology Development`s Mixed Waste Integrated Program (MWIP). Technical solutions in the areas of characterization, treatment, and disposal were matched to a select number of US Department of Energy (DOE) treatability groups represented by waste streams found in the Mixed Waste Inventory Report (MWIR).

  7. Expanding application of the Wiggers diagram to teach cardiovascular physiology.

    PubMed

    Mitchell, Jamie R; Wang, Jiun-Jr

    2014-06-01

    Dr. Carl Wiggers' careful observations have provided a meaningful resource for students to learn how the heart works. Throughout the many years from his initial reports, the Wiggers diagram has been used, in various degrees of complexity, as a fundamental tool for cardiovascular instruction. Often, the various electrical and mechanical plots are the novice learner's first exposure to simulated data. As the various temporal relationships throughout a heartbeat could simply be memorized, the challenge for the cardiovascular instructor is to engage the learner so the underlying mechanisms governing the changing electrical and mechanical events are truly understood. Based on experience, we suggest some additions to the Wiggers diagram that are not commonly used to enhance cardiovascular pedagogy. For example, these additions could be, but are not limited to, introducing the concept of energy waves and their role in influencing pressure and flow in health and disease. Also, integrating concepts of exercise physiology, and the differences in cardiac function and hemodynamics between an elite athlete and normal subject, can have a profound impact on student engagement. In describing the relationship between electrical and mechanical events, the instructor may find the introduction of premature ventricular contractions as a useful tool to further understanding of this important principle. It is our hope that these examples can aid cardiovascular instructors to engage their learners and promote fundamental understanding at the expense of simple memorization.

  8. Expanding application of the Wiggers diagram to teach cardiovascular physiology

    PubMed Central

    Wang, Jiun-Jr

    2014-01-01

    Dr. Carl Wiggers' careful observations have provided a meaningful resource for students to learn how the heart works. Throughout the many years from his initial reports, the Wiggers diagram has been used, in various degrees of complexity, as a fundamental tool for cardiovascular instruction. Often, the various electrical and mechanical plots are the novice learner's first exposure to simulated data. As the various temporal relationships throughout a heartbeat could simply be memorized, the challenge for the cardiovascular instructor is to engage the learner so the underlying mechanisms governing the changing electrical and mechanical events are truly understood. Based on experience, we suggest some additions to the Wiggers diagram that are not commonly used to enhance cardiovascular pedagogy. For example, these additions could be, but are not limited to, introducing the concept of energy waves and their role in influencing pressure and flow in health and disease. Also, integrating concepts of exercise physiology, and the differences in cardiac function and hemodynamics between an elite athlete and normal subject, can have a profound impact on student engagement. In describing the relationship between electrical and mechanical events, the instructor may find the introduction of premature ventricular contractions as a useful tool to further understanding of this important principle. It is our hope that these examples can aid cardiovascular instructors to engage their learners and promote fundamental understanding at the expense of simple memorization. PMID:24913453

  9. Influence of Height in Simulation of Soil Structure Interaction Problems with Dampers

    NASA Astrophysics Data System (ADS)

    Bogdanovic, Aleksandra; Edip, Kemal; Stojmanovska, Marta

    2016-12-01

    In numerical simulation of soil structure interaction problems the presence of dampers in the frame is an advantage yet a special topic to be considered. This paper presents valuable observation on the dynamic soil structure interaction analysis of multi storey frames and considers the effect of height in simulation of soil structure interaction problems. Comparison of these problems has been done by comparing the obtained results from different set up in the software ANSYS. The results of numerical analysis illustrate that it has to be paid more attention when considering the structures not alone but also considering the effect of soil medium.

  10. Influence of Depth of Interaction upon the Performance of Scintillator Detectors

    PubMed Central

    Brown, Mark S.; Gundacker, Stefan; Taylor, Alaric; Tummeltshammer, Clemens; Auffray, Etiennette; Lecoq, Paul; Papakonstantinou, Ioannis

    2014-01-01

    The uncertainty in time of particle detection within a scintillator detector, characterised by the coinci- dence time resolution (CTR), is explored with respect to the interaction position within the scintillator crystal itself. Electronic collimation between two scintillator detectors is utilised to determine the CTR with depth of interaction (DOI) for different materials, geometries and wrappings. Significantly, no rela- tionship between the CTR and DOI is observed within experimental error. Confinement of the interaction position is seen to degrade the CTR in long scintillator crystals by 10%. PMID:24875832

  11. 75 FR 61512 - Outer Continental Shelf Official Protraction Diagrams

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Bureau of Ocean Energy Management, Regulation and Enforcement Outer Continental Shelf Official Protraction Diagrams AGENCY: Bureau of Ocean Energy Management, Regulation and Enforcement, Interior. ACTION... Outer Continental Shelf Official Protraction Diagrams (OPDs) located within Atlantic Ocean areas,...

  12. NEW APPROACHES: Using free body diagrams as a diagnostic instrument

    NASA Astrophysics Data System (ADS)

    Whiteley, Peter

    1996-09-01

    A selection of `Free Body Diagrams' were completed by Advanced Level physics students prior to instruction. The diagrams drawn pointed to a range of understandings and conceptions held by the students that might help to guide instructional strategies.

  13. Proof test diagrams for Zerodur glass-ceramic

    NASA Technical Reports Server (NTRS)

    Tucker, D. S.

    1991-01-01

    Proof test diagrams for Zerodur glass-ceramics are calculated from available fracture mechanics data. It is shown that the environment has a large effect on minimum time-to-failure as predicted by proof test diagrams.

  14. Automated D/3 to Visio Analog Diagrams

    SciTech Connect

    Posey, Stephen B.

    2000-08-10

    ADVAD1 reads an ASCII file containing the D/3 DCS MDL input for analog points for a D/3 continuous database. It uses the information in the files to create a series of Visio files representing the structure of each analog chain, one drawing per Visio file. The actual drawing function is performed by Visio (requires Visio version 4.5+). The user can configure the program to select which fields in the database are shown on the diagram and how the information is to be presented. This gives a visual representation of the structure of the analog chains, showing selected fields in a consistent manner. Updating documentation can be done easily and the automated approach eliminates human error in the cadding process. The program can also create the drawings far faster than a human operator is capable, able to create approximately 270 typical diagrams in about 8 minutes on a Pentium II 400 MHz PC. The program allows for multiple option sets to be saved to provide different settings (i.e., different fields, different field presentations, and /or different diagram layouts) for various scenarios or facilities on one workstation. Option sets may be exported from the Windows registry to allow duplication of settings on another workstation.

  15. Antiferromagnetic phase diagram of the cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Nunes, L. H. C. M.; Teixeira, A. W.; Marino, E. C.

    2017-02-01

    Taking the spin-fermion model as the starting point for describing the cuprate superconductors, we obtain an effective nonlinear sigma-field hamiltonian, which takes into account the effect of doping in the system. We obtain an expression for the spin-wave velocity as a function of the chemical potential. For appropriate values of the parameters we determine the antiferromagnetic phase diagram for the YBa2Cu3O6+x compound as a function of the dopant concentration in good agreement with the experimental data. Furthermore, our approach provides a unified description for the phase diagrams of the hole-doped and the electron doped compounds, which is consistent with the remarkable similarity between the phase diagrams of these compounds, since we have obtained the suppression of the antiferromagnetic phase as the modulus of the chemical potential increases. The aforementioned result then follows by considering positive values of the chemical potential related to the addition of holes to the system, while negative values correspond to the addition of electrons.

  16. Asteroseismic Diagram for Subgiants and Red Giants

    NASA Astrophysics Data System (ADS)

    Gai, Ning; Tang, Yanke; Yu, Peng; Dou, Xianghua

    2017-02-01

    Asteroseismology is a powerful tool for constraining stellar parameters. NASA’s Kepler mission is providing individual eigenfrequencies for a huge number of stars, including thousands of red giants. Besides the frequencies of acoustic modes, an important breakthrough of the Kepler mission is the detection of nonradial gravity-dominated mixed-mode oscillations in red giants. Unlike pure acoustic modes, mixed modes probe deeply into the interior of stars, allowing the stellar core properties and evolution of stars to be derived. In this work, using the gravity-mode period spacing and the large frequency separation, we construct the ΔΠ1–Δν asteroseismic diagram from models of subgiants and red giants with various masses and metallicities. The relationship ΔΠ1–Δν is able to constrain the ages and masses of the subgiants. Meanwhile, for red giants with masses above 1.5 M ⊙, the ΔΠ1–Δν asteroseismic diagram can also work well to constrain the stellar age and mass. Additionally, we calculate the relative “isochrones” τ, which indicate similar evolution states especially for similar mass stars, on the ΔΠ1–Δν diagram.

  17. Nonthermal Radio Emission and the HR Diagram

    NASA Technical Reports Server (NTRS)

    Gibson, D. M.

    1985-01-01

    Perhaps the most reliable indicator of non-radiative heating/momentum in a stellar atmosphere is the presence of nonthermal radio emission. To date, 77 normal stellar objects have been detected and identified as nonthermal sources. These stellar objects are tabulated herein. It is apparent that non-thermal radio emission is not ubiquitous across the HR diagram. This is clearly the case for the single stars; it is not as clear for the binaries unless the radio emission is associated with their late-type components. Choosing to make this association, the single stars and the late-type components are plotted together. The following picture emerges: (1) there are four locations on the HR diagram where non-thermal radio stars are found; (2) the peak incoherent 5 GHz luminosities show a suprisingly small range for stars within each class; (3) the fraction of stellar energy that escapes as radio emission can be estimated by comparing the integrated maximum radio luminosity to the bolometric luminosity; (4) there are no apparent differences in L sub R between binaries with two cool components, binaries with one hot and one cool component, and single stars for classes C and D; and (5) The late-type stars (classes B, C, and D) are located in parts of the HR diagram where there is reason to suspect that the surfaces of the stars are being braked with respect to their interiors.

  18. The Critical Importance of Russell's Diagram

    NASA Astrophysics Data System (ADS)

    Gingerich, O.

    2013-04-01

    The idea of dwarf and giants stars, but not the nomenclature, was first established by Eijnar Hertzsprung in 1905; his first diagrams in support appeared in 1911. In 1913 Henry Norris Russell could demonstrate the effect far more strikingly because he measured the parallaxes of many stars at Cambridge, and could plot absolute magnitude against spectral type for many points. The general concept of dwarf and giant stars was essential in the galactic structure work of Harlow Shapley, Russell's first graduate student. In order to calibrate the period-luminosity relation of Cepheid variables, he was obliged to fall back on statistical parallax using only 11 Cepheids, a very sparse sample. Here the insight provided by the Russell diagram became critical. The presence of yellow K giant stars in globular clusters credentialed his calibration of the period-luminosity relation by showing that the calibrated luminosity of the Cepheids was comparable to the luminosity of the K giants. It is well known that in 1920 Shapley did not believe in the cosmological distances of Heber Curtis' spiral nebulae. It is not so well known that in 1920 Curtis' plot of the period-luminosity relation suggests that he didn't believe it was a physical relation and also he failed to appreciate the significance of the Russell diagram for understanding the large size of the Milky Way.

  19. Influence of predominant patterns of coordination on the exploitation of interaction torques in a two-joint rhythmic arm movement.

    PubMed

    de Rugy, Aymar; Riek, Stephan; Carson, Richard G

    2006-11-01

    In this study we investigate the coordination between rhythmic flexion-extension (FE) and supination-pronation (SP) movements at the elbow joint-complex, while manipulating the intersegmental dynamics by means of a 2-degrees of freedom (df) robot arm. We hypothesized that constraints imposed by the structure of the neuromuscular-skeletal system would (1) result in predominant pattern(s) of coordination in the absence of interaction torques and (2) influence the capabilities of participants to exploit artificially induced interaction torques. Two experiments were conducted in which different conditions of interaction torques were applied on the SP-axis as a function of FE movements. These conditions promoted different patterns of coordination between the 2-df. Control trials conducted in the absence of interaction torques revealed that both the in-phase (supination synchronized with flexion) and the anti-phase (pronation synchronized with flexion) patterns were spontaneously established by participants. The predominance of these patterns of coordination is explained in terms of the mechanical action of bi-articular muscles acting at the elbow joint-complex, and in terms of the reflexes that link the activity of the muscles involved. Results obtained in the different conditions of interaction torques revealed that those neuromuscular-skeletal constraints either impede or favor the exploitation of intersegmental dynamics depending on the context. Interaction torques were indeed found to be exploited to a greater extent in conditions in which the profiles of interaction torques favored one of the two predominant patterns of coordination (i.e., in-phase or anti-phase) as opposed to other patterns of coordination (e.g., 90 degrees or 270 degrees). Those results are discussed in relation to recent studies reporting exploitation of interaction torques in the context of rhythmic movements.

  20. Phase Diagrams of Quasispecies Theory with Recombination and Horizontal Gene Transfer

    NASA Astrophysics Data System (ADS)

    Park, J.-M.; Deem, M. W.

    2007-02-01

    We consider how transfer of genetic information between individuals influences the phase diagram and mean fitness of both the Eigen and the parallel, or Crow-Kimura, models of evolution. In the absence of genetic transfer, these physical models of evolution consider the replication and point mutation of the genomes of independent individuals in a large population. A phase transition occurs, such that below a critical mutation rate an identifiable quasispecies forms. We show how transfer of genetic information changes the phase diagram and mean fitness and introduces metastability in quasispecies theory, via an analytic field theoretic mapping.

  1. Groundwater-surface water interactions in a glacierized catchment and their influence on proglacial water supply

    NASA Astrophysics Data System (ADS)

    Gordon, R. P.; Lautz, L. K.; McKenzie, J. M.; Mark, B. G.

    2012-12-01

    The tropical glaciers of the Cordillera Blanca of Peru are retreating rapidly due to climate change, which threatens water resources for the quarter-million inhabitants of the upper Rio Santa river valley and many more downstream. Recent studies have shown that glacial melt supplies approximately half of dry season stream discharge in Cordillera Blanca valleys. The remainder of streamflow is supplied by groundwater stored in alpine meadows, moraines and talus slopes. In the future, when glacier loss has reduced the influence of melt water on streams, groundwater discharge will be the primary dry-season source of stream water for irrigation, municipalities, and hydropower in the Santa watershed. A better understanding of the dynamics of alpine groundwater, including sources and exchange fluxes, is therefore important for future planning in this region. Understanding these groundwater-surface water interactions is necessary for making accurate estimates of meltwater contributions to the hydrologic budget, and for our ability to make predictions about future water resources under deglaciating conditions. We combined measurements of groundwater-surface water exchange during the dry season with synoptic sampling of stream water and end-members in order to quantify the groundwater contributions to streamflow from an alpine meadow, debris fan, and moraine complex in a glacierized valley of the Cordillera Blanca. Using stream tracer-dilution techniques, we calculated channel water balances for 9 stream reaches of 100-200 m throughout the meadow and measured the discharge of glacial meltwater into debris fan and moraine units. We used vertical heat tracing to measure stream-groundwater exchange at 2-hour increments over 2 weeks in 13 stream locations in the meadow, debris fan, and moraine units. Channel water balance and heat tracing results show that, during the studied portion of the dry season, the stream loses water (2.5 l/s or ~25% of flow) to the subsurface in the

  2. Understanding the H -T phase diagram of the monoaxial helimagnet

    NASA Astrophysics Data System (ADS)

    Laliena, Victor; Campo, Javier; Kousaka, Yusuke

    2016-09-01

    Some unexpected features of the phase diagram of the monoaxial helimagnet in presence of an applied magnetic field perpendicular to the chiral axis are theoretically predicted. A rather general Hamiltonian with long-range Heisenberg exchange and Dzyaloshinskii-Moriya interactions is considered. The continuum limit simplifies the free energy, which contains only a few parameters which in principle are determined by the many parameters of the Hamiltonian, although in practice they may be tuned to fit the experiments. The phase diagram contains a chiral soliton lattice phase and a forced ferromagnetic phase separated by a line of phase transitions, which are of second order at low T and of first order in the vicinity of the zero-field ordering temperature, and are separated by a tricritical point. A highly nonlinear chiral soliton lattice, in which many harmonics contribute appreciably to the spatial modulation of the local magnetic moment, develops only below the tricritical temperature, and in this case, the scaling shows a logarithmic behavior similar to that at T =0 , which is a universal feature of the chiral soliton lattice. Below the tricritical temperature, the normalized soliton density curves are found to be independent of T , in agreement with the experimental results of magnetorresistance curves, while above the tricritical temperature they show a noticeable temperature dependence. The implications in the interpretation of experimental results of CrNb3S6 are discussed.

  3. Recursive graphical construction of feynman diagrams and their multiplicities in straight phi(4) and straight phi2A theory

    PubMed

    Kleinert; Pelster; Kastening; Bachmann

    2000-08-01

    The free energy of a field theory can be considered as a functional of the free correlation function. As such it obeys a nonlinear functional differential equation that can be turned into a recursion relation. This is solved order by order in the coupling constant to find all connected vacuum diagrams with their proper multiplicities. The procedure is applied to a multicomponent scalar field theory with a straight phi(4) self-interaction and then to a theory of two scalar fields straight phi and A with an interaction straight phi2A. All Feynman diagrams with external lines are obtained from functional derivatives of the connected vacuum diagrams with respect to the free correlation function. Finally, the recursive graphical construction is automatized by computer algebra with the help of a unique matrix notation for the Feynman diagrams.

  4. Glass and liquid phase diagram of a polyamorphic monatomic system

    NASA Astrophysics Data System (ADS)

    Reisman, Shaina; Giovambattista, Nicolas

    2013-02-01

    We perform out-of-equilibrium molecular dynamics (MD) simulations of a monatomic system with Fermi-Jagla (FJ) pair potential interactions. This model system exhibits polyamorphism both in the liquid and glass state. The two liquids, low-density (LDL) and high-density liquid (HDL), are accessible in equilibrium MD simulations and can form two glasses, low-density (LDA) and high-density amorphous (HDA) solid, upon isobaric cooling. The FJ model exhibits many of the anomalous properties observed in water and other polyamorphic liquids and thus, it is an excellent model system to explore qualitatively the thermodynamic properties of such substances. The liquid phase behavior of the FJ model system has been previously characterized. In this work, we focus on the glass behavior of the FJ system. Specifically, we perform systematic isothermal compression and decompression simulations of LDA and HDA at different temperatures and determine "phase diagrams" for the glass state; these phase diagrams varying with the compression/decompression rate used. We obtain the LDA-to-HDA and HDA-to-LDA transition pressure loci, PLDA-HDA(T) and PHDA-LDA(T), respectively. In addition, the compression-induced amorphization line, at which the low-pressure crystal (LPC) transforms to HDA, PLPC-HDA(T), is determined. As originally proposed by Poole et al. [Phys. Rev. E 48, 4605 (1993)], 10.1103/PhysRevE.48.4605 simulations suggest that the PLDA-HDA(T) and PHDA-LDA(T) loci are extensions of the LDL-to-HDL and HDL-to-LDL spinodal lines into the glass domain. Interestingly, our simulations indicate that the PLPC-HDA(T) locus is an extension, into the glass domain, of the LPC metastability limit relative to the liquid. We discuss the effects of compression/decompression rates on the behavior of the PLDA-HDA(T), PHDA-LDA(T), PLPC-HDA(T) loci. The competition between glass polyamorphism and crystallization is also addressed. At our "fast rate," crystallization can be partially suppressed and the

  5. Harnessing nanotopography and integrin-matrix interactions to influence stem cell fate

    NASA Astrophysics Data System (ADS)

    Dalby, Matthew J.; Gadegaard, Nikolaj; Oreffo, Richard O. C.

    2014-06-01

    Stem cells respond to nanoscale surface features, with changes in cell growth and differentiation mediated by alterations in cell adhesion. The interaction of nanotopographical features with integrin receptors in the cells' focal adhesions alters how the cells adhere to materials surfaces, and defines cell fate through changes in both cell biochemistry and cell morphology. In this Review, we discuss how cell adhesions interact with nanotopography, and we provide insight as to how materials scientists can exploit these interactions to direct stem cell fate and to understand how the behaviour of stem cells in their niche can be controlled. We expect knowledge gained from the study of cell-nanotopography interactions to accelerate the development of next-generation stem cell culture materials and implant interfaces, and to fuel discovery of stem cell therapeutics to support regenerative therapies.

  6. Harnessing nanotopography and integrin-matrix interactions to influence stem cell fate.

    PubMed

    Dalby, Matthew J; Gadegaard, Nikolaj; Oreffo, Richard O C

    2014-06-01

    Stem cells respond to nanoscale surface features, with changes in cell growth and differentiation mediated by alterations in cell adhesion. The interaction of nanotopographical features with integrin receptors in the cells' focal adhesions alters how the cells adhere to materials surfaces, and defines cell fate through changes in both cell biochemistry and cell morphology. In this Review, we discuss how cell adhesions interact with nanotopography, and we provide insight as to how materials scientists can exploit these interactions to direct stem cell fate and to understand how the behaviour of stem cells in their niche can be controlled. We expect knowledge gained from the study of cell-nanotopography interactions to accelerate the development of next-generation stem cell culture materials and implant interfaces, and to fuel discovery of stem cell therapeutics to support regenerative therapies.

  7. Influence of the Anomeric Conformation in the Intermolecular Interactions of Glucose.

    PubMed

    Usabiaga, Imanol; González, Jorge; León, Iker; Arnaiz, Pedro F; Cocinero, Emilio J; Fernández, José A

    2017-02-24

    Carbohydrates are, together with amino acids, DNA bases, and lipids, the building blocks of living beings. They play a central role in basic functions such as immunity and signaling, which are governed by noncovalent interactions between sugar units and other biomolecules. To get insights into such interactions between monosaccharide units, we used a combination of mass-resolved laser spectroscopy in supersonic expansions and molecular structure calculations. The results obtained clearly demonstrate that the small stability difference between the α/β anomers of glucopyranose derivatives is reversed and amplified during molecular aggregation, making the complexes of the β-anomers significantly more stable. The amplification mechanism seems to be formation of extensive hydrogen-bond networks extending through the two interacting molecules. The same mechanism must be at play in the interactions of biological and synthetic receptors with glycans, which exhibit, in general, a higher affinity for a specific anomer, usually the beta anomer.

  8. Influence of the Coulomb interaction on the exchange coupling in granular magnets

    NASA Astrophysics Data System (ADS)

    Udalov, O. G.; Beloborodov, I. S.

    2017-04-01

    We develop a theory of the exchange interaction between ferromagnetic (FM) metallic grains embedded into insulating matrix by taking into account the Coulomb blockade effects. For bulk ferromagnets separated by the insulating layer the exchange interaction strongly depends on the height and thickness of the tunneling barrier created by the insulator. We show that for FM grains embedded into insulating matrix the exchange coupling additionally depends on the dielectric properties of this matrix due to the Coulomb blockade effects. In particular, the FM coupling decreases with decreasing the dielectric permittivity of insulating matrix. We find that the change in the exchange interaction due to the Coulomb blockade effects can be a few tens of percent. Also, we study dependence of the intergrain exchange interaction on the grain size and other parameters of the system.

  9. Influence of strong field vacuum polarization on gravitational-electromagnetic wave interaction

    SciTech Connect

    Forsberg, M.; Brodin, G.; Papadopoulos, D.

    2010-07-15

    The interaction between gravitational and electromagnetic waves in the presence of a static magnetic field is studied. The field strength of the static field is allowed to surpass the Schwinger critical field, such that the QED effects of vacuum polarization and magnetization are significant. Equations governing the interaction are derived and analyzed. It turns out that the energy conversion from gravitational to electromagnetic waves can be significantly altered due to the QED effects. The consequences of our results are discussed.

  10. The influence of interactive technology on student performance in an Oklahoma secondary Biology I program

    NASA Astrophysics Data System (ADS)

    Feltman, Vallery

    Over the last decade growth in technologies available to teach students and enhance curriculum has become an important consideration in the educational system. The profile of today's secondary students have also been found to be quite different than those of the past. Their learning styles and preferences are issues that should be addressed by educators. With the growth and availability of new technologies students are increasingly expecting to use these as learning tools in their classrooms. This study investigates how interactive technology may impact student performance. This study specifically focuses on the use of the Apple Ipad in 4 Biology I classrooms. This study used an experimental mixed method design to examine how using Ipads for learning impacted student achievement, motivation to learn, and learning strategies. Qualitatively the study examined observed student behaviors and student perceptions regarding the use of interactive technologies. Data was analyzed using descriptive statistics, t-tests, 2-way ANOVAs, and qualitative analysis. Quantitatively the results revealed no significant difference between students who used the interactive technology to learn and those who did not. Qualitative data revealed behaviors indicative of being highly engaged with the subject matter and the development of critical thinking skills which may improve student performance. Student perceptions also revealed overall positive experiences with using interactive technology in the classroom. It is recommended that further studies be done to look at using interactive technologies for a longer period of time using multiple subjects areas. This would provide a more in-depth exploration of interactive technologies on student achievement.

  11. Phase diagrams and magnetic properties of a superlattice with alternate layers

    NASA Astrophysics Data System (ADS)

    Feraoun, A.; Zaim, A.; Kerouad, M.

    2015-03-01

    The phase diagrams and magnetic properties of an Ising superlattice are investigated by means of Monte Carlo simulation based on Metropolis algorithm. The system is formed by alternate layers of spins S = 1 and σ = 3 / 2. The effects of the exchange coupling interactions and the crystal field on the phase diagrams and magnetic properties of the system are examined. A number of characteristic behaviors have been found. In particular, tricritical point, critical end point, and isolated critical point may occur in the present system.

  12. Phase diagram of a rotating Bose-Einstein condensate with anharmonic confinement

    SciTech Connect

    Jackson, A.D.; Kavoulakis, G.M.; Lundh, E.

    2004-05-01

    We examine the phase diagram of an effectively repulsive Bose-Einstein condensate of atoms that rotates in a quadratic-plus-quartic potential. With use of a variational method we identify the three possible phases of the system as a function of the rotational frequency of the trap and of the coupling constant. The derived phase diagram is shown to be universal and partly exact in the limit of weak interactions and small anharmonicity. The variational results are found to be consistent with numerical solutions of the Gross-Pitaevskii equation.

  13. The Problem of Labels in E-Assessment of Diagrams

    ERIC Educational Resources Information Center

    Jayal, Ambikesh; Shepperd, Martin

    2009-01-01

    In this article we explore a problematic aspect of automated assessment of diagrams. Diagrams have partial and sometimes inconsistent semantics. Typically much of the meaning of a diagram resides in the labels; however, the choice of labeling is largely unrestricted. This means a correct solution may utilize differing yet semantically equivalent…

  14. Students' Learning Activities While Studying Biological Process Diagrams

    ERIC Educational Resources Information Center

    Kragten, Marco; Admiraal, Wilfried; Rijlaarsdam, Gert

    2015-01-01

    Process diagrams describe how a system functions (e.g. photosynthesis) and are an important type of representation in Biology education. In the present study, we examined students' learning activities while studying process diagrams, related to their resulting comprehension of these diagrams. Each student completed three learning tasks. Verbal…

  15. Oak Ridge National Laboratory Technology Logic Diagram. Executive Summary

    SciTech Connect

    Not Available

    1993-06-30

    This executive summary contains a description of the logic diagram format; some examples from the diagram (Vol. 2) and associated technology evaluation data sheets (Vol. 3); a complete (albeit condensed) listing of the RA, D&D, and WM problems at ORNL; and a complete listing of the technology rankings for all the areas covered by the diagram.

  16. Science Visual Literacy: Learners' Perceptions and Knowledge of Diagrams

    ERIC Educational Resources Information Center

    McTigue, Erin M.; Flowers, Amanda C.

    2011-01-01

    Constructing meaning from science texts relies not only on comprehending the words but also the diagrams and other graphics. The goal of this study was to explore elementary students' perceptions of science diagrams and their skills related to diagram interpretation. 30 students, ranging from second grade through middle school, completed a diagram…

  17. Parasympathetic cardio-regulation during social interactions in individuals with obesity-The influence of negative body image.

    PubMed

    Schrimpf, Anne; Kube, Jana; Neumann, Jane; Horstmann, Annette; Villringer, Arno; Gaebler, Michael

    2017-04-01

    Individuals with obesity in Western societies often face weight-related stigmatization and social exclusion. Recurrent exposure to prejudice and negative social feedback alters one's behavior in future social interactions. In this study, we aimed to investigate autonomic nervous system and affective responses to social interactions in individuals with obesity. Women and men with (n = 56) and without (n = 56) obesity participated in episodes of social inclusion and social exclusion using a virtual ball-tossing game. During the experiment, heart rate was measured and parasympathetic activity (overall high-frequency power and event-related cardiac slowing) was analyzed. Our results show that in novel social interactions, women with obesity, relative to the other groups, exhibited the strongest increase in parasympathetic activity. Furthermore, parasympathetic activity was related to a more negative body image in individuals with obesity, but not in lean individuals. Additionally, women with obesity reported a stronger decrease in mood after social exclusion than did the other participants. Our results demonstrate influences of objective and subjective bodily characteristics on parasympathetic cardio-regulation during social interactions. In particular, they show behavioral and physiological alterations during social interactions in women with obesity.

  18. [Influence of hypertension disorder complicating pregancy and its interaction with other factors on incidence of small for gestational age].

    PubMed

    Wang, Y; Li, M; Xie, B J; Guo, P G; Cheng, Y P; Feng, Y L; Zhang, P; Wu, W W; Wang, S P; Zhang, Y W; Yang, H L

    2016-09-10

    Objective: To understand the influence of hypertension disorder complicating pregancy on the incidence of small for gestational age (SGA) and its interaction with other factors. Methods: A nested case-control study was conducted to analyze the influence of hypertension disorder complicating pregancy on the incidence of small for gestational age and evaluate the interaction between hypertension disorder complicating pregancy and other factors. Results: Data from 6 297 subjects were collected, including 836 (13.28%) pregnant women with hypertension disorder complicating pregancy, 789 (12.53%) infants who were small for gestational age. Compared with the pregnant women without hypertension disorder complicating pregancy, women with hypertension disorder complicating pregancy (aOR=2.185, 95% CI: 1.266-3.770), preeclampsia- eclampsia (aOR=5.322, 95% CI: 4.224-6.707) and with chronic hypertension complicated with superimposed preeclampsia (aOR=3.794, 95% CI: 2.190-6.573) had increased risk for the incidence of small for gestational age. The Interaction analysis showed that there was strong positive interactions between hypertension disorder complicating pregancy and premature birth on small for gestational age infants (RERI=5.260, AP=0.586, SI=2.941), (OR=2.331, 95%CI: 1.443-3.767). Addictive interaction was found between hypertension disorder complicating pregancy and placental abruption (RERI=5.631, AP= 0.522, SI=2.352), and between hypertension disorder complicating pregancy and female fetuses (RERI= 3.660, AP=0.374, SI=1.714), and between hypertension disorder complicating pregancy and oligohydramnios (RERI=10.619, AP=0.636, SI=3.093). However, no significant multiplication interaction was found. Conclusions: Hypertension disorder complicating pregancy is the risk factor of the incidence of small for gestational age. Hypertension disorder complicating pregancy also showed addictive interaction on the incidence of small for gestational age with female fetuses

  19. Universal mean-field phase diagram for biaxial nematics obtained from a minimax principle.

    PubMed

    Bisi, Fulvio; Virga, Epifanio G; Gartland, Eugene C; De Matteis, Giovanni; Sonnet, André M; Durand, Georges E

    2006-05-01

    We study a class of quadratic Hamiltonians which describe both fully attractive and partly repulsive molecular interactions, characteristic of biaxial liquid crystal molecules. To treat the partly repulsive interactions we establish a minimax principle for the associated mean-field free energy. We show that the phase diagram described by Sonnet [Phys. Rev. E 67, 061701 (2003)] is universal. Our predictions are in good agreement with the recent observations on both V-shaped and tetrapodal molecules.

  20. Does the type of event influence how user interactions evolve on Twitter?

    PubMed

    del Val, Elena; Rebollo, Miguel; Botti, Vicente

    2015-01-01

    The number of people using on-line social networks as a new way of communication is continually increasing. The messages that a user writes in these networks and his/her interactions with other users leave a digital trace that is recorded. Thanks to this fact and the use of network theory, the analysis of messages, user interactions, and the complex structures that emerge is greatly facilitated. In addition, information generated in on-line social networks is labeled temporarily, which makes it possible to go a step further analyzing the dynamics of the interaction patterns. In this article, we present an analysis of the evolution of user interactions that take place in television, socio-political, conference, and keynote events on Twitter. Interactions have been modeled as networks that are annotated with the time markers. We study changes in the structural properties at both the network level and the node level. As a result of this analysis, we have detected patterns of network evolution and common structural features as well as differences among the events.

  1. Influence of World and Gravity Model Selection on Surface Interacting Vehicle Simulations

    NASA Technical Reports Server (NTRS)

    Madden, Michael M.

    2007-01-01

    A vehicle simulation is surface-interacting if the state of the vehicle (position, velocity, and acceleration) relative to the surface is important. Surface-interacting simulations perform ascent, entry, descent, landing, surface travel, or atmospheric flight. Modeling of gravity is an influential environmental factor for surface-interacting simulations. Gravity is the free-fall acceleration observed from a world-fixed frame that rotates with the world. Thus, gravity is the sum of gravitation and the centrifugal acceleration due to the world s rotation. In surface-interacting simulations, the fidelity of gravity at heights above the surface is more significant than gravity fidelity at locations in inertial space. A surface-interacting simulation cannot treat the gravity model separately from the world model, which simulates the motion and shape of the world. The world model's simulation of the world's rotation, or lack thereof, produces the centrifugal acceleration component of gravity. The world model s reproduction of the world's shape will produce different positions relative to the world center for a given height above the surface. These differences produce variations in the gravitation component of gravity. This paper examines the actual performance of world and gravity/gravitation pairs in a simulation using the Earth.

  2. Does the Type of Event Influence How User Interactions Evolve on Twitter?

    PubMed Central

    del Val, Elena; Rebollo, Miguel; Botti, Vicente

    2015-01-01

    The number of people using on-line social networks as a new way of communication is continually increasing. The messages that a user writes in these networks and his/her interactions with other users leave a digital trace that is recorded. Thanks to this fact and the use of network theory, the analysis of messages, user interactions, and the complex structures that emerge is greatly facilitated. In addition, information generated in on-line social networks is labeled temporarily, which makes it possible to go a step further analyzing the dynamics of the interaction patterns. In this article, we present an analysis of the evolution of user interactions that take place in television, socio-political, conference, and keynote events on Twitter. Interactions have been modeled as networks that are annotated with the time markers. We study changes in the structural properties at both the network level and the node level. As a result of this analysis, we have detected patterns of network evolution and common structural features as well as differences among the events. PMID:25961305

  3. Inbreeding depression in an insect with maternal care: influences of family interactions, life stage and offspring sex.

    PubMed

    Meunier, J; Kölliker, M

    2013-10-01

    Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here, we demonstrate that these three factors jointly shape inbreeding depression in the European earwig, Forficula auricularia. Using a series of cross-breeding, split-clutch and brood size manipulation experiments conducted over two generations, we first showed that sib mating (leading to inbred offspring) did not influence the reproductive success of earwig parents. Second, the presence of tending mothers and the strength of sibling competition (i.e. brood size) did not influence the expression of inbreeding depression in the inbred offspring. By contrast, our results revealed that inbreeding dramatically depressed the reproductive success of inbred adult male offspring, but only had little effect on the reproductive success of inbred adult female offspring. Overall, this study demonstrates limited effects of family interactions on inbreeding depression in this species and emphasizes the importance of disentangling effects of sib mating early and late during development to better understand the evolution of mating systems and population dynamics.

  4. Generation of pedigree diagrams for web display using scalable vector graphics from a clinical trials database.

    PubMed Central

    Fernando, S. K.; Brandt, C.; Nadkarni, P.

    2001-01-01

    The standard method of studying inherited disease is to observe its pattern of distribution in families, that is, its pattern in a pedigree. For clinical studies focused on inherited disease, a pedigree diagram is a valuable visual tool for the display of inheritance patterns. We describe the creation of a web-based pedigree display module for Trial/DB, a Web accessible database developed at the Yale Center for Medical Informatics (YCMI) to support clinical research studies. The pedigree diagram is generated dynamically from the database. The icons representing each subject in the pedigree are selectable hyperlinks that will display detailed clinical data collected on the subject. Microsoft Active Server Page and Scalable Vector Graphics (SVG) are used to create the interactive pedigree diagrams. PMID:11825175

  5. Phase diagram of softly repulsive systems: the Gaussian and inverse-power-law potentials.

    PubMed

    Prestipino, Santi; Saija, Franz; Giaquinta, Paolo V

    2005-10-08

    We redraw, using state-of-the-art methods for free-energy calculations, the phase diagrams of two reference models for the liquid state: the Gaussian and inverse-power-law repulsive potentials. Notwithstanding the different behaviors of the two potentials for vanishing interparticle distances, their thermodynamic properties are similar in a range of densities and temperatures, being ruled by the competition between the body-centered-cubic (bcc) and face-centered-cubic (fcc) crystalline structures and the fluid phase. We confirm the existence of a reentrant bcc phase in the phase diagram of the Gaussian-core model, just above the triple point. We also trace the bcc-fcc coexistence line of the inverse-power-law model as a function of the power exponent n and relate the common features in the phase diagrams of such systems to the softness degree of the interaction.

  6. Building a responsive teacher: how temporal contingency of gaze interaction influences word learning with virtual tutors.

    PubMed

    Lee, Hanju; Kanakogi, Yasuhiro; Hiraki, Kazuo

    2015-01-01

    Animated pedagogical agents are lifelike virtual characters designed to augment learning. A review of developmental psychology literature led to the hypothesis that the temporal contingency of such agents would promote human learning. We developed a Pedagogical Agent with Gaze Interaction (PAGI), an experimental animated pedagogical agent that engages in gaze interaction with students. In this study, university students learned words of a foreign language, with temporally contingent PAGI (live group) or recorded version of PAGI (recorded group), which played pre-recorded sequences from live sessions. The result revealed that students in the live group scored considerably better than those in the recorded group. The finding indicates that incorporating temporal contingency of gaze interaction from a pedagogical agent has positive effect on learning.

  7. The influence of arene-ring size on stacking interaction with canonical base pairs

    NASA Astrophysics Data System (ADS)

    Formánek, Martin; Burda, Jaroslav V.

    2014-04-01

    Stacking interactions between aromatic molecules (benzene, p-cymene, biphenyl, and di- and tetra-hydrogen anthracene) and G.C and A.T canonical Watson-Crick (WC) base pairs are explored. Two functionals with dispersion corrections: ω-B97XD and B3LYP-D3 are used. For a comparison also the MP2 and B3LYP-D3/PCM methods were used for the most stable p-cymene…WC geometries. It was found that the stacking interaction increases with the size of π-conjugation system. Its extent is in agreement with experimental finding on anticancer activity of Ru(II) piano-stool complexes where intercalation of these aromatic molecules should play an important role. The explored structures are considered as ternary system so that decomposition of the interaction energy to pairwise and non-additivity contributions is also examined.

  8. Intramembrane aromatic interactions influence the lipid sensitivities of pentameric ligand-gated ion channels.

    PubMed

    Carswell, Casey L; Sun, Jiayin; Baenziger, John E

    2015-01-23

    Although the Torpedo nicotinic acetylcholine receptor (nAChR) reconstituted into phosphatidylcholine (PC) membranes lacking cholesterol and anionic lipids adopts a conformation where agonist binding is uncoupled from channel gating, the underlying mechanism remains to be defined. Here, we examine the mechanism behind lipid-dependent uncoupling by comparing the propensities of two prokaryotic homologs, Gloebacter and Erwinia ligand-gated ion channel (GLIC and ELIC, respectively), to adopt a similar uncoupled conformation. Membrane-reconstituted GLIC and ELIC both exhibit folded structures in the minimal PC membranes that stabilize an uncoupled nAChR. GLIC, with a large number of aromatic interactions at the interface between the outermost transmembrane α-helix, M4, and the adjacent transmembrane α-helices, M1 and M3, retains the ability to flux cations in this uncoupling PC membrane environment. In contrast, ELIC, with a level of aromatic interactions intermediate between that of the nAChR and GLIC, does not undergo agonist-induced channel gating, although it does not exhibit the expected biophysical characteristics of the uncoupled state. Engineering new aromatic interactions at the M4-M1/M3 interface to promote effective M4 interactions with M1/M3, however, increases the stability of the transmembrane domain to restore channel function. Our data provide direct evidence that M4 interactions with M1/M3 are modulated during lipid sensing. Aromatic residues strengthen M4 interactions with M1/M3 to reduce the sensitivities of pentameric ligand-gated ion channels to their surrounding membrane environment.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Titanium Matrix/Continuous Fiber Composite Interface Interactions and their Influence on Mechanical Properties.

    DTIC Science & Technology

    1983-02-25

    March 1983. -.... ...... ... ... ... ... 13 Coupled Interactions 3 mThe following interactions involving our research took place in 1981 and 1982: 1...b 2 0 isothermal treated 00 0 10 0 30M Ditac aln th inerae z Figue 2 Sufur oncntrtio chagesalog th marixsid inerac;_a) Ssz ) (b ortmf tigo sz for SC...is about 20%, for B4C/B/Ti-6AI-4V thermal cycled in sulfur to 540’C. -l - 00m Ti i 0 11 0 o 0)0 0 03 Si N 0 P4 13 ~ *JL .* * 0 0 10 20 (#m) Depth

  11. Dimensionality-strain phase diagram of strontium iridates

    NASA Astrophysics Data System (ADS)

    Kim, Bongjae; Liu, Peitao; Franchini, Cesare

    2017-03-01

    The competition between spin-orbit coupling, bandwidth (W ), and electron-electron interaction (U ) makes iridates highly susceptible to small external perturbations, which can trigger the onset of novel types of electronic and magnetic states. Here we employ first principles calculations based on density functional theory and on the constrained random phase approximation to study how dimensionality and strain affect the strength of U and W in (SrIrO3)m/(SrTiO3) superlattices. The result is a phase diagram explaining two different types of controllable magnetic and electronic transitions, spin-flop and insulator-to-metal, connected with the disruption of the Jeff=1 /2 state which cannot be understood within a simplified local picture.

  12. Particle diagrams and embedded many-body random matrix theory.

    PubMed

    Small, R A; Müller, S

    2014-07-01

    We present a method which uses Feynman-like diagrams to calculate the statistical quantities of embedded many-body random matrix problems. The method provides a promising alternative to existing techniques and offers many important simplifications. We use it here to find the fourth, sixth, and eighth moments of the level density of an m-body system with k fermions or bosons interacting through a random Hermitian potential (k ≤ m) in the limit where the number of possible single-particle states is taken to infinity. All share the same transition, starting immediately after 2k = m, from moments arising from a semicircular level density to Gaussian moments. The results also reveal a striking feature; the domain of the 2nth moment is naturally divided into n subdomains specified by the points 2k = m,3 k = m,...,nk = m.

  13. The Mental Health Outcomes of Drought: A Systematic Review and Causal Process Diagram.

    PubMed

    Vins, Holly; Bell, Jesse; Saha, Shubhayu; Hess, Jeremy J

    2015-10-22

    Little is understood about the long term, indirect health consequences of drought (a period of abnormally dry weather). In particular, the implications of drought for mental health via pathways such as loss of livelihood, diminished social support, and rupture of place bonds have not been extensively studied, leaving a knowledge gap for practitioners and researchers alike. A systematic review of literature was performed to examine the mental health effects of drought. The systematic review results were synthesized to create a causal process diagram that illustrates the pathways linking drought effects to mental health outcomes. Eighty-two articles using a variety of methods in different contexts were gathered from the systematic review. The pathways in the causal process diagram with greatest support in the literature are those focusing on the economic and migratory effects of drought. The diagram highlights the complexity of the relationships between drought and mental health, including the multiple ways that factors can interact and lead to various outcomes. The systematic review and resulting causal process diagram can be used in both practice and theory, including prevention planning, public health programming, vulnerability and risk assessment, and research question guidance. The use of a causal process diagram provides a much needed avenue for integrating the findings of diverse research to further the understanding of the mental health implications of drought.

  14. The Mental Health Outcomes of Drought: A Systematic Review and Causal Process Diagram

    PubMed Central

    Vins, Holly; Bell, Jesse; Saha, Shubhayu; Hess, Jeremy J.

    2015-01-01

    Little is understood about the long term, indirect health consequences of drought (a period of abnormally dry weather). In particular, the implications of drought for mental health via pathways such as loss of livelihood, diminished social support, and rupture of place bonds have not been extensively studied, leaving a knowledge gap for practitioners and researchers alike. A systematic review of literature was performed to examine the mental health effects of drought. The systematic review results were synthesized to create a causal process diagram that illustrates the pathways linking drought effects to mental health outcomes. Eighty-two articles using a variety of methods in different contexts were gathered from the systematic review. The pathways in the causal process diagram with greatest support in the literature are those focusing on the economic and migratory effects of drought. The diagram highlights the complexity of the relationships between drought and mental health, including the multiple ways that factors can interact and lead to various outcomes. The systematic review and resulting causal process diagram can be used in both practice and theory, including prevention planning, public health programming, vulnerability and risk assessment, and research question guidance. The use of a causal process diagram provides a much needed avenue for integrating the findings of diverse research to further the understanding of the mental health implications of drought. PMID:26506367

  15. Influence of Sound Immersion and Communicative Interaction on the Lombard Effect

    ERIC Educational Resources Information Center

    Garnier, Maeva; Henrich, Nathalie; Dubois, Daniele

    2010-01-01

    Purpose: To examine the influence of sound immersion techniques and speech production tasks on speech adaptation in noise. Method: In Experiment 1, we compared the modification of speakers' perception and speech production in noise when noise is played into headphones (with and without additional self-monitoring feedback) or over loudspeakers. We…

  16. The Analysis of Challenging Relations: Influences on Interactive Behaviour of Staff towards Clients with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Willems, A. P. A. M.; Embregts, P. J. C. M.; Bosman, A. M. T.; Hendriks, A. H. C.

    2014-01-01

    Background: Relationships between support staff and clients with intellectual disability (ID) are important for quality of care, especially when dealing with challenging behaviour. Building upon an interpersonal model, this study investigates the influence of client challenging behaviour, staff attitude and staff emotional intelligence on…

  17. A Short Report: Word-Level Phonological and Lexical Characteristics Interact to Influence Phoneme Awareness

    ERIC Educational Resources Information Center

    Hogan, Tiffany P.

    2010-01-01

    In this study, we examined the influence of word-level phonological and lexical characteristics on early phoneme awareness. Typically developing children, ages 61 to 78 months, completed a phoneme-based, odd-one-out task that included consonant-vowel-consonant word sets (e.g., "chair-chain-ship") that varied orthogonally by a phonological…

  18. Language Interaction in Nahuatl Discourse: The Influence of Spanish in Child and Adult Narratives.

    ERIC Educational Resources Information Center

    Francis, Norbert; Gomez, Pablo Rogelio Navarrete

    2003-01-01

    This study on code-mixing focuses on the influence of Spanish in Nahuatl discourse as revealed in narratives produced by adults and children. Results indicate differences in frequency of content word embedded language (Spanish), lexical items across grade level (for children), grade level attained (for adults), and correlations (for children)…

  19. Sinc function representation and three-loop master diagrams

    SciTech Connect

    Easther, Richard; Guralnik, Gerald; Hahn, Stephen

    2001-04-15

    We test the Sinc function representation, a novel method for numerically evaluating Feynman diagrams, by using it to evaluate the three-loop master diagrams. Analytical results have been obtained for all these diagrams, and we find excellent agreement between our calculations and the exact values. The Sinc function representation converges rapidly, and it is straightforward to obtain accuracies of 1 part in 10{sup 6} for these diagrams and with longer runs we found results better than 1 part in 10{sup 12}. Finally, this paper extends the Sinc function representation to diagrams containing massless propagators.

  20. Quantitative study of FORC diagrams in thermally corrected Stoner- Wohlfarth nanoparticles systems

    NASA Astrophysics Data System (ADS)

    De Biasi, E.; Curiale, J.; Zysler, R. D.

    2016-12-01

    The use of FORC diagrams is becoming increasingly popular among researchers devoted to magnetism and magnetic materials. However, a thorough interpretation of this kind of diagrams, in order to achieve quantitative information, requires an appropriate model of the studied system. For that reason most of the FORC studies are used for a qualitative analysis. In magnetic systems thermal fluctuations "blur" the signatures of the anisotropy, volume and particle interactions distributions, therefore thermal effects in nanoparticles systems conspire against a proper interpretation and analysis of these diagrams. Motivated by this fact, we have quantitatively studied the degree of accuracy of the information extracted from FORC diagrams for the special case of single-domain thermal corrected Stoner- Wohlfarth (easy axes along the external field orientation) nanoparticles systems. In this work, the starting point is an analytical model that describes the behavior of a magnetic nanoparticles system as a function of field, anisotropy, temperature and measurement time. In order to study the quantitative degree of accuracy of our model, we built FORC diagrams for different archetypical cases of magnetic nanoparticles. Our results show that from the quantitative information obtained from the diagrams, under the hypotheses of the proposed model, is possible to recover the features of the original system with accuracy above 95%. This accuracy is improved at low temperatures and also it is possible to access to the anisotropy distribution directly from the FORC coercive field profile. Indeed, our simulations predict that the volume distribution plays a secondary role being the mean value and its deviation the only important parameters. Therefore it is possible to obtain an accurate result for the inversion and interaction fields despite the features of the volume distribution.

  1. The Asymmetrical Influence of Identity: A Triadic Interaction among Israeli Jews, Israeli Arabs, and Historical Texts

    ERIC Educational Resources Information Center

    Kolikant, Yifat Ben-David; Pollack, Sarah

    2009-01-01

    This study engaged Israeli-Jewish and Israeli-Arab students in a joint investigation of their common past by means of secondary historical sources. The hypothesis was that a triadic interaction among agents of groups with opposing views and historical texts can foster historical thinking. It was expected that while ethnic identity would drive both…

  2. Influence of Interactive Videoconferencing on the Performance of Pharmacy Students and Instructors.

    ERIC Educational Resources Information Center

    Chisholm, Marie A.; Miller, Allison W.; Spruill, William J.; Cobb, Henry H.; Reinhardt, Bess O.; Terry, Alvin V.; Reese, R. Lee; Wade, William E.

    2000-01-01

    Examined effects of interactive videoconferencing (IVC) on pharmacy students' (n=26) academic performance and pharmacy instructors' (n=4) teaching evaluations. There was no difference in performance between students who attended live lectures and students who received lectures via IVC. However, students rated IVC instructors lower than live…

  3. Transformed Social Interaction, Augmented Gaze, and Social Influence in Immersive Virtual Environments

    ERIC Educational Resources Information Center

    Bailenson, Jeremy N.; Beall, Andrew C.; Loomis, Jack; Blascovich, Jim; Turk, Matthew

    2005-01-01

    Immersive collaborative virtual environments (CVEs) are simulations in which geographically separated individuals interact in a shared, three-dimensional, digital space using immersive virtual environment technology. Unlike videoconference technology, which transmits direct video streams, immersive CVEs accurately track movements of interactants…

  4. Strategies and Intervening Factors Influencing Student Social Interaction and Experiential Learning in an Interdisciplinary Research Team

    ERIC Educational Resources Information Center

    Ryser, Laura; Halseth, Greg; Thien, Deborah

    2009-01-01

    Faculty have long incorporated students into interdisciplinary research projects to meet increasingly common demands for collaborative research by federal funding agencies. Despite the critical role of experiential learning in building student research skills and capacity, few have explored social interaction mechanisms used to facilitate student…

  5. Multisensory Interactions Influence Neuronal Spike Train Dynamics in the Posterior Parietal Cortex

    PubMed Central

    VanGilder, Paul; Shi, Ying; Apker, Gregory; Dyson, Keith; Buneo, Christopher A.

    2016-01-01

    Although significant progress has been made in understanding multisensory interactions at the behavioral level, their underlying neural mechanisms remain relatively poorly understood in cortical areas, particularly during the control of action. In recent experiments where animals reached to and actively maintained their arm position at multiple spatial locations while receiving either proprioceptive or visual-proprioceptive position feedback, multisensory interactions were shown to be associated with reduced spiking (i.e. subadditivity) as well as reduced intra-trial and across-trial spiking variability in the superior parietal lobule (SPL). To further explore the nature of such interaction-induced changes in spiking variability we quantified the spike train dynamics of 231 of these neurons. Neurons were classified as Poisson, bursty, refractory, or oscillatory (in the 13–30 Hz “beta-band”) based on their spike train power spectra and autocorrelograms. No neurons were classified as Poisson-like in either the proprioceptive or visual-proprioceptive conditions. Instead, oscillatory spiking was most commonly observed with many neurons exhibiting these oscillations under only one set of feedback conditions. The results suggest that the SPL may belong to a putative beta-synchronized network for arm position maintenance and that position estimation may be subserved by different subsets of neurons within this network depending on available sensory information. In addition, the nature of the observed spiking variability suggests that models of multisensory interactions in the SPL should account for both Poisson-like and non-Poisson variability. PMID:28033334

  6. The Effectiveness of an Interactive Multimedia Program to Influence Eating Habits

    ERIC Educational Resources Information Center

    Irvine, A. Blair; Ary, Dennis V.; Grove, Dean A.; Gilfillan-Morton, Lynn

    2004-01-01

    An interactive multimedia program to encourage individuals to decrease their dietary fat consumption and to increase consumption of fruits and vegetables was developed and evaluated at two worksites. The program presented content tailored to the user by gender, content interests, race, and age group. It was tested using a randomized treatment and…

  7. How Do Interaction Experiences Influence Doctoral Students' Academic Pursuits in Biomedical Research?

    ERIC Educational Resources Information Center

    Kong, Xiaoqing; Chakraverty, Devasmita; Jeffe, Donna B.; Andriole, Dorothy A.; Wathington, Heather D.; Tai, Robert H.

    2013-01-01

    This exploratory qualitative study investigated how doctoral students reported their personal and professional interaction experiences that they believed might facilitate or impede their academic pursuits in biomedical research. We collected 19 in-depth interviews with doctoral students in biomedical research from eight universities, and we based…

  8. Obstructive Interactive Television Designs: The Influence of Culture, Gender and Power.

    ERIC Educational Resources Information Center

    Knupfer, Nancy Nelson; Gram, Theresa E.

    This study contributes to discourse surrounding equity in opportunities for constituencies who are under-represented in the decision making process surrounding interactive television (ITV) adoption, yet account for a great portion of faculty and students who must then use it. The paper touches on the material expression of a culture's value…

  9. Interpersonal Interaction within the Violin Teaching Studio: The Influence of Interpersonal Dynamics on Outcomes for Teachers

    ERIC Educational Resources Information Center

    Creech, Andrea; Hallam, Susan

    2010-01-01

    The overall aims of this study were to identify qualities of interpersonal interaction within teacher-parent-pupil learning partnerships and to explore whether these characteristics were predictors of learning and teaching outcomes for teachers, parents and pupils participating in pursuit of expertise on musical instruments. This article presents…

  10. Long-Term Musical Group Interaction Has a Positive Influence on Empathy in Children

    ERIC Educational Resources Information Center

    Rabinowitch, Tal-Chen; Cross, Ian; Burnard, Pamela

    2013-01-01

    Musical group interaction (MGI) is a complex social setting requiring certain cognitive skills that may also elicit shared psychological states. We argue that many MGI-specific features may also be important for emotional empathy, the ability to experience another person's emotional state. We thus hypothesized that long-term repeated participation…

  11. Impact and Influence of the Natural Vibrio-Squid Symbiosis in Understanding Bacterial–Animal Interactions

    PubMed Central

    Mandel, Mark J.; Dunn, Anne K.

    2016-01-01

    Animals are colonized by bacteria, and in many cases partners have co-evolved to perform mutually beneficial functions. An exciting and ongoing legacy of the past decade has been an expansion of technology to enable study of natural associations in situ/in vivo. As a result, more symbioses are being examined, and additional details are being revealed for well-studied systems with a focus on the interactions between partners in the native context. With this framing, we review recent literature from the Vibrio fischeri–Euprymna scolopes symbiosis and focus on key studies that have had an impact on understanding bacteria–animal interactions broadly. This is not intended to be a comprehensive review of the system, but rather to focus on particular studies that have excelled at moving from pattern to process in facilitating an understanding of the molecular basis to intriguing observations in the field of host–microbe interactions. In this review we discuss the following topics: processes regulating strain and species specificity; bacterial signaling to host morphogenesis; multiple roles for nitric oxide; flagellar motility and chemotaxis; and efforts to understand unannotated and poorly annotated genes. Overall these studies demonstrate how functional approaches in vivo in a tractable system have provided valuable insight into general principles of microbe–host interactions. PMID:28018314

  12. Interactions between Three Phonological Subsystems of Young Multilinguals: The Influence of Language Status

    ERIC Educational Resources Information Center

    Kopecková, Romana; Marecka, Marta; Wrembel, Magdalena; Gut, Ulrike

    2016-01-01

    This study examines the interactions between three vocalic subsystems of multilingual speakers and explores the role language status might play in explaining variability across them. Eight 14-year-olds raised in Germany, who had learnt English at school for 6 years and Polish for 1 year, participated in the study. They were divided into three…

  13. Explaining Student Interaction and Satisfaction: An Empirical Investigation of Delivery Mode Influence

    ERIC Educational Resources Information Center

    Johnson, Zachary S.; Cascio, Robert; Massiah, Carolyn A.

    2014-01-01

    How interpersonal interactions within a course affect student satisfaction differently between face-to-face and online modes is an important research question to answer with confidence. Using students from a marketing course delivered face-to-face and online concurrently, our first study demonstrates that student-to-professor and…

  14. Influence of a Parent-Child Interaction Focused Bookmaking Approach on Maternal Parenting Self-Efficacy

    ERIC Educational Resources Information Center

    Boyce, Lisa K.; Seedall, Ryan B.; Innocenti, Mark S.; Roggman, Lori A.; Cook, Gina A.; Hagman, Amanda M.; Jump Norman, Vonda K.

    2017-01-01

    We examined the effects of our parent-child interaction focused bookmaking intervention with 89 families and their toddlers receiving early intervention services. Participating early intervention providers (N = 24) were assigned to either continue providing services as usual or participate in training to implement the bookmaking approach in their…

  15. The influence of bonding agents in improving interactions in composite propellants determined using image analysis.

    PubMed

    Dostanić, J; Husović, T V; Usćumlić, G; Heinemann, R J; Mijin, D

    2008-12-01

    Binder-oxidizer interactions in rocket composite propellants can be improved using adequate bonding agents. In the present work, the effectiveness of different 1,3,5-trisubstituted isocyanurates was determined by stereo and metallographic microscopy and using the software package Image-Pro Plus. The chemical analysis of samples was performed by a scanning electron microscope equipped for energy dispersive spectrometry.

  16. Impact and Influence of the Natural Vibrio-Squid Symbiosis in Understanding Bacterial-Animal Interactions.

    PubMed

    Mandel, Mark J; Dunn, Anne K

    2016-01-01

    Animals are colonized by bacteria, and in many cases partners have co-evolved to perform mutually beneficial functions. An exciting and ongoing legacy of the past decade has been an expansion of technology to enable study of natural associations in situ/in vivo. As a result, more symbioses are being examined, and additional details are being revealed for well-studied systems with a focus on the interactions between partners in the native context. With this framing, we review recent literature from the Vibrio fischeri-Euprymna scolopes symbiosis and focus on key studies that have had an impact on understanding bacteria-animal interactions broadly. This is not intended to be a comprehensive review of the system, but rather to focus on particular studies that have excelled at moving from pattern to process in facilitating an understanding of the molecular basis to intriguing observations in the field of host-microbe interactions. In this review we discuss the following topics: processes regulating strain and species specificity; bacterial signaling to host morphogenesis; multiple roles for nitric oxide; flagellar motility and chemotaxis; and efforts to understand unannotated and poorly annotated genes. Overall these studies demonstrate how functional approaches in vivo in a tractable system have provided valuable insight into general principles of microbe-host interactions.

  17. Influence of Image Interactivity on Approach Responses towards an Online Retailer.

    ERIC Educational Resources Information Center

    Fiore, Ann Marie; Jin, Hyun-Jeong

    2003-01-01

    Measured the effect of exposure to an image interactivity function from an apparel retailer's Web site on approach responses towards the retailer. Dependent variables included attitude towards the online store, willingness to purchase, probability of spending more time than planned shopping, and likelihood of patronizing the online retailer's…

  18. Are leftists more emotion-driven than rightists? The interactive influence of ideology and emotions on support for policies.

    PubMed

    Pliskin, Ruthie; Bar-Tal, Daniel; Sheppes, Gal; Halperin, Eran

    2014-12-01

    Although emotions and ideology are important factors guiding policy support in conflict, their interactive influence remains unclear. Based on prior findings that ideological leftists' beliefs are more susceptible to change than rightists' beliefs, we tested a somewhat counterintuitive extension that leftists would be more susceptible to influence by their emotional reactions than rightists. In three laboratory studies, inducing positive and negative emotions affected Jewish-Israeli leftists', but not rightists', support for conciliatory policies toward an adversarial (Studies 1 and 3) and a non-adversarial (Study 2) outgroup. Three additional field studies showed that positive and negative emotions were related to leftists', but not rightists', policy support in positive as well as highly negative conflict-related contexts, among both Jewish (Studies 4 and 5) and Palestinian (Study 6) citizens of Israel. Across different conflicts, emotions, conflict-related contexts, and even populations, leftists' policy support changed in accordance with emotional reactions more than rightists' policy support.

  19. Serum stimulation, cell-cell interactions, and extracellular matrix independently influence smooth muscle cell phenotype in vitro.

    PubMed Central

    Kato, S.; Shanley, J. R.; Fox, J. C.

    1996-01-01

    Vascular injury profoundly alters the vessel wall microenvironment, and smooth muscle cells respond with cell cycle re-entry, loss of contractile elements, extracellular matrix remodeling, and altered signaling by endogenous growth factors and their receptors. Environmental cues include stimulation by exogenous mitogens and both cell-cell and cell-matrix interactions. Modeling this process in smooth muscle cells in vitro, these environmental determinants were varied independently and the phenotypic consequences assessed. Mitogenic stimulation with serum promoted the synthesis of collagen and fibronectin and the expression of fibroblast growth factor receptor-1 and suppressed the content of smooth muscle alpha-actin, myosin heavy chain, and basic fibroblast growth factor. Low cell density (reduced cell-cell contact) was also associated with enhanced extracellular matrix protein production, increased fibroblast growth factor receptor-1 expression, and reduced contractile protein and basic fibroblast growth factor content. The influence of serum stimulation and reduced cell-cell contact were independent and additive. Provision of a type I collagen matrix blunted the influence of serum and cell-cell contact on collagen synthesis but had minor effects on other measures of phenotype. Environmental factors thus independently influence smooth muscle cell phenotype, including endogenous growth factor expression and responsiveness, which can in turn influence the microenvironment of the vessel wall after injury. Images Figure 1 Figure 5 Figure 6 PMID:8702006

  20. State-transition diagrams for biologists.

    PubMed

    Bersini, Hugues; Klatzmann, David; Six, Adrien; Thomas-Vaslin, Véronique

    2012-01-01

    It is clearly in the tradition of biologists to conceptualize the dynamical evolution of biological systems in terms of state-transitions of biological objects. This paper is mainly concerned with (but obviously not limited too) the immunological branch of biology and shows how the adoption of UML (Unified Modeling Language) state-transition diagrams can ease the modeling, the understanding, the coding, the manipulation or the documentation of population-based immune software model generally defined as a set of ordinary differential equations (ODE), describing the evolution in time of populations of various biological objects. Moreover, that same UML adoption naturally entails a far from negligible representational economy since one graphical item of the diagram might have to be repeated in various places of the mathematical model. First, the main graphical elements of the UML state-transition diagram and how they can be mapped onto a corresponding ODE mathematical model are presented. Then, two already published immune models of thymocyte behavior and time evolution in the thymus, the first one originally conceived as an ODE population-based model whereas the second one as an agent-based one, are refactored and expressed in a state-transition form so as to make them much easier to understand and their respective code easier to access, to modify and run. As an illustrative proof, for any immunologist, it should be possible to understand faithfully enough what the two software models are supposed to reproduce and how they execute with no need to plunge into the Java or Fortran lines.

  1. State-Transition Diagrams for Biologists

    PubMed Central

    Bersini, Hugues; Klatzmann, David; Six, Adrien; Thomas-Vaslin, Véronique

    2012-01-01

    It is clearly in the tradition of biologists to conceptualize the dynamical evolution of biological systems in terms of state-transitions of biological objects. This paper is mainly concerned with (but obviously not limited too) the immunological branch of biology and shows how the adoption of UML (Unified Modeling Language) state-transition diagrams can ease the modeling, the understanding, the coding, the manipulation or the documentation of population-based immune software model generally defined as a set of ordinary differential equations (ODE), describing the evolution in time of populations of various biological objects. Moreover, that same UML adoption naturally entails a far from negligible representational economy since one graphical item of the diagram might have to be repeated in various places of the mathematical model. First, the main graphical elements of the UML state-transition diagram and how they can be mapped onto a corresponding ODE mathematical model are presented. Then, two already published immune models of thymocyte behavior and time evolution in the thymus, the first one originally conceived as an ODE population-based model whereas the second one as an agent-based one, are refactored and expressed in a state-transition form so as to make them much easier to understand and their respective code easier to access, to modify and run. As an illustrative proof, for any immunologist, it should be possible to understand faithfully enough what the two software models are supposed to reproduce and how they execute with no need to plunge into the Java or Fortran lines. PMID:22844438

  2. Comprehending 3D Diagrams: Sketching to Support Spatial Reasoning.

    PubMed

    Gagnier, Kristin M; Atit, Kinnari; Ormand, Carol J; Shipley, Thomas F

    2016-11-25

    Science, technology, engineering, and mathematics (STEM) disciplines commonly illustrate 3D relationships in diagrams, yet these are often challenging for students. Failing to understand diagrams can hinder success in STEM because scientific practice requires understanding and creating diagrammatic representations. We explore a new approach to improving student understanding of diagrams that convey 3D relations that is based on students generating their own predictive diagrams. Participants' comprehension of 3D spatial diagrams was measured in a pre- and post-design where students selected the correct 2D slice through 3D geologic block diagrams. Generating sketches that predicated the internal structure of a model led to greater improvement in diagram understanding than visualizing the interior of the model without sketching, or sketching the model without attempting to predict unseen spatial relations. In addition, we found a positive correlation between sketched diagram accuracy and improvement on the diagram comprehension measure. Results suggest that generating a predictive diagram facilitates students' abilities to make inferences about spatial relationships in diagrams. Implications for use of sketching in supporting STEM learning are discussed.

  3. The influence of habitat fragmentation on multiple plant-animal interactions and plant reproduction.

    PubMed

    Brudvig, Lars A; Damschen, Ellen I; Haddad, Nick M; Levey, Douglas J; Tewksbury, Joshua J

    2015-10-01

    Despite broad recognition that habitat loss represents the greatest threat to the world's biodiyersity, a mechanistic understanding of how habitat loss and associated fragmentation affect ecological systems has proven remarkably challenging. The challenge stems from the multiple interdependent ways that landscapes change following fragmentation and the ensuing complex impacts on populations and communities of interacting species. We confronted these challenges by evaluating how fragmentation affects individual plants through interactions with animals, across five herbaceous species native to longleaf pine savannas. We created a replicated landscape experiment that provides controlled tests of three major fragmentation effects (patch isolation, patch shape [i.e., edge-to-area ratio], and distance to edge), established experimental founder populations of the five species to control for spatial distributions and densities of individual plants, and employed structural equation modeling to evaluate the effects of fragmentation on plant reproductive output and the degree to which these impacts are mediated through altered herbivory, pollination, or pre-dispersal seed predation. Across species, the most consistent response to fragmentation was a reduction in herbivory. Herbivory, however, had little impact.on plant reproductive output, and thus we found little evidence for any resulting benefit to plants in fragments. In contrast, fragmentation rarely impacted pollination or pre-dispersal seed predation, but both of these interactions had strong and consistent impacts on plant reproductive output. As a result, our models robustly predicted plant reproductive output (r2 = 0.52-0.70), yet due to the weak effects of fragmentation on pollination and pre-dispersal seed predation, coupled with the weak effect of herbivory on plant reproduction, the effects of fragmentation on reproductive output were generally small in magnitude and inconsistent. This work provides mechanistic

  4. Algorithms for Disconnected Diagrams in Lattice QCD

    SciTech Connect

    Gambhir, Arjun Singh; Stathopoulos, Andreas; Orginos, Konstantinos; Yoon, Boram; Gupta, Rajan; Syritsyn, Sergey

    2016-11-01

    Computing disconnected diagrams in Lattice QCD (operator insertion in a quark loop) entails the computationally demanding problem of taking the trace of the all to all quark propagator. We first outline the basic algorithm used to compute a quark loop as well as improvements to this method. Then, we motivate and introduce an algorithm based on the synergy between hierarchical probing and singular value deflation. We present results for the chiral condensate using a 2+1-flavor clover ensemble and compare estimates of the nucleon charges with the basic algorithm.

  5. On critical exponents without Feynman diagrams

    NASA Astrophysics Data System (ADS)

    Sen, Kallol; Sinha, Aninda

    2016-11-01

    In order to achieve a better analytic handle on the modern conformal bootstrap program, we re-examine and extend the pioneering 1974 work of Polyakov’s, which was based on consistency between the operator product expansion and unitarity. As in the bootstrap approach, this method does not depend on evaluating Feynman diagrams. We show how this approach can be used to compute the anomalous dimensions of certain operators in the O(n) model at the Wilson-Fisher fixed point in 4-ɛ dimensions up to O({ɛ }2). AS dedicates this work to the loving memory of his mother.

  6. Supply determines demand: influence of partner quality and quantity on the interactions between bats and pitcher plants.

    PubMed

    Schöner, Caroline R; Schöner, Michael G; Kerth, Gerald; Grafe, T Ulmar

    2013-09-01

    Interspecific relationships such as mutualism and parasitism are major drivers of biodiversity. Because such interactions often comprise more than two species, ecological studies increasingly focus on complex multispecies systems. However, the spatial heterogeneity of multi-species interactions is often poorly understood. Here, we investigate the unusual interaction of a bat (Kerivoula hardwickii hardwickii) and two pitcher plant species (Nepenthes hemsleyana and N. bicalcarata) whose pitchers serve as roost for bats. Nepenthes hemsleyana offers roosts of higher quality, indicated by a more stable microclimate compared to N. bicalcarata but occurs at lower abundance and is less common than the latter. Whereas N. hemsleyana benefits from the roosting bats by gaining nitrogen from their feces, the bats' interaction with N. bicalcarata seems to be commensal or even parasitic. Bats stayed longer in roosts of higher quality provided by N. hemsleyana and preferred them to pitchers of N. bicalcarata in a disturbance experiment. Moreover, bats roosting only in pitchers of N. hemsleyana had a higher body condition and were less infested with parasites compared to bats roosting in pitchers of N. bicalcarata. Our study shows how the local supply of roosts with different qualities affects the behavior and status of their inhabitants and-as a consequence-how the demand of the inhabitants can influence evolutionary adaptations of the roost providing species.

  7. Casimir-Polder interaction between an atom and a cavity wall under the influence of real conditions

    SciTech Connect

    Babb, J.F.; Klimchitskaya, G.L.; Mostepanenko, V.M.

    2004-10-01

    The Casimir-Polder interaction between an atom and a metal wall is investigated under the influence of real conditions including the dynamic polarizability of the atom, finite conductivity of the wall metal, and nonzero temperature of the system. Both analytical and numerical results for the free energy and force are obtained over a wide range of atom-wall distances. Numerical computations are performed for an Au wall and metastable He*, Na, and Cs atoms. For the He* atom we demonstrate, as an illustration, that at short separations of about the Au plasma wavelength at room temperature the free energy deviates up to 35% and the force up to 57% from the classical Casimir-Polder result. Accordingly, such large deviations should be taken into account in precision experiments on atom-wall interactions. The combined account of different corrections to the Casimir-Polder interaction leads to the conclusion that at short separations the corrections due to the dynamic polarizability of an atom play a more important role than--and suppress--the corrections due to the nonideality of the metal wall. By comparison of the exact atomic polarizabilities with those in the framework of the single oscillator model, it is shown that the obtained asymptotic expressions enable calculation of the free energy and force for the atom-wall interaction under real conditions with a precision of 1%.

  8. An investigation of the influence of extracellular matrix anisotropy and cell-matrix interactions on tissue architecture.

    PubMed

    Dyson, R J; Green, J E F; Whiteley, J P; Byrne, H M

    2016-06-01

    Mechanical interactions between cells and the fibrous extracellular matrix (ECM) in which they reside play a key role in tissue development. Mechanical cues from the environment (such as stress, strain and fibre orientation) regulate a range of cell behaviours, including proliferation, differentiation and motility. In turn, the ECM structure is affected by cells exerting forces on the matrix which result in deformation and fibre realignment. In this paper we develop a mathematical model to investigate this mechanical feedback between cells and the ECM. We consider a three-phase mixture of collagen, culture medium and cells, and formulate a system of partial differential equations which represents conservation of mass and momentum for each phase. This modelling framework takes into account the anisotropic mechanical properties of the collagen gel arising from its fibrous microstructure. We also propose a cell-collagen interaction force which depends upon fibre orientation and collagen density. We use a combination of numerical and analytical techniques to study the influence of cell-ECM interactions on pattern formation in tissues. Our results illustrate the wide range of structures which may be formed, and how those that emerge depend upon the importance of cell-ECM interactions.

  9. Influence of intron length on interaction characters between post-spliced intron and its CDS in ribosomal protein genes

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoqing; Li, Hong; Bao, Tonglaga; Ying, Zhiqiang

    2012-09-01

    Many experiment evidences showed that sequence structures of introns and intron loss/gain can influence gene expression, but current mechanisms did not refer to the functions of post-spliced introns directly. We propose that postspliced introns play their functions in gene expression by interacting with their mRNA sequences and the interaction is characterized by the matched segments between introns and their CDS. In this study, we investigated the interaction characters with length series by improved Smith-Waterman local alignment software for the ribosomal protein genes in C. elegans and D. melanogaster. Our results showed that RF values of five intron groups are significantly high in the central non-conserved region and very low in 5'-end and 3'-end splicing region. It is interesting that the number of the optimal matched regions gradually increases with intron length. Distributions of the optimal matched regions are different for five intron groups. Our study revealed that there are more interaction regions between longer introns and their CDS than shorter, and it provides a positive pattern for regulating the gene expression.

  10. Interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator-prey system.

    PubMed

    Smolinský, Radovan; Gvoždík, Lumír

    2012-09-01

    The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system. Dragonfly nymphs (Aeshna cyanea) and newt eggs (Ichthyosaura alpestris) were subjected to fluctuating cold and warm thermal regimes (7-12 and 12-22°C, respectively) and the presence/absence of a predator or prey chemical cues. Preferred body temperatures were measured in an aquatic thermal gradient (5-33°C) over a 24-h period. Newt T (p) increased with developmental temperature irrespective of the presence/absence of predator cues. In dragonflies, thermal reaction norms for T (p) were affected by the interaction between temperature and prey cues. Specifically, the presence of newt scents in cold regime lowered dragonfly T (p). We concluded that predator-prey interactions influenced thermally-induced plasticity of T (p) but not in a reciprocal fashion. The occurrence of frequency-dependent thermal plasticity may have broad implications for predator-prey population dynamics, the evolution of thermal biology traits, and the consequences of sustaining climate change within ecological communities.

  11. SEWAGE DECOMPOSITION IN AMBIENT WATER: INFLUENCE OF SOLARRADIATION AND BIOTIC INTERACTIONS ON MICROORGANISM COMMUNITIES AND BACTEROIDALES REAL-TIME QUANTITATIVE PCR MEASUREMENTS - poster

    EPA Science Inventory

    AIMS: Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, solar radiation and biotic interactions (predation and competition) can influence pathogen decay based on experiments targeting indicator ...

  12. Sewage Decomposition in Ambient Water: Influence of Solarradiation and Biotic Interactions on Microorganism Communities and Bacteroidales Real-Time Quantitative PCR Measurements - poster/abstract

    EPA Science Inventory

    AIMS: Sewage and ambient water both consist of a highly complex array of bacteria and eukaryotic microbes. When these communities are mixed, solar radiation and biotic interactions (predation and competition) can influence pathogen decay based on experiments targeting indicator ...

  13. BDNF val66met genotype and schizotypal personality traits interact to influence probabilistic association learning.

    PubMed

    Skilleter, Ashley Jayne; Weickert, Cynthia Shannon; Moustafa, Ahmed Abdelhalim; Gendy, Rasha; Chan, Mico; Arifin, Nur; Mitchell, Philip Bowden; Weickert, Thomas Wesley

    2014-11-01

    The brain derived neurotrophic factor (BDNF) val66met polymorphism rs6265 influences learning and may represent a risk factor for schizophrenia. Healthy people with high schizotypal personality traits display cognitive deficits that are similar to but not as severe as those observed in schizophrenia and they can be studied without confounds of antipsychotics or chronic illness. How genetic variation in BDNF may impact learning in individuals falling along the schizophrenia spectrum is unknown. We predicted that schizotypal personality traits would influence learning and that schizotypal personality-based differences in learning would vary depending on the BDNF val66met genotype. Eighty-nine healthy adults completed the Schizotypal Personality Questionnaire (SPQ) and a probabilistic association learning test. Blood samples were genotyped for the BDNF val66met polymorphism. An ANOVA was performed with BDNF genotype (val homozygotes and met-carriers) and SPQ score (high/low) as grouping variables and probabilistic association learning as the dependent variable. Participants with low SPQ scores (fewer schizotypal personality traits) showed significantly better learning than those with high SPQ scores. BDNF met-carriers displaying few schizotypal personality traits performed best, whereas BDNF met-carriers displaying high schizotypal personality traits performed worst. Thus, the BDNF val66met polymorphism appears to influence probabilistic association learning differently depending on the extent of schizotypal personality traits displayed.

  14. Substitution effects on the temperature versus magnetic field phase diagrams of the quasi-one-dimensional effective Ising spin-1/2 chain system BaCo2V2O8

    NASA Astrophysics Data System (ADS)

    Niesen, S. K.; Breunig, O.; Salm, S.; Seher, M.; Valldor, M.; Warzanowski, P.; Lorenz, T.

    2014-09-01

    BaCo2V2O8 is a quasi-one-dimensional antiferromagnetic spin-1/2 chain system with pronounced Ising anisotropy of the magnetic exchange. Due to finite interchain interactions, long-range antiferromagnetic order develops below TN≃5.5K, which is accompanied by a structural distortion in order to lift magnetic frustration effects. The corresponding temperature versus magnetic-field phase diagram is highly anisotropic with respect to the magnetic-field direction and various details are still under vivid discussion. Here, we report the influence of several substitutions on the magnetic properties and the phase diagrams of BaCo2V2O8. We investigate the substitution series Ba1-xSrxCo2V2O8 over the full range 0≤x≤1 as well as the influence of a partial substitution of the magnetic Co2+ by small amounts of other magnetic transition metals or by nonmagnetic magnesium. In all cases, the phase diagrams were obtained on single crystals from magnetization data and/or high-resolution studies of the thermal expansion and magnetostriction.

  15. Behaviors of Polymer Additives Under EHL and Influences of Interactions Between Additives on Friction Modification

    NASA Technical Reports Server (NTRS)

    Sakurai, T.

    1984-01-01

    Polymer additives have become requisite for the formulation of multigrade engine oils. The behavior of polymethacrylate (PMA)-thickened oils as lubricants in concentrated contacts under nominal rolling and pure sliding conditions was investigated by conventional optical interferometry. The PMA thickened oils behaved differently from the base oil in the formation of elastohydrodynamic (EHL) films. The higher the elastohydrodynamic molecular weight of the PMA contained in the lubricant, the thinner was the oil film under EHL conditions. The film thickness of shear-degraded PMA-thickened oils was also investigated. The behavior of graphite particles dispersed in both the base oil and the PMA-thickened oil was studied under pure sliding by taking photomicrographs. Many kinds of additives are contained in lubricating oil and the interactions between additives are considered. The interactions of zinc-organodithiophosphates (ZDP) with other additives is discussed.

  16. The influence of PAMAM dendrimers surface groups on their interaction with porcine pepsin.

    PubMed

    Ciolkowski, Michal; Rozanek, Monika; Bryszewska, Maria; Klajnert, Barbara

    2013-10-01

    In this study the ability of three polyamidoamine (PAMAM) dendrimers with different surface charge (positive, neutral and negative) to interact with a negatively charged protein (porcine pepsin) was examined. It was shown that the dendrimer with a positively charged surface (G4 PAMAM-NH2), as well as the dendrimer with a neutral surface (G4 PAMAM-OH), were able to inhibit enzymatic activity of pepsin. It was also found that these dendrimers act as mixed partially non-competitive pepsin inhibitors. The negatively charged dendrimer (G3.5 PAMAM-COOH) was not able to inhibit the enzymatic activity of pepsin, probably due to the electrostatic repulsion between this dendrimer and the protein. No correlation between changes in enzymatic activity of pepsin and alterations in CD spectrum of the protein was observed. It indicates that the interactions between dendrimers and porcine pepsin are complex, multidirectional and not dependent only on disturbances of the secondary structure.

  17. Influence of the electronic plasma density on the wave particle interaction

    NASA Astrophysics Data System (ADS)

    Sicard-Piet, Angelica; Boscher, Daniel

    2013-04-01

    The wave particle interaction, which is well known to be a major phenomenon in the electron radiation belts dynamics, is based on two main parameters: the characteristics of the wave (type of wave, intensity,…) and the characteristics of the ambient plasma. In this work we studied the second parameter. On one side, the electronic plasma density can be derived from in-situ measurements. On the other side, several empirical models exist: GCPM, IZMIRAN or Carpenter models. Here, we compared electronic plasma densities derived from in-situ measurements each other and with existing models. Then, we investigated on the electronic plasma density distribution to distinguish the inside to the outside plasmasphere. Finally, the effect of the electronic plasma density on the diffusion coefficients due to wave particle interaction has been studied via a numerical code, called WAPI, based on quasi linear theory.

  18. Influence of Confinement and Substrate Interaction on the Crystallization Kinetics of PET Ultrathin Films

    SciTech Connect

    Capaccioli, S.; Lucchesi, M.; Prevosto, D.; Rolla, P. A.; Rotella, C.; Bertoldo, M.; Pingue, P.

    2008-07-07

    The cold crystallization kinetics of ultra-thin polymeric films (thickness: 10 nm divide 0.250 mm) of poly(ethylene terephthalate) (PET) have been investigated by dielectric spectroscopy, X-ray diffraction, infrared spectroscopy (FTIR, ATR, RAIR) and Atomic Force Microscopy (AFM) imaging. The crystallization kinetics, as well as the structural dynamics, departed form the bulk behavior in a region below 100 nm, with a stronger slowing down associated to films deposited on strongly interacting substrates. By means of AFM technique, the crystallization kinetics located at the free surface (air/polymer) were monitored: for thick samples, the kinetics at the free surface were found much faster than within the bulk. Reducing the thickness, as the free surface approached the substrate, the crystallization kinetics probed by AFM technique became slower. This effect was more relevant for strongly interacting substrates, up to prevent crystallization in very thin films.

  19. Influence of interactions with noncondensed particles on the coherence of a one-dimensional polariton condensate

    NASA Astrophysics Data System (ADS)

    Schmutzler, Johannes; Kazimierczuk, Tomasz; Bayraktar, Ömer; Aßmann, Marc; Bayer, Manfred; Brodbeck, Sebastian; Kamp, Martin; Schneider, Christian; Höfling, Sven

    2014-03-01

    One-dimensional polariton condensates (PoCos) in a photonic wire are generated through nonresonant laser excitation, by which also a reservoir of background carriers is created. Interaction with this reservoir may affect the coherence of the PoCo, which is studied here by injecting a condensate locally and monitoring the coherence along the wire. While the incoherent reservoir is mostly present within the excitation laser spot, the condensate can propagate ballistically through the wire. Photon correlation measurements show that far from the laser spot the second-order correlation function approaches unity value, as expected for the coherent condensed state. When approaching the spot, however, the correlation function increases up to values of 1.2 showing the addition of noise to the emission due to interaction with the reservoir. This finding is substantiated by measuring the first-order coherence by a double-slit experiment, which shows a reduced visibility of interference at the excitation laser spot.

  20. Parasites and deleterious mutations: interactions influencing the evolutionary maintenance of sex.

    PubMed

    Park, A W; Jokela, J; Michalakis, Y

    2010-05-01

    The restrictive assumptions associated with purely genetic and purely ecological mechanisms suggest that neither of the two forces, in isolation, can offer a general explanation for the evolutionary maintenance of sex. Consequently, attention has turned to pluralistic models (i.e. models that apply both ecological and genetic mechanisms). Existing research has shown that combining mutation accumulation and parasitism allows restrictive assumptions about genetic and parasite parameter values to be relaxed while still predicting the maintenance of sex. However, several empirical studies have shown that deleterious mutations and parasitism can reduce fitness to a greater extent than would be expected if the two acted independently. We show how interactions between these genetic and ecological forces can completely reverse predictions about the evolution of reproductive modes. Moreover, we demonstrate that synergistic interactions between infection and deleterious mutations can render sex evolutionarily stable even when there is antagonistic epistasis among deleterious mutations, thereby widening the conditions for the evolutionary maintenance of sex.