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Sample records for interactive influence diagrams

  1. Pseudohaptic interaction with knot diagrams

    NASA Astrophysics Data System (ADS)

    Weng, Jianguang; Zhang, Hui

    2012-07-01

    To make progress in understanding knot theory, we need to interact with the projected representations of mathematical knots, which are continuous in three dimensions (3-D) but significantly interrupted in the projective images. One way to achieve such a goal is to design an interactive system that allows us to sketch two-dimensional (2-D) knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress in this direction. Pseudohaptics that simulate haptic effects using pure visual feedback can be used to develop such an interactive system. We outline one such pseudohaptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2-D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a physically reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudohaptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of which the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudohaptic four-dimensional (4-D) visualization system that simulates the continuous navigation on 4-D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2-D knot diagrams of 3-D knots and 3-D projective images of 4-D mathematical objects.

  2. Entanglement interaction and the phase diagram of strongly interacting matter

    NASA Astrophysics Data System (ADS)

    Shao, G. Y.; Tang, Z. D.; Di Toro, M.; Colonna, M.; Gao, X. Y.; Gao, N.; Zhao, Y. L.

    2015-12-01

    The entanglement interactions between the Polyakov loop and chiral condensate have been recently studied in the entangled Polyakov-loop Nambu-Jona-Lasinio model (EPNJL). The calculation shows that such an interaction plays an important role in the pseudocritical temperatures of deconfinement and chiral symmetry restoration. As a further study, here we construct a hadron-quark two-equation-of-state (two-EoS) model, based on the Walecka-quantum hadrodynamics and the EPNJL pictures, in order to study the equilibrium transition between hadronic and quark matter in heavy-ion collisions at finite densities and temperatures. We can explore the phase diagram of strongly interacting matter and the transition boundaries from nuclear to quark matter. We discuss the influence of the entanglement interaction on the critical point of the expected first-order phase transition in the two-EoS model. In particular, for charge asymmetric matter, we analyze the local asymmetry of the u , d quarks as a function of quark concentration in the hadron-quark mixed phase during the phase transition. We finally propose some related observables that are possibly measurable in heavy-ion collision experiments.

  3. The Classroom as Rhizome: New Strategies for Diagramming Knotted Interactions

    ERIC Educational Resources Information Center

    de Freitas, Elizabeth

    2012-01-01

    This article calls attention to the unexamined role of diagrams in educational research and offers examples of alternative diagramming practices or tools that shed light on classroom interaction as a rhizomatic process. Drawing extensively on the work of Latour, Deleuze and Guattari, and Chatelet, this article explores the power of diagramming as…

  4. 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...

  5. Search the Foot and Ankle: Interactive Foot Diagram

    MedlinePlus

    ... Search by GPS Please enter a city or last name. Use your current position? {{ps.position.alert.message}} ... digit zip code. Please enter a city or last name. Search Where do you hurt? Interactive Foot Diagram ...

  6. 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.

  7. 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.

  8. Use of influence diagrams in gas transfer system option prioritization

    SciTech Connect

    Heger, A.S.; Garcia, M.D.

    1995-08-01

    A formal decision-analysis methodology was applied to aid the Department of Energy (DOE) in deciding which of several gas transfer system (GTS) options should be selected. The decision objectives for this case study, i.e., risk and cost, were directly derived from the DOE guidelines. Influence diagrams were used to define the structure of the decision problem and clearly delineate the flow if information. A set of performance matrices wee used in conjunction with the influence diagrams to assess and evaluate the degree to which the objectives of the case study were met. These performance measures were extracted from technical models, design and operating data, and professional judgments. The results were aggregated to provide an overall evaluation of the different design options of the gas transfer system. Consequently, the results of this analysis were used as an aid to DOE to select a viable GTS option.

  9. 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.

  10. A new symbolic language for diagramming pacemaker/heart interaction.

    PubMed

    Brownlee, R R; Shimmel-Golden, J B; Del Marco, C J; Furman, S

    1982-09-01

    A new symbolic language is presented that can be used to diagram pacemaker/heart interactions. The language symbolically indicates "normally" conducted and ectopic events; pacemaker stimuli; pacemaker capture of the chamber; triggered pacemaker stimuli by "normal" or ectopic events; as well as such anomalous pacemaker/heart interactions as failure to sense; "crosstalk" between electrodes; and "normal," ectopic, or paced events in one chamber sensed by the electrode in the other chamber. In addition, symbols are provided to represent antegrade and retrograde accessory pathway conduction, and electronic and physiological refractory intervals. A common baseline is used to separate symbols for atrial activity, above the baseline, from those for ventricular activity, below the baseline. Parallel baselines are used to plot refractory intervals. Thus, even complex dual-chamber pacemaker operating modes can be represented with intrinsic and stimulated cardiac response to pacemaker operation. The language can be sketched out informally for description of general concepts or drafted on millimeter grid paper to make precise timing notations. It is especially useful for interdisciplinary communication of ideas about complex pacemaker/heart interactions. PMID:6182542

  11. Effect of anisotropic Dzyaloshinskii-Moriya interactions on phase diagrams of the Ashkin-Teller model

    NASA Astrophysics Data System (ADS)

    Dani, I.; Tahiri, N.; Ez-Zahraouy, H.; Benyoussef, A.

    2016-08-01

    In this paper we study, using mean field theory (MFT), the effect of the anisotropic Dzyaloshinskii-Moriya (DM) interaction on the phase diagrams of the spin-half Ashkin-Teller model on hypercubic lattice. Different new phase diagrams are found by varying the anisotropy of DM interaction. The multicritical behavior is studied as a function of four-spin interaction coefficient J4 /J1 and for two fixed values of spin interaction coefficient J2 /J1.

  12. 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.

  13. 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...

  14. Phase diagrams for the adsorption of monomers with non-additive interactions

    NASA Astrophysics Data System (ADS)

    Pinto, O. A.; Ramirez-Pastor, A. J.; Nieto, F.

    2016-09-01

    In several experimental systems phase diagrams coverage-temperature show a strong asymmetry. This behavior can be reproduced by including non-additive lateral interactions. In this work a Monte Carlo study on the canonical assembly of the criticality of monomer adsorption with non-additive interactions is presented. Traditional pairwise energies were replaced by other more general ones where the lateral interaction between two ad-atoms depends on the coverage at first sphere of coordination. This kind of energies includes multibody interactions like three-body interactions and four-body interactions, etc. These energies induce the formation of several non-additive ordered structures. Finite size scaling method was used to classify the order of phase transition of each non-additive phase. On the other hand, the corresponding phase diagrams are formed naturally, in which case the diagrams show strong asymmetries.

  15. THE FUELING DIAGRAM: LINKING GALAXY MOLECULAR-TO-ATOMIC GAS RATIOS TO INTERACTIONS AND ACCRETION

    SciTech Connect

    Stark, David V.; Kannappan, Sheila J.; Eckert, Kathleen D.; Wei, Lisa H.; Baker, Andrew J.; Leroy, Adam K.; Vogel, Stuart N.

    2013-05-20

    To assess how external factors such as local interactions and fresh gas accretion influence the global interstellar medium of galaxies, we analyze the relationship between recent enhancements of central star formation and total molecular-to-atomic (H{sub 2}/H I) gas ratios, using a broad sample of field galaxies spanning early-to-late type morphologies, stellar masses of 10{sup 7.2}-10{sup 11.2} M{sub Sun }, and diverse stages of evolution. We find that galaxies occupy several loci in a ''fueling diagram'' that plots H{sub 2}/H I ratio versus mass-corrected blue-centeredness, a metric tracing the degree to which galaxies have bluer centers than the average galaxy at their stellar mass. Spiral galaxies of all stellar masses show a positive correlation between H{sub 2}/H I ratio and mass-corrected blue-centeredness. When combined with previous results linking mass-corrected blue-centeredness to external perturbations, this correlation suggests a systematic link between local galaxy interactions and molecular gas inflow/replenishment. Intriguingly, E/S0 galaxies show a more complex picture: some follow the same correlation, some are quenched, and a distinct population of blue-sequence E/S0 galaxies (with masses below key scales associated with transitions in gas richness) defines a separate loop in the fueling diagram. This population appears to be composed of low-mass merger remnants currently in late- or post-starburst states, in which the burst first consumes the H{sub 2} while the galaxy center keeps getting bluer, then exhausts the H{sub 2}, at which point the burst population reddens as it ages. Multiple lines of evidence suggest connected evolutionary sequences in the fueling diagram. In particular, tracking total gas-to-stellar mass ratios within the fueling diagram provides evidence of fresh gas accretion onto low-mass E/S0s emerging from their central starburst episodes. Drawing on a comprehensive literature search, we suggest that virtually all galaxies

  16. 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...

  17. Recent Progresses in Studying Helix-Helix Interactions in Proteins by Incorporating the Wenxiang Diagram into the NMR Spectroscopy.

    PubMed

    Zhou, Guo-Ping; Chen, Dong; Liao, Siming; Huang, Ri-Bo

    2016-01-01

    All residues in an alpha helix can be characterized and dispositioned on a 2D the wenxiang diagram, which possesses the following features: (1) the relative locations of the amino acids in the α-helix can be clearly displayed regardless how long it is; (2) direction of an alphahelix can be indicated; and (3) more information regarding each of the constituent amino acid residues in an alpha helix. Owing to its intuitionism and easy visibility, wenxiang diagrams have had an immense influence on our understanding of protein structure, protein-protein interactions, and the effect of helical structural stability on protein conformational transitions. In this review, we summarize two recent applications of wenxiang diagrams incorporating NMR spectroscopy in the researches of the coiled-coil protein interactions related to the regulation of contraction or relaxation states of vascular smooth muscle cells, and the effects of α-helical stability on the protein misfolding in prion disease, in hopes that the gained valuable information through these studies can stimulate more and more widely applications of wenxiang diagrams in structural biology. PMID:26286215

  18. 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. PMID:26102155

  19. 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. PMID:21875054

  20. Solving Algebra Problems with Interactive Diagrams: Demonstration and Construction of Examples

    ERIC Educational Resources Information Center

    Naftaliev, Elena; Yerushalmy, Michal

    2011-01-01

    We investigated how students use the representation of data in a given example appearing in an interactive diagram (ID) and how they create additional examples with the ID. Students who worked with the ID that offered limited representations and tools ("illustrating ID") looked for ways to bypass the designed constraints: they changed the…

  1. Quantized Pumping and Topology of the Phase Diagram for a System of Interacting Bosons

    NASA Astrophysics Data System (ADS)

    Berg, Erez; Levin, Michael; Altman, Ehud

    2011-03-01

    Interacting lattice bosons at integer filling can support two distinct insulating phases, which are separated by a critical point: the Mott insulator and the Haldane insulator [E. G. Dalla Torre, E. Berg, and E. Altman, Phys. Rev. Lett. 97, 260401 (2006).PRLTAO0031-900710.1103/PhysRevLett.97.260401]. The critical point can be gapped out by breaking lattice inversion symmetry. Here, we show that encircling this critical point adiabatically pumps one boson across the system. When multiple chains are coupled, the two insulating phases are no longer sharply distinct, but the pumping property survives. This leads to strict constraints on the topology of the phase diagram of systems of quasi-one-dimensional interacting bosons.

  2. Phase diagram of Rydberg atoms with repulsive van der Waals interaction

    SciTech Connect

    Osychenko, O. N.; Astrakharchik, G. E.; Boronat, J.; Lutsyshyn, Y.; Lozovik, Yu. E.

    2011-12-15

    We report a quantum Monte Carlo calculation of the phase diagram of bosons interacting with a repulsive inverse sixth power pair potential, a model for assemblies of Rydberg atoms in the local van der Waals blockade regime. The model can be parametrized in terms of just two parameters, the reduced density and temperature. Solidification happens to the fcc phase. At zero temperature, the transition density is found with the diffusion Monte Carlo method at density {rho}=3.9 (({Dirac_h}/2{pi}){sup 2}/mC{sub 6}){sup 3/4}, where C{sub 6} is the strength of the interaction. The solidification curve at nonzero temperature is studied with the path-integral Monte Carlo approach and is compared with transitions in corresponding harmonic and classical crystals. Relaxation mechanisms are considered in relation to present experiments.

  3. Computational analysis of RNA-protein interaction interfaces via the Voronoi diagram.

    PubMed

    Mahdavi, Sedigheh; Mohades, Ali; Salehzadeh Yazdi, Ali; Jahandideh, Samad; Masoudi-Nejad, Ali

    2012-01-21

    Cellular functions are mediated by various biological processes including biomolecular interactions, such as protein-protein, DNA-protein and RNA-protein interactions in which RNA-Protein interactions are indispensable for many biological processes like cell development and viral replication. Unlike the protein-protein and protein-DNA interactions, accurate mechanisms and structures of the RNA-Protein complexes are not fully understood. A large amount of theoretical evidence have shown during the past several years that computational geometry is the first pace in understanding the binding profiles and plays a key role in the study of intricate biological structures, interactions and complexes. In this paper, RNA-Protein interaction interface surface is computed via the weighted Voronoi diagram of atoms. Using two filter operations provides a natural definition for interface atoms as classic methods. Unbounded parts of Voronoi facets that are far from the complex are trimmed using modified convex hull of atom centers. This algorithm is implemented to a database with different RNA-Protein complexes extracted from Protein Data Bank (PDB). Afterward, the features of interfaces have been computed and compared with classic method. The results show high correlation coefficients between interface size in the Voronoi model and the classical model based on solvent accessibility, as well as high accuracy and precision in comparison to classical model. PMID:22004995

  4. Gender Influences in Classroom Interaction.

    ERIC Educational Resources Information Center

    Wilkinson, Louise Cherry, Ed.; Marrett, Cora B., Ed.

    The 11 chapters comprising this work focus on the interactional influences that may be related to differential classroom experiences for males and females. The effects of contextual factors, teacher characteristics, and student characteristics are investigated. Addressed primarily to researchers, this information should prove useful to teachers,…

  5. Generic Phase Diagram for Bose-Einstein Condensation of Weakly Interacting Symmetric Bosonic Mixtures

    NASA Astrophysics Data System (ADS)

    Kuklov, A. B.; Blanchard, T.; Svistunov, B. V.

    2009-03-01

    Weakly interacting Bose gas represents strongly correlated classical field within a domain (determined by the gas parameter ) of its Bose-Einstein condensation (BEC) temperature T=Tc. Thus, N-component weakly interacting mixtures representing some symmetry can potentially exhibit rich phase diagram (PD). In particular, it can feature quasi-molecular phases preceding actual formation of the ODLRO in the vicinity of Tc. However, realization of a specific part of the PD depends on details of interactions. As examples, we consider mixtures characterized by O(2)xO(2) symmetry (N=2) and spin S=1 with the symmetry reduced to U(1)xU(1) (N=3). Monte Carlo simulations of these systems find a single line of the respective two- and three-component BEC transitions which has tricritical point separating II and I order transitions. No quasi-molecular phases have been found despite that na"ive mean field (with one loop correction) predicts it. We discuss how such phases can emerge above the actual N-component BEC transition. One suggestion relies on Feschbach resonance detuned into negative inter-specie scattering length even when the gas parameter remains small. We acknowledge support from NSF grants PHY 0653135, 0653183 and CUNY grant 80209-0914.

  6. The phase diagram in the SU(3) Nambu-Jona-Lasinio model with 't Hooft and eight-quark interactions

    SciTech Connect

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

    2010-08-05

    It is shown that the endpoint 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 towards vanishing chemical potential and higher temperatures with increasing strength of the OZI-violating eight-quark interactions. We clarify a connection between the location of the endpoint in the phase diagram and the mechanism of chiral symmetry breaking at the quark level. Constraints on the coupling strengths based on groundstate stability and physical considerations are explained.

  7. Bridging and depletion mechanisms in colloid-colloid effective interactions: A reentrant phase diagram.

    PubMed

    Fantoni, Riccardo; Giacometti, Achille; Santos, Andrés

    2015-06-14

    A general class of nonadditive sticky-hard-sphere binary mixtures, where small and large spheres represent the solvent and the solute, respectively, is introduced. The solute-solute and solvent-solvent interactions are of hard-sphere type, while the solute-solvent interactions are of sticky-hard-sphere type with tunable degrees of size nonadditivity and stickiness. Two particular and complementary limits are studied using analytical and semi-analytical tools. The first case is characterized by zero nonadditivity, lending itself to a Percus-Yevick approximate solution from which the impact of stickiness on the spinodal curves and on the effective solute-solute potential is analyzed. In the opposite nonadditive case, the solvent-solvent diameter is zero and the model can then be reckoned as an extension of the well-known Asakura-Oosawa model with additional sticky solute-solvent interaction. This latter model has the property that its exact effective one-component problem involves only solute-solute pair potentials for size ratios such that a solvent particle fits inside the interstitial region of three touching solutes. In particular, we explicitly identify the three competing physical mechanisms (depletion, pulling, and bridging) giving rise to the effective interaction. Some remarks on the phase diagram of these two complementary models are also addressed through the use of the Noro-Frenkel criterion and a first-order perturbation analysis. Our findings suggest reentrance of the fluid-fluid instability as solvent density (in the first model) or adhesion (in the second model) is varied. Some perspectives in terms of the interpretation of recent experimental studies of microgels adsorbed onto large polystyrene particles are discussed. PMID:26071729

  8. 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 study was…

  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. Summation of time-dependent folded diagrams for effective interactions with a non-degenerate model space

    NASA Astrophysics Data System (ADS)

    Kuo, T. T. S.; Krmpotić, F.; Suzuki, K.; Okamoto, R.

    1995-02-01

    We analyze the diagrammatic structure of the effective interaction for the case of a non-degenerate model space. A time-dependent folded-diagram formulation is used. It is found that the valence-linked time-ordered diagrams contained in such effective interactions can also be expressed in terms of the multi-energy Q¯-boxes of the form overlineQn(ɛ 1ɛ 2…ɛ n+1), which were introduced by Suzuki et al. for a time-independent description of the effective interaction. A partial-fraction method for the evaluation of the multi-energy Q¯-box, in terms of valence-linked diagrams, is discussed. A generalized Krenciglowa-Kuo iteration method for summing up the folded-diagram series is also designed. A schematic mosel is solved to compare the non-degenerate theory with the usual degenerate theory. It is shown that the present approach makes a distinct improvement in the calculation of effective interactions.

  11. 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 → ∞.

  12. Effect of Dzyaloshinskii-Moriya interaction on phase diagrams of spin-1 Heisenberg-Ising alternating chains

    NASA Astrophysics Data System (ADS)

    Liu, Guang-Hua; Dou, Jun-Ya; Lu, Peng

    2016-03-01

    The effect of the Dzyaloshinskii-Moriya interaction (DMI) on ground-state phase diagrams of spin-1 Heisenberg-Ising alternating chains is investigated by the infinite time-evolving block decimation method. Three rich phase diagrams for three cases with different DMIs are obtained and discussed systematically. The DMI on even bonds plays a key role in the ground-state phase diagram, especially the appearance of the Haldane phase. However, the DMI on odd bonds seems to have very weak effect on the phase diagram. Both the odd- and even-string orders become nonzero in the Haldane phase, and have their maximum values at θ = π. For the odd-dimer phase, the even-string correlator vanishes absolutely despite varying θ, but a double-peak structure of the odd-string correlator is observed. Odd-string correlator becomes maximum at θ = π / 2 and 3 π / 2, but vanishes at θ = π. It indicates that the generalized string correlator can be used to distinguish the odd-dimer from the Haldane phase. Doubly degenerate entanglement spectrum is observed in the Haldane phase, which can be regarded as a clear signature of the existence of topological orders. Strong enough transverse nearest-neighbor correlations are found to be very important for the appearance of the Haldane and the odd-dimer phases.

  13. 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.

  14. 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…

  15. 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…

  16. 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.

  17. Flow Effects on the Flammability Diagrams of Solid Fuels: Microgravity Influence on Ignition Delay

    NASA Technical Reports Server (NTRS)

    Cordova, J. L.; Walther, D. C.; Fernandez-Pello, A. C.; Steinhaus, T.; Torero, J. L.; Quintere, J. G.; Ross, H. D.

    1999-01-01

    The possibility of an accidental fire in space-based facilities is a primary concern of space exploration programs. Spacecraft environments generally present low velocity air currents produced by ventilation and heating systems (of the order of 0.1 m/s), and fluctuating oxygen concentrations around that of air due to CO2 removal systems. Recent experiments of flame spread in microgravity show the spread rate to be faster and the limiting oxygen concentration lower than in normal-gravity. To date, there is not a material flammability-testing protocol that specifically addresses issues related to microgravity conditions. The present project (FIST) aims to establish a testing methodology that is suitable for the specific conditions of reduced gravity. The concepts underlying the operation of the LIFT apparatus, ASTM-E 1321-93, have been used to develop the Forced-flow Ignition and flame-Spread Test (FIST). As in the LIFT, the FIST is used to obtain the flammability diagrams of the material, i.e., graphs of ignition delay time and flame spread rate as a function of the externally applied radiant flux, but under forced flow rather than natural convection conditions, and for different oxygen concentrations. Although the flammability diagrams are similar, the flammability properties obtained with the FIST are found to depend on the flow characteristics. A research program is currently underway with the purpose of implementing the FIST as a protocol to characterize the flammability performance of solid materials to be used in microgravity facilities. To this point, tests have been performed with the FIST apparatus in both normal-gravity and microgravity conditions to determine the effects of oxidizer flow characteristics on the flammability diagrams of polymethylmethacrylate (PMMA) fuel samples. The experiments are conducted at reduced gravity in a KC- 135 aircraft following a parabolic flight trajectory that provides up to 25 seconds of low gravity. The objective of the

  18. 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.

  19. Liquid/liquid metal extraction: Phase diagram topology resulting from molecular interactions between extractant, ion, oil and water

    NASA Astrophysics Data System (ADS)

    Bauer, C.; Bauduin, P.; Dufrêche, J. F.; Zemb, T.; Diat, O.

    2012-11-01

    We consider the class of surfactants called "extractants" since they specifically interact with some cations and are used in liquid-liquid separation processes. We review here features of water-poor reverse micelles in water/oil/ extractant systems as determined by combined structural studies including small angle scattering techniques on absolute scale. Origins of instabilities, liquid-liquid separation as well as emulsification failure are detected. Phase diagrams contain the same multi-phase domains as classical microemulsions, but special unusual features appear due to the high spontaneous curvature directed towards the polar cores of aggregates as well as rigidity of the film made by extracting molecules.

  20. 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.

  1. Phase Diagrams of Iron Rich Alloys and Their Influence on the Chemical Structure of Planetary Cores

    NASA Astrophysics Data System (ADS)

    Campbell, A. J.; Miller, N. A.; Fischer, R. A.; Seagle, C. T.; Prakapenka, V. B.

    2008-12-01

    Many planetary bodies are thought to have metallic, iron rich cores, with a significant component of some 'light' alloying element(s). The identity of this light alloying component has a profound effect on the chemical properties of the core, including its melting/crystallization behavior, partitioning of minor and trace elements during core/mantle segregation and core crystallization, and other phase relations. Despite this importance, the light element component(s) of planetary bodies generally remain unknown, apart from those of a few iron meteorite parent bodies. Experimentally determined physical and chemical properties of iron-rich systems can be compared to observations and models of planetary interiors to constrain compositions of planetary cores. Here we summarize our recent high pressure, high temperature experiments on the phase diagrams of iron+light element (Fe-X) binaries, specifically iron-sulfide, iron-silicide, and iron-oxide systems. Melting as well as subsolidus phase relations have been determined in the laser heated diamond anvil cell, using either synchrotron X-ray diffraction or optical methods to establish phase boundaries. X-ray diffraction while laser heating the sample reveals the nature of structural transitions (including partial melting), and optical methods (such as temperature vs. emissivity and related methods) establish the phase boundaries with finer precision. Drawing on these and other recent experimental results, we compare and contrast the binary Fe-X phase diagrams to address such questions as: Which candidate light elements (S, Si, O, C) cause the largest melting point depression, and how does this change with pressure? Which can produce large density constrasts against crystallizing iron metal? and others. These results are compared to thermal and chemical models of terrestrial planet interiors (including Earth's), and important gaps and discrepancies in the available experimental data are highlighted.

  2. 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.

  3. 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.

  4. Phase diagrams of Wyoming Na-montmorillonite clay. Influence of particle anisotropy.

    PubMed

    Michot, Laurent J; Bihannic, Isabelle; Porsch, Katharina; Maddi, Solange; Baravian, Christophe; Mougel, Julien; Levitz, Pierre

    2004-12-01

    Natural Na-Wyoming montmorillonite was size fractionated by successive centrifugation. Polydisperse particles with average sizes of 400, 290, and 75 nm were then obtained. As the structural charge of the particles belonging to three fractions (determined by cationic exchange capacity measurements) is the same, such a procedure allows studying the effect of particle anisotropy on the colloidal phase behavior of swelling clay particles. Osmotic stress experiments were carried out at different ionic strengths. The osmotic pressure curves display a plateau whose beginning systematically coincides with the sol/gel transition determined by oscillatory stress measurements. The concentration corresponding to the sol/gel transition increases linearly with particle anisotropy, which shows that the sol/gel transition is not directly related to an isotropic/nematic transition of individual clay particles. Indeed, a reverse evolution should be observed for an I/N transition involving the individual clay particles. Still, when observed between crossed polarizer and analyzer, the gel samples exhibit permanent birefringent textures, whereas in the "sol" region, transient birefringence is observed when the samples are sheared. This suggests that interacting clay particles are amenable to generate, at rest and/or under shear, large anisotropic particle associations. PMID:15568830

  5. 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…

  6. The Hubble diagram for a system within dark energy: influence of some relevant quantities

    NASA Astrophysics Data System (ADS)

    Saarinen, J.; Teerikorpi, P.

    2014-08-01

    Aims: We study the influence of relevant quantities, including the density of dark energy (DE), to the predicted Hubble outflow around a system of galaxies. In particular, we are interested in the difference between two models: 1) the standard ΛCDM model, with the everywhere constant DE density, and 2) the "Swiss cheese model", where the Universe is as old as the standard model and the DE density is zero on short scales, including the environment of the system. Methods: We calculated the current predicted outflow patterns of dwarf galaxies around the Local Group-like system, using different values for the mass of the group, the local DE density, and the time of ejection of the dwarf galaxies, which are treated as test particles. These results are compared with the observed Hubble flow around the Local Group. Results: The predicted distance-velocity relations around galaxy groups are not very sensitive indicators of the DE density, owing to the observational scatter and the uncertainties caused by the mass used for the group and a range in the ejection times. In general, the Local Group outflow data agree with the local DE density being equal to the global one, if the Local Group mass is about 4 × 1012 M⊙; a lower mass ≲ 2 × 1012 M⊙ could suggest a zero local DE density. The dependence of the inferred DE density on the mass is a handicap in this and other common dynamical methods. This emphasizes the need to use different approaches together, for constraining the local DE density.

  7. Anomaly in the phase diagram of the spin quantum 1/2 anisotropic Heisenberg antiferromagnet model with Dzyaloshinskii-Moriya interaction: A low temperature analysis

    NASA Astrophysics Data System (ADS)

    Parente, Walter E. F.; Pacobahyba, J. T. M.; Araújo, Ijanílio G.; Neto, Minos A.; Ricardo de Sousa, J.

    2015-11-01

    We will study phase diagram the quantum spin-1/2 anisotropic Heisenberg antiferromagnet model in the presence of a Dzyaloshinskii-Moriya interaction (D) and a uniform longitudinal (H) magnetic field, where we have observed an anomaly at low temperatures. Using the effective-field theory with a finite cluster N=2 spin (EFT-2) we calculate the phase diagram in the H - D plane on a simple cubic lattice (z=6). We analyzed the cases: anisotropic Heisenberg - case I: (Δ = 1), anisotropic Heisenberg - case II: (Δ = 0.5) and anisotropic Heisenberg - case III: (Δ = 0), where only second order phase transitions are observed.

  8. Interplay between competing exchange interactions and magnetocrystalline anisotropies in YFexMn12-x : The magnetic phase diagram

    NASA Astrophysics Data System (ADS)

    Piqué, C.; Abad, E.; Blanco, J. A.; Burriel, R.; Fernández-Díaz, M. T.

    2005-05-01

    The magnetic properties of tetragonal YFexMn12-x compounds, which crystallize in the ThMn12 -type structure, are governed by both strong competing exchange interactions between the magnetic moments on three nonequivalent sites 8i , 8j , and 8f occupied by Mn (Fe) atoms preferentially in 8i (8f) and Mn-planar (Fe-axial) magnetocrystalline anisotropies. Using low field ac magnetic susceptibility versus temperature, zero-field-cooled and field-cooled magnetization versus temperature, and applied magnetic field, specific heat, x-ray-absorption spectroscopy at FeK and MnK edges, and neutron-diffraction experiments, the magnetic phase diagram of YFexMn12-x has been determined. Up to six different phases were found as a function of the Fe concentration x . Some of them have not been thoroughly investigated until now. In particular, the antiferromagnetic ordering of the itinerant YMn12 is different from the phase proposed before, and the spin-glass-like phase observed at low temperatures for 2⩽x⩽6 has been characterized in more detail. Contrary to other intermetallic Mn-based systems, the magnetism in YFexMn12-x cannot be correlated in a straightforward way to 3d-3d distances and it seems to be more sensitive to the electronic density and the localization-delocalization of electronic band states on the three sites 8i , 8j , and 8f .

  9. On the influence of the parameter constraint on the stability of the poles and the discrimination capabilities of the stabilisation diagrams

    NASA Astrophysics Data System (ADS)

    Cauberghe, B.; Guillaume, P.; Verboven, P.; Vanlanduit, S.; Parloo, E.

    2005-09-01

    This paper analyses the influence of the parameter constraint for modal parameter estimation (MPE) methods and its impact on the quality of the stabilisation diagram. It is shown that by a proper choice of the parameter constraint a distinction can be made between physical and mathematical poles based on the sign of the damping. As a result the quality of stabilisation diagrams can be improved. This approach can be applied for several well-known modal parameter estimation methods and the user can benefit from this. Several MPE applications in aerospace, automotive and civil engineering show the implication of the constraint and the specific advantages of obtaining an easy-to-interpret stabilisation diagram.

  10. Thermodynamic Diagrams

    NASA Astrophysics Data System (ADS)

    Chaston, Scot

    1999-02-01

    Thermodynamic data such as equilibrium constants, standard cell potentials, molar enthalpies of formation, and standard entropies of substances can be a very useful basis for an organized presentation of knowledge in diverse areas of applied chemistry. Thermodynamic data can become particularly useful when incorporated into thermodynamic diagrams that are designed to be easy to recall, to serve as a basis for reconstructing previous knowledge, and to determine whether reactions can occur exergonically or only with the help of an external energy source. Few students in our chemistry-based courses would want to acquire the depth of knowledge or rigor of professional thermodynamicists. But they should nevertheless learn how to make good use of thermodynamic data in their professional occupations that span the chemical, biological, environmental, and medical laboratory fields. This article discusses examples of three thermodynamic diagrams that have been developed for this purpose. They are the thermodynamic energy account (TEA), the total entropy scale, and the thermodynamic scale diagrams. These diagrams help in the teaching and learning of thermodynamics by bringing the imagination into the process of developing a better understanding of abstract thermodynamic functions, and by allowing the reader to keep track of specialist thermodynamic discourses in the literature.

  11. Influence of interstitial Fe to the phase diagram of Fe1+yTe1-xSex single crystals.

    PubMed

    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

  12. Influence of local-field anisotropy in the description of the resonance in dielectrics and their corresponding Argand diagrams

    NASA Astrophysics Data System (ADS)

    Buep, A. H.; Casaubon, J. I.

    1995-10-01

    The local field existing in an ellipsoidal cavity within a dielectric is introduced as an improvement to the classical description of resonance in a dielectric under a harmonic electric field. Considering that the ellipsoids representing polarizable molecules may have any orientation with respect to the applied field, we obtained expressions for the real and imaginary parts of the permittivity as a function of the angular frequency and form factors. A shift in frequency is observed for the maximum of the imaginary permittivity with respect to the natural angular frequencies of resonance that depends on the form factors. In the particular case that all the ellipsoids are lined up with the applied field, the shift of the angular frequency of the resonance depends in a simple way on the form factor of the ellipsoid. The Argand diagrams are shown and compared to those corresponding with different approximations of the local field.

  13. A Monte Carlo study of the influence of molecular flexibility on the phase diagram of a fused hard sphere model

    NASA Astrophysics Data System (ADS)

    McBride, Carl; Vega, Carlos

    2002-12-01

    A study of a rigid fully flexible fused hard sphere model [C. McBride, C. Vega, and L. G. MacDowell, Phys. Rev. E 64, 011703 (2001)] is extended to the smectic and solid branches of the phase diagram. Computer simulations have been performed for a completely rigid model composed of 15 fused hard spheres (15+0), a model of 15 fused hard spheres of which 2 monomers at one end of the model form a flexible tail (13+2), and a model consisting of 15 fused hard spheres with 5 monomers forming a flexible tail (10+5). For the 15+0 model the phase sequence isotropic-nematic-smectic A-columnar is found on compression, and the sequence solid-smectic A-nematic-isotropic on expansion. For the 13+2 model the phase sequence isotropic-nematic-smectic C is found on compression, and the sequence solid-smectic A-nematic-isotropic on expansion. For the 10+5 model the phase sequence isotropic-glass is found on compression. The expansion runs displayed the phase sequence solid-smectic A-isotropic. The introduction of flexibility was seen to stabilize the smectic A phase at the expense of the nematic phase.

  14. Phase diagram in the entanglement PNJL model

    NASA Astrophysics Data System (ADS)

    Friesen, A.; Kalinovsky, Y.; Toneev, V.

    2016-01-01

    Effects of the vector interaction in the Nambu-Jona-Lasinio model with Polyakov loop are studied in combination with the entanglement interaction between the quark and pure gauge sectors. We investigate the QCD phase diagram and find that the first order chiral phase transition at finite baryon chemical potentials and its critical endpoint disappear for sufficiently large values of the vector interaction constant Gv. The presence of an entanglement interaction between quark and pure gauge sectors leads to an increase of the value Gv for which the first order transition disappears. The influence of a nonzero Gv on the curvature of the crossover boundary in the T - μ plane nearby μ= 0 is also examined for both cases.

  15. Phase diagram of the alternating-spin Heisenberg chain with extra isotropic three-body exchange interactions

    NASA Astrophysics Data System (ADS)

    Ivanov, Nedko B.; Ummethum, Jörg; Schnack, Jürgen

    2014-10-01

    For the time being isotropic three-body exchange interactions are scarcely explored and mostly used as a tool for constructing various exactly solvable one-dimensional models, although, generally speaking, such competing terms in generic Heisenberg spin systems can be expected to support specific quantum effects and phases. The Heisenberg chain constructed from alternating S = 1 and σ = 1/2 site spins defines a realistic prototype model admitting extra three-body exchange terms. Based on numerical density-matrix renormalization group (DMRG) and exact diagonalization (ED) calculations, we demonstrate that the additional isotropic three-body terms stabilize a variety of partially-polarized states as well as two specific non-magnetic states including a critical spin-liquid phase controlled by two Gaussinal conformal theories as well as a critical nematic-like phase characterized by dominant quadrupolar S-spin fluctuations. Most of the established effects are related to some specific features of the three-body interaction such as the promotion of local collinear spin configurations and the enhanced tendency towards nearest-neighbor clustering of the spins. It may be expected that most of the predicted effects of the isotropic three-body interaction persist in higher space dimensions.

  16. Phase diagram in the (Bi,Pb)SrCaCuO system: influence of partial constraint oxygen pressure

    NASA Astrophysics Data System (ADS)

    Mansori, M.; Satre, P.; Roubin, M.; Vacquier, G.; Strobel, P.; Sebaoun, A.

    1994-12-01

    DTA-DTG, X ray diffraction and metallographic measurements at different temperatures and partial oxygen pressure in the isoplethic cut “(Bi,Pb) 2Sr 2CuO xCaCuO 2”, were carried out to analyze the influence of partial constraint oxygen pressure on phase transformations. An isobaric invariant equilibrium has been found in the P o2 range 0.5-1. Supplementary phase appearing at invariant equilibrium is (Sr,Ca) 3Cu 5O y. That phase fixes oxygen and then the weight loss is stopped.

  17. Twistor Diagrams and Quantum Field Theory.

    NASA Astrophysics Data System (ADS)

    O'Donald, Lewis

    Available from UMI in association with The British Library. Requires signed TDF. This thesis uses twistor diagram theory, as developed by Penrose (1975) and Hodges (1990c), to try to approach some of the difficulties inherent in the standard quantum field theoretic description of particle interactions. The resolution of these issues is the eventual goal of the twistor diagram program. First twistor diagram theory is introduced from a physical view-point, with the aim of studying larger diagrams than have been typically explored. Methods are evolved to tackle the double box and triple box diagrams. These lead to three methods of constructing an amplitude for the double box, and two ways for the triple box. Next this theory is applied to translate the channels of a Yukawa Feynman diagram, which has more than four external states, into various twistor diagrams. This provides a test of the skeleton hypothesis (of Hodges, 1990c) in these cases, and also shows that conformal breaking must enter into twistor diagrams before the translation of loop level Feynman diagrams. The issue of divergent Feynman diagrams is then considered. By using a twistor equivalent of the sum-over -states idea of quantum field theory, twistor translations of loop diagrams are conjectured. The various massless propagator corrections and vacuum diagrams calculated give results consistent with Feynman theory. Two diagrams are also found that give agreement with the finite parts of the Feynman "fish" diagrams of phi^4 -theory. However it is found that a more rigorous translation for the time-like fish requires new boundaries to be added to the twistor sum-over-states. The twistor diagram obtained is found to give the finite part of the relevant Feynman diagram.

  18. Influence of Radioactivity on Surface Interaction Forces

    SciTech Connect

    Walker, Mark E; McFarlane, Joanna; Glasgow, David C; Chung, Eunhyea; Taboada Serrano, Patricia L; Yiacoumi, Sotira; Tsouris, Costas

    2010-01-01

    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{sup 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.

  19. The Influence of Proxemic Variables on Dyadic Interaction Between Peers.

    ERIC Educational Resources Information Center

    Weiss, Michael; Keys, Christopher

    This study addresses three issues: (1) the influence of proxemic variables (distance, furniture presence) on dyadic interaction; (2) the consistency between measures of self-disclosure; and (3) the applicability of reciprocity and distance-equilibrium views of dyadic interaction. Dyads of male college students were randomly assigned to one of four…

  20. Language, Culture, and Disability: Interacting Influences on Preschool Inclusion.

    ERIC Educational Resources Information Center

    Hanson, Marci J.; Gutierrez, Sonya; Morgan, Maria; Brennan, Elizabeth L.; Zercher, Craig

    1997-01-01

    A study investigated the interplay among language, culture, and disability in 112 children in inclusive preschools. Results found a lack of language goals on Individualized Education Programs, interaction of language with disability, the influence of communication skills on peer interactions, and the need for more training for service providers.…

  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. PMID:27041322

  2. Lipid-alamethicin interactions influence alamethicin orientation.

    PubMed

    Huang, H W; Wu, Y

    1991-11-01

    dipole-electric field interactions. We speculate that the phase-transitionlike behavior is a manifestation of membrane-mediated intermolecular interactions between peptide molecules. PMID:19431805

  3. 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.

  4. Influence of the vector interaction and an external magnetic field on the isentropes near the chiral critical end point

    NASA Astrophysics Data System (ADS)

    Costa, Pedro

    2016-06-01

    The location of the critical end point (CEP) and the isentropic trajectories in the QCD phase diagram are investigated. We use the (2 +1 ) Nambu-Jona-Lasinio model with the Polyakov loop coupling for different scenarios, namely by imposing zero strange quark density, which is the case in the ultrarelativistic heavy ion collisions, and β equilibrium. The influence of strong magnetic fields and of the vector interaction on the isentropic trajectories around the CEP is discussed. It is shown that the vector interaction and the magnetic field, having opposite effects on the first-order transition, affect the isentropic trajectories differently: as the vector interaction increases, the first-order transition becomes weaker and the isentropes become smoother; when a strong magnetic field is considered, the first-order transition is strengthened and the isentropes are pushed to higher temperatures. No focusing of isentropes in region towards the CEP is seen.

  5. 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.

  6. Gravity wave transmission diagram

    NASA Astrophysics Data System (ADS)

    Tomikawa, Yoshihiro

    2016-07-01

    A possibility of gravity wave propagation from a source region to the airglow layer around the mesopause has been discussed based on the gravity wave blocking diagram taking into account the critical level filtering alone. This paper proposes a new gravity wave transmission diagram in which both the critical level filtering and turning level reflection of gravity waves are considered. It shows a significantly different distribution of gravity wave transmissivity from the blocking diagram.

  7. Reading fitness landscape diagrams through HSAB concepts

    NASA Astrophysics Data System (ADS)

    Vigneresse, Jean-Louis

    2014-10-01

    Fitness landscapes are conceived as range of mountains, with local peaks and valleys. In terms of potential, such topographic variations indicate places of local instability or stability. The chemical potential, or electronegativity, its value changed of sign, carries similar information. In addition to chemical descriptors defined through hard-soft acid-base (HSAB) concepts and computed through density functional theory (DFT), the principles that rule chemical reactions allow the design of such landscape diagrams. The simplest diagram uses electrophilicity and hardness as coordinates. It allows examining the influence of maximum hardness or minimum electrophilicity principles. A third dimension is introduced within such a diagram by mapping the topography of electronegativity, polarizability or charge exchange. Introducing charge exchange during chemical reactions, or mapping a third parameter (f.i. polarizability) reinforces the information carried by a simple binary diagram. Examples of such diagrams are provided, using data from Earth Sciences, simple oxides or ligands.

  8. Hand gestures and perceived influence in small group interaction.

    PubMed

    Maricchiolo, Fridanna; Livi, Stefano; Bonaiuto, Marino; Gnisci, Augusto

    2011-11-01

    A laboratory study was carried out to establish the relative importance of verbal and gestural behavior, as well as their interaction, for perceived social influence in more or less competitive small groups. Forty women (psychology students) participated in leaderless small group discussions of different sizes (four-member and eight-member): at the end, each member rated the perceived influence in decision-making of every other member. Verbal dominance coding is based on traditional quantitative conversational dominance (number of talk turns). Gestural coding (conversational, ideational, object-adaptor, self-adaptor gestures) is based on classical gesture classifications. Beside a substantial effect of verbal dominance, the main result is that frequency of object-adaptors and conversational (only in large groups) and ideational (in both small and large groups) gestures increases perceived influence scores particularly when the verbal dominance of the speaker is low. PMID:22059321

  9. 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: ...

  10. 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.

  11. 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.

  12. 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

  13. Biotic-Abiotic Interactions: Factors that Influence Peptide-Graphene Interactions.

    PubMed

    Kim, Steve S; Kuang, Zhifeng; Ngo, Yen H; Farmer, Barry L; Naik, Rajesh R

    2015-09-16

    Understanding the factors that influence the interaction between biomolecules and abiotic surfaces is of utmost interest in biosensing and biomedical research. Through phage display technology, several peptides have been identified as specific binders to abiotic material surfaces, such as gold, graphene, silver, and so forth. Using graphene-peptide as our model abiotic-biotic pair, we investigate the effect of graphene quality, number of layers, and the underlying support substrate effect on graphene-peptide interactions using both experiments and computation. Our results indicate that graphene quality plays a significant role in graphene-peptide interactions. The graphene-biomolecule interaction appears to show no significant dependency on the number of graphene layers or the underlying support substrate. PMID:26305504

  14. 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.

  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. 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.

  17. 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…

  18. 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'…

  19. Upgrading Diagnostic Diagrams

    NASA Astrophysics Data System (ADS)

    Proxauf, B.; Kimeswenger, S.; Öttl, S.

    2014-04-01

    Diagnostic diagrams of forbidden lines have been a useful tool for observers in astrophysics for many decades now. They are used to obtain information on the basic physical properties of thin gaseous nebulae. Moreover they are also the initial tool to derive thermodynamic properties of the plasma from observations to get ionization correction factors and thus to obtain proper abundances of the nebulae. Some diagnostic diagrams are in wavelengths domains which were difficult to take either due to missing wavelength coverage or low resolution of older spectrographs. Thus they were hardly used in the past. An upgrade of this useful tool is necessary because most of the diagrams were calculated using only the species involved as a single atom gas, although several are affected by well-known fluorescence mechanisms as well. Additionally the atomic data have improved up to the present time. The new diagnostic diagrams are calculated by using large grids of parameter space in the photoionization code CLOUDY. For a given basic parameter the input radiation field is varied to find the solutions with cooling-heating-equilibrium. Empirical numerical functions are fitted to provide formulas usable in e.g. data reduction pipelines. The resulting diagrams differ significantly from those used up to now and will improve the thermodynamic calculations.

  20. Trace element indiscrimination diagrams

    NASA Astrophysics Data System (ADS)

    Li, Chusi; Arndt, Nicholas T.; Tang, Qingyan; Ripley, Edward M.

    2015-09-01

    We tested the accuracy of trace element discrimination diagrams for basalts using new datasets from two petrological databases, PetDB and GEOROC. Both binary and ternary diagrams using Zr, Ti, V, Y, Th, Hf, Nb, Ta, Sm, and Sc do a poor job of discriminating between basalts generated in various tectonic environments (continental flood basalt, mid-ocean ridge basalt, ocean island basalt, oceanic plateau basalt, back-arc basin basalt, and various types of arc basalt). The overlaps between the different types of basalt are too large for the confident application of such diagrams when used in the absence of geological and petrological constraints. None of the diagrams we tested can clearly discriminate between back-arc basin basalt and mid-ocean ridge basalt, between continental flood basalt and oceanic plateau basalt, and between different types of arc basalt (intra-oceanic, island and continental arcs). Only ocean island basalt and some mid-ocean ridge basalt are generally distinguishable in the diagrams, and even in this case, mantle-normalized trace element patterns offer a better solution for discriminating between the two types of basalt.

  1. Weyl card diagrams

    SciTech Connect

    Jones, Gregory; Wang, John E.

    2005-06-15

    To capture important physical properties of a spacetime we construct a new diagram, the card diagram, which accurately draws generalized Weyl spacetimes in arbitrary dimensions by encoding their global spacetime structure, singularities, horizons, and some aspects of causal structure including null infinity. Card diagrams draw only nontrivial directions providing a clearer picture of the geometric features of spacetimes as compared to Penrose diagrams, and can change continuously as a function of the geometric parameters. One of our main results is to describe how Weyl rods are traversable horizons and the entirety of the spacetime can be mapped out. We review Weyl techniques and as examples we systematically discuss properties of a variety of solutions including Kerr-Newman black holes, black rings, expanding bubbles, and recent spacelike-brane solutions. Families of solutions will share qualitatively similar cards. In addition we show how card diagrams not only capture information about a geometry but also its analytic continuations by providing a geometric picture of analytic continuation. Weyl techniques are generalized to higher dimensional charged solutions and applied to generate perturbations of bubble and S-brane solutions by Israel-Khan rods.

  2. Weyl card diagrams

    NASA Astrophysics Data System (ADS)

    Jones, Gregory; Wang, John E.

    2005-06-01

    To capture important physical properties of a spacetime we construct a new diagram, the card diagram, which accurately draws generalized Weyl spacetimes in arbitrary dimensions by encoding their global spacetime structure, singularities, horizons, and some aspects of causal structure including null infinity. Card diagrams draw only nontrivial directions providing a clearer picture of the geometric features of spacetimes as compared to Penrose diagrams, and can change continuously as a function of the geometric parameters. One of our main results is to describe how Weyl rods are traversable horizons and the entirety of the spacetime can be mapped out. We review Weyl techniques and as examples we systematically discuss properties of a variety of solutions including Kerr-Newman black holes, black rings, expanding bubbles, and recent spacelike-brane solutions. Families of solutions will share qualitatively similar cards. In addition we show how card diagrams not only capture information about a geometry but also its analytic continuations by providing a geometric picture of analytic continuation. Weyl techniques are generalized to higher dimensional charged solutions and applied to generate perturbations of bubble and S-brane solutions by Israel-Khan rods.

  3. A pseudo-haptic knot diagram interface

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Weng, Jianguang; Hanson, Andrew J.

    2011-01-01

    To make progress in understanding knot theory, we will need to interact with the projected representations of mathematical knots which are of course continuous in 3D but significantly interrupted in the projective images. One way to achieve such a goal would be to design an interactive system that allows us to sketch 2D knot diagrams by taking advantage of a collision-sensing controller and explore their underlying smooth structures through a continuous motion. Recent advances of interaction techniques have been made that allow progress to be made in this direction. Pseudo-haptics that simulates haptic effects using pure visual feedback can be used to develop such an interactive system. This paper outlines one such pseudo-haptic knot diagram interface. Our interface derives from the familiar pencil-and-paper process of drawing 2D knot diagrams and provides haptic-like sensations to facilitate the creation and exploration of knot diagrams. A centerpiece of the interaction model simulates a "physically" reactive mouse cursor, which is exploited to resolve the apparent conflict between the continuous structure of the actual smooth knot and the visual discontinuities in the knot diagram representation. Another value in exploiting pseudo-haptics is that an acceleration (or deceleration) of the mouse cursor (or surface locator) can be used to indicate the slope of the curve (or surface) of whom the projective image is being explored. By exploiting these additional visual cues, we proceed to a full-featured extension to a pseudo-haptic 4D visualization system that simulates the continuous navigation on 4D objects and allows us to sense the bumps and holes in the fourth dimension. Preliminary tests of the software show that main features of the interface overcome some expected perceptual limitations in our interaction with 2D knot diagrams of 3D knots and 3D projective images of 4D mathematical objects.

  4. The Interplay among Gestures, Discourse, and Diagrams in Students' Geometrical Reasoning

    ERIC Educational Resources Information Center

    Chen, Chia-Ling; Herbst, Patricio

    2013-01-01

    This study explores interactions with diagrams that are involved in geometrical reasoning; more specifically, how students publicly make and justify conjectures through multimodal representations of diagrams. We describe how students interact with diagrams using both gestural and verbal modalities, and examine how such multimodal interactions with…

  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. Pressure-enthalpy diagrams for alternative refrigerants

    SciTech Connect

    Chen, J.; Kruse, H.

    1996-10-01

    Thermodynamic diagrams, particularly log(p)-h diagrams, have become very convenient tools for refrigeration and air-conditioning industries. To promote alternative refrigerants-related development and application, it is urgently required to provide the industries with reliable engineering diagrams for the most promising candidate refrigerants. A computer program has been developed for automatically producing log(p)-h diagrams for alternative refrigerants. The Lee Kesler Ploecker (LKP) equation of state has been used to calculate thermodynamic data. Some modifications have been made to the LKP to improve the calculation convergency. In this paper three sample diagrams for R134a, a binary R410A and a ternary R407B which have been enclosed and analyzed. To investigate the LKP calculation accuracy details, an extensive deviation analysis has been made for R134a. For mixed refrigerants, good calculation accuracy was achieved by optimizing the binary interactive parameters. The system can produce log(p)-h diagrams with reliable accuracy, high quality, and flexibility to meet any size and color requirements.

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

    NASA Astrophysics Data System (ADS)

    Otto, Charlotte A.; Everett, Susan A.

    2013-03-01

    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 pedagogy and context relates to the ways that each of these general topics influences the other. The overlap of all three circles represents a complete lesson that is an integration of the three major components of PCK. The Venn diagram is an easily remembered graphic illustration of PCK that can be useful in planning lessons. The use of this graphic organizer in a science capstone course required of all pre-service elementary teachers is described.

  8. 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.

  9. Tectonic discrimination diagrams revisited

    NASA Astrophysics Data System (ADS)

    Vermeesch, Pieter

    2006-06-01

    The decision boundaries of most tectonic discrimination diagrams are drawn by eye. Discriminant analysis is a statistically more rigorous way to determine the tectonic affinity of oceanic basalts based on their bulk-rock chemistry. This method was applied to a database of 756 oceanic basalts of known tectonic affinity (ocean island, mid-ocean ridge, or island arc). For each of these training data, up to 45 major, minor, and trace elements were measured. Discriminant analysis assumes multivariate normality. If the same covariance structure is shared by all the classes (i.e., tectonic affinities), the decision boundaries are linear, hence the term linear discriminant analysis (LDA). In contrast with this, quadratic discriminant analysis (QDA) allows the classes to have different covariance structures. To solve the statistical problems associated with the constant-sum constraint of geochemical data, the training data must be transformed to log-ratio space before performing a discriminant analysis. The results can be mapped back to the compositional data space using the inverse log-ratio transformation. An exhaustive exploration of 14,190 possible ternary discrimination diagrams yields the Ti-Si-Sr system as the best linear discrimination diagram and the Na-Nb-Sr system as the best quadratic discrimination diagram. The best linear and quadratic discrimination diagrams using only immobile elements are Ti-V-Sc and Ti-V-Sm, respectively. As little as 5% of the training data are misclassified by these discrimination diagrams. Testing them on a second database of 182 samples that were not part of the training data yields a more reliable estimate of future performance. Although QDA misclassifies fewer training data than LDA, the opposite is generally true for the test data. Therefore LDA is a cruder but more robust classifier than QDA. Another advantage of LDA is that it provides a powerful way to reduce the dimensionality of the multivariate geochemical data in a similar

  10. 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

  11. Impulse-Momentum Diagrams

    NASA Astrophysics Data System (ADS)

    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.2 These representations include: pictures, free-body diagrams,3 energy bar charts,4 electrical circuits, and, more recently, computer simulations and animations.5 However, instructors have limited choices when they want to help their students understand impulse and momentum. One of the only available options is the impulse-momentum bar chart.6 The bar charts can effectively show the magnitude of the momentum as well as help students understand conservation of momentum, but they do not easily show the actual direction. This paper highlights a new representation instructors can use to help their students with momentum and impulse—the impulse-momentum diagram (IMD).

  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. 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

  14. 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

  15. 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.

  16. A new method for diagramming pacemaker electrocardiograms.

    PubMed

    Hesselson, A B; Parsonnet, V

    1994-08-01

    Advancements in technology have made paced ECG interpretation increasingly difficult. A new method for depicting the complex pacemaker/heart interactions that eliminates the extensive use of symbols and repetitious use of refractory period and rate limit information of previous methods has been devised. The method uses a framework of parallel horizontal lines drawn on grid paper underneath the ECG. The lines are spaced apart by the actual programmed values (lower rate, AV, VA intervals) of the pacemaker in question. This framework allows the simultaneous use of the horizontal and vertical directions for the diagram of pacemaker timing intervals. Also, a single representation of refractory periods, upper rate intervals, and other variables can be labeled vertically and extrapolated horizontally across the entire diagram. Single chamber, dual chamber, and rate-modulated ECGs are readily represented. The diagram is easily plotted on standard ECG paper and flexible enough to represent complex ECGs. PMID:7526348

  17. Phase diagram of a truncated tetrahedral model.

    PubMed

    Krcmar, Roman; Gendiar, Andrej; Nishino, Tomotoshi

    2016-08-01

    Phase diagram of a discrete counterpart of the classical Heisenberg model, the truncated tetrahedral model, is analyzed on the square lattice, when the interaction is ferromagnetic. Each spin is represented by a unit vector that can point to one of the 12 vertices of the truncated tetrahedron, which is a continuous interpolation between the tetrahedron and the octahedron. Phase diagram of the model is determined by means of the statistical analog of the entanglement entropy, which is numerically calculated by the corner transfer matrix renormalization group method. The obtained phase diagram consists of four different phases, which are separated by five transition lines. In the parameter region, where the octahedral anisotropy is dominant, a weak first-order phase transition is observed. PMID:27627273

  18. Developmentally Delayed Children's Influence Attempts with Mothers Predict Interactions with Peers over Time

    ERIC Educational Resources Information Center

    Guralnick, Michael J.; Connor, Robert T.; Neville, Brian; Hammond, Mary A.

    2008-01-01

    We examined whether influence attempts of 4-6 year-old children with mild developmental delays occurring when interacting with their mothers predicted children's interactions with peers two years later. Hierarchical regressions controlling for relevant child characteristics and a measure of direct parental actions to influence their children's…

  19. Wilson Loop Diagrams and Positroids

    NASA Astrophysics Data System (ADS)

    Agarwala, Susama; Marin-Amat, Eloi

    2016-07-01

    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.

  20. 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.

  1. Spin wave Feynman diagram vertex computation package

    NASA Astrophysics Data System (ADS)

    Price, Alexander; Javernick, Philip; Datta, Trinanjan

    Spin wave theory is a well-established theoretical technique that can correctly predict the physical behavior of ordered magnetic states. However, computing the effects of an interacting spin wave theory incorporating magnons involve a laborious by hand derivation of Feynman diagram vertices. The process is tedious and time consuming. Hence, to improve productivity and have another means to check the analytical calculations, we have devised a Feynman Diagram Vertex Computation package. In this talk, we will describe our research group's effort to implement a Mathematica based symbolic Feynman diagram vertex computation package that computes spin wave vertices. Utilizing the non-commutative algebra package NCAlgebra as an add-on to Mathematica, symbolic expressions for the Feynman diagram vertices of a Heisenberg quantum antiferromagnet are obtained. Our existing code reproduces the well-known expressions of a nearest neighbor square lattice Heisenberg model. We also discuss the case of a triangular lattice Heisenberg model where non collinear terms contribute to the vertex interactions.

  2. 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…

  3. Influence of hydrodynamic interactions on mechanical unfolding of proteins

    NASA Astrophysics Data System (ADS)

    Szymczak, P.; Cieplak, Marek

    2007-07-01

    We incorporate hydrodynamic interactions in a structure-based model of ubiquitin and demonstrate that the hydrodynamic coupling may reduce the peak force when stretching the protein at constant speed, especially at larger speeds. Hydrodynamic interactions are also shown to facilitate unfolding at constant force and inhibit stretching by fluid flows.

  4. 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. PMID:21653581

  5. 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

  6. 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., Jr.; 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

  7. The Influence of Ethnicity, Gender, and Dyadic Composition on Uncertainty Reduction in Initial Interactions.

    ERIC Educational Resources Information Center

    Gudykunst, William B.; Hammer, Mitchell R.

    1987-01-01

    Observation of 485 Black and White students demonstrates that ethnicity and self-monitoring have independent influences upon uncertainty reduction in initial interactions, while the effects of gender and dyadic composition are interactive in nature. Many of the relationships between interaction variables posited by Berger and Calabrese are…

  8. 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. PMID:26154622

  9. Argument Diagramming: The Araucaria Project

    NASA Astrophysics Data System (ADS)

    Rowe, Glenn; Reed, Chris

    Formal arguments, such as those used in science, medicine and law to establish a conclusion by providing supporting evidence, are frequently represented by diagrams such as trees and graphs. We describe the software package Araucaria which allows textual arguments to be marked up and represented as standard, Toulmin or Wigmore diagrams. Since each of these diagramming techniques was devised for a particular domain or argumentation, we discuss some of the issues involved in translating between diagrams. The exercise of translating between different diagramming types illustrates that any one diagramming system often cannot capture all of the nuances inherent in an argument. Finally, we describe some areas, such as critical thinking courses in colleges and universities and the analysis of evidence in court cases, where Araucaria has been put to practical use.

  10. Band diagram of strained graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Prabhakar, Sanjay; Melnik, Roderick; Bonilla, Luis

    2016-04-01

    The influence of ripple waves on the band diagram of zigzag strained graphene nanoribbons (GNRs) is analyzed by utilizing the finite element method. Such waves have their origin in electromechanical effects. With a novel model, we demonstrate that electron-hole band diagrams of GNRs are highly influenced (i.e. level crossing of the bands are possible) by two combined effects: pseudo-magnetic fields originating from electroelasticity theory and external magnetic fields. In particular, we show that the level crossing point can be observed at large external magnetic fields (B ≈ 100T ) in strained GNRs, when the externally applied tensile edge stress is on the order of -100 eV/nm and the amplitude of the out-of-plane ripple waves is on the order of 1nm.

  11. 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.

  12. Magnetic Interactions Influence the Properties of Helium Defects in Iron.

    SciTech Connect

    Seletskaia, Tatiana; Osetskiy, Yury N; Stoller, Roger E; Stocks, George Malcolm

    2005-01-01

    Density functional theory calculations of He defect properties in iron have shown an unexpected influence of magnetism arising from the defect's electronic structure. In contrast with previous work that neglected such effects, the results indicate that the tetrahedral position is energetically more favorable for the He interstitial than the octahedral site. This may have significant implications for He clustering and bubble nucleation, which will impact material performance in future fusion reactors. These results provide the basis for development of improved atomistic models.

  13. Contingency diagrams as teaching tools

    PubMed Central

    Mattaini, Mark A.

    1995-01-01

    Contingency diagrams are particularly effective teaching tools, because they provide a means for students to view the complexities of contingency networks present in natural and laboratory settings while displaying the elementary processes that constitute those networks. This paper sketches recent developments in this visualization technology and illustrates approaches for using contingency diagrams in teaching. ImagesFigure 2Figure 3Figure 4 PMID:22478208

  14. 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)

  15. Cryptococcus and Phagocytes: Complex Interactions that Influence Disease Outcome

    PubMed Central

    Leopold Wager, Chrissy M.; Hole, Camaron R.; Wozniak, Karen L.; Wormley, Floyd L.

    2016-01-01

    Cryptococcus neoformans and C. gattii are fungal pathogens that cause life-threatening disease. These fungi commonly enter their host via inhalation into the lungs where they encounter resident phagocytes, including macrophages and dendritic cells, whose response has a pronounced impact on the outcome of disease. Cryptococcus has complex interactions with the resident and infiltrating innate immune cells that, ideally, result in destruction of the yeast. These phagocytic cells have pattern recognition receptors that allow recognition of specific cryptococcal cell wall and capsule components. However, Cryptococcus possesses several virulence factors including a polysaccharide capsule, melanin production and secretion of various enzymes that aid in evasion of the immune system or enhance its ability to thrive within the phagocyte. This review focuses on the intricate interactions between the cryptococci and innate phagocytic cells including discussion of manipulation and evasion strategies used by Cryptococcus, anti-cryptococcal responses by the phagocytes and approaches for targeting phagocytes for the development of novel immunotherapeutics. PMID:26903984

  16. Cooperative or Anticooperative: How Noncovalent Interactions Influence Each Other.

    PubMed

    Saha, Soumen; Sastry, G Narahari

    2015-08-27

    This computational study examines the key factors that control the structures and energetics of the coexistence of multiple noncovalent interactions. 4-Amino-2-iodophenol is taken as a model that exhibits nine different kinds of noncovalent interactions, viz., cation-π (CP), hydrogen bond (HB) through O (OHB), HB through N (NHB), halogen bond (XB), π-π (PP), metal ion-lone pair (ML) through O (OML), ML through N (NML), charge assisted hydrogen bond (CHB) through O (OCHB), and CHB through N (NCHB). Through all possible combinations of these noncovalent interactions, based on energy, geometry, charge, and atoms in molecules (AIM) analysis, we have systematically analyzed the cooperativity among 40 ternary systems and 105 quaternary systems. We have observed that CP-HB, CP-XB, CP-PP, HB-HB, HB-XB, HB-PP, HB-ML, HB-CHB, XB-PP, XB-ML, XB-CHB, PP-ML, and PP-OCHB can form cooperative ternary systems. While studying the quaternary systems, we have observed that HB, XB, and PP work together by enhancing each other's strength. The study highlights that the positively charged species enhances HB-HB and HB-PP interactions and forms cooperative HB-HB-CHB, HB-HB-ML, HB-PP-ML, and HB-PP-CHB systems. Surprisingly, OHB-OML-NML, OHB-OML-OCHB, OHB-OML-NCHB, OHB-NML-OCHB, NHB-OML-NML, NHB-OML-NCHB, and NHB-NML-OCHB are also cooperative in nature despite the electrostatic repulsion between two positive charge species. The current study shows the widespread presence of cooperativity as well as anticooperativity in supramolecular assembles. PMID:25938813

  17. The wolfpack effect. Perception of animacy irresistibly influences interactive behavior.

    PubMed

    Gao, Tao; McCarthy, Gregory; Scholl, Brian J

    2010-12-01

    Imagine a pack of predators stalking their prey. The predators may not always move directly toward their target (e.g., when circling around it), but they may be consistently facing toward it. The human visual system appears to be extremely sensitive to such situations, even in displays involving simple shapes. We demonstrate this by introducing the wolfpack effect, which is found when several randomly moving, oriented shapes (darts, or discs with "eyes") consistently point toward a moving disc. Despite the randomness of the shapes' movement, they seem to interact with the disc--as if they are collectively pursuing it. This impairs performance in interactive tasks (including detection of actual pursuit), and observers selectively avoid such shapes when moving a disc through the display themselves. These and other results reveal that the wolfpack effect is a novel "social" cue to perceived animacy. And, whereas previous work has focused on the causes of perceived animacy, these results demonstrate its effects, showing how it irresistibly and implicitly shapes visual performance and interactive behavior. PMID:21078895

  18. Influence of basalt/groundwater interactions on radionuclide migration

    SciTech Connect

    Vandegrift, G.F.

    1984-01-01

    The work presented here is a partial summary of the experimental results obtained in the Laboratory Analog Program. Two aspects of this effort are (1) the interaction between simulated basaltic groundwater and basalt fissures that were either freshly cleaved or laboratory altered by hydrothermal treatment with the simulated groundwater and (2) the effect of this interaction on radionuclide migration through these basalt fissures. The following conclusions of this study bear heavily on the predicted safety of a basalt repository: Sorption properties of freshly fissured basalt and naturally aged basalt are quite different for different chemical species. Analog experiments predict that aged basalt would be an effective retarder of cesium, but would be much less so for actinide elements. Distribution ratios measured from batch experiments with finely ground rock samples (presenting unaltered rock surfaces) are not a reliable means of predicting radionuclide migration in geological repositories. As the near-repository area is resaturated by groundwater, its ability to retard actinide migration will be degraded with time. Disturbing the natural flow of groundwater through the repository area by constructing and backfilling the repository will modify the composition of groundwater. This modified groundwater is likely to interact with and to modify naturally aged basalt surfaces downstream from the repository.

  19. Magnetic interactions influence the properties of helium defects in iron.

    PubMed

    Seletskaia, Tatiana; Osetsky, Yuri; Stoller, R E; Stocks, G M

    2005-02-01

    Density functional theory calculations of He defect properties in iron have shown an unexpected influence of magnetism arising from the defect's electronic structure. In contrast with previous work that neglected such effects, the results indicate that the tetrahedral position is energetically more favorable for the He interstitial than the octahedral site. This may have significant implications for He clustering and bubble nucleation, which will impact material performance in future fusion reactors. These results provide the basis for development of improved atomistic models. PMID:15783579

  20. The Influence of Context-Specific and Dispositional Achievement Goals on Children's Paired Collaborative Interaction

    ERIC Educational Resources Information Center

    Harris, Amanda; Yuill, Nicola; Luckin, Rosemary

    2008-01-01

    Background: Research has demonstrated that working collaboratively can have positive effects on children's learning. While key factors have been identified which influence the quality of these interactions, little research has addressed the influence of children's achievement goals on collaborative behaviour. Aims: This paper investigates the…

  1. Influence of polymer-molecule/wall interactions on mobility control

    SciTech Connect

    Duda, J.L.; Klaus, E.E.; Fan, S.K.

    1981-10-01

    This study presents the results of a study of molecule/wall interactions on permeability modification of consolidated porous media by polymer solutions. The experiments were conducted with a newly developed low-shear porous media viscometer. The key for obtaining reproducible, steady-state results was to expose the porous medium to several hundred pore volumes of polymer solution to saturate it with polymer. The effective permeability during polymer flow and the residual permeability were determined for xanthan gum and polyacrylamide solutions in Berea sandstone, Bradford sandstone, filter papers, and Nuclepore filters. 25 refs.

  2. Exercising influence: distinct biotic interactions shape root microbiomes.

    PubMed

    Sloan, Sarah Stuart; Lebeis, Sarah L

    2015-08-01

    Root microbiomes are formed from diverse microbial soil settings with extraordinary consistency, suggesting both defined mechanisms of assembly and specific microbial activity. Recent improvements in sequencing technologies, data analysis techniques, and study design, allow definition of the microbiota within these intimate and important relationships with increasing accuracy. Comparing datasets provides powerful insights into the overlap of plant microbiomes, as well as the impacts of surrounding plants and microbes on root microbiomes and long-term soil conditioning. Here we address how recent studies tease apart the impact of various biotic interactions, including: plant-plant, plant-microbe, and microbe-microbe on root microbiome composition. PMID:26116973

  3. 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…

  4. 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).

  5. 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.

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

    PubMed

    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

  7. 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

  8. Concrete and abstract Voronoi diagrams

    SciTech Connect

    Klein, R. )

    1989-01-01

    The Voronoi diagram of a set of sites is a partition of the plane into regions, one to each site, such that the region of each site contains all points of the plane that are closer to this site than to the other ones. Such partitions are of great importance to computer science and many other fields. The challenge is to compute Voronoi diagrams quickly. The problem is that their structure depends on the notion of distance and the sort of site. In this book the author proposes a unifying approach by introducing abstract Voronoi diagrams. These are based on the concept of bisecting curves which are required to have some simple properties that are actually possessed by most bisectors of concrete Voronoi diagrams. Abstract Voronoi diagrams can be computed efficiently and there exists a worst-case efficient algorithm of divide-and-conquer type that applies to all abstract Voronoi diagrams satisfying a certain constraint. The author shows that this constraint is fulfilled by the concrete diagrams based no large classes of metrics in the plane.

  9. Phase diagram and dynamics of Yukawa systems

    NASA Astrophysics Data System (ADS)

    Robbins, Mark. O.; Kremer, Kurt; Grest, Gary S.

    1988-03-01

    The phase diagram and dynamical properties of systems of particles interacting through a repulsive screened Coulomb (Yukawa) potential have been calculated using molecular and lattice dynamics techniques. The phase diagram contains both a melting transition and a transition from fcc to bcc crystalline phases. These phase transitions have been studied as a function of potential shape (screening length) and compared to phenomenological criteria for transition temperatures such as those of Lindemann and of Hansen and Verlet. The transition from fcc to bcc with increasing temperature is shown to result from a higher entropy in the bcc phase because of its softer shear modes. Even when the stable solid phase below the melting temperature is fcc, bcc-like local order is found in the liquid phase. This may substantially slow crystallization. The calculated phase diagram and shear modulus are in good agreement with experiments on colloidal suspensions of polystyrene spheres. The single particle dynamics of Yukawa systems show several unusual features. There is a pronounced subdiffusive regime in liquids near and below the melting temperature. This regime reflects the existence of two time scales: a typical phonon period, and the time for a particle to feel a new environment. The second time scale becomes longer as the temperature is lowered or the range of interaction (screening length) increases.

  10. 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.

  11. 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.

  12. Anion–π interactions influence pK a values

    PubMed Central

    Cadman, Christopher J

    2011-01-01

    Summary Five 8-(4-R-phenyl)-1-naphthol derivatives were prepared by PdCl2-catalysed electrophilic aromatic substitution. The pK a' values for these 1,8-disubstituted arene naphthols have been measured in acetonitrile/water (R = NO2, 8.42; R = Cl, 8.52; R = H, 8.56; R = Me 8.68; and R = OMe, 8.71) and indicate a correlation with the electronic nature of the arene substituent, as determined through LFER analysis. Contributions to the relative pK a' values have been interpreted, using M06-2X DFT calculations, as consisting of two components: A small contribution from initial OH–π bonding in the starting materials and a larger contribution from anion–π interactions in the products. Such effects have implications for a range of other systems. PMID:21512592

  13. Influence of plasma surface interactions on tokamak startup

    SciTech Connect

    Goswami, Rajiv

    2013-08-15

    The startup phase of a tokamak is a complex phenomenon involving burnthrough of the low-Z impurities and rampup of I{sub p}, the plasma current. The design considerations of a tokamak are closely connected with the startup modeling. Plasma evolution is analysed using a zero-dimensional model. The particle and energy balance is considered of two subclasses of plasmas which are penetrable by neutral gas, together with another component, neutrals trapped in the wall. The first subclass includes plasmas being penetrated by slow neutrals of (∼few eV) temperature. The second includes plasmas being penetrated only by fast neutrals having a temperature comparable to that of the ions. The impact of impurities on energy balance is considered through their generation by ion induced desorption of adsorbed oxygen on the first wall and physical and chemical sputtering of carbon. The paper demonstrates self-consistently that the evolution of initial phase of the discharge is intimately linked to the condition of the plasma facing components (PFCs) and the resultant plasma surface interactions.

  14. 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)

  15. 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.

  16. Influence of the σ-ω meson interaction on neutron star matter

    NASA Astrophysics Data System (ADS)

    Shao, Guo-Yun; Liu, Yu-Xin

    2009-02-01

    Relativistic mean field theory with nonlinear scalar self-interaction and isoscalar scalar-vector cross-interaction is used to study the properties of neutron star matter in β equilibrium with and without hyperons. The influence of σ-ω meson cross-interaction on the properties of neutron star matter and the mass-radius relation of neutron stars is examined with attractive and repulsive Σ potential, respectively. The calculated result indicates that the cross-interaction softens the equation of state (EOS) of nuclear (hadronic) matter and reduces the maximum mass of neutron stars. It also decreases the densities for hyperonization to occur and lowers the center density of neutron stars. The increase of the cross-interaction strength enhances the softening effect of hyperons on the EOS. Meanwhile the repulsive Σ potential stiffens slightly the EOS and influences obviously the composition of neutron star matter.

  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. PMID:23876073

  18. 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).

  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. PMID:25492100

  20. 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. PMID:19861091

  1. 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.

  2. Jupiter Torus Diagram

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A cut-away schematic of Jupiter's space environment shows magnetically trapped radiation ions (in red), the neutral gas torus of the volcanic moon Io (green) and the newly discovered neutral gas torus of the moon Europa (blue). The white lines represent magnetic field lines.

    Energetic neutral atoms (ENA) are emitted from the Europa torus regions because of the interaction between the trapped ions and the neutral gases. The Magnetospheric Imaging Instrument on NASA's Cassini spacecraft imaged those energetic neutral atoms in early 2001 during Cassini's flyby of Jupiter. Energetic neutral atoms also come from Jupiter when radiation ions impinge onto Jupiter's upper atmosphere.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages Cassini for NASA's Office of Space Science, Washington, D.C.

  3. The influence of protein-protein interactions on the organization of proteins within thylakoid membranes.

    PubMed

    Tremmel, I G; Weis, E; Farquhar, G D

    2005-04-01

    The influence of attractive protein-protein interactions on the organization of photosynthetic proteins within the thylakoid membrane was investigated. Protein-protein interactions were simulated using Monte Carlo techniques and the influence of different interaction energies was examined. It was found that weak interactions led to protein clusters whereas strong interactions led to ramified chains. An optimum curve for the relationship between interaction energy and the number of contact sites emerged. With increasing particle densities the effect decreased. In a mixture of interacting and noninteracting particles the distance between the noninteracting particles was increased and there seemed to be much more free space around them. In thylakoids, this could lead to a more homogeneous distribution of the noninteracting but rate-limiting cytochrome bf complexes. Due to the increased free space between cytochrome bf, obstruction of binding sites--occurring unavoidably in a random distribution--may be drastically reduced. Furthermore, protein-protein interactions in thylakoids may lead to a decrease in plastoquinone diffusion. PMID:15665125

  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. Understanding the influence of Coulomb and dispersion interactions on the wetting behavior of ionic liquids.

    PubMed

    Rane, Kaustubh S; Errington, Jeffrey R

    2014-11-01

    We study the role of dispersion and electrostatic interactions in the wetting behavior of ionic liquids on non-ionic solid substrates. We consider a simple model of an ionic liquid consisting of spherical ions that interact via Lennard-Jones and Coulomb potentials. Bulk and interfacial properties are computed for five fluids distinguished by the strength of the electrostatic interaction relative to the dispersion interaction. We employ Monte Carlo simulations and an interface-potential-based approach to calculate the liquid-vapor and substrate-fluid interfacial properties. Surface tensions for each fluid are evaluated over a range of temperatures that spans from a reduced temperature of approximately 0.6 to the critical point. Contact angles are calculated at select temperatures over a range of substrate-fluid interaction strengths that spans from the near-drying regime to the wetting regime. We observe that an increase in the relative strength of Coulombic interactions between ions leads to increasing deviation from Guggenheim's corresponding states theory. We show how this deviation is related to lower values of liquid-vapor excess entropies observed for strongly ionic fluids. Our results show that the qualitative nature of wetting behavior is significantly influenced by the competition between dispersion and electrostatic interactions. We discuss the influence of electrostatic interactions on the nature of wetting and drying transitions and corresponding states like behavior observed for contact angles. For all of the fluids studied, we observe a relatively narrow range of substrate-fluid interaction strengths wherein the contact angle is nearly independent of temperature. The influence of the ionic nature of the fluid on the temperature dependence of contact angle is also discussed. PMID:25381536

  6. 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…

  7. 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,…

  8. 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…

  9. 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…

  10. Interaction in Instrumental Learning: The Influence of Interpersonal Dynamics on Parents

    ERIC Educational Resources Information Center

    Creech, Andrea; Hallam, Susan

    2009-01-01

    The research reported here forms part of a UK study that investigated the impact of interpersonal interaction on teaching and learning outcomes, in the context of learning a musical instrument. This article presents the findings relating to parents, exploring how parental involvement, self-efficacy and personal satisfaction were influenced by…

  11. 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…

  12. Father Caretaking Characteristics and Their Influence on Infant-Father Interaction.

    ERIC Educational Resources Information Center

    Kotelchuck, Milton

    This paper describes five experimental studies which explored the influence of fathers' home caregiving and interactional characteristics on their infant's laboratory behavior. Approximately 300 families with children ranging in age from 6 to 24 months were studied. Each infant's reactions were observed as a function of the manipulation of the…

  13. 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…

  14. Individual Variation in Agrammatism: A Single Case Study of the Influence of Interaction

    ERIC Educational Resources Information Center

    Beeke, Suzanne; Wilkinson, Ray; Maxim, Jane

    2007-01-01

    Background: Agrammatic speech can manifest in different ways in the same speaker if task demands change. Individual variation is considered to reflect adaptation, driven by psycholinguistic factors such as underlying deficit. Recently, qualitative investigations have begun to show ways in which conversational interaction can influence the form of…

  15. Attentional Engagement in Infancy: The Interactive Influence of Attentional Inertia and Attentional State

    ERIC Educational Resources Information Center

    Oakes, Lisa M.; Ross-Sheehy, Shannon; Kannass, Kathleen N.

    2004-01-01

    We evaluated the interactive influences of attentional state and attentional inertia on infants' level of attentional engagement. We assessed infants' distraction latencies longitudinally at 6.5 and 9 months as they explored toys, and we coded both their attentional state (focused vs. casual) and how long they had been looking at the toy at each…

  16. 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…

  17. 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.

  18. Modeling the Influence of Interaction Layer Formation on Thermal Conductivity of U–Mo Dispersion Fuel

    SciTech Connect

    Burkes, Douglas; Casella, Andrew M.; Huber, Tanja K.

    2015-01-01

    The Global Threat Reduction Initiative Program continues to develop existing and new plate- and rod-type research and test reactor fuels with maximum attainable uranium loadings capable of potentially converting a number of the world’s remaining high-enriched uranium fueled reactors to low-enriched uranium fuel. Currently, the program is focused on assisting with the development and qualification of an even higher density fuel type consisting of a uranium-molybdenum (U-Mo) alloy dispersed in an aluminum matrix. Thermal conductivity is an important consideration in determining the operational temperature of the fuel plate and can be influenced by interaction layer formation between the fuel and matrix, porosity that forms during fabrication of the fuel plates, and upon the concentration of the dispersed phase within the matrix. This paper develops and validates a simple model to study the influence of interaction layer formation and conductivity, fuel particle size, and volume fraction of fuel dispersed in the matrix on the effective conductivity of the composite. The model shows excellent agreement with results previously presented in the literature. In particular, the thermal conductivity of the interaction layer does not appear to be important in determining the overall conductivity of the composite, while formation of the interaction layer and subsequent consumption of the matrix reveals a rather significant effect. The effective thermal conductivity of the composite can be influenced by the fuel particle distribution by minimizing interaction layer formation and preserving the higher thermal conductivity matrix.

  19. Pharmacists’ Perceptions of the Influence of Interactions with the Pharmaceutical Industry on Clinical Decision-Making

    PubMed Central

    Tejani, Aaron M; Loewen, Peter; Bachand, Richard; Harder, Curtis K

    2015-01-01

    Background: There is a paucity of literature examining the perceptions of Canadian pharmacists toward drug promotion by the pharmaceutical industry and pharmacist–industry interactions. Objectives: To determine whether hospital pharmacists perceive their interactions with the pharmaceutical industry as influencing their clinical decision-making or that of their colleagues and whether hospital pharmacists perceive that interactions with the pharmaceutical industry create a conflict of interest. Methods: A cross-sectional survey of the complete sample of hospital pharmacists practising in 3 large health authorities in a single Canadian province was conducted from February to April 2010. Results: A total of 224 responses were received from the approximately 480 pharmacists in the target health authorities (response rate approximately 47%). Fifty-eight percent of respondents (127/218) did not believe that information received at industry-sponsored events influenced their clinical decision-making. Most (142/163 [87%]) disagreed that small gifts influenced their clinical decision-making, whereas responses were divided for large gifts. Respondents were also divided on the issue of whether their interactions created conflicts of interest, with most of those who had received gifts agreeing that large gifts would create a conflict of interest (134/163 [82%]) whereas small gifts would not (100/163 [61%]). There were positive correlations between respondents’ beliefs about their own susceptibility to influence from sponsored events or receipt of small or large gifts and the susceptibility of others, but 22% of respondents (28/127) expressed a different perception about sponsored events, all believing themselves to be less influenced than their colleagues. Only 6% (4/64) of those who received large gifts and 4% (5/142) of those who received small gifts and felt they were not influenced by these gifts reported that it was likely others would be influenced by the receipt of

  20. 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. PMID:25681294

  1. 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…

  2. Predator Cue and Prey Density Interactively Influence Indirect Effects on Basal Resources in Intertidal Oyster Reefs

    PubMed Central

    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. PMID:22970316

  3. 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. PMID:21214419

  4. Mixtures of charged colloid and neutral polymer: influence of electrostatic interactions on demixing and interfacial tension.

    PubMed

    Denton, Alan R; Schmidt, Matthias

    2005-06-22

    The equilibrium phase behavior of a binary mixture of charged colloids and neutral, nonadsorbing polymers is studied within free-volume theory. A model mixture of charged hard-sphere macroions and ideal, coarse-grained, effective-sphere polymers is mapped first onto a binary hard-sphere mixture with nonadditive diameters and then onto an effective Asakura-Oosawa model [S. Asakura and F. Oosawa, J. Chem. Phys. 22, 1255 (1954)]. The effective model is defined by a single dimensionless parameter-the ratio of the polymer diameter to the effective colloid diameter. For high salt-to-counterion concentration ratios, a free-volume approximation for the free energy is used to compute the fluid phase diagram, which describes demixing into colloid-rich (liquid) and colloid-poor (vapor) phases. Increasing the range of electrostatic interactions shifts the demixing binodal toward higher polymer concentration, stabilizing the mixture. The enhanced stability is attributed to a weakening of polymer depletion-induced attraction between electrostatically repelling macroions. Comparison with predictions of density-functional theory reveals a corresponding increase in the liquid-vapor interfacial tension. The predicted trends in phase stability are consistent with observed behavior of protein-polysaccharide mixtures in food colloids. PMID:16035820

  5. The Effect of Diagrams on Online Reading Processes and Memory

    ERIC Educational Resources Information Center

    McCrudden, Matthew T.; Magliano, Joseph P.; Schraw, Gregory

    2011-01-01

    This work examined how adjunct displays influence college readers' moment-by-moment processing of text and the products of reading, using reading time (Experiments 1 & 2), and think-aloud methodologies (Experiment 3). Participants did or did not study a diagram before reading a text. Overall, the reading time data, think-aloud data, and recall…

  6. Electrochemical phase diagrams for Ti oxides from density functional calculations

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Feng; Rondinelli, James M.

    2015-12-01

    Developing an accurate simulation method for the electrochemical stability of solids, as well as understanding the physics related with its accuracy, is critically important for improving the performance of compounds and predicting the stability of new materials in aqueous environments. Herein we propose a workflow for the accurate calculation of first-principles electrochemical phase (Pourbaix) diagrams. With this scheme, we study the electrochemical stabilities of Ti and Ti oxides using density-functional theory. First, we find the accuracy of an exchange-correlation functional in predicting formation energies and electrochemical stabilities is closely related with the electronic exchange interaction therein. Second, the metaGGA and hybrid functionals with a more precise description of the electronic exchange interaction lead to a systematic improvement in the accuracy of the Pourbaix diagrams. Furthermore, we show that accurate Ti Pourbaix diagrams also require that thermal effects are included through vibrational contributions to the free energy. We then use these diagrams to explain various experimental electrochemical phenomena for the Ti-O system, and show that if experimental formation energies for Ti oxides, which contain contributions from defects owing to their generation at high (combustion) temperatures, are directly used to predict room temperature Pourbaix diagrams then significant inaccuracies result. In contrast, the formation energies from accurate first-principles calculations, e.g., using metaGGA and hybrid functionals, are found to be more reliable. Finally, to facilitate the future application of our accurate electrochemical phase equilibria diagrams, the variation of the Ti Pourbaix diagrams with aqueous ion concentration is also provided.

  7. The Influence of AN Interacting Vacuum Energy on the Gravitational Collapse of a Star Fluid

    NASA Astrophysics Data System (ADS)

    Campos, M.

    2014-02-01

    To explain the accelerated expansion of the universe, models with interacting dark components has been considered in the literature. Generally, the dark energy component is physically interpreted as the vacuum energy. However, at the other side of the same coin, the influence of the vacuum energy in the gravitational collapse is a topic of scientific interest. Based in a simple assumption on the collapsed rate of the matter fluid density that is altered by the inclusion of a vacuum energy component that interacts with the matter fluid, we study the final fate of the collapse process.

  8. Conflict and expectancies interact to predict sexual behavior under the influence among gay and bisexual men

    PubMed Central

    Wells, Brooke E; Starks, Tyrel J; Parsons, Jeffrey T; Golub, Sarit

    2013-01-01

    As the mechanisms of the associations between substance use and risky sex remain unclear, this study investigates the interactive roles of conflicts about casual sex and condom use and expectancies of the sexual effects of substances in those associations among gay men. Conflict interacted with expectancies to predict sexual behavior under the influence; low casual sex conflict coupled with high expectancies predicted the highest number of casual partners, and high condom use conflict and high expectancies predicted the highest number of unprotected sex acts. Results have implications for intervention efforts that aim to improve sexual decision-making and reduce sexual expectancies. PMID:23584507

  9. [The influences of interaction during online gaming on sociability and aggression in real life].

    PubMed

    Fuji, Kei; Yoshida, Fujio

    2010-02-01

    This study examined the influences of online gaming on sociability and aggression in real life. It was hypothesized that the effects of online gaming would differ depending on the interaction style of the online-gamers. Online-gamers in Japan (n = 1 477) were asked to respond to questionnaires that measured interaction style during online gaming, the effects of sociability and aggression, as well as social and individual orientation in real life. Factor analysis of the scores for interaction style extracted five factors. Covariance structure analysis indicated that sociable interactions such as "Broadening relations" and "Feeling of belonging" promoted sociability in real life. In addition, "Release from daily hassles" promoted sociability and decreased aggression. In contrast, non-sociable and aggressive interactions decreased sociability and increased aggression. The results also suggested that a social orientation in real life promoted sociable interactions during game playing, while an individual orientation promoted non-sociable and aggressive interactions. These results supported the hypotheses and suggested that online gaming resulted in positive outcomes for those who are socially, but negative outcomes for those who are not. PMID:20235474

  10. Spectral Determinants on Mandelstam Diagrams

    NASA Astrophysics Data System (ADS)

    Hillairet, Luc; Kalvin, Victor; Kokotov, Alexey

    2016-04-01

    We study the regularized determinant of the Laplacian as a functional on the space of Mandelstam diagrams (noncompact translation surfaces glued from finite and semi-infinite cylinders). A Mandelstam diagram can be considered as a compact Riemann surface equipped with a conformal flat singular metric {|ω|^2}, where {ω} is a meromorphic one-form with simple poles such that all its periods are pure imaginary and all its residues are real. The main result is an explicit formula for the determinant of the Laplacian in terms of the basic objects on the underlying Riemann surface (the prime form, theta-functions, the canonical meromorphic bidifferential) and the divisor of the meromorphic form {ω}. As an important intermediate result we prove a decomposition formula of the type of Burghelea-Friedlander-Kappeler for the determinant of the Laplacian for flat surfaces with cylindrical ends and conical singularities.

  11. 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.

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

    DOE PAGESBeta

    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 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

  13. 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.

  14. 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…

  15. 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…

  16. 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

  17. Looking inside the butterfly diagram

    NASA Astrophysics Data System (ADS)

    Ternullo, M.

    2007-12-01

    The suitability of Maunder's butterfly diagram to give a realistic picture of the photospheric magnetic flux large scale distribution is discussed. The evolution of the sunspot zone in cycle 20 through 23 is described. To reduce the noise which covers any structure in the diagram, a smoothing algorithm has been applied to the sunspot data. This operation has eliminated any short period fluctuation, and given visibility to long duration phenomena. One of these phenomena is the fact that the equatorward drift of the spot zone center of mass results from the alternation of several prograde (namely, equatorward) segments with other stationary or poleward segments. The long duration of the stationary/retrograde phases as well as the similarities among the spot zone alternating paths in the cycles under examination prevent us from considering these features as meaningless fluctuations, randomly superimposed on the continuous equatorward migration. On the contrary, these features should be considered physically meaningful phenomena, requiring adequate explanations. Moreover, even the smoothed spotted area markedly oscillates. The compared examination of area and spot zone evolution allows us to infer details about the spotted area distribution inside the butterfly diagram. Links between the changing structure of the spot zone and the tachocline rotation rate oscillations are proposed.

  18. 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.

  19. Preliminary Master Logic Diagram for ITER operation

    SciTech Connect

    Cadwallader, L.C.; Taylor, N.P.; Poucet, A.E.

    1998-04-01

    This paper describes the work performed to develop a Master Logic Diagram (MLD) for the operations phase of the International Thermonuclear Experimental Reactor (ITER). The MLD is a probabilistic risk assessment tool used to identify the broad set of potential initiating events that could lead to an offsite radioactive or toxic chemical release from the facility under study. The MLD described here is complementary to the failure modes and effects analyses (FMEAs) that have been performed for ITER`s major plant systems in the engineering evaluation of the facility design. While the FMEAs are a bottom-up or component level approach, the MLD is a top-down or facility level approach to identifying the broad spectrum of potential events. Strengths of the MLD are that it analyzes the entire plant, depicts completeness in the accident initiator process, provides an independent method for identification, and can also identify potential system interactions. MLDs have been used successfully as a hazard analysis tool. This paper describes the process used for the ITER MLD to treat the variety of radiological and toxicological source terms present in the ITER design. One subtree of the nineteen page MLD is shown to illustrate the levels of the diagram.

  20. The influence of print exposure on the body-object interaction effect in visual word recognition

    PubMed Central

    Hansen, Dana; Siakaluk, Paul D.; Pexman, Penny M.

    2012-01-01

    We examined the influence of print exposure on the body-object interaction (BOI) effect in visual word recognition. High print exposure readers and low print exposure readers either made semantic categorizations (“Is the word easily imageable?”; Experiment 1) or phonological lexical decisions (“Does the item sound like a real English word?”; Experiment 2). The results from Experiment 1 showed that there was a larger BOI effect for the low print exposure readers than for the high print exposure readers in semantic categorization, though an effect was observed for both print exposure groups. However, the results from Experiment 2 showed that the BOI effect was observed only for the high print exposure readers in phonological lexical decision. The results of the present study suggest that print exposure does influence the BOI effect, and that this influence varies as a function of task demands. PMID:22563312

  1. 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…

  2. The Influence of Gene-Gene and Gene-Environment Interactions on the Risk of Asbestosis

    PubMed Central

    Franko, A.; Dolžan, V.; Arnerić, N.; Dodič-Fikfak, M.

    2013-01-01

    This study investigated the influence of gene-gene and gene-environment interactions on the risk of developing asbestosis. The study comprised 262 cases with asbestosis and 265 controls with no asbestos-related disease previously studied for MnSOD, ECSOD, CAT, GSTT1, GSTM1, GSTP1, and iNOS polymorphisms. Data on cumulative asbestos and smoking were available for all subjects. To assess gene-gene and gene-environmental interactions, logistic regression was used. The associations between MnSOD Ala −9Val polymorphism and the risk of asbestosis and between iNOS genotypes and asbestosis were modified by CAT –262 C > T polymorphism (P = 0.038; P = 0.031). A strong interaction was found between GSTM1-null polymorphism and smoking (P = 0.007), iNOS (CCTTT)n polymorphism and smoking (P = 0.054), and between iNOS (CCTTT)n polymorphism and cumulative asbestos exposure (P = 0.037). The findings of this study suggest that the interactions between different genotypes, genotypes and smoking, and between genotypes and asbestos exposure have an important influence on the development of asbestosis and should be seriously considered in future research on occupational/environmental asbestos-related diseases. PMID:23984360

  3. Influence of social interactions on the response to social cues in spiderlings.

    PubMed

    Lesne, Pierre; Jeanson, Raphaël

    2015-02-01

    Mutual attraction is one central mechanism involved in the maintenance of cohesion in group-living species and relies on a modulation of individual behaviours in response to the presence of conspecifics. Social markers left in the environment can play an additional role in the modulation of behaviours and can substantially impact the cohesion of social groups. In this study, our objective was to examine the interplay between the presence of social cues and the individual responsiveness to conspecifics in spiderlings. Spiders are relevant models to address this issue as juveniles lay silk draglines during their displacements and display a transient gregarious phase. We introduced single or pairs of spiderlings in an experimental arena covered with different amounts of silk. Our results indicated that the probability of moving increased with the presence and the quantity of silk in single individuals. In contrast, we did not find evidence for any influence of the quantity of silk on interacting spiderlings and we showed that social interactions inhibited the individual response to social markers. Overall, our study suggests that the influence of social interactions on the modulation of individual behaviours prevailed over the presence of social cues. We discussed our results in the framework of chemical communication to explain the interplay between social cues and social interactions on the modulation of individual behaviours. PMID:25475913

  4. 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.

  5. Size Dependent Phase Diagrams of Nickel-Carbon Nanoparticles

    NASA Astrophysics Data System (ADS)

    Magnin, Y.; Zappelli, A.; Amara, H.; Ducastelle, F.; Bichara, C.

    2015-11-01

    The carbon rich phase diagrams of nickel-carbon nanoparticles, relevant to catalysis and catalytic chemical vapor deposition synthesis of carbon nanotubes, are calculated for system sizes up to about 3 nm (807 Ni atoms). A tight binding model for interatomic interactions drives the grand canonical Monte Carlo simulations used to locate solid, core shell and liquid stability domains, as a function of size, temperature, and carbon chemical potential or concentration. Melting is favored by carbon incorporation from the nanoparticle surface, resulting in a strong relative lowering of the eutectic temperature and a phase diagram topology different from the bulk one. This should lead to a better understanding of the nanotube growth mechanisms.

  6. Phase diagram of baryon matter in the SU(2) Nambu – Jona-Lasinio model with a Polyakov loop

    NASA Astrophysics Data System (ADS)

    Kalinovsky, Yu L.; Toneev, V. D.; Friesen, A. V.

    2016-04-01

    The nature of phase transitions in hot and dense nuclear matter is discussed in the framework of the effective SU(2) Nambu – Jona-Lasinio model with a Polyakov loop with two quark flavor — one of a few models describing the properties of both chiral and confinement-deconfinement phase transitions. We consider the parameters of the model and examine additional interactions that influence the structure of the phase diagram and the positions of critical points in it. The effect of meson correlations on the thermodynamic properties of the quark-meson system is examined. The evolution of the model with changes in the understanding of the phase diagram structure is discussed.

  7. Arrows in Comprehending and Producing Mechanical Diagrams

    ERIC Educational Resources Information Center

    Heiser, Julie; Tversky, Barbara

    2006-01-01

    Mechanical systems have structural organizations--parts, and their relations--and functional organizations--temporal, dynamic, and causal processes--which can be explained using text or diagrams. Two experiments illustrate the role of arrows in diagrams of mechanical systems. In Experiment 1, people described diagrams with or without arrows,…

  8. Differential Effectiveness of Two Science Diagram Types.

    ERIC Educational Resources Information Center

    Holliday, William G.

    Reported is an Aptitude Treatment Instruction (ATI) Study designed to evaluate the aptitude of verbal comprehension in terms of two unitary complex science diagram types: a single complex block word diagram and a single complex picture word diagram.. ATI theory and research indicate that different effective instructional treatments tend to help…

  9. Interpretation of the Hubble diagram in a nonhomogeneous universe

    NASA Astrophysics Data System (ADS)

    Fleury, Pierre; Dupuy, Hélène; Uzan, Jean-Philippe

    2013-06-01

    In the standard cosmological framework, the Hubble diagram is interpreted by assuming that the light emitted by standard candles propagates in a spatially homogeneous and isotropic spacetime. However, the light from “point sources”—such as supernovae—probes the Universe on scales where the homogeneity principle is no longer valid. Inhomogeneities are expected to induce a bias and a dispersion of the Hubble diagram. This is investigated by considering a Swiss-cheese cosmological model, which (1) is an exact solution of the Einstein field equations, (2) is strongly inhomogeneous on small scales, but (3) has the same expansion history as a strictly homogeneous and isotropic universe. By simulating Hubble diagrams in such models, we quantify the influence of inhomogeneities on the measurement of the cosmological parameters. Though significant in general, the effects reduce drastically for a universe dominated by the cosmological constant.

  10. 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

  11. 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…

  12. 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…

  13. 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

  14. Stability Diagram of Mg-Al-O System Inclusions in Molten Steel

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Ren, Ying; Duan, Haojian; Yang, Wen; Sun, Liyuan

    2015-08-01

    In the current study, the stability diagrams of Mg-Al-O system in molten steel are calculated using two methods. After comparing the result of connecting iso-oxygen contours of different phases (iso-oxygen contours method) and calculating the border lines of different phases (border lines method), the former method is more accurate and popular. Particularly, the detailed calculation procedures and connection line principles of stability diagram are exhibited. The effects of interaction coefficient, temperature, and activity of oxides on the stability diagram are also discussed. With the currently reported method, stability diagrams of various inclusions in molten steel can be calculated to predict the formation of inclusions.

  15. Phase diagram of a model of the protein amelogenin.

    PubMed

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

    2016-08-28

    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. PMID:27586954

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

    PubMed

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

    2016-01-19

    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

  17. Understanding machines from text and diagrams

    NASA Astrophysics Data System (ADS)

    Hegarty, Mary; Just, Marcel A.

    1987-12-01

    Instructional materials typically use both text and diagrams to explain how machines work. In this paper we give an account of what information is involved in understanding a mechanical device and the role that diagrams might play in communicating this information. We propose a model of how people read a text and inspect an accompanying diagram which states that people inspect diagrams for three reasons: (1) to form a representation of information read in the text, (2) to reactivate information that has already been represented, and (3) to encode information that is absent from the text. Using data from subjects' eye fixations while they read a text and inspected an accompanying diagram, we find that low-ability subjects need to inspect diagrams more often than high-ability text. The data also suggest that knowledge of what is relevant in a diagram might be a prerequisite for encoding new information from a diagram. Instructional materials typically use both text and diagrams to explain how machines work. In this paper we give an account of what information is involved in understanding a mechanical device and the role that diagrams might play in communicating this information. We propose a model of how people read a text and inspect an accompanying diagram which states that people inspect diagrams for three reasons: (1) to form a representation of information read in the text; (2) to reactivate information that was alsready represented, and *3) to encode information that is absent from the text. Uinsg data from subjects' eye fixations while they read a text and inspected an accompanying diagram, we find that low-ability subjects need to inspect diagrmas more often than high-ability tesxt. The data also suggest that knowledge of what is relevant in a diagram might be a prerequisite and encoding information on a diagram.

  18. 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.

  19. 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.

  20. 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…

  1. 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…

  2. 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.

  3. 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

  4. 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

  5. A Hubble Diagram for Quasars

    NASA Astrophysics Data System (ADS)

    Risaliti, Guido; Lusso, Elisabeta

    2015-09-01

    We present a new method to test the cosmological model at high z, and measure the cosmological parameters, based on the non-linear correlation between UV and X-ray luminosity in quasars. While the method can be successfully tested with the data available today, a deep X-ray survey matching the future LSST and Euclid quasar catalogs is needed to achieve a high precision. Athena could provide a Hubble diagram for quasar analogous to that available today for supernovae, but extending up to z>6.

  6. Optical generation of Voronoi diagram.

    PubMed

    Giavazzi, F; Cerbino, R; Mazzoni, S; Giglio, M; Vailati, A

    2008-03-31

    We present results of experiments of diffraction by an amplitude screen, made of randomly distributed circular holes. By careful selection of the experimental parameters we obtain an intensity pattern strongly connected to the Voronoi diagram (VD) generated by the centers of the apertures. With the help of simulations we give a description of the observed phenomenon and elucidate the optimal parameters for its observation. Finally, we also suggest how it can be used for a fast, all-optical generation of VDs. PMID:18542580

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

    PubMed

    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. PMID:27078402

  8. 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.

  9. Influence of the inverse magnetic catalysis and the vector interaction in the location of the critical end point

    NASA Astrophysics Data System (ADS)

    Costa, Pedro; Ferreira, Márcio; Menezes, Débora P.; Moreira, João; Providência, Constança

    2015-08-01

    The effect of a strong magnetic field on the location of the critical end point (CEP) in the QCD phase diagram is discussed under different scenarios. In particular, we consider the contribution of the vector interaction and take into account the inverse magnetic catalysis obtained in lattice QCD calculations at zero chemical potential. The discussion is realized within the (2 +1 ) Polyakov-Nambu-Jona-Lasinio model. It is shown that the vector interaction and the magnetic field have opposite competing effects, and that the winning effect depends strongly on the intensity of the magnetic field. The inverse magnetic catalysis at zero chemical potential has two distinct effects for magnetic fields above ≳0.3 GeV2: it shifts the CEP to lower chemical potentials, hinders the increase of the CEP temperature and prevents a too large increase of the baryonic density at the CEP. For fields e B <0.1 GeV2 the competing effects between the vector contribution and the magnetic field can move the CEP to regions of temperature and density in the phase diagram that could be more easily accessible to experiments.

  10. T cell receptor interactions with class I heavy-chain influence T cell selection

    PubMed Central

    Kuhns, Scott T.; Tallquist, Michelle D.; Johnson, Aaron J.; Mendez-Fernandez, Yanice; Pease, Larry R.

    2000-01-01

    The interaction of the T cell receptor (TCR) with peptide in the binding site of the major histocompatibility complex molecule provides the basis for T cell recognition during immune surveillance, repertoire development, and tolerance. Little is known about the extent to which repertoire selection is influenced directly by variation of the structure of the class I heavy chain. We find that the 2C TCR, normally positively selected in the context of the Kb molecule, is minimally selected into the CD8 lineage in the absence of antigen-processing genes. This finding underscores the importance of peptides in determining the positive-selecting class I ligands in the thymus. In contrast, Kbm3, a variant class I molecule that normally exerts a negative selection pressure on 2C-bearing T cells, positively selects 2C transgenic T cells into the CD8 lineage in an antigen-processing gene-deficient environment. These findings indicate that structural changes in the heavy chain can have direct influence in T cell recognition, from which we conclude that the nature of TCR interaction with class I heavy chain influences the array of TCRs selected during development of the functional adult repertoire. PMID:10639152

  11. Sexual interactions influence the molecular oscillations in DN1 pacemaker neurons in Drosophila melanogaster.

    PubMed

    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 per (S) 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

  12. The Influence of Seasonally Changing Groundwater/Surface Water Interaction on the Composition of Sediment Fauna

    NASA Astrophysics Data System (ADS)

    Schmidt, S. I.; Hahn, H. J.; Hatton, T. J.; Woodbury, R. J.; Watson, G. D.

    2005-05-01

    Sediment fauna in both streams and groundwater are crucial to the functioning of sediment processes, and are known to be highly influenced by hydraulics. But how does the seasonal variation of groundwater/surface water interactions influence the faunal composition? This question was addressed in a small Western Australian catchment, where four stream sediment sites and 30 groundwater bores were sampled over the period of one year. Mixed fauna at those sites displaying groundwater/surface water interaction was expected. However, there were virtually no species common to groundwater bores and stream sediment tubes, although they were sampled using the same method. The missing species exchange was probably due to the small pore spaces. Since the hydrological and chemical variety within groundwater sites was surprising, going far beyond gradually changing interactions with surface water, we grouped the groundwater sites into four major hydrogeological classes and looked for patterns with which fauna reflected these groups. In two of these hydrogeological groups (Artesian and concentration zones) no fauna was found at all, while fauna was sampled regularly in discharging and recharging zones. Fauna in groundwater bores also reflected whether groundwater was recharged from precipitation alone or also at least seasonally from the stream.

  13. Cell flipping in permutation diagrams

    NASA Astrophysics Data System (ADS)

    Golumbic, Martin Charles; Kaplang, Haim

    Permutation diagrams have been used in circuit design to model a set of single point nets crossing a channel, where the minimum number of layers needed to realize the diagram equals the clique number ω(G) of its permutation graph, the value of which can be calculated in O(n log n) time. We consider a generalization of this model motivated by "standard cell" technology in which the numbers on each side of the channel are partitioned into consecutive subsequences, or cells, each of which can be left unchanged or flipped (i.e., reversed). We ask, for what choice of fiippings will the resulting clique number be minimum or maximum. We show that when one side of the channel is fixed (no flipping), an optimal flipping for the other side can be found in O(n log n) time for the maximum clique number. We prove that the general problem is NP-complete for the minimum clique number and O(n 2) for the maximum clique number. Moreover, since the complement of a permutation graph is also a permutation graph, the same complexity results hold for the independence number.

  14. 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.

  15. 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. PMID:27575211

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

    NASA Astrophysics Data System (ADS)

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

    PubMed Central

    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. PMID:26161895

  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. PMID:26161895

  19. Vertical Dynamic Interaction Between Train and Track Influence of Wheel and Track Imperfections

    NASA Astrophysics Data System (ADS)

    Nielsen, J. C. O.; Igeland, A.

    1995-11-01

    The vertical dynamic behaviour is investigated for a railway bogie moving on a rail which is discretely supported, via railpads, by sleepers resting on an elastic foundation. The transient interaction problem is numerically solved by use of an extended state-spacer vector approach in conjunction with a complex modal superposition for the track. Application examples are given in which the influences of three types of practically important imperfections in the compound vehicle/track system are investigated. The first is a sinusoidal corrugation of the railhead and the second a skid flat on the wheel tread (a wheelflat). The third imperfection is a case where a single sleeper has lost its support due to erosion of the ballast. Physical explanations of the calculated interaction behaviour are given.

  20. 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.

  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. The influence of early neutrophil-Leishmania interactions on the host immune response to infection

    PubMed Central

    Ribeiro-Gomes, Flavia L.; Sacks, David

    2012-01-01

    Neutrophils are the first cells recruited to the dermal site of Leishmania infection following injection by needle or sand fly bite. The role of neutrophils in either promoting or suppressing host immunity remains controversial. We discuss the events driving neutrophil recruitment, their interaction with the parasite and apoptotic fate, and the nature of their encounters with other innate cells. We suggest that the influence of the neutrophil response on infection outcome critically depends on the timing of their recruitment and the tissue environment in which it occurs. PMID:22919650

  3. 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.

  4. The influence of land-atmosphere interactions on variability of the North American Monsoon

    NASA Technical Reports Server (NTRS)

    Small, Eric; Lakshmi, Venkat

    2005-01-01

    Our project focused on the influence of land-atmosphere interactions on variability of North American Monsoon System (NAMS) precipitation is summarized in seven published manuscripts (listed below). Three of these manuscripts (Matsui et al. 2003; Matsui et al. 2005; Small and Kurc 2003) were completed solely with support from this NASA project. The remaining four were completed with additional support from NOAA. Our primary results are summarized: 1) Test of Rocky Mountains snowcover-NAMS rainfall hypothesis. Testing radiation and convective precipitation parameterization in MM5. Analysis of soil moisture-radiation feedbacks in semiarid environments from field observations and modeling.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Campanell, Michael; Wang, Hongyue

    2013-09-01

    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. 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

  8. Active colonization dynamics and diversity patterns are influenced by dendritic network connectivity and species interactions

    PubMed Central

    Seymour, Mathew; Altermatt, Florian

    2014-01-01

    Habitat network connectivity influences colonization dynamics, species invasions, and biodiversity patterns. Recent theoretical work suggests dendritic networks, such as those found in rivers, alter expectations regarding colonization and dispersal dynamics compared with other network types. As many native and non-native species are spreading along river networks, this may have important ecological implications. However, experimental studies testing the effects of network structure on colonization and diversity patterns are scarce. Up to now, experimental studies have only considered networks where sites are connected with small corridors, or dispersal was experimentally controlled, which eliminates possible effects of species interactions on colonization dynamics. Here, we tested the effect of network connectivity and species interactions on colonization dynamics using continuous linear and dendritic (i.e., river-like) networks, which allow for active dispersal. We used a set of six protist species and one rotifer species in linear and dendritic microcosm networks. At the start of the experiment, we introduced species, either singularly or as a community within the networks. Species subsequently actively colonized the networks. We periodically measured densities of species throughout the networks over 2 weeks to track community dynamics, colonization, and diversity patterns. We found that colonization of dendritic networks was faster compared with colonization of linear networks, which resulted in higher local mean species richness in dendritic networks. Initially, community similarity was also greater in dendritic networks compared with linear networks, but this effect vanished over time. The presence of species interactions increased community evenness over time, compared with extrapolations from single-species setups. Our experimental findings confirm previous theoretical work and show that network connectivity, species-specific dispersal ability, and species

  9. Factors influencing the magnitude and clinical significance of drug interactions between azole antifungals and select immunosuppressants.

    PubMed

    Saad, Aline H; DePestel, Daryl D; Carver, Peggy L

    2006-12-01

    The magnitude of drug interactions between azole antifungals and immunosuppressants is drug and patient specific and depends on the potency of the azole inhibitor involved, the resulting plasma concentrations of each drug, the drug formulation, and interpatient variability. Many factors contribute to variability in the magnitude and clinical significance of drug interactions between an immunosuppressant such as cyclosporine, tacrolimus, or sirolimus and an antifungal agent such as ketoconazole, fluconazole, itraconazole, voriconazole, or posaconazole. By bringing similarities and differences among these agents and their potential interactions to clinicians' attention, they can appreciate and apply these findings in a individualized patient approach rather than follow only the one-size-fits-all dosing recommendations suggested in many tertiary references. Differences in metabolism and in the inhibitory potency of cytochrome P450 3A4 and P-glycoprotein influence the onset, magnitude, and resolution of drug interactions and their potential effect on clinical outcomes. Important issues are the route of administration and the decision to preemptively adjust dosages versus intensive monitoring with subsequent dosage adjustments. We provide recommendations for the concomitant use of these agents, including suggestions regarding contraindicated combinations, those best avoided, and those requiring close monitoring of drug dosages and plasma concentrations. PMID:17125435

  10. 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. PMID:23757232

  11. Phase diagram of the disordered Bose-Hubbard model

    SciTech Connect

    Gurarie, V.; Pollet, L.; Prokof'ev, N. V.; Svistunov, B. V.; Troyer, M.

    2009-12-01

    We establish the phase diagram of the disordered three-dimensional Bose-Hubbard model at unity filling which has been controversial for many years. The theorem of inclusions, proven by Pollet et al. [Phys. Rev. Lett. 103, 140402 (2009)] states that the Bose-glass phase always intervenes between the Mott insulating and superfluid phases. Here, we note that assumptions on which the theorem is based exclude phase transitions between gapped (Mott insulator) and gapless phases (Bose glass). The apparent paradox is resolved through a unique mechanism: such transitions have to be of the Griffiths type when the vanishing of the gap at the critical point is due to a zero concentration of rare regions where extreme fluctuations of disorder mimic a regular gapless system. An exactly solvable random transverse field Ising model in one dimension is used to illustrate the point. A highly nontrivial overall shape of the phase diagram is revealed with the worm algorithm. The phase diagram features a long superfluid finger at strong disorder and on-site interaction. Moreover, bosonic superfluidity is extremely robust against disorder in a broad range of interaction parameters; it persists in random potentials nearly 50 ({exclamation_point}) times larger than the particle half-bandwidth. Finally, we comment on the feasibility of obtaining this phase diagram in cold-atom experiments, which work with trapped systems at finite temperature.

  12. 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.

  13. 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

  14. 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.

  15. 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. PMID:25481818

  16. Mnemonic aspects of Escherichia coli DNA polymerase I. Interaction with one template influences the next interaction with another template.

    PubMed

    Papanicolaou, C; Lecomte, P; Ninio, J

    1986-06-01

    beginning of synthesis. Interaction of Pol I with poly(dA).(dT) or with poly(dC).(dG) modifies its exo/pol characteristics in the replication of poly(dI).(dC) and poly(dA).(dT), respectively. The Klenow enzyme is not sensitive to such influences and this correlates with its reduced processivity on the influencing templates. Our results reveal the existence of differences between Pol I and its Klenow fragment that are more profound than has been thought previously.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3537308

  17. 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,…

  18. Electrostatic, elastic and hydration-dependent interactions in dermis influencing volume exclusion and macromolecular transport.

    PubMed

    Øien, Alf H; Wiig, Helge

    2016-07-01

    Interstitial exclusion refers to the limitation of space available for plasma proteins and other macromolecules based on collagen and negatively charged glycosaminoglycans (GAGs) in the interstitial space. It is of particular importance to interstitial fluid and plasma volume regulation. Here we present a novel mechanical and mathematical model of the dynamic interactions of structural elements within the interstitium of the dermis at the microscopic level that may explain volume exclusion of charged and neutral macroparticles. At this level, the interstitium is considered to consist of elements called extracellular matrix (ECM) cells, again containing two main interacting structural components on a fluid background including anions and cations setting up osmotic forces: one smaller GAG component, having an intrinsic expansive electric force, and one bigger collagen component, having an intrinsic elastic force. Because of size differences, the GAG component interacts with a fraction of the collagen component only at normal hydration. This fraction, however, increases with rising hydration as a consequence of the modeled form of the interaction force between the GAGs and collagen. Collagen is locally displaced at variable degrees as hydration changes. Two models of GAGs are considered, having largely different geometries which demands different, but related, forms of GAG-collagen interaction forces. The effects of variable fixed charges on GAGs and of GAG density in tissue are evaluated taking into account observed volume exclusion properties of charged macromolecules as a function of tissue hydration. The presented models may improve our biophysical understanding of acting forces influencing tissue fluid dynamics. Such knowledge is significant when evaluating the transport of electrically charged and neutral macromolecules into and through the interstitium, and therefore to drug uptake and the therapeutic effects of macromolecular agents. PMID:27079466

  19. Interleukin-6 promoter polymorphism interacts with pain and life stress influencing depression phenotypes.

    PubMed

    Kovacs, David; Eszlari, Nora; Petschner, Peter; Pap, Dorottya; Vas, Szilvia; Kovacs, Peter; Gonda, Xenia; Bagdy, Gyorgy; Juhasz, Gabriella

    2016-05-01

    Interleukin-6 (IL-6) has emerged as a potent biomarker for depression as its elevated plasma levels in patients with clinical depression have been confirmed by meta-analyses. Increased plasma IL-6 concentration was associated with various psychological stress factors and physical disorders accompanied by pain. Another modulator of the IL-6 level is rs1800795, a promoter polymorphism in the IL-6 gene which is able to influence its expression rate. Therefore, we examined in a Hungarian population sample of 1053 volunteers with European origins if rs1800795 polymorphism can affect depression symptoms measured by Zung Self-rating Depression Scale (ZSDS), and Brief Symptom Inventory (BSI). We also investigated the interactions of the polymorphism with reported painful physical conditions and Recent Negative Life Events (RLE) measured by the List of Life Threatening Experiences. Rs1800795 significantly interacted with both RLE and painful condition on depressive symptoms measured by ZSDS and BSI using different heritability models, while no main effects of the polymorphism were identified. After correction for multiple testing only the rs1800795 × RLE interaction effect (recessive model) remained significant on the BSI score, while both RLE and painful conditions significantly interacted on the ZSDS. In conclusion, the functional IL-6 rs1800795 polymorphism in interaction with various stress factors increases the risk of depression and has a greater impact on symptoms measured by the ZSDS. Thus, IL-6 and other cytokines may be more relevant in the development of somatic symptoms compared to affective signs of depression, delineating a specific genotype-phenotype relationship in this heterogeneous disorder. PMID:26821321

  20. Influence of Trifluoroethanol on Membrane Interfacial Anchoring Interactions of Transmembrane α-Helical Peptides

    PubMed Central

    Özdirekcan, Suat; Nyholm, Thomas K. M.; Raja, Mobeen; Rijkers, Dirk T. S.; Liskamp, Rob M. J.; Killian, J. Antoinette

    2008-01-01

    Interfacial anchoring interactions between aromatic amino acid residues and the lipid-water interface are believed to be important determinants for membrane protein structure and function. Thus, it is possible that molecules that partition into the lipid-water interface can influence membrane protein activity simply by interfering with these anchoring interactions. Here we tested this hypothesis by investigating the effects of 2,2,2-trifluoroethanol (TFE) on the interaction of a Trp-flanked synthetic transmembrane peptide (acetyl-GW2(LA)8LW2A-NH2) with model membranes of dimyristoylphosphatidylcholine. Two striking observations were made. First, using 2H nuclear magnetic resonance on acyl chain deuterated lipids, we found that addition of 4 or 8 vol % of TFE completely abolishes the ability of the peptide to order and stretch the lipid acyl chains in these relatively thin bilayers. Second, we observed that addition of 8 vol % TFE reduces the tilt angle of the peptide from 5.3° to 2.5°, as measured by 2H NMR on Ala-d4 labeled peptides. The “straightening” of the peptide was accompanied by an increased exposure of Trp to the aqueous phase, as shown by Trp-fluorescence quenching experiments using acrylamide. The observation of a reduced tilt angle was surprising because we also found that TFE partioning results in a significant thinning of the membrane, which would increase the extent of hydrophobic mismatch. In contrast to the Trp-flanked peptide, no effect of TFE was observed on the interaction of a Lys-flanked analog (acetyl-GK2(LA)8LK2A-NH2) with the lipid bilayer. These results emphasize the importance of interfacial anchoring interactions for membrane organization and provide new insights into how molecules such as TFE that can act as anesthetics may affect the behavior of membrane proteins that are enriched in aromatic amino acids at the lipid-water interface. PMID:17905843

  1. The neptunium-iron phase diagram

    NASA Astrophysics Data System (ADS)

    Gibson, J. K.; Haire, R. G.; Beahm, E. C.; Gensini, M. M.; Maeda, A.; Ogawa, T.

    1994-08-01

    The phase relations in the Np-Fe alloy system have been elucidated using differential thermal analysis. A phase diagram for this system is postulated based upon the experimental results, regular-solution model calculations, and an expected correspondence to the U-Fe and Pu-Fe diagrams. The postulated Np-Fe diagram is characterized by limited terminal solid solubilities, two intermetallic solid phases, NpFe 2 and Np 6Fe, and two eutectics.

  2. School Influences on Student Interaction Patterns. Johns Hopkins University Center for Social Organization of Schools. Report No. 220.

    ERIC Educational Resources Information Center

    Karweit, Nancy

    This paper explores how organizational features of high schools influence the informal interaction of students attending them. Size of school, composition of the student body, and differentiation into curriculum and grade levels are factors which affect the patterns of informal interaction among students. The informal social arrangement of…

  3. The Influence of Attachment Pattern on Developmental Changes in Peer Interaction from the Toddler to the Preschool Period.

    ERIC Educational Resources Information Center

    Jacobson, Joseph L.; Wille, Diane E.

    1986-01-01

    Investigates the influence of infant-mother attachment patterns on the development of peer interaction between the toddler and preschool periods. Notes that, in an initial encounter with an unfamiliar peer, attachment patterns appear to be related more to the child's attractiveness as an interactive partner than to the child's own active interest…

  4. The Influence of Social Interaction on the Perception of Emotional Expression: A Case Study with a Robot Head

    NASA Astrophysics Data System (ADS)

    Murray, John C.; Cañamero, Lola; Bard, Kim A.; Ross, Marina Davila; Thorsteinsson, Kate

    In this paper we focus primarily on the influence that socio-emotional interaction has on the perception of emotional expression by a robot. We also investigate and discuss the importance of emotion expression in socially interactive situations involving human robot interaction (HRI), and show the importance of utilising emotion expression when dealing with interactive robots, that are to learn and develop in socially situated environments. We discuss early expressional development and the function of emotion in communication in humans and how this can improve HRI communications. Finally we provide experimental results showing how emotion-rich interaction via emotion expression can affect the HRI process by providing additional information.

  5. 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.

  6. Ion potential diagrams for electrochromic devices

    SciTech Connect

    Varsano, F. |; Cahen, D.; Decker, F.; Guillemoles, J.F. |; Masetti, E.

    1998-12-01

    Ion potential diagrams can facilitate the description of systems in which ionic species are mobile. They depict qualitatively the spatial dependence of the potential energy for mobile ions, somewhat akin to band diagrams for electrons. The authors construct ion potential diagrams for the mixed conducting (oxide), optically active electrodes of five-layer electrochromic devices, based on reversible Li{sup +} intercalation. These serve to analyze stability problems that arise in these systems. The authors then use them as building blocks to arrive at ion diagrams for complete devices. This allows analyses of (dis)coloration kinetics.

  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. Factors Influencing Occupant-To-Seat Belt Interaction in Far-Side Crashes

    PubMed Central

    Douglas, C.A.; Fildes, B.N.; Gibson, T.J.; Boström, O.; Pintar, F.A.

    2007-01-01

    Seat belt interaction with a far-side occupant’s shoulder and thorax is critical to governing excursion towards the struck-side of the vehicle in side impact. In this study, occupant-to-belt interaction was simulated using a modified MADYMO human model and finite element belts. Quasi-static tests with volunteers and dynamic sled tests with PMHS and WorldSID were used for model validation and comparison. Parameter studies were then undertaken to quantify the effect of impact direction, seat belt geometry and pretension on occupant-to-seat belt interaction. Results suggest that lowering the D-ring and increasing pretension reduces the likelihood of the belt slipping off the shoulder. Anthropometry was also shown to influence restraint provided by the shoulder belt. Furthermore, the belt may slip off the occupant’s shoulder at impact angles greater than 40 degrees from frontal when no pretension is used. However, the addition of pretension allowed the shoulder to engage the belt in all impacts from 30 to 90 degrees. PMID:18184500

  9. Influence of membrane-solvent-solute interactions on solute permeation in model membranes.

    PubMed

    Dias, Monica; Hadgraft, Jonathan; Lane, Majella E

    2007-05-01

    The interaction of the components of topical formulations with the skin is an important consideration for effective drug delivery and efficacy. The relative importance of solubility parameters and other solvent properties on membrane diffusion processes has not been fully elucidated in the literature. In this paper, the effect of different vehicles on the permeation of caffeine, salicylic acid and benzoic acid through silicone membranes was evaluated. Polydimethylsiloxane membranes were used as model membranes for comparing the release characteristics of saturated solutions of model permeants because of their homogeneity and uniformity. Log P (octanol-water partition coefficient) and solubility parameter values were calculated for the compounds under study. In vitro diffusion studies indicated that the permeation profiles of all solutes showed a similar pattern. The permeation rates of benzoic acid and salicylic acid through silicone membrane from saturated solutions were higher than those for caffeine reflecting the more lipophilic nature of these compounds in comparison with caffeine. Solvent uptake studies confirmed that the vehicles that were highly sorbed by the membrane altered its properties and hence the flux. Vehicles that were not sorbed by the membrane showed similar steady-state fluxes for the model drugs. This suggests that the diffusion process is mainly influenced by the interactions between the vehicles and the membrane. Solubility parameter alone cannot explain the interactions between the membrane and the vehicles in all cases. Rather, it is likely that membrane flux reflects a combination of different solvent and solute characteristics, such as size, shape and charge distribution. PMID:17204382

  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

    2011-04-01

    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. PMID:21215548

  11. 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.

  12. Phase Diagram of the Bose Hubbard Model with Weak Links

    NASA Astrophysics Data System (ADS)

    Hettiarachchilage, Kalani; Rousseau, Valy; Tam, Ka-Ming; Moreno, Juana; Jarrell, Mark; Sheehy, Daniel

    2012-02-01

    We study the ground state phase diagram of strongly interacting ultracold Bose gas in a one-dimensional optical lattice with a tunable weak link, by means of Quantum Monte Carlo simulation. This model contains an on-site repulsive interaction (U) and two different near-neighbor hopping terms, J and t, for the weak link and the remainder of the chain, respectively. We show that by reducing the strength of J, a novel intermediate phase develops which is compressible and non-superfluid. This novel phase is identified as a Normal Bose Liquid (NBL) which does not appear in the phase diagram of the homogeneous bosonic Hubbard model. Further, we find a linear variation of the phase boundary of Normal Bose Liquid (NBL) to SuperFluid (SF) as a function of the strength of the weak link. These results may provide a new path to design advanced atomtronic devices in the future.

  13. The influence of rough lipopolysaccharide structure on molecular interactions with mammalian antimicrobial peptides.

    PubMed

    Bello, Gianluca; Bodin, Alice; Lawrence, M Jayne; Barlow, David; Mason, A James; Barker, Robert D; Harvey, Richard D

    2016-02-01

    The influence of Escherichia coli rough lipopolysaccharide chemotype on the membrane activity of the mammalian antimicrobial peptides (AMPs) human cathelicidin (LL37) and bovine lactoferricin (LFb) was studied on bilayers using solid state (2)H NMR (ssNMR) and on monolayers using the subphase injection technique, Brewster angle microscopy (BAM) and neutron reflectivity (NR). The two AMPs were selected because of their differing biological activities. Chain-deuterated dipalmitoylphosphatidylcholine (d62-DPPC) was added to the LPS samples, to highlight alterations in the system properties caused by the presence of the different LPS chemotypes and upon AMP challenge. Both LPS chemotypes showed a temperature dependent influence on the packing of the DPPC molecules, with a fluidizing effect exerted below the DPPC phase transition temperature (Tm), and an ordering effect observed above the Tm. The magnitude of these effects was influenced by LPS structure; the shorter Rc LPS promoted more ordered lipid packing compared to the longer Ra LPS. These differential ordering effects in turn influenced the penetrative activity of the two peptides, as the perturbation induced by both AMPs to Ra LPS-containing models was greater than that observed in those containing Rc LPS. The NR data suggests that in addition to penetrating into the monolayers, both LL37 and LFb formed a non-interacting layer below the LPS/DPPC monolayer. The overall activity of LL37, which showed a deeper penetration into the model membranes, was more marked than that of LFb, which appeared to localise at the interfacial region, thus providing evidence for the molecular origins of their different biological activities. PMID:26592318

  14. How Do Argumentation Diagrams Compare when Student Pairs Use Them as a Means for Debate or as a Tool for Representing Debate?

    ERIC Educational Resources Information Center

    Lund, Kristine; Molinari, Gaelle; Sejourne, Arnauld; Baker, Michael

    2007-01-01

    The objective of the research presented here was to study the influence of two types of instruction for using an argumentation diagram during pedagogical debates over the Internet. In particular, we studied how using an argumentation diagram as a medium of debate compared to using an argumentation diagram as a way of representing a debate. Two…

  15. Equilibrium phase diagrams of alloys using nested sampling

    NASA Astrophysics Data System (ADS)

    Bernstein, Noam; Baldock, Robert J. N.; Bartók-Partáy, Livia; Csányi, Gábor

    Temperature-pressure-composition phase diagrams describe the structures of materials in thermal equilibrium, and are an essential tool in understanding material properties. Predicting phase diagrams is challenging, even given a description of the interatomic interactions, because of the need to sample a very large configuration space. Nested sampling (NS) has been shown to be an efficient tool for calculating the partition function, and therefore all thermodynamic properties and ensemble averages, by systematically sampling the configuration space of isolated and periodic systems. Its effectiveness comes from sampling starting from high energy, where barriers are relatively low and equilibration is relatively fast, and iteratively eliminating a fixed fraction of the remaining configuration space. We present an application of NS at constant pressure to the phase diagram of a model binary alloy, CuAu, using an embedded atom method potential. We identify phase transitions indicated by peaks in the calculated specific heat, and the dominant phase at each temperature from ensemble-averaged structural ordering, as represented by quantities such as the radial distribution function. These results demonstrate the power of NS as a method for calculating complete phase diagrams.

  16. The influence of volatiles on the interaction of mafic and felsic magmas

    NASA Astrophysics Data System (ADS)

    Pistone, M.; Jarvis, P.; Blundy, J. D.

    2013-12-01

    (particularly, K) 'uphill diffusion' in the mafic end-member. The experimental and analytical results are against the existing state-of-the-art that does not consider the influence of volatiles in a realistic scenario where two magmas display different initial composition, water content and crystallinity prior to interaction. Moreover, the results demonstrate the striking chemical and microstructural similarity between the run products and what observed in the textures of natural enclaves within felsic host rocks. This research is fundamental for understanding numerous, well-documented physico-chemical processes such as: magma mixing/mingling, alkali migration, formation of mafic enclaves, magma defrosting or partial melting of crystal mushes and their rheological remobilization within the Earth's crust.

  17. Scaling analysis and application: Phase diagram of magnetic nanorings and elliptical nanoparticles

    SciTech Connect

    Zhang Wen; Singh, Rohit; Bray-Ali, Noah; Haas, Stephan

    2008-04-01

    The magnetic properties of single-domain nanoparticles with different geometric shapes, crystalline anisotropies, and lattice structures are investigated. A recently proposed scaling approach is shown to be universal and in agreement with dimensional analysis coupled with the assumption of incomplete self-similarity. It is used to obtain phase diagrams of magnetic nanoparticles featuring three competing configurations: in-plane ferromagnetism, out-of-plane ferromagnetism, and vortex formation. The influence of the vortex core on the scaling behavior and phase diagram is analyzed. Three-dimensional phase diagrams are obtained for cylindrical nanorings depending on their height and outer and inner radii. The triple points in these phase diagrams are shown to be in a linear relationship with the inner radius of the ring. Elliptically shaped magnetic nanoparticles are also studied. A new parametrization for double vortex configurations is proposed, and regions in the phase diagram where the double vortex is a stable ground state are identified.

  18. Detention Times of Microswimmers Close to Surfaces: Influence of Hydrodynamic Interactions and Noise.

    PubMed

    Schaar, Konstantin; Zöttl, Andreas; Stark, Holger

    2015-07-17

    After colliding with a surface, microswimmers reside there during the detention time. They accumulate and may form complex structures such as biofilms. We introduce a general framework to calculate the distribution of detention times using the method of first-passage times and study how rotational noise and hydrodynamic interactions influence the escape from a surface. We compare generic swimmer models to the simple active Brownian particle. While the respective detention times of source dipoles are smaller, the ones of pullers are larger by up to several orders of magnitude, and pushers show both trends. We apply our results to the more realistic squirmer model, for which we use lubrication theory, and validate them by simulations with multiparticle collision dynamics. PMID:26230827

  19. 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.

  20. Functional trait differences influence neighbourhood interactions in a hyperdiverse Amazonian forest.

    PubMed

    Fortunel, Claire; Valencia, Renato; Wright, S Joseph; Garwood, Nancy C; Kraft, Nathan J B

    2016-09-01

    As distinct community assembly processes can produce similar community patterns, assessing the ecological mechanisms promoting coexistence in hyperdiverse rainforests remains a considerable challenge. We use spatially explicit neighbourhood models of tree growth to quantify how functional trait and phylogenetic similarities predict variation in growth and crowding effects for the 315 most abundant tree species in a 25-ha lowland rainforest plot in Ecuador. We find that functional trait differences reflect variation in (1) species maximum potential growth, (2) the intensity of interspecific interactions for some species, and (3) species sensitivity to neighbours. We find that neighbours influenced tree growth in 28% of the 315 focal tree species. Neighbourhood effects are not detected in the remaining 72%, which may reflect the low statistical power to model rare taxa and/or species insensitivity to neighbours. Our results highlight the spectrum of ways in which functional trait differences can shape community dynamics in highly diverse rainforests. PMID:27358248

  1. 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.

  2. 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.

  3. Dynamic phase diagram of soft nanocolloids.

    PubMed

    Gupta, Sudipta; Camargo, Manuel; Stellbrink, Jörg; Allgaier, Jürgen; Radulescu, Aurel; Lindner, Peter; Zaccarelli, Emanuela; Likos, Christos N; Richter, Dieter

    2015-09-01

    We present a comprehensive experimental and theoretical study covering micro-, meso- and macroscopic length and time scales, which enables us to establish a generalized view in terms of structure-property relationship and equilibrium dynamics of soft colloids. We introduce a new, tunable block copolymer model system, which allows us to vary the aggregation number, and consequently its softness, by changing the solvophobic-to-solvophilic block ratio (m : n) over two orders of magnitude. Based on a simple and general coarse-grained model of the colloidal interaction potential, we verify the significance of interaction length σint governing both structural and dynamic properties. We put forward a quantitative comparison between theory and experiment without adjustable parameters, covering a broad range of experimental polymer volume fractions (0.001 ≤ϕ≤ 0.5) and regimes from ultra-soft star-like to hard sphere-like particles, that finally results in the dynamic phase diagram of soft colloids. In particular, we find throughout the concentration domain a strong correlation between mesoscopic diffusion and macroscopic viscosity, irrespective of softness, manifested in data collapse on master curves using the interaction length σint as the only relevant parameter. A clear reentrance in the glass transition at high aggregation numbers is found, recovering the predicted hard-sphere (HS) value in the hard-sphere like limit. Finally, the excellent agreement between our new experimental systems with different but already established model systems shows the relevance of block copolymer micelles as a versatile realization of soft colloids and the general validity of a coarse-grained approach for the description of the structure and dynamics of soft colloids. PMID:26219628

  4. 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.

  5. 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

  6. Overlap population diagram for ELNES and XANES: peak assignment and interpretation

    NASA Astrophysics Data System (ADS)

    Mizoguchi, Teruyasu

    2009-03-01

    This article reviews overlap population (OP) diagrams for electron energy loss near-edge structure (ELNES) and x-ray absorption near-edge structure (XANES). By using the OP diagrams, peaks in ELNES and XANES of MgO, ZnO, AlN, GaN, InN, and YBa2Cu3O7-x are interpreted in terms of cation-anion and cation-cation interactions. Common features are found in the OP diagrams for different edges. A reconstruction of the unoccupied electronic structure is demonstrated by aligning the different edges with the common features in the OP diagrams. The OP diagram is also applied to the Cu/Al2O3 hetero-interface to find the relationships among ELNES, atomic and electronic structures, and properties.

  7. Influence of metal ions on the interaction between gatifloxacin and calf thymus DNA

    NASA Astrophysics Data System (ADS)

    Yuan, Xiao-ying; Qin, Jun; Lu, Ling-ling

    2010-02-01

    To study the interaction between gatifloxacin (GT), metal ions (Cu 2+, Cd 2+, Co 2+, Mg 2+) and calf thymus DNA under condition of physiology pH, UV absorption and fluorescence methods were adopted. Result shows that metal ions and DNA are able to react with GT in ground state. In further research, by studying the influence of metal ions on binding of GT with DNA in metal ions-GT-DNA ternary system, we found that influential mechanism of Mg 2+ on the binding of GT with DNA may be different from the other three. Mg 2+ can act as a bridge in the binding of GT's carboxyl/carbonyl with DNA phosphate in certain concentration range; while Cu 2+, Cd 2+, Co 2+ can combine directly with GT by reaction between GT carboxyl/carbonyl and DNA base, and enhance the binding ability of GT with DNA. The influence extent and type depend not only on the binding site of DNA with metal ions (phosphate or base), but also the binding ability of which. The stronger the binding ability of metal ions with DNA base is, the larger their promotion to binding of GT with DNA is. The order of metal ions' influential ability on the binding of GT-DNA is identical to the binding ability order of metal ions with DNA base, that is: Cu 2+ > Cd 2+ > Co 2+ > Mg 2+.

  8. 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.

  9. 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

  10. 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.

  11. 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. PMID:26035225

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

    PubMed

    Kim, Ji Sun; Lee, Seung-Hwan

    2016-10-01

    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. PMID:26827636

  13. Modelling 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.

    2015-12-01

    We study the influence of plumes in Europa's atmosphere on the interaction with Jupiter's magnetosphere and the plasma environment. We apply a three-dimensional magnetohydrodynamic (MHD) model, which includes plasma production and loss due to electron impact ionization and dissociative recombination, and electromagnetic induction in a subsurface water ocean.The model considers the magnetospheric and ionospheric electrons separately. We show that an atmospherical inhomogeneity, such as a plume, affects the plasma interaction in the way that a pronounced north-south asymmetry in the near and the Alfvénic far field develops. Furthermore, a "small Alfvén winglet" within Europa's Alfvén wing forms. We also investigate if such signatures of atmospherical inhomogeneities are visible in magnetic field measurements of the Galileo magnetometer. In addition to our MHD model we apply an analytical approach based on the model by Saur et al. (2007) for our studies. We compare the model results with the observed magnetic field data from three flybys of Europa that occurred during the Alfvén wing crossing.

  14. Influence of electrostatic interactions on the release of charged molecules from lipid cubic phases.

    PubMed

    Negrini, Renata; Sánchez-Ferrer, Antoni; Mezzenga, Raffaele

    2014-04-22

    The release of positive, negative, and neutral hydrophilic drugs from pH responsive bicontinuous cubic phases was investigated under varying conditions of electrostatic interactions. A weak acid, linoleic acid (LA), or a weak base, pyridinylmethyl linoleate (PML), were added to the neutral monolinolein (ML) in order to form lyotropic liquid-crystalline (LLC) phases, which are negatively charged at neutral pH and positively charged at acidic pH. Release studies at low ionic strength (I = 20 mM) and at different pH values (3 and 7) revealed that electrostatic attraction between a positive drug, proflavine (PF), and the negatively charged LLC at pH = 7 or between a negative drug, antraquinone 2-sulfonic acid sodium salt (AQ2S), and the positively charged LLC at pH = 3 did delay the release behavior, while electrostatic repulsion affects the transport properties only to some extent. Release profiles of a neutral drug, caffeine, were not affected by the surface charge type and density in the cubic LLCs. Moreover, the influence of ionic strength was also considered up to 150 mM, corresponding to a Debye length smaller than the LLC water channels radius, which showed that efficient screening of electrostatic attractions occurring within the LLC water domains results in an increased release rate. Four transport models were applied to fit the release data, providing an exhaustive, quantitative insight on the role of electrostatic interactions in transport properties from pH responsive bicontinuous cubic phases. PMID:24673189

  15. Sporadic inclusion body myositis: HLA-DRB1 allele interactions influence disease risk and clinical phenotype.

    PubMed

    Mastaglia, Frank L; Needham, Merrilee; Scott, Adrian; James, Ian; Zilko, Paul; Day, Timothy; Kiers, Lynette; Corbett, Alastair; Witt, Campbell S; Allcock, Richard; Laing, Nigel; Garlepp, Michael; Christiansen, Frank T

    2009-11-01

    Susceptibility to sIBM is strongly associated with the HLA-DRB1*03 allele and the 8.1 MHC ancestral haplotype (HLA-A1, B8, DRB1*03) but little is known about the effects of allelic interactions at the DRB1 locus or disease-modifying effects of HLA alleles. HLA-A, B and DRB1 genotyping was performed in 80 Australian sIBM cases and the frequencies of different alleles and allele combinations were compared with those in a group of 190 healthy controls. Genotype-phenotype correlations were also investigated. Amongst carriers of the HLA-DRB1*03 allele, DRB1*03/*01 heterozygotes were over-represented in the sIBM group (p<0.003) while. DRB1*03/*04 heterozygotes were under-represented (p<0.008). The mean age-at-onset (AAO) was 6.5 years earlier in DRB1*03/*01 heterozygotes who also had more severe quadriceps muscle weakness than the rest of the cohort. The findings indicate that interactions between the HLA-DRB1*03 allele and other alleles at the DRB1 locus can influence disease susceptibility and the clinical phenotype in sIBM. PMID:19720533

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

    PubMed

    Schober, Amanda L; Peterson, Devin G

    2004-05-01

    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. PMID:15113168

  17. BDNF Val66Met is Associated with Introversion and Interacts with 5-HTTLPR to Influence Neuroticism

    PubMed Central

    Terracciano, Antonio; Tanaka, Toshiko; Sutin, Angelina R; Deiana, Barbara; Balaci, Lenuta; Sanna, Serena; Olla, Nazario; Maschio, Andrea; Uda, Manuela; Ferrucci, Luigi; Schlessinger, David; Costa, Paul T

    2010-01-01

    Brain-derived neurotrophic factor (BDNF) regulates synaptic plasticity and neurotransmission, and has been linked to neuroticism, a major risk factor for psychiatric disorders. A recent genome-wide association (GWA) scan, however, found the BDNF Val66Met polymorphism (rs6265) associated with extraversion but not with neuroticism. In this study, we examine the links between BDNF and personality traits, assessed using the Revised NEO Personality Inventory (NEO-PI-R), in a sample from SardiNIA (n=1560) and the Baltimore Longitudinal Study of Aging (BLSA; n=1131). Consistent with GWA results, we found that BDNF Met carriers were more introverted. By contrast, in both samples and in a meta-analysis inclusive of published data (n=15251), we found no evidence for a main effect of BDNF Val66Met on neuroticism. Finally, on the basis of recent reports of an epistatic effect between BDNF and the serotonin transporter, we explored a Val66Met × 5-HTTLPR interaction in a larger SardiNIA sample (n=2333). We found that 5-HTTLPR LL carriers scored lower on neuroticism in the presence of the BDNF Val variant, but scored higher on neuroticism in the presence of the BDNF Met variant. Our findings support the association between the BDNF Met variant and introversion and suggest that BDNF interacts with the serotonin transporter gene to influence neuroticism. PMID:20042999

  18. Influence of plant-earthworm interactions on SOM chemistry and p,p'-DDE bioaccumulation.

    PubMed

    Kelsey, Jason W; Slizovskiy, Ilya B; Petriello, Michael C; Butler, Kelly L

    2011-05-01

    Laboratory experiments assessed how bioaccumulation of weathered p,p'-DDE from soil and humic acid (HA) chemistry are affected by interactions between the plants Cucurbita pepo ssp. pepo and ssp. ovifera and the earthworms Eisenia fetida, Lumbricus terrestris, and Apporectodea caliginosa. Total organochlorine phytoextraction by ssp. pepo increased at least 25% in the presence of any of the earthworm species (relative to plants grown in isolation). Uptake of the compound by ssp. ovifera was unaffected by earthworms. Plants influenced earthworm bioaccumulation as well. When combined with pepo, p,p'-DDE levels in E. fetida decreased by 50%, whereas, in the presence of ovifera, bioconcentration by L. terrestris increased by more than 2-fold. Spectral analysis indicated a decrease in hydrophobicity of HA in each of the soils in which both pepo and earthworms were present. However, HA chemistry from ovifera treatments was largely unaffected by earthworms. Risk assessments of contaminated soils should account for species interactions, and SOM chemistry may be a useful indictor of pollutant bioaccumulation. PMID:21421253

  19. Influence of microenvironment and liposomal formulation on secondary structure and bilayer interaction of lysozyme.

    PubMed

    Witoonsaridsilp, Wasu; Panyarachun, Busaba; Sarisuta, Narong; Müller-Goymann, Christel C

    2010-02-01

    The conformation of peptide and protein drugs in various microenvironments and the interaction with drug carriers such as liposomes are of considerable interest. In this study the influence of microenvironments such as pH, salt concentration, and surface charge on the secondary structure of a model protein, lysozyme, either in solution or entrapped in liposomes with various molar ratios of phosphatidylcholine (PC):cholesterol (Chol) was investigated. It was found that entrapment efficiency was more pronounced in negatively charged liposomes than in non-charged liposomes, which was independent of Chol content and pH of hydration medium. The occurrence of aggregation, decrease in zeta potential, and alteration of 31P NMR chemical shift of negatively charged lysozyme liposomes compared to blank liposomes suggested that the electrostatic interaction plays a major role in protein-lipid binding. Addition of sodium chloride could impair the neutralizing ability of positively charged lysozyme on negatively charged membrane via chloride counterion binding. Neither lysozyme in various buffer solutions with sodium chloride nor that entrapped in liposomes showed any significant change in their secondary structures. However, significant decrease in alpha-helical content of lysozyme in non-charged liposomes at higher pH and salt concentrations was discovered. PMID:19880295

  20. 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.

  1. 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

  2. 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. PMID:22234428

  3. 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. PMID:25899738

  4. The Sinorhizobium meliloti RNA chaperone Hfq influences central carbon metabolism and the symbiotic interaction with alfalfa

    PubMed Central

    2010-01-01

    Background The bacterial Hfq protein is able to interact with diverse RNA molecules, including regulatory small non-coding RNAs (sRNAs), and thus it is recognized as a global post-transcriptional regulator of gene expression. Loss of Hfq has an extensive impact in bacterial physiology which in several animal pathogens influences virulence. Sinorhizobium meliloti is a model soil bacterium known for its ability to establish a beneficial nitrogen-fixing intracellular symbiosis with alfalfa. Despite the predicted general involvement of Hfq in the establishment of successful bacteria-eukaryote interactions, its function in S. meliloti has remained unexplored. Results Two independent S. meliloti mutants, 2011-3.4 and 1021Δhfq, were obtained by disruption and deletion of the hfq gene in the wild-type strains 2011 and 1021, respectively, both exhibiting similar growth defects as free-living bacteria. Transcriptomic profiling of 1021Δhfq revealed a general down-regulation of genes of sugar transporters and some enzymes of the central carbon metabolism, whereas transcripts specifying the uptake and metabolism of nitrogen sources (mainly amino acids) were more abundant than in the wild-type strain. Proteomic analysis of the 2011-3.4 mutant independently confirmed these observations. Symbiotic tests showed that lack of Hfq led to a delayed nodulation, severely compromised bacterial competitiveness on alfalfa roots and impaired normal plant growth. Furthermore, a large proportion of nodules (55%-64%) elicited by the 1021Δhfq mutant were non-fixing, with scarce content in bacteroids and signs of premature senescence of endosymbiotic bacteria. RT-PCR experiments on RNA from bacteria grown under aerobic and microoxic conditions revealed that Hfq contributes to regulation of nifA and fixK1/K2, the genes controlling nitrogen fixation, although the Hfq-mediated regulation of fixK is only aerobiosis dependent. Finally, we found that some of the recently identified S. meliloti s

  5. Phase diagrams of scalemic mixtures: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Vlot, Margot J.; van Miltenburg, J. Cornelis; Oonk, Harry A. J.; van der Eerden, Jan P.

    1997-12-01

    In this paper, a simplified model was used to describe the interactions between the enantiomers in a scalemic mixture. Monte Carlo simulations were performed to determine several thermodynamic properties as a function of temperature and mole fraction of solid, liquid, and gas phase. Phase diagrams were constructed using a macroscopic thermodynamic program, PROPHASE. The model consists of spherical D and L molecules interacting via modified Lennard-Jones potentials (σDD=σLL, ɛDD=ɛLL, ɛDL=eɛDD, and σDL=sσDD.) The two heterochiral interaction parameters, e and s, were found to be sufficient to produce all types of phase diagrams that have been found for these systems experimentally. Conglomerates were found when the heterochiral interaction strength was smaller than the homochiral value, e<1. A different heterochiral interaction distance, s≠1, led to racemic compounds, with an ordered distribution of D and L molecules. The CsCl-structured compound was found to be stable for short DL interactions, s<1 (e=1), with an enantiotropic transition to a solid solution for s=0.96. Longer heterochiral distances, s>1, result in the formation of layered fcc compounds. The liquid regions in the phase diagram become larger for s≠1, caused by a strong decrease of the melting point for s<1 and s>1, in combination with only a small effect on the boiling point for s<1, and even an increase of the boiling point for s>1. Segregation into two different solid solutions, one with low mole fraction and the other one close to x=0.25, was obtained for these mixtures as well.

  6. Faceting diagram for sticky steps

    NASA Astrophysics Data System (ADS)

    Akutsu, Noriko

    2016-03-01

    Faceting diagrams for the step-faceting zone, the step droplet zone, and the Gruber-Mullins-Pokrovsky-Talapov (GMPT) zone for a crystal surface are obtained by using the density matrix renormalization group method to calculate the surface tension. The model based on these calculations is the restricted solid-on-solid (RSOS) model with a point-contact-type step-step attraction (p-RSOS model) on a square lattice. The point-contact-type step-step attraction represents the energy gain obtained by forming a bonding state with orbital overlap at the meeting point of the neighboring steps. In the step-faceting zone, disconnectedness in the surface tension leads to the formation of a faceted macrostep on a vicinal surface at equilibrium. The disconnectedness in the surface tension also causes the first-order shape transition for the equilibrium shape of a crystal droplet. The lower zone boundary line (ZBL), which separates the step-faceting zone and the step droplet zone, is obtained by the condition γ 1 = lim n → ∞ γ n / n , where γn is the step tension of the n-th merged step. The upper ZBL, which separates the GMPT zone and the step droplet zone, is obtained by the condition Aq,eff = 0 and Bq,eff = 0, where Aq,eff and Bq,eff represent the coefficients for the | q → | 2 term and the | q → | 3 term, respectively, in the | q → | -expanded form of the surface free energy f eff ( q → ) . Here, q → is the surface gradient relative to the (111) surface. The reason why the vicinal surface inclined in the <101> direction does not exhibit step-faceting is explained in terms of the one-dimensional spinless quasi-impenetrable attractive bosons at absolute zero.

  7. 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.

  8. Influences of the third and fourth nearest neighbouring interactions on the surface anisotropy of face-centred-cubic metals

    NASA Astrophysics Data System (ADS)

    Luo, Yongkun; Qin, Rongshan

    2014-06-01

    The structure and the anisotropic properties of the surfaces of face-centred-cubic (FCC) metals have been studied using the broken-bond model while considering the third and fourth nearest neighbouring (3rd and 4th NN) interactions. The pair potential expressions are obtained using the Rose-Vinet universal potential equation. The model is suitable for calculation of the property of a surface with arbitrary crystallographic orientations and can provide absolute unrelaxed surface energy values using three input parameters, namely the lattice constant, bulk modulus and cohesive energy. These parameters are available for the majority of FCC metals. The numerical results for 7 FCC metals have been obtained and compared with these obtained from ab initio calculations and experimental measurements. Good agreement is observed between the two. Taking into account up to the 4th NN interactions, the overall surface energy anisotropy for FCC metals was found to be between 12% to 16%, and the ratio between the surface energies at (100) and (111) planes was found to be 1.05. These values are less than those reported by conventional calculations but more similar to experimental measurements. It is found that the strength of 3rd and 4th NN interactions differs from one element to another, the Ni and Cu interactions being the most significant while the Au, Pt and Pb interactions are the least significant. This suggests that the polar diagrams of the surface energy of Ni and Cu are different from those of Au, Pt and Pb by showing cusps of the unconventional {110} and high-index {210}, {311} and possibly {135} poles. This provides explanations to the recent experimental observations of the {110}, {210}, {311} and {135} facets in equilibrated Ni and Cu crystallines.

  9. Influence of Constitution and Charge on Radical Pairing Interactions in Tris-radical Tricationic Complexes.

    PubMed

    Cheng, Chuyang; Cheng, Tao; Xiao, Hai; Krzyaniak, Matthew D; Wang, Yuping; McGonigal, Paul R; Frasconi, Marco; Barnes, Jonathan C; Fahrenbach, Albert C; Wasielewski, Michael R; Goddard, William A; Stoddart, J Fraser

    2016-07-01

    The results of a systematic investigation of trisradical tricationic complexes formed between cyclobis(paraquat-p-phenylene) bisradical dicationic (CBPQT(2(•+))) rings and a series of 18 dumbbells, containing centrally located 4,4'-bipyridinium radical cationic (BIPY(•+)) units within oligomethylene chains terminated for the most part by charged 3,5-dimethylpyridinium (PY(+)) and/or neutral 3,5-dimethylphenyl (PH) groups, are reported. The complexes were obtained by treating equimolar amounts of the CBPQT(4+) ring and the dumbbells containing BIPY(2+) units with zinc dust in acetonitrile solutions. Whereas UV-Vis-NIR spectra revealed absorption bands centered on ca. 1100 nm with quite different intensities for the 1:1 complexes depending on the constitutions and charges on the dumbbells, titration experiments showed that the association constants (Ka) for complex formation vary over a wide range, from 800 M(-1) for the weakest to 180 000 M(-1) for the strongest. While Coulombic repulsions emanating from PY(+) groups located at the ends of some of the dumbbells undoubtedly contribute to the destabilization of the trisradical tricationic complexes, solid-state superstructures support the contention that those dumbbells with neutral PH groups at the ends of flexible and appropriately constituted links to the BIPY(•+) units stand to gain some additional stabilization from C-H···π interactions between the CBPQT(2(•+)) rings and the PH termini on the dumbbells. The findings reported in this Article demonstrate how structural changes implemented remotely from the BIPY(•+) units influence their non-covalent bonding interactions with CBPQT(2(•+)) rings. Different secondary effects (Coulombic repulsions versus C-H···π interactions) are uncovered, and their contributions to both binding strengths associated with trisradical interactions and the kinetics of associations and dissociations are discussed at some length, supported by extensive DFT

  10. Methylation interactions in Arabidopsis hybrids require RNA-directed DNA methylation and are influenced by genetic variation.

    PubMed

    Zhang, Qingzhu; Wang, Dong; Lang, Zhaobo; He, Li; Yang, Lan; Zeng, Liang; Li, Yanqiang; Zhao, Cheng; Huang, Huan; Zhang, Heng; Zhang, Huiming; Zhu, Jian-Kang

    2016-07-19

    DNA methylation is a conserved epigenetic mark in plants and many animals. How parental alleles interact in progeny to influence the epigenome is poorly understood. We analyzed the DNA methylomes of Arabidopsis Col and C24 ecotypes, and their hybrid progeny. Hybrids displayed nonadditive DNA methylation levels, termed methylation interactions, throughout the genome. Approximately 2,500 methylation interactions occurred at regions where parental DNA methylation levels are similar, whereas almost 1,000 were at differentially methylated regions in parents. Methylation interactions were characterized by an abundance of 24-nt small interfering RNAs. Furthermore, dysfunction of the RNA-directed DNA methylation pathway abolished methylation interactions but did not affect the increased biomass observed in hybrid progeny. Methylation interactions correlated with altered genetic variation within the genome, suggesting that they may play a role in genome evolution. PMID:27382183

  11. 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.

  12. Influence of Effects of Self-Polarization and Exciton-Phonon Interactions on the Exciton Energy in Lead Iodide Nanofilms

    NASA Astrophysics Data System (ADS)

    Kramar, V. M.; Pugantseva, O. V.

    2014-08-01

    In the approximation of effective masses for electronic and phononic - dielectric continuum - systems, the influence of spatial bounding, self-polarization, and exciton-phonon interactions on the exciton state in a flat double nanoheterostructure (a nanofilm) - lead iodide in a polymer matrix -is theoretically investigated for the model of a single infinitely deep quantum well. It is demonstrated that the dominating factor determining the energy of the bottom of the ground exciton band and its binding energy is spatial bounding. The relationship between two other effects depends on the nanofilm thickness, namely, the influence of the self-polarization effect in ultrathin films significantly exceeds that of exciton-phonon interaction.

  13. The Influence of Social Norms upon Behavioral Expressions of Implicit and Explicit Weight-Related Stigma in an Interactive Game

    PubMed Central

    Pryor, John B.; Reeder, Glenn D.; Wesselmann, Eric D.; Williams, Kipling D.; Wirth, James H.

    2013-01-01

    This research explored the roles of social influence and stigma-related attitudes in how people behaved toward an overweight female in an interactive computer game. Photographs were used to manipulate whether one of the players in the game was overweight or average weight. We found that both explicit and implicit anti-fat attitudes influenced interactions with an overweight player, but only when other players ostracized the overweight player, not when they included her. Under conditions of ostracism, explicit attitudes were better predictors of more controllable behaviors, while implicit attitudes were better predictors of more automatic behaviors. PMID:23766740

  14. The influence of social norms upon behavioral expressions of implicit and explicit weight-related stigma in an interactive game.

    PubMed

    Pryor, John B; Reeder, Glenn D; Wesselmann, Eric D; Williams, Kipling D; Wirth, James H

    2013-06-01

    This research explored the roles of social influence and stigma-related attitudes in how people behaved toward an overweight female in an interactive computer game. Photographs were used to manipulate whether one of the players in the game was overweight or average weight. We found that both explicit and implicit anti-fat attitudes influenced interactions with an overweight player, but only when other players ostracized the overweight player, not when they included her. Under conditions of ostracism, explicit attitudes were better predictors of more controllable behaviors, while implicit attitudes were better predictors of more automatic behaviors. PMID:23766740

  15. The stacking interactions of bipyridine complexes: the influence of the metal ion type on the strength of interactions.

    PubMed

    Sredojević, Dušan N; Petrović, Predrag V; Janjić, Goran V; Brothers, Edward N; Hall, Michael B; Zarić, Snežana D

    2016-01-01

    The strength of the stacking interactions in the bipy complexes of nickel, palladium, and platinum, [M(CN)2 bipy]2 (M = Ni, Pd, Pt), was calculated using the ωB97xD/def2-TZVP method. The results show that for all considered geometries, interactions are the strongest for platinum, and weakest for nickel complexes, as a result of higher dispersion contributions of platinum over the palladium and nickel complexes. It was also shown that strength of interactions considerably rises with an increase of the stacking overlap area. As a consequence of the favorable electrostatic term, the strength of interactions also rises when metal atom and cyano ligands are involved in the overlap with bipy ligand. The strongest interaction was calculated in the platinum complex, for the geometry that has overlap of metal and cyano ligands with bipy ligand with an energy of -39.80 kcal mol(-1). The energies for similar geometries of palladium and nickel complexes are -34.60 and -32.45 kcal mol(-1). These energies, remarkably, exceed the strength of the stacking interactions between organic aromatic molecules. These results can be of importance in all systems with stacking interactions, from materials to biomolecules. PMID:26757913

  16. Algorithmic Identification for Wings in Butterfly Diagrams.

    NASA Astrophysics Data System (ADS)

    Illarionov, E. A.; Sokolov, D. D.

    2012-12-01

    We investigate to what extent the wings of solar butterfly diagrams can be separated without an explicit usage of Hale's polarity law as well as the location of the solar equator. Two algorithms of cluster analysis, namely DBSCAN and C-means, have demonstrated their ability to separate the wings of contemporary butterfly diagrams based on the sunspot group density in the diagram only. Here we generalize the method for continuous tracers, give results concerning the migration velocities and presented clusters for 12 - 20 cycles.

  17. Global Phase Diagram of the High-Tc Cuprates

    NASA Astrophysics Data System (ADS)

    Chen, Han-Dong; Zhang, Shou-Cheng

    2006-02-01

    We propose a bosonic effective quantum Hamiltonian based on the projected SO(5) model with extended interactions, which can be derived from the microscopic models of the cuprates. The global phase diagram of this model is obtained using mean-field theory and the quantum Monte Carlo simulation. We show that this single quantum model can account for most salient features observed in the high-Tc cuprates, with different families of the cuprates attributed to different traces in the global phase diagram. A particular prediction of this theory is the checkerboard state of the d-wave hole pairs formed at certain magic filling fractions. We shall describe various properties of this state and present evidence that this novel state has been detected in recent STM and transport experiments.

  18. Size Dependent Phase Diagrams of Nickel-Carbon Nanoparticles.

    PubMed

    Magnin, Y; Zappelli, A; Amara, H; Ducastelle, F; Bichara, C

    2015-11-13

    The carbon rich phase diagrams of nickel-carbon nanoparticles, relevant to catalysis and catalytic chemical vapor deposition synthesis of carbon nanotubes, are calculated for system sizes up to about 3 nm (807 Ni atoms). A tight binding model for interatomic interactions drives the grand canonical Monte Carlo simulations used to locate solid, core shell and liquid stability domains, as a function of size, temperature, and carbon chemical potential or concentration. Melting is favored by carbon incorporation from the nanoparticle surface, resulting in a strong relative lowering of the eutectic temperature and a phase diagram topology different from the bulk one. This should lead to a better understanding of the nanotube growth mechanisms. PMID:26613451

  19. A Hubble Diagram for Quasars

    NASA Astrophysics Data System (ADS)

    Risaliti, G.; Lusso, E.

    2015-12-01

    We present a new method to test the ΛCDM cosmological model and to estimate cosmological parameters based on the nonlinear relation between the ultraviolet and X-ray luminosities of quasars. We built a data set of 1138 quasars by merging several samples from the literature with X-ray measurements at 2 keV and SDSS photometry, which was used to estimate the extinction-corrected 2500 Å flux. We obtained three main results: (1) we checked the nonlinear relation between X-ray and UV luminosities in small redshift bins up to z˜ 6, confirming that the relation holds at all redshifts with the same slope; (2) we built a Hubble diagram for quasars up to z˜ 6, which is well matched to that of supernovae in the common z = 0-1.4 redshift interval and extends the test of the cosmological model up to z˜ 6; and (3) we showed that this nonlinear relation is a powerful tool for estimating cosmological parameters. Using the present data and assuming a ΛCDM model, we obtain {{{Ω }}}M = 0.22{}-0.08+0.10 and {{{Ω }}}{{Λ }} = 0.92{}-0.30+0.18 ({{{Ω }}}M = 0.28 ± 0.04 and {{{Ω }}}{{Λ }} = 0.73 +/- 0.08 from a joint quasar-SNe fit). Much more precise measurements will be achieved with future surveys. A few thousand SDSS quasars already have serendipitous X-ray observations from Chandra or XMM-Newton, and at least 100,000 quasars with UV and X-ray data will be made available by the extended ROentgen Survey with an Imaging Telescope Array all-sky survey in a few years. The Euclid, Large Synoptic Survey Telescope, and Advanced Telescope for High ENergy Astrophysics surveys will further increase the sample size to at least several hundred thousand. Our simulations show that these samples will provide tight constraints on the cosmological parameters and will allow us to test for possible deviations from the standard model with higher precision than is possible today.

  20. Several genetic polymorphisms interact with overweight/obesity to influence serum lipid levels

    PubMed Central

    2012-01-01

    B (MTHFR); HDL-C and ApoA1 (MYLIP) in normal weight subjects were different among the genotypes (P < 0.01-0.001). The levels of LDL-C, ApoB and ApoA1/ApoB (ABCA-1); HDL-C, ApoA1, ApoB and ApoA1/ApoB (LIPC); TC, HDL-C, ApoA1 and ApoB (LIPG); TC, TG, HDL-C, LDL-C, ApoA1 and ApoB (MTHFR); TC, TG and ApoB (MYLIP); TG (PCSK9); TG, ApoA1 and ApoB (PPARD); and TC, HDL-C, LDL-C, ApoA1 and ApoB (SCARB1) in overweight/obese subjects were different among the genotypes (P < 0.01-0.001). The SNPs of ABCA-1 (LDL-C and ApoA1/ApoB); LIPC (TC, LDL-C, ApoA1 and ApoB); LIPG (ApoB); MTHFR (TC, TG and LDL-C); MYLIP (TC and TG); PCSK9 (TG, HDL-C, ApoB and ApoA1/ApoB); PPARD (TG and ApoA1/ApoB); and SCARB1 (TG, ApoA1 and ApoB) interacted with overweight/obesity to influence serum lipid levels (P < 0.05-0.001). Conclusions The differences in serum lipid levels between normal weight and overweight/obese subjects might partly result from different genetic polymorphisms and the interactions between several SNPs and overweight/obesity. PMID:23039238

  1. 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

  2. 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.

  3. A PER3 Polymorphism Interacts with Sleep Duration to Influence Transient Mood States in Women

    PubMed Central

    Gobin, Christina M.; Fins, Ana I.; Craddock, Travis J.A.; Tartar, Aurélien; Tartar, Jaime L.

    2016-01-01

    Background: Expression of the clock family of genes in the suprachiasmatic nuclei (SCN) regulates the molecular control of circadian timing. Increasing evidence also implicates clock gene activity in the development of mood disorders. In particular, variation in the PER3 clock gene has been shown to influence diurnal preference and sleep homeostasis. However, there is not currently a clear association between PER3 polymorphisms and mood. This is possibly because the PER3 gene has been shown to influence homeostatic sleep drive, rather than circadian timing, and the PER3 gene may be behaviorally relevant only under chronic sleep loss conditions. Methods: To test the association between PER3 allele status and impaired mood, a total of 205 healthy women were genotyped for PER3 allele status and responded to previously-validated psychological questionnaires surveying self-reported sleep habits (MEQ, PSQI) and mood. Our mood measures included two measures of short-term, transient mood (state anxiety and mood disturbance) and two measures of longer term, ongoing mood (trait anxiety and depressive symptomology). Results: The PER3 genotype distribution was 88 (42.9%) for PER3(4/4), 98 (47.8%) for PER3(4/5), and 19 (9.3%) for PER3(5/5). Our sleep duration x genotype interaction analyses showed that, relative to longer allele carriers, PER3(4/4) genotypes were at greater risk for transient psychological effects (mood and state anxiety) when they reported reduced sleep durations. Conclusion: Sleep duration plays a critical role in understanding the extent to which PER3 allele status relates to mood states. PMID:27103936

  4. Above-Belowground Herbivore Interactions in Mixed Plant Communities Are Influenced by Altered Precipitation Patterns.

    PubMed

    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

  5. 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

  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. 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

  8. 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. PMID:24604603

  9. 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

  10. 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. PMID:25832115

  11. Interactions among benthic insects, algae, and bacteria in a geothermally influenced stream. [Helicopsyche borealis (Hagen)

    SciTech Connect

    Lamberti, G.A.

    1983-01-01

    This dissertation examines the interactions between benthic macroinvertebrates and microorganisms in stream habitats that were exposed to varying levels of geothermal contamination. Stream microcosms were used in situ to evaluate the separate effects of the thermal and chemical components of geothermal effluents on aquatic biota in Big Sulphur Creek, a third-order stream at the Geysers. The thermal component of those effluents had greater influence than the chemical component in determining benthic community structure. The effects of grazing by the herbivorous caddisfly Helicopsyche borealis (Hagen) on benthic algae and bacteria were experimentally studied in an undisturbed segment of Big Sulphur Creek. Exclusion of Helicopsyche larvae from introduced substrates resulted in high standing crops of algae and bacteria, but a low algal turnover rate. On substrate that was grazed by natural densities of Helicopsyche larvae, algal and bacterial standing crops were reduced by 83-98%, but the turnover rate of algae was substantially increased. Thus, grazing by Helicopsyche resulted in a low-biomass algal community that, because of a high turnover rate, was able to support a high biomass of consumers. These results emphasize the importance of consumer-producer interactions in stream ecosystems; disturbance of either component during geothermal development may result in substantial changes at other trophic levels as well. Complementary studies to those summarized above include (1) comparison of introduced and natural substrates for sampling benthic organisms, (2) distributional analysis of benthic biota along a geothermal gradient, and (3) evaluation of seasonal dynamics of suspended microorganisms in three streams that have different geothermal characteristics. This dissertation concludes with a review of primary consumption patterns in aquatic insects.

  12. Host-Synthesized Secondary Compounds Influence the In Vitro Interactions between Fungal Endophytes of Maize▿

    PubMed Central

    Saunders, Megan; Kohn, Linda M.

    2008-01-01

    Maize produces a suite of allelopathic secondary metabolites, the benzoxazinoids. 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-one and 2,4-dihydroxy-2H-1,4-benzoxazin-3-one reside as glucosides in plant tissue and spontaneously degrade to 6-methoxy-2-benzoxazolinone (MBOA) and 2-benzoxazolinone (BOA) upon plant cell disruption. Several maize-associated fungi in the genus Fusarium can metabolize MBOA and BOA. BOA tolerance levels in 10 species of Fusarium and in the maize endophytes Nigrospora oryzae, Acremonium zeae, and Periconia macrospinosa were characterized. BOA tolerance ranged from 0.25 to 1.10 mg/ml among species. The influence of substrate alteration by one species on the subsequent growth of another species was assessed in the presence and absence of BOA. The colony area of the secondary colonizer in heterospecific interactions was compared to that in autospecific interactions (one isolate follows itself). In the presence of BOA, four of six secondary colonizers had greater growth (facilitation) when primary colonizers had higher BOA tolerance than the secondary colonizer. When the primary colonizer had lower tolerance than the secondary, three of six secondary colonizers were inhibited (competition) and three not significantly affected. In BOA-free medium, the number of isolates that were facilitated or inhibited was the same regardless of the tolerance level of the primary colonizer. Two of six secondary colonizers were facilitated, two inhibited, and two not significantly affected. This study provides some support for facilitation in stressful conditions under the Menge-Sutherland model. The results are not consistent with the corresponding prediction of competition in the absence of stress. The hypothesis drawn from these data is that in the presence of a toxin, fungal species that detoxify their substrate can enhance the colonization rate of less tolerant fungi. PMID:17993551

  13. Does a methionine-to-norleucine substitution in PGLa influence peptide-membrane interactions?

    PubMed

    Radchenko, Dmytro S; Kattge, Saskia; Kara, Sezgin; Ulrich, Anne S; Afonin, Sergii

    2016-09-01

    Yes. To understand the molecular mechanisms of amphiphilic membrane-active peptides, it is essential to study their interactions with lipid bilayers under near-native conditions. Amino acid composition largely determines the non-specific properties of peptides, on the basis of the physicochemical properties of the side chains. The resultant effects on peptides' functional properties include influences on the conformation, structural dynamics and binding affinities within the peptide interactome. Here, we studied the effect of substituting oxidation-prone methionine (Met) with non-oxidizable norleucine (Nle) in the model α-helical antimicrobial peptide PGLa, through systematic comparison of PGLa with the (2)Met/(2)Nle mutant. Both peptides were evaluated for their bacteriostatic and hemolytic activities (using in situ assays), for their conformational preferences in isotropic solutions (using circular dichroism spectropolarimetry) and for their abilities to modulate membrane curvature (using a solid-state (31)P NMR assay). We determined the membrane-bound states in detail and characterized the orientational dynamics of both peptides in oriented phospholipid membranes by solid-state (19)F NMR spectroscopy. On the one hand, the bioactivity results, the structure in the diluted membrane-mimicking environments and the strong inhibition of the negative membrane curvature were comparable between PGLa and the mutant. On the other hand, the alignments in DMPC bilayer were qualitatively the same but differed in absolute values - the more hydrophobic Nle residue inserted deeper in the membrane core. Furthermore, the mutant peptide displayed a significantly reduced ability to re-orient from the monomeric, surficial to the putative dimeric, tilted state. Overall, these results confirm the functional isosterism of Nle and Met in the helical membrane-active peptides but highlight differences in the ways in which the two residues affect non-specific binding to the lipid bilayer

  14. Host-synthesized secondary compounds influence the in vitro interactions between fungal endophytes of maize.

    PubMed

    Saunders, Megan; Kohn, Linda M

    2008-01-01

    Maize produces a suite of allelopathic secondary metabolites, the benzoxazinoids. 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-one and 2,4-dihydroxy-2H-1,4-benzoxazin-3-one reside as glucosides in plant tissue and spontaneously degrade to 6-methoxy-2-benzoxazolinone (MBOA) and 2-benzoxazolinone (BOA) upon plant cell disruption. Several maize-associated fungi in the genus Fusarium can metabolize MBOA and BOA. BOA tolerance levels in 10 species of Fusarium and in the maize endophytes Nigrospora oryzae, Acremonium zeae, and Periconia macrospinosa were characterized. BOA tolerance ranged from 0.25 to 1.10 mg/ml among species. The influence of substrate alteration by one species on the subsequent growth of another species was assessed in the presence and absence of BOA. The colony area of the secondary colonizer in heterospecific interactions was compared to that in autospecific interactions (one isolate follows itself). In the presence of BOA, four of six secondary colonizers had greater growth (facilitation) when primary colonizers had higher BOA tolerance than the secondary colonizer. When the primary colonizer had lower tolerance than the secondary, three of six secondary colonizers were inhibited (competition) and three not significantly affected. In BOA-free medium, the number of isolates that were facilitated or inhibited was the same regardless of the tolerance level of the primary colonizer. Two of six secondary colonizers were facilitated, two inhibited, and two not significantly affected. This study provides some support for facilitation in stressful conditions under the Menge-Sutherland model. The results are not consistent with the corresponding prediction of competition in the absence of stress. The hypothesis drawn from these data is that in the presence of a toxin, fungal species that detoxify their substrate can enhance the colonization rate of less tolerant fungi. PMID:17993551

  15. Influence of external inputs and asymmetry of connections on information-geometric measures involving up to ten neuronal interactions.

    PubMed

    Nie, Yimin; Fellous, Jean-Marc; Tatsuno, Masami

    2014-10-01

    The investigation of neural interactions is crucial for understanding information processing in the brain. Recently an analysis method based on information geometry (IG) has gained increased attention, and the property of the pairwise IG measure has been studied extensively in relation to the two-neuron interaction. However, little is known about the property of IG measures involving more neuronal interactions. In this study, we systematically investigated the influence of external inputs and the asymmetry of connections on the IG measures in cases ranging from 1-neuron to 10-neuron interactions. First, the analytical relationship between the IG measures and external inputs was derived for a network of 10 neurons with uniform connections. Our results confirmed that the single and pairwise IG measures were good estimators of the mean background input and of the sum of the connection weights, respectively. For the IG measures involving 3 to 10 neuronal interactions, we found that the influence of external inputs was highly nonlinear. Second, by computer simulation, we extended our analytical results to asymmetric connections. For a network of 10 neurons, the simulation showed that the behavior of the IG measures in relation to external inputs was similar to the analytical solution obtained for a uniformly connected network. When the network size was increased to 1000 neurons, the influence of external inputs almost disappeared. This result suggests that all IG measures from 1-neuron to 10-neuron interactions are robust against the influence of external inputs. In addition, we investigated how the strength of asymmetry influenced the IG measures. Computer simulation of a 1000-neuron network showed that all the IG measures were robust against the modulation of the asymmetry of connections. Our results provide further support for an information-geometric approach and will provide useful insights when these IG measures are applied to real experimental spike data. PMID

  16. A Smart Thermal Block Diagram Tool

    NASA Technical Reports Server (NTRS)

    Tsuyuki, Glenn; Miyake, Robert; Dodge, Kyle

    2008-01-01

    The presentation describes a Smart Thermal Block Diagram Tool. It is used by JPL's Team X in studying missions during the Pre-Phase A. It helps generate cost and mass estimates using proprietary data bases.

  17. The Art of Free-Body Diagrams.

    ERIC Educational Resources Information Center

    Puri, Avinash

    1996-01-01

    Discusses the difficulty of drawing free-body diagrams which only show forces exerted on a body from its neighbors. Presents three ways a body may be modeled: a particle, rigid extended, and nonrigid extended. (MKR)

  18. Phase diagram for passive electromagnetic scatterers.

    PubMed

    Lee, Jeng Yi; Lee, Ray-Kuang

    2016-03-21

    With the conservation of power, a phase diagram defined by amplitude square and phase of scattering coefficients for each spherical harmonic channel is introduced as a universal map for any passive electromagnetic scatterers. Physically allowable solutions for scattering coefficients in this diagram clearly show power competitions among scattering and absorption. It also illustrates a variety of exotic scattering or absorption phenomena, from resonant scattering, invisible cloaking, to coherent perfect absorber. With electrically small core-shell scatterers as an example, we demonstrate a systematic method to design field-controllable structures based on the allowed trajectories in this diagram. The proposed phase diagram and inverse design can provide tools to design functional electromagnetic devices. PMID:27136839

  19. 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)

  20. 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.

  1. Reliability computation from reliability block diagrams

    NASA Technical Reports Server (NTRS)

    Chelson, P. O.; Eckstein, R. E.

    1971-01-01

    A method and a computer program are presented to calculate probability of system success from an arbitrary reliability block diagram. The class of reliability block diagrams that can be handled include any active/standby combination of redundancy, and the computations include the effects of dormancy and switching in any standby redundancy. The mechanics of the program are based on an extension of the probability tree method of computing system probabilities.

  2. Fluctuations and the QCD phase diagram

    SciTech Connect

    Schaefer, B.-J.

    2012-06-15

    In this contribution the role of quantum fluctuations for the QCD phase diagram is discussed. This concerns in particular the importance of the matter back-reaction to the gluonic sector. The impact of these fluctuations on the location of the confinement/deconfinement and the chiral transition lines as well as their interrelation are investigated. Consequences of our findings for the size of a possible quarkyonic phase and location of a critical endpoint in the phase diagram are drawn.

  3. A universal structured-design diagramer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Program (FLOWCHARTER) generates standardized flowcharts and concordances for development and debugging of programs in any language. User describes programming-language grammar, providing syntax rules in Backus-Naur form (BNF), list of semantic rules, and set of concordance rules. Once grammar is described, user supplies only source code of program to be diagrammed. FLOWCHARTER automatically produces flow diagram and concordance. Source code for program is written for PASCAL Release 2 compiler, as distributed by University of Minnesota.

  4. ISS EPS Orbital Replacement Unit Block Diagrams

    NASA Technical Reports Server (NTRS)

    Schmitz, Gregory V.

    2001-01-01

    The attached documents are being provided to Switching Power Magazine for information purposes. This magazine is writing a feature article on the International Space Station Electrical Power System, focusing on the switching power processors. These units include the DC-DC Converter Unit (DDCU), the Bi-directional Charge/Discharge Unit (BCDU), and the Sequential Shunt Unit (SSU). These diagrams are high-level schematics/block diagrams depicting the overall functionality of each unit.

  5. 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

    2014-05-01

    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

  6. 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.; Department of Chemistry, Howard Hughes Medical Institute, University of California San Diego, La Jolla, California 92093-0636

    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

  7. 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

  8. miRNA Influences in NRF2 Pathway Interactions within Cancer Models

    PubMed Central

    Ayers, Duncan; Baron, Byron; Hunter, Therese

    2015-01-01

    The NRF2 transcription factor (nuclear factor-erythroid 2 p45-related factor 2) has been identified as a key molecular player in orchestrating adaptive cellular interactions following a wide spectrum of cellular stress conditions that could be either extracellular or intracellular. Dysregulation of the NRF2 system is implicated in various disease states, including inflammatory conditions. The NRF2 transcription factor is also known to permit cross talk with several other essential cellular signaling pathways. Recent literature has also elucidated the potential influences of miRNA activity over modulations of the NRF2 signalling network. Consequently, further delving into the knowledge regarding the extent of miRNA-induced epigenetic gene regulatory control on key elements of the NRF2 signalling pathway and its cross talk, particularly within the context of cancer models, can prove to be of high clinical importance. This is so since such miRNAs, once identified and validated, can be potentially exploited as novel drug targets for emerging translational medicine-based therapies. PMID:26345522

  9. Quality of interactions influences everyday life in psychiatric inpatient care--patients' perspectives.

    PubMed

    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

  10. Influence of Acoustic Field Structure on Polarization Characteristics of Acousto-optic Interaction in Crystals

    NASA Astrophysics Data System (ADS)

    Muromets, A. V.; Trushin, A. S.

    Influence of acoustic field structure on polarization characteristics of acousto-optic interaction is investigated. It is shown that inhomogeneity of acoustic field and mechanism of ultrasound excitation causes changes in values of acousto-optic figure of merit for ordinary and extraordinary light beams in comparison with theoretic values. The theoretic values were derived under assumption that acoustic wave is homogeneous. Experimental analysis was carried out in acousto-optic cell based on lithium niobate crystal where the acoustic wave propagates at the angle 13 degrees to Z axis of the crystal. We used three different methods of ultrasound generation in the crystal: by means of external piezotransducer, by interdigital transducer and by two sets of electrodes placed on top of the crystal surface. In the latter case, the first pair of the electrodes was directed along X crystal axis, while the second pair of the electrodes was directed orthogonally to X crystal axis and the direction of ultrasound. Obtained values for diffraction efficiencies for ordinary and extraordinary polarized optical beams were qualitatively different which may be caused by spatial inhomogeneity of the generated acoustic waves in the crystal. Structure of acoustic field generated by these sets of electrodes was examined by laser probing. We performed the analysis of the acoustic field intensity using acousto-optic method. A relation of diffraction efficiencies for ordinary and extraordinary light waves was measured during each iteration of the laser probing.

  11. 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

  12. The interaction of perfluorooctane sulfonate with hemoglobin: Influence on protein stability.

    PubMed

    Wang, Yanqing; Zhang, Hongmei; Kang, Yijun; Fei, Zhenghao; Cao, Jian

    2016-07-25

    Perfluorooctane sulfonate (PFOS) is among the most prominent xenobiotics contaminants in human blood. To evaluate the toxicity of PFOS at the protein level, the influences of PFOS on the stability and conformation of hemoglobin (Hb) has been investigated by circular dichroism (CD), UV-vis, and fluorescence spectroscopic methods and molecular modeling. CD spectral data indicated that the binding process of PFOS with Hb induced the relatively large changes in secondary structure of protein. Thermal denaturation of Hb, when carried out in the presence of PFOS, also indicated that PFOS acted as a structure destabilizer for protein. UV-vis, and fluorescence spectroscopic data indicated that the tertiary structures of Hb were also changed by PFOS binding. Hb did undergo significant changes in the heme group symmetry, implying that the functions of Hb could be disturbed by PFOS. In addition, molecular modeling study shows that PFOS could enter into the binding cavity of Hb by many noncovalent interactions. Overall, these data provide a mechanist explanation for the longer biological half-life of PFOS in human blood and provide useful information that could be associated with the toxicity of PFOS. PMID:27206695

  13. Dopamine and cognitive control: sex-by-genotype interactions influence the capacity to switch attention.

    PubMed

    Gurvich, C; Rossell, S L

    2015-03-15

    Cognitive performance in healthy persons varies widely between individuals. Sex differences in cognition are well reported, and there is an emerging body of evidence suggesting that the relationship between dopaminergic neurotransmission, implicated in many cognitive functions, is modulated by sex. Here, we examine the influence of sex and genetic variations along the dopaminergic pathway on aspects of cognitive control. A total of 415 healthy individuals, selected from an international consortium linked to Brain Research and Integrative Neuroscience Network (BRAINnet), were genotyped for two common and functional genetic variations of dopamine regulating genes: the catechol-O-methyltransferase [COMT] gene (rs4680) and the dopamine receptor D2 [DRD2] gene (rs6277). Cognitive measures were selected to explore sustained attention (using a continuous performance task), switching of attention (using a Trails B adaptation) and working memory (a visual computerised adaptation of digit span). While there were no main effects for genotype across any tasks, analyses revealed significant sex by genotype interactions for the capacity to switch attention. In relation to COMT, superior performance was noted in females with the Val/Val genotype and for DRD2, superior performance was seen for TT females and CC males. These findings highlight the importance of considering genetic variation in baseline dopamine levels in addition to sex, when considering the impact of dopamine on cognition in healthy populations. These findings also have important implications for the many neuropsychiatric disorders that implicate dopamine, cognitive changes and sex differences. PMID:25510197

  14. 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.

  15. Categorical information influences conscious perception: An interaction between object-substitution masking and repetition blindness.

    PubMed

    Goodhew, Stephanie C; Greenwood, John A; Edwards, Mark

    2016-05-01

    The visual system is constantly bombarded with dynamic input. In this context, the creation of enduring object representations presents a particular challenge. We used object-substitution masking (OSM) as a tool to probe these processes. In particular, we examined the effect of target-like stimulus repetitions on OSM. In visual crowding, the presentation of a physically identical stimulus to the target reduces crowding and improves target perception, whereas in spatial repetition blindness, the presentation of a stimulus that belongs to the same category (type) as the target impairs perception. Across two experiments, we found an interaction between spatial repetition blindness and OSM, such that repeating a same-type stimulus as the target increased masking magnitude relative to presentation of a different-type stimulus. These results are discussed in the context of the formation of object files. Moreover, the fact that the inducer only had to belong to the same "type" as the target in order to exacerbate masking, without necessarily being physically identical to the target, has important implications for our understanding of OSM per se. That is, our results show the target is processed to a categorical level in OSM despite effective masking and, strikingly, demonstrate that this category-level content directly influences whether or not the target is perceived, not just performance on another task (as in priming). PMID:26902249

  16. Class diagram based evaluation of software performance

    NASA Astrophysics Data System (ADS)

    Pham, Huong V.; Nguyen, Binh N.

    2013-03-01

    The evaluation of software performance in the early stages of the software life cycle is important and it has been widely studied. In the software model specification, class diagram is the important object-oriented software specification model. The measures based on a class diagram have been widely studied to evaluate quality of software such as complexity, maintainability, reuse capability, etc. However the software performance evaluation based on Class model has not been widely studied, especially for object-oriented design of embedded software. Therefore, in this paper we propose a new approach to directly evaluate the software performance based on class diagrams. From a class diagram, we determine the parameters which are used to evaluate and build formula of the measures such as Size of Class Variables, Size of Class Methods, Size of Instance Variables, Size of Instance Methods, etc. Then, we do analysis of the dependence of performance on these measures and build the performance evaluation function from class diagram. Thereby we can choose the best class diagram based on this evaluation function.

  17. 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…

  18. 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...

  19. Influence of nanoparticle-ion and nanoparticle-polymer interactions on ion transport and viscoelastic properties of polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Mogurampelly, Santosh; Sethuraman, Vaidyanathan; Pryamitsyn, Victor; Ganesan, Venkat

    2016-04-01

    We use atomistic simulations to probe the ion conductivities and mechanical properties of polyethylene oxide electrolytes containing Al2O3 nanoparticles. We specifically study the influence of repulsive polymer-nanoparticle and ion-nanoparticle interactions and compare the results with those reported for electrolytes containing the polymorph β-Al2O3 nanoparticles. We observe that incorporating repulsive nanoparticle interactions generally results in increased ionic mobilities and decreased elastic moduli for the electrolyte. Our results indicate that both ion transport and mechanical properties are influenced by the polymer segmental dynamics in the interfacial zones of the nanoparticle in the ion-doped systems. Such effects were seen to be determined by an interplay between the nanoparticle-polymer, nanoparticle-ion, and ion-polymer interactions. In addition, such interactions were also observed to influence the number of dissociated ions and the resulting conductivities. Within the perspective of the influence of nanoparticles on the polymer relaxation times in ion-doped systems, our results in the context of viscoelastic properties were consistent with the ionic mobilities. Overall, our results serve to highlight some issues that confront the efforts to use nanoparticle dispersions to simultaneously enhance the conductivity and the mechanical strength of polymer electrolyte.

  20. 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…

  1. 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,…

  2. Phase diagrams properties of the mixed traffic flow on a crossroad

    NASA Astrophysics Data System (ADS)

    Li, Qi-Lang; Wang, Bing-Hong; Liu, Mu-Ren

    2010-11-01

    Based on the Ishibashi and Fukui crossroad traffic flow model [Y. Ishibashi and M. Fukui. J. Phys. Soc. Japan. 70 (2001) 2793], mixed traffic flow (i.e., the fast and slow vehicles with different maximum velocities are mixed) is investigated in this work. According to the numerical simulation results and the principle for constructing the phase diagram, phase diagrams for mixed traffic flow are constructed. It is noted that the topology of these phase diagrams is similar to that of phase diagrams for homogeneous vehicles (which refers to slow vehicles only). From the phase diagrams, it is evident that mixed traffic flow is influenced by the mixing rate f (fraction of slow and fast vehicles) in regions II and V, but not in other regions. Although a mixture of fast and slow vehicles is introduced in the crossroad traffic flow model, the separation between phases in the phase diagrams remains linear. For a given q (the vehicle density on the northbound road), one flow plateau appears in regions IIx or IVy, while two maximum flow plateaus appear in region V in each of the phase diagrams. The maximum flow values in region V reflect the maximum traffic capacity for the traffic system as defined in this work. Since mixed traffic flow is a common phenomenon in real traffic, this work may offer help in real traffic simulations and traffic management.

  3. 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. PMID:20230070

  4. Superconducting phase diagram of itinerant antiferromagnets

    NASA Astrophysics Data System (ADS)

    Rømer, A. T.; Eremin, I.; Hirschfeld, P. J.; Andersen, B. M.

    2016-05-01

    We study the phase diagram of the Hubbard model in the weak-coupling limit for coexisting spin-density-wave order and spin-fluctuation-mediated superconductivity. Both longitudinal and transverse spin fluctuations contribute significantly to the effective interaction potential, which creates Cooper pairs of the quasiparticles of the antiferromagnetic metallic state. We find a dominant dx2-y2-wave solution in both electron- and hole-doped cases. In the quasi-spin-triplet channel, the longitudinal fluctuations give rise to an effective attraction supporting a p -wave gap, but are overcome by repulsive contributions from the transverse fluctuations which disfavor p -wave pairing compared to dx2-y2. The subleading pair instability is found to be in the g -wave channel, but complex admixtures of d and g are not energetically favored since their nodal structures coincide. Inclusion of interband pairing, in which each fermion in the Cooper pair belongs to a different spin-density-wave band, is considered for a range of electron dopings in the regime of well-developed magnetic order. We demonstrate that these interband pairing gaps, which are nonzero in the magnetic state, must have the same parity under inversion as the normal intraband gaps. The self-consistent solution to the full system of five coupled gap equations gives intraband and interband pairing gaps of dx2-y2 structure and similar gap magnitude. In conclusion, the dx2-y2 gap dominates for both hole and electron doping inside the spin-density-wave phase.

  5. Global phase diagram and single particle excitations in Kondo insulators

    NASA Astrophysics Data System (ADS)

    Si, Qimiao; Pixley, Jedediah; Yu, Rong; Paschen, Silke

    Motivated by quantum criticality in Kondo insulators tuned by pressure or doping we study the effects of magnetic frustration and the properties of the single particle excitations in a Kondo lattice model. Focusing on the Kondo insulating limit we study the Shastry-Sutherland Kondo lattice and determine the zero temperature phase diagram, which incorporates a valence bond solid, antiferromagnet, and Kondo insulating ground states, with metal-to-insulator quantum phase transitions. We argue that this phase diagram is generic and represents a ``global'' phase diagram of Kondo insulators in terms of quantum fluctuations and the Kondo interaction. We then focus on the momentum distribution of single particle excitations within the Kondo insulating ground state. We show how features of the Fermi-surface of the underlying conduction electrons appear in the Kondo insulating phase. Lastly, we discuss the implications of our results for quantum criticality in Kondo insulators as well as for the recent de Haas-von Alphen measurements in the Kondo insulator SmB6.

  6. 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.

  7. Influence of the rotor-stator interaction on the dynamic stresses of Francis runners

    NASA Astrophysics Data System (ADS)

    Guillaume, R.; Deniau, J. L.; Scolaro, D.; Colombet, C.

    2012-11-01

    Thanks to advances in computing capabilities and Computational Fluid Dynamics (CFD) techniques, it is now possible to calculate realistic unsteady pressure fields in Francis turbines. This paper will explain methods to calculate the structural loads and the dynamic behaviour in order to optimize the turbine design and maximize its reliability and lifetime. Depending on the operating conditions of a Francis turbine, different hydraulic phenomena may impact the mechanical behaviour of the structure. According to their nature, these highly variable phenomena should be treated differently and specifically in order to estimate the potential risks arising on submerged structures, in particular the runner. The operating condition studied thereafter is the point at maximum power with the maximum head. Under this condition, the runner is excited by only one dynamic phenomenon named the Rotor-Stator Interaction (RSI). The origin of the phenomenon is located on the radial gap of the turbine and is the source of pressure fluctuations. A fluid-structure analysis is performed to observe the influence of that dynamic pressure field on the runner behaviour. The first part of the paper deals with the unsteady fluid computation. The RSI phenomenon is totally unsteady so the fluid simulation must take into account the entire machine and its rotation movement, in order to obtain a dynamic pressure field. In the second part of the paper, a method suitable for the RSI study is developed. It is known that the fluctuating pressure in this gap can be described as a sum of spatial components. By evaluating these components in the CFD results and on the scale model, it is possible to assess the relevance of the numerical results on the whole runner. After this step, the numerical pressure field can be used as the dynamic load of the structure. The final part of the paper presentsthe mechanical finite element calculations. A modal analysis of the runner in water and a harmonic analysis of its

  8. Calculation of binary phase diagrams between the actinide elements, rare earth elements, and transition metal elements

    SciTech Connect

    Selle, J E

    1992-06-26

    Attempts were made to apply the Kaufman method of calculating binary phase diagrams to the calculation of binary phase diagrams between the rare earths, actinides, and the refractory transition metals. Difficulties were encountered in applying the method to the rare earths and actinides, and modifications were necessary to provide accurate representation of known diagrams. To calculate the interaction parameters for rare earth-rare earth diagrams, it was necessary to use the atomic volumes for each of the phases: liquid, body-centered cubic, hexagonal close-packed, and face-centered cubic. Determination of the atomic volumes of each of these phases for each element is discussed in detail. In some cases, empirical means were necessary. Results are presented on the calculation of rare earth-rare earth, rare earth-actinide, and actinide-actinide diagrams. For rare earth-refractory transition metal diagrams and actinide-refractory transition metal diagrams, empirical means were required to develop values for the enthalpy of vaporization for rare earth elements and values for the constant (C) required when intermediate phases are present. Results of using the values determined for each element are presented.

  9. 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

  10. 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

  11. Influence of Dzyaloshinshkii-Moriya interaction on quantum correlations in two-qubit Werner states and MEMS

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    In this paper, we study the influence of Dzyaloshinskii-Moriya (DM) interaction on quantum correlations in two-qubit Werner states and maximally entangled mixed states (MEMS). We consider our system as a closed system of a qubit pair and one auxiliary qubit, which interact with any one of the qubit of the pair through DM interaction. We show that DM interaction, taken along any direction ( x or y or z), does not affect two-qubit Werner states. On the other hand, the MEMS are affected by x and z components of DM interaction and remain unaffected by the y component. Further, we find that the state (i.e., probability amplitude) of auxiliary qubit does not affect the quantum correlations in both the states, and only DM interaction strength influences the quantum correlations. So one can avoid the intention to prepare the specific state of auxiliary qubit to manipulate the quantum correlations in both the states. We mention here that avoiding the preparation of state can contribute to cost reduction in quantum information processing. We also observe the phenomenon of entanglement sudden death in the present study.

  12. 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

  13. 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. PMID:27242605

  14. Family and School Socioeconomic Disadvantage: Interactive Influences on Adolescent Dating Violence Victimization

    PubMed Central

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

    2010-01-01

    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 soecioeconomic 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. PMID:19375207

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. Influence of wave normal angles on hiss-electron interaction in Earth's slot region

    NASA Astrophysics Data System (ADS)

    Gao, Yuzhu; Xiao, Fuliang; Yan, Qi; Yang, Chang; Liu, Si; He, Yihua; Zhou, Qinghua

    2015-11-01

    Wave-particle interaction which occurs in the radiation belts is generally determined by variations in wave normal angles. Using the Gaussian wave normal angle (X=tanθ) distribution, we study the influence of peak wave normal angle (Xm = tanθm) on gyroresonance between plasmaspheric hiss waves and energetic electrons in the slot regions L = 2.5, 3.0, and 3.5. The bounce-averaged diffusion coefficients are calculated for different Xm = 0,1,3,5, and then the phase space density (PSD) evolutions of energetic electrons driven by hiss waves are simulated over a continuous energy range 0.2-5 MeV. As Xm increases, diffusion coefficients basically decrease mainly from the medium to a critical pitch angle αc for Ek≤1.0 MeV but increase at lower pitch angles for Ek>1.0 MeV. Differences of diffusion coefficients between Xm = 0 and 1 are close but become substantial as Xm≥3. Hiss can cause substantial drops in electron PSDs for Ek≤0.5 MeV and Xm≤1 from the loss cone αL to αc. For Ek≥1.0 MeV, such PSD drops become much smaller and confined in the lower pitch angles close to αL for each Xm. In contrast, electron PSD increases for Ek≤1.0 MeV above αc at L = 2.5 and 3.0, probably because momentum diffusion coefficients increase steeply above αc. The current results demonstrate that gyroresonance between plasmaspheric hiss and energetic electrons in the slot region is strongly associated with variations of peak wave normal angles, which should be integrated into future global modeling of radiation belt dynamics.

  20. 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.

  1. Temperature-mediated biotic interactions influence enemy release of nonnative species in warming environments.

    PubMed

    Fey, Samuel B; Herren, Cristina M

    2014-08-01

    "Enemy release" occurs when invading species suffer from interactions with pathogens, parasites, herbivores, or predators to a lesser degree than native species due to a lack of shared evolutionary history. Here we provide strong support for the hypothesis that variable thermal sensitivities between a consumer and its resources can generate temperature-dependent enemy release using both a mathematical model and a field experiment. We identify three common scenarios where changes in temperature should alter enemy release based on asymmetric responses among enemies and their resources to changes in temperature: (1) the vital rates of a shared enemy are more sensitive to changes in temperature than its resources, (2) the enemy's thermal maximum for consumption is higher than the resources' maxima for growth, and (3) the invading resource has a higher thermal maximum for growth than its native competitor. Mathematical representations indicated that warming is capable of altering enemy release in each of these three scenarios. We also tested our hypothesis using a mesocosm warming experiment in a system that exhibits variable thermal sensitivities between a predator and its native and nonnative prey. We conducted a six-week experiment manipulating the presence of Lepomis sunfish (present, absent) and water temperature (ambient, heated) using the nonnative crustacean zooplankter, Daphnia lumholtzi, whose morphological defenses reduce predation from juvenile sunfish relative to native Daphnia pulex. Our results indicate that D. lumholtzi benefited to a greater extent from the presence of Lepomis predators as temperatures increase. Taken together, our model and experiment indicate that changes in environmental temperature may directly influence the success of nonnative species and may assist with forecasting the community consequences of biological invasions in a warming world. PMID:25230475

  2. 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...

  3. Non-planar on-shell diagrams

    NASA Astrophysics Data System (ADS)

    Franco, Sebastián; Galloni, Daniele; Penante, Brenda; Wen, Congkao

    2015-06-01

    We initiate a systematic study of non-planar on-shell diagrams in SYM and develop powerful technology for doing so. We introduce canonical variables generalizing face variables, which make the d log form of the on-shell form explicit. We make significant progress towards a general classification of arbitrary on-shell diagrams by means of two classes of combinatorial objects: generalized matching and matroid polytopes. We propose a boundary measurement that connects general on-shell diagrams to the Grassmannian. Our proposal exhibits two important and non-trivial properties: positivity in the planar case and it matches the combinatorial description of the diagrams in terms of generalized matroid polytopes. Interestingly, non-planar diagrams exhibit novel phenomena, such as the emergence of constraints on Plücker coordinates beyond Plücker relations when deleting edges, which are neatly captured by the generalized matching and matroid polytopes. This behavior is tied to the existence of a new type of poles in the on-shell form at which combinations of Plücker coordinates vanish. Finally, we introduce a prescription, applicable beyond the MHV case, for writing the on-shell form as a function of minors directly from the graph.

  4. Surface charge of polymer coated SPIONs influences the serum protein adsorption, colloidal stability and subsequent cell interaction in vitro

    NASA Astrophysics Data System (ADS)

    Hirsch, Vera; Kinnear, Calum; Moniatte, Marc; Rothen-Rutishauser, Barbara; Clift, Martin J. D.; Fink, Alke

    2013-04-01

    It is known that the nanoparticle-cell interaction strongly depends on the physicochemical properties of the investigated particles. In addition, medium density and viscosity influence the colloidal behaviour of nanoparticles. Here, we show how nanoparticle-protein interactions are related to the particular physicochemical characteristics of the particles, such as their colloidal stability, and how this significantly influences the subsequent nanoparticle-cell interaction in vitro. Therefore, different surface charged superparamagnetic iron oxide nanoparticles were synthesized and characterized. Similar adsorbed protein profiles were identified following incubation in supplemented cell culture media, although cellular uptake varied significantly between the different particles. However, positively charged nanoparticles displayed a significantly lower colloidal stability than neutral and negatively charged particles while showing higher non-sedimentation driven cell-internalization in vitro without any significant cytotoxic effects. The results of this study strongly indicate therefore that an understanding of the aggregation state of NPs in biological fluids is crucial in regards to their biological interaction(s).It is known that the nanoparticle-cell interaction strongly depends on the physicochemical properties of the investigated particles. In addition, medium density and viscosity influence the colloidal behaviour of nanoparticles. Here, we show how nanoparticle-protein interactions are related to the particular physicochemical characteristics of the particles, such as their colloidal stability, and how this significantly influences the subsequent nanoparticle-cell interaction in vitro. Therefore, different surface charged superparamagnetic iron oxide nanoparticles were synthesized and characterized. Similar adsorbed protein profiles were identified following incubation in supplemented cell culture media, although cellular uptake varied significantly between

  5. 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.

  6. 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. PMID:27421400

  7. Influence of the anisotropic hyperfine interaction on the 14N ENDOR and the ESEEM orientation-disordered spectra.

    PubMed

    Benetis, Nikolas P; Dikanov, Sergei A

    2005-07-01

    The influence of the anisotropic hyperfine interaction on the 14N electron-nuclear double resonance/electron spin echo envelope modulation spectra is studied by approximate analytical and graphical methods for the case of the isotropic g-factor. The suggested determination of the modified characteristic directions of the magnetic field due to anisotropy enhances the insight in the structural details of the system and analytical solutions of the secular equation for these conditions are derived. The graphical method, previously used for the analysis of the orientation dependence of the 14N nuclear-transition frequencies in orientation-disordered samples for isotropic hyperfine interaction is extended to the case of arbitrary anisotropic hyperfine tensor. The above analytical and graphical methods are illustrated and tested against exact simulations in two practically important cases: (i) isotropic hyperfine interaction (hfi) exceeding other nuclear interactions in nuclear spin Hamiltonian. (ii) Cancellation of the isotropic part of the hfi. PMID:15878298

  8. Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

    PubMed Central

    Winiger, Christian B; Langenegger, Simon M; Khorev, Oleg

    2014-01-01

    Summary Aromatic π–π stacking interactions are ubiquitous in nature, medicinal chemistry and materials sciences. They play a crucial role in the stacking of nucleobases, thus stabilising the DNA double helix. The following paper describes a series of chimeric DNA–polycyclic aromatic hydrocarbon (PAH) hybrids. The PAH building blocks are electron-rich pyrene and electron-poor perylenediimide (PDI), and were incorporated into complementary DNA strands. The hybrids contain different numbers of pyrene–PDI interactions that were found to directly influence duplex stability. As the pyrene–PDI ratio approaches 1:1, the stability of the duplexes increases with an average value of 7.5 °C per pyrene–PDI supramolecular interaction indicating the importance of electrostatic complementarity for aromatic π–π stacking interactions. PMID:25161715

  9. Independent and Interactive Influences of the APOE Genotype and Beta-Amyloid Burden on Cognitive Function in Mild Cognitive Impairment

    PubMed Central

    2016-01-01

    This study aimed to investigate the independent and interactive influences of apolipoprotein E (APOE) ε4 and beta-amyloid (Aβ) on multiple cognitive domains in a large group of cognitively normal (CN) individuals and patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Participants were included if clinical and cognitive assessments, amyloid imaging, and APOE genotype were all available from the Alzheimer’s Disease Neuroimaging Initiative database (CN = 324, MCI = 502, AD = 182). Individuals with one or two copies of ε4 were designated as APOE ε4 carriers (ε4+); individuals with no ε4 were designated as APOE ε4 non-carriers (ε4−). Based on mean florbetapir standard uptake value ratios, participants were classified as Aβ burden-positive (Aβ+) or Aβ burden-negative (Aβ−). In MCI, APOE ε4 effects were predominantly observed on frontal executive function, with ε4+ participants exhibiting poorer performances; Aβ positivity had no influence on this effect. Aβ effects were observed on global cognition, memory, and visuospatial ability, with Aβ+ participants exhibiting poorer performances. Measures of frontal executive function were not influenced by Aβ. Interactive effects of APOE ε4+ and Aβ were observed on global cognition and verbal recognition memory. Aβ, not APOE ε4+, influenced clinical severity and functional status. The influences of APOE ε4+ and Aβ on cognitive function were minimal in CN and AD. In conclusion, we provide further evidence of both independent and interactive influences of APOE ε4+ and Aβ on cognitive function in MCI, with APOE ε4+ and Aβ showing dissociable effects on executive and non-executive functions, respectively. PMID:26839485

  10. 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…

  11. 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,…

  12. The Use of Computational Diagrams and Nomograms in Higher Education.

    ERIC Educational Resources Information Center

    Brandenburg, Richard K.; Simpson, William A.

    1984-01-01

    The use of computational diagrams and nomographs for the calculations that frequently occur in college administration is examined. Steps in constructing a nomograph and a four-dimensional computational diagram are detailed, and uses of three- and four-dimensional diagrams are covered. Diagrams and nomographs are useful in the following cases: (1)…

  13. 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...

  14. 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…

  15. 49 CFR 1152.10 - System diagram map.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 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...

  16. 49 CFR 1152.10 - System diagram map.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 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...

  17. 49 CFR 1152.10 - System diagram map.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 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...

  18. 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...

  19. Computationally useful bridge diagram series. II. Diagrams in h-bonds

    NASA Astrophysics Data System (ADS)

    Perkyns, John S.; Dyer, Kippi M.; Pettitt, B. Montgomery

    2002-06-01

    Equations for calculating accurate 4-point and 5-point bridge diagrams in terms of h-bonds have been presented and solved for various phase points of the Lennard-Jones fluid. A method of finding a self-consistent solution for the bridge function and the radial distribution function is demonstrated. The significance of this result over bridge diagrams expressed as f-bonds, in terms of its applicability to charged and dipolar models is discussed. Two very simple phenomenological bridge diagram forms for the bridge function for this model are examined and found to give results almost as accurate and in some cases more accurate than previous forms in the literature. This work represents the first use of directly calculated 5-point bridge diagrams in terms of h-bonds, and the many extra orders of f-bond diagrams which they include, in an integral equation result.

  20. Computationally Useful Bridge Diagram Series. II. Diagrams in H-Bonds

    SciTech Connect

    Perkyns, John S.; Dyer, Kippi M.; Pettitt, Bernard M.

    2002-06-01

    Equations for calculating accurate 4-point and 5-point bridge diagrams in terms of h-bonds have been presented and solved for various phase points of the Lennard-Jones fluid. A method of finding a self-consistent solution for the bridge function and the radial distribution function is demonstrated. The significance of this result over bridge diagrams expressed as f-bonds, in terms of its applicability to charged and dipolar models is discussed. Two very simple phenomenological bridge diagram forms for the bridge function for this model are examined and found to give results almost as accurate and in some cases more accurate than previous forms in the literature. This work represents the first use of directly calculated 5-point bridge diagrams in terms of h-bonds, and the many extra orders of f-bond diagrams which they include, in an integral equation result.

  1. The renormalon diagram in gauge theories on

    NASA Astrophysics Data System (ADS)

    Anber, Mohamed M.; Sulejmanpasic, Tin

    2015-01-01

    We analyze the renormalon diagram of gauge theories on . In particular, we perform exact one loop calculations for the vacuum polarization in QCD with adjoint matter and observe that all infrared logarithms, as functions of the external momentum, cancel between the vacuum part and finite volume part, which eliminates the IR renormalon problem. We argue that the singularities in the Borel plane, arising from the topological neutral bions, are not associated with the renormalon diagram, but with the proliferation of the Feynman diagrams. As a byproduct, we obtain, for the first time, an exact one-loop result of the vacuum polarization which can be adapted to the case of thermal compactification of QCD.

  2. 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.

  3. Minkowski diagram in relativity and holography.

    PubMed

    Abramson, N

    1988-05-01

    Now that ultrashort laser pulses can be used in holography, the temporal and spatial resolution approach the same order of magnitude. In that case the limited speed of light sometimes causes large measuring errors if correction methods are not introduced. Therefore, we want to revive the Minkowski diagram, which was invented in 1908 to visualize relativistic relations between time and space. We show how this diagram in a modified form can be used to derive both the static holodiagram, used for conventional holography, including ultrahigh-speed recordings of wavefronts, and a dynamic holodiagram used for studying the apparent distortions of objects recorded at relativistic speeds. PMID:20531662

  4. B-Fe-U Phase Diagram

    NASA Astrophysics Data System (ADS)

    Dias, Marta; Carvalho, Patrícia Almeida; Mardolcar, Umesh Vinaica; Tougait, Olivier; Noël, Henri; Gonçalves, António Pereira

    2014-04-01

    The liquidus projection of the U-rich corner of the B-Fe-U phase diagram is proposed based on X-ray powder diffraction measurements, differential thermal analysis, and scanning electron microscopy observations complemented with energy- and wavelength-dispersive X-ray spectroscopies. Two ternary reactions in this U-rich region were observed and their approximate temperatures were established. In addition, an overview of the complete phase diagram is given, including the liquidus projection; isothermal sections at 1053 K, 1223 K, and 1373 K (780 °C, 950 °C, and 1100 °C); and a U:(Fe,B) = 1:5 isopleth.

  5. Maternal rank influences the outcome of aggressive interactions between immature chimpanzees

    PubMed Central

    Markham, A. Catherine; Lonsdorf, Elizabeth V.; Pusey, Anne E.; Murray, Carson M.

    2015-01-01

    For many long-lived mammalian species, extended maternal investment has a profound effect on offspring integration in complex social environments. One component of this investment may be aiding young in aggressive interactions, which can set the stage for offspring social position later in life. Here we examined maternal effects on dyadic aggressive interactions between immature (<12 years) chimpanzees. Specifically, we tested whether relative maternal rank predicted the probability of winning an aggressive interaction. We also examined maternal responses to aggressive interactions to determine whether maternal interventions explain interaction outcomes. Using a 12-year behavioural data set (2000–2011) from Gombe National Park, Tanzania, we found that relative maternal rank predicted the probability of winning aggressive interactions in male–male and male–female aggressive interactions: offspring were more likely to win if their mother outranked their opponent’s mother. Female–female aggressive interactions occurred infrequently (two interactions), so could not be analysed. The probability of winning was also higher for relatively older individuals in male–male interactions, and for males in male–female interactions. Maternal interventions were rare (7.3% of 137 interactions), suggesting that direct involvement does not explain the outcome for the vast majority of aggressive interactions. These findings provide important insight into the ontogeny of aggressive behaviour and early dominance relationships in wild apes and highlight a potential social advantage for offspring of higher-ranking mothers. This advantage may be particularly pronounced for sons, given male philopatry in chimpanzees and the potential for social status early in life to translate more directly to adult rank. PMID:25624528

  6. 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. PMID:27154839

  7. Influence of electrostatic interactions on the morphology and properties of blends containing perfluorinated ionomers

    NASA Astrophysics Data System (ADS)

    Taylor, Eric Paul

    2002-01-01

    The first goal of this research project was to investigate the influence of the electrostatic interactions within the ion-containing domains of Nafion RTM perfluorosulfonate ionomer (PFSI) on the morphology and resultant properties of blend systems with poly(propylene imine) dendrimers of a variety of generational sizes and poly(vinylidene fluoride) (PVDF). Perfluorosulfonate ionomers (PFSIs) are a commercially successful class of semi-crystalline, ion-containing polymers whose most extensive application is in use as a polymer electrolytic membrane in fuel cell applications. NafionRTM was blended and high temperature solution processed with poly(propylene imine) dendrimer as the minor component in order to increase the efficiency of direct methanol fuel cells by decreasing methanol crossover without significant loss of protonic conductivity. The preferential insertion of the dendrimer into the ionic cluster due to proton transfer reactions and the creation of ammonium-sulfonate ion pairs served to alter the transport properties through the ionic network of the membrane. In the second major system investigated, blends of poly(vinylidene fluoride) (PVDF) with NafionRTM, a perfluorosulfonate ionomer, have been prepared and examined in terms of the crystallization kinetics and crystal morphology of the PVDF component in the blend. DSC analysis showed faster rates of bulk crystallization when PVDF was crystallized in the presence of Na+-form NafionRTM suggesting a high degree of phaseseparation in this blend system and an increase in the nucleation density. NafionRTM neutralized with alkylammonium-form counterions display an increase in blend compatibility with PVDF with an increase in the alkylammonium counterion size. As the alkylammonium counterion size increases, the strength of the electrostatic network within the ionic domains of Nafion RTM decrease resulting in a reduction in the driving force for ionic aggregation. Thus, a decrease is observed in the crystal

  8. 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

  9. Estimating peak and solidification temperatures for anatectic pelitic migmatites using phase diagrams: sampling heterogeneous migmatites and confronting melt loss

    NASA Astrophysics Data System (ADS)

    Hamilton, Brett M.; Pattison, David R. M.

    2016-04-01

    Calculating a pressure-temperature phase diagram relevant to an anatectic pelitic migmatite sampled in outcrop is challenging because it is unclear what constitutes a meaningful bulk composition. Melt loss during metamorphism may have changed the bulk composition. The heterogeneous nature of migmatites, with light and dark coloured domains (leucosome and melanosome), means a choice must be made regarding how a migmatitic outcrop should be sampled. To address these issues, migmatites were simulated using thermodynamic modelling techniques for different melting and crystallization scenarios and bulk compositions. Using phase diagrams calculated for varying proportions of simulated melanosome and leucosome, temperatures of interest were estimated and compared with known values. Our modelling suggests: (1) It is generally possible to constrain the peak temperature using phase diagrams calculated with the composition of the melanosome; the more leucosome that is incorporated, the more innaccurate the estimate. For phase diagrams calculated using a combination of leucosome and melanosome material, peak temperature estimates differ from actual peak conditions by ‑25 to +50°C. In certain of these cases, such as those involving high proportions of leucosome to melanosome, or in which solid K-feldspar was absent at peak conditions, but is now present in the rock due to later crystallization from melt, it is not possible to estimate peak temperature. (2) The solidification temperature, whether due to crystallization of the last melt or physical loss of the melt during crystallization, will fall between the peak temperature and the water-saturated solidus (~660°C) if the melt and solids chemically interacted during cooling. This temperature can be accurately constrained from the phase diagram. If the melt crystallized in chemical isolation from the melanosome, the solidification temperature is the water-saturated solidus (625-645°C); however, physical melt loss during

  10. Thermodynamic modeling of the UO2-ThO2 phase diagram

    NASA Astrophysics Data System (ADS)

    Kim, Jinwon; Kim, Sung S.

    2016-02-01

    The phase diagram in the UO2-ThO2 system has been assessed by thermodynamic modeling with existing data from the literature. The subregular solution model was used to represent the Gibbs free energies of the liquid and the solid phases. By considering the liquidus, solidus and miscibility gap data, the interaction parameters of the liquid and the solid phases were optimized through a multiple linear regression method. A consistent set of interaction parameters were derived for describing the miscibility gap as well as the liquidus/solidus. The phase diagram calculated in the present work is in good agreement with experimental data in the literature.

  11. Influence of momentum dependent interactions on the fragment structures at balance energies

    NASA Astrophysics Data System (ADS)

    Chugh, Rajiv; Kumar, Rohit

    2016-05-01

    We study the role of momentum-dependent interactions on fragment structures at balance energies for semi-peripheral collisions over a wide range of system masses using quantum molecular dynamics (QMD) model. We find a meagre role of momentum-dependent interactions for fragments in case of lighter system masses. But as we go towards higher system masses, the effect of momentum-dependent interactions increases for free nucleons, light charged particles and intermediate mass fragments at corresponding balance energies.

  12. On the influence of a high-frequency electric field on the exchange interaction in magnetic crystals

    NASA Astrophysics Data System (ADS)

    Gladkov, S. O.

    1992-03-01

    It is shown that the presence of a high-frequency electric field E( t) strongly influences the exchange interaction magnitude Jex. It is noted that due to this circumstance the liquid crystallization temperature or the phase transition temperature in magnetic substances can be changed, by varying the frequency ω and the amplitude of the external electric field E0. The dependence Jex(ω, E0) is determined.

  13. Influence of the solvent on the interaction of phenyl isocyanate with proton donors, catalyzed by copper(II) acetylacetonate

    SciTech Connect

    Bakalo, L.A.; Rakhlevskii, L.V.

    1987-09-01

    The influence of the medium on the noncatalytic and copper(II)-acetylacetonate-catalyzed interaction of phenyl isocyanate with n-butanol under conditions of an excess of isocyanate was investigated. It was shown that the product of superequimolar conversion of isocyanate is n-butyl-..cap alpha.., ..gamma..-diphenylallophanate. The kinetic and thermodynamic peculiarities of the process of formation of urethane and allophanate in various solvents are discussed.

  14. 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.

  15. Global phase diagram of a doped Kitaev-Heisenberg model

    SciTech Connect

    Okamoto, Satoshi

    2013-01-01

    The global phase diagram of a doped Kitaev-Heisenberg model is studied using an $SU(2)$ slave-boson mean-field method. Near the Kitaev limit, $p$-wave superconducting states which break the time-reversal symmetry are stabilized as reported by You {\\it et al.} [Phys. Rev. B {\\bf 86}, 085145 (2012)] irrespective of the sign of the Kitaev interaction. By further doping, a $d$-wave superconducting state appears when the Kitaev interaction is antiferromagnetic, while another $p$-wave superconducting state appears when the Kitaev interaction is ferromagnetic. This $p$-wave superconducting state does not break the time-reversal symmetry as reported by Hyart {\\it et al.} [Phys. Rev. B {\\bf 85}, 140510 (2012)], and such a superconducting state also appears when the antiferromagnetic Kitaev interaction and the ferromagnetic Heisenberg interaction compete. This work, thus, demonstrates the clear difference between the antiferromagnetic Kitaev model and the ferromagnetic Kitaev model when carriers are doped while these models are equivalent in the undoped limit, and how novel superconducting states emerge when the Kitaev interaction and the Heisenberg interaction compete.

  16. Individual differences in boldness influence patterns of social interactions and the transmission of cuticular bacteria among group-mates.

    PubMed

    Keiser, Carl N; Pinter-Wollman, Noa; Augustine, David A; Ziemba, Michael J; Hao, Lingran; Lawrence, Jeffrey G; Pruitt, Jonathan N

    2016-04-27

    Despite the importance of host attributes for the likelihood of associated microbial transmission, individual variation is seldom considered in studies of wildlife disease. Here, we test the influence of host phenotypes on social network structure and the likelihood of cuticular bacterial transmission from exposed individuals to susceptible group-mates using female social spiders (Stegodyphus dumicola). Based on the interactions of resting individuals of known behavioural types, we assessed whether individuals assorted according to their behavioural traits. We found that individuals preferentially interacted with individuals of unlike behavioural phenotypes. We next applied a green fluorescent protein-transformed cuticular bacterium,Pantoeasp., to individuals and allowed them to interact with an unexposed colony-mate for 24 h. We found evidence for transmission of bacteria in 55% of cases. The likelihood of transmission was influenced jointly by the behavioural phenotypes of both the exposed and susceptible individuals: transmission was more likely when exposed spiders exhibited higher 'boldness' relative to their colony-mate, and when unexposed individuals were in better body condition. Indirect transmission via shared silk took place in only 15% of cases. Thus, bodily contact appears key to transmission in this system. These data represent a fundamental step towards understanding how individual traits influence larger-scale social and epidemiological dynamics. PMID:27097926

  17. 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.

  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. PMID:27277404

  19. Brownian dynamics study of the influences of electrostatic interaction and diffusion on protein-protein association kinetics.

    PubMed Central

    Zhou, H X

    1993-01-01

    A unified model is presented for protein-protein association processes that are under the influences of electrostatic interaction and diffusion (e.g., protein oligomerization, enzyme catalysis, electron and energy transfer). The proteins are modeled as spheres that bear point charges and undergo translational and rotational Brownian motion. Before association can occur the two spheres have to be aligned properly to form a reaction complex via diffusion. The reaction complex can either go on to form the product or it can dissociate into the separate reactants through diffusion. The electrostatic interaction, like diffusion, influences every step except the one that brings the reaction complex into the product. The interaction potential is obtained by extending the Kirkwood-Tanford protein model (Tanford, C., and J. G. Kirkwood. 1957. J. Am. Chem. Soc. 79:5333-5339) to two charge-embedded spheres and solving the consequent equations under a particular basis set. The time-dependent association rate coefficient is then obtained through Brownian dynamics simulations according an algorithm developed earlier (Zhou, H.-X. 1990. J. Phys. Chem. 94:8794-8800). This method is applied to a model system of the cytochrome c and cytochrome c peroxidase association process and the results confirm the experimental dependence of the association rate constant on the solution ionic strength. An important conclusion drawn from this study is that when the product is formed by very specific alignment of the reactants, as is often the case, the effect of the interaction potential is simply to scale the association rate constant by a Boltzmann factor. This explains why mutations in the interface of the reaction complex have strong influences on the association rate constant whereas those away from the interface have minimal effects. It comes about because the former mutations change the interaction potential of the reaction complex significantly and the latter ones do not. PMID:8396447

  20. Lack of Influence of Substrate on Ligand Interaction with the Human Multidrug and Toxin Extruder, MATE1.

    PubMed

    Martínez-Guerrero, Lucy J; Morales, Mark; Ekins, Sean; Wright, Stephen H

    2016-09-01

    Multidrug and toxin extruder (MATE) 1 plays a central role in mediating renal secretion of organic cations, a structurally diverse collection of compounds that includes ∼40% of prescribed drugs. Because inhibition of transport activity of other multidrug transporters, including the organic cation transporter (OCT) 2, is influenced by the structure of the transported substrate, the present study screened over 400 drugs as inhibitors of the MATE1-mediated transport of four structurally distinct organic cation substrates: the commonly used drugs: 1) metformin and 2) cimetidine; and two prototypic cationic substrates, 3) 1-methyl-4-phenylpyridinium (MPP), and 4) the novel fluorescent probe, N,N,N-trimethyl-2-[methyl(7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)amino]ethanaminium iodide. Transport was measured in Chinese hamster ovary cells that stably expressed the human ortholog of MATE1. Comparison of the resulting inhibition profiles revealed no systematic influence of substrate structure on inhibitory efficacy. Similarly, IC50 values for 26 structurally diverse compounds revealed no significant influence of substrate structure on the kinetic interaction of inhibitor with MATE1. The IC50 data were used to generate three-dimensional quantitative pharmacophores that identified hydrophobic regions, H-bond acceptor sites, and an ionizable (cationic) feature as key determinants for ligand binding to MATE1. In summary, in contrast to the behavior observed with some other multidrug transporters, including OCT2, the results suggest that substrate identity exerts comparatively little influence on ligand interaction with MATE1. PMID:27418674

  1. 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

  2. The Influence of National Culture toward Learner Interaction: Shanghai TV University and Wawasan Open University

    ERIC Educational Resources Information Center

    Bing, Wu; Ai-Ping, Teoh

    2008-01-01

    The authors conducted a comparative analysis to examine learners' interaction in the Web-based learning environment of 2 distance education institutions. The interaction was critically analyzed based on social, procedural, expository, explanatory, and cognitive dimensions, across 7 categories of exchanges between course coordinator to groups,…

  3. The Influence of Social Interaction on Meaning Construction in a Virtual Community

    ERIC Educational Resources Information Center

    Yang, Yu-Fen; Yeh, Hui-Chin; Wong, Wing-Kwong

    2010-01-01

    As proposed by social constructive theorists, meaningful learning and individual development were achieved through social interaction. To foster social interaction among students, this study formed an online learning community in which they played multiple roles as writers, editors and commentators. In playing different roles, they read peers'…

  4. NFHS Court and Field Diagram Guide.

    ERIC Educational Resources Information Center

    Gillis, John, Ed.

    This guide contains a comprehensive collection of diagrams and specifications of playing fields and courts used in interscholastic and recreational sports, along with information on how to set up various formats of tournament drawings, how to compute golf handicaps, and how to convert metric-to-English distances. Lists are provided of national…

  5. Journeys on the H-R diagram

    SciTech Connect

    Kaler, J.B.

    1988-05-01

    The evolution of various types of stars along the H-R diagram is discussed. Star birth and youth is addressed, and the events that occur due to core contraction, shell burning, and double-shell burning are described. The evolutionary courses of planetary nebulae, white dwarfs, and supernovas are examined.

  6. 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.

  7. 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…

  8. 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,…

  9. 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)

  10. 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.

  11. 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)

  12. Constructing Causal Diagrams to Learn Deliberation

    ERIC Educational Resources Information Center

    Easterday, Matthew W.; Aleven, Vincent; Scheines, Richard; Carver, Sharon M.

    2009-01-01

    Policy problems like "What should we do about global warming?" are ill-defined in large part because we do not agree on a system to represent them the way we agree Algebra problems should be represented by equations. As a first step toward building a policy deliberation tutor, we investigated: (a) whether causal diagrams help students learn to…

  13. Fine structure of the butterfly diagram revisited

    NASA Astrophysics Data System (ADS)

    Major, Balázs

    The latitudinal time distribution of sunspots (butterfly diagram) was studied by Becker (1959) and Antalová & Gnevyshev (1985). Our goal is to revisit these studies. In the first case we check whether there is a poleward migration in sunspot activity. In the second case we confirm the results, and make more quantitative statements concerning their significance and the position of the activity peaks.

  14. 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

  15. 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…

  16. Electrostatic Interactions Between the Bni1p Formin FH2 Domain and Actin Influence Actin Filament Nucleation

    PubMed Central

    Baker, Joseph L.; Courtemanche, Naomi; Parton, Daniel L.; McCullagh, Martin; Pollard, Thomas D.; Voth, Gregory A.

    2014-01-01

    SUMMARY Formins catalyze nucleation and growth of actin filaments. Here we study the structure and interactions of actin with the FH2 domain of budding yeast formin Bni1p. We built an all-atom model of the formin dimer on an Oda actin filament 7-mer and studied structural relaxation and inter-protein interactions by molecular dynamics simulations. These simulations produced a refined model for the FH2 dimer associated with the barbed end of the filament and revealed electrostatic interactions between the formin knob and actin target-binding cleft. Mutations of two formin residues contributing to these interactions (R1423N, K1467L or both) reduced the interaction energies between the proteins, and in coarse-grained simulations the formin lost more inter-protein contacts with an actin dimer than with an actin 7-mer. Biochemical experiments confirmed a strong influence of these mutations on Bni1p-mediated actin filament nucleation, but not elongation, suggesting that different interactions contribute to these two functions of formins. PMID:25482541

  17. 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.

  18. 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.

  19. 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. PMID:25253636

  20. The Binding of Antigenic Peptides to HLA-DR Is Influenced by Interactions between Pocket 6 and Pocket 91

    PubMed Central

    James, Eddie A.; Moustakas, Antonis K.; Bui, John; Nouv, Randi; Papadopoulos, George K.; Kwok, William W.

    2013-01-01

    Peptide binding to class II MHC protein is commonly viewed as a combination of discrete anchor residue preferences for pockets 1, 4, 6/7, and 9. However, previous studies have suggested cooperative effects during the peptide binding process. Investigation of the DRB1*0901 binding motif demonstrated a clear interaction between peptide binding pockets 6 and 9. In agreement with prior studies, pockets 1 and 4 exhibited clear binding preferences. Previously uncharacterized pockets 6 and 7 accommodated a wide variety of residues. However, although it was previously reported that pocket 9 is completely permissive, several substitutions at this position were unable to bind. Structural modeling revealed a probable interaction between pockets 6 and 9 through β9Lys. Additional binding studies with doubly substituted peptides confirmed that the amino acid bound within pocket 6 profoundly influences the binding preferences for pocket 9 of DRB1*0901, causing complete permissiveness of pocket 9 when a small polar residue is anchored in pocket 6 but accepting relatively few residues when a basic residue is anchored in pocket 6. The β9Lys residue is unique to DR9 alleles. However, similar studies with doubly substituted peptides confirmed an analogous interaction effect for DRA1/B1*0301, a β9Glu allele. Accounting for this interaction resulted in improved epitope prediction. These findings provide a structural explanation for observations that an amino acid in one pocket can influence binding elsewhere in the MHC class II peptide binding groove. PMID:19648278

  1. COMT Val158Met polymorphism interacts with stressful life events and parental warmth to influence decision making

    PubMed Central

    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 Val158Met 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. PMID:22997551

  2. Upstream-influence scaling of fin-generated shock wave boundary-layer interactions

    NASA Technical Reports Server (NTRS)

    Lu, Frank K.; Settles, Gary S.

    1990-01-01

    An upstream-influence scaling law, previously formulated through analysis of Mach 3 data, has been extended to Mach numbers from 2.5 through 4. For adiabatic, equilibrium, turbulent boundary layers, there is no Mach number effect on the constants in the Reynolds number parameters of this law. In addition, based on local similarity, a new Mach number parameter, namely, the Mach number component of the incoming stream normal to the farfield upstream influence, is proposed. Scaling by either the incoming Mach number normal to the inviscid shock or by the incoming Mach number normal to the farfield upstream influence is equivalent to scaling by the hypersonic similarity parameter.

  3. Impersonal parameters from Hertzsprung-Russell diagrams

    NASA Astrophysics Data System (ADS)

    Wilson, R. E.; Hurley, Jarrod R.

    2003-10-01

    An objective process for estimation of star cluster parameters from Hertzsprung-Russell (HR) diagrams is introduced, with direct inclusion of multiple stars, a least-squares fitting criterion, and standard error estimates. No role is played by conventional isochrones. Instead the quantity compared between observation and theory is the density of points (areal ) as it varies over the diagram. With as the effective observable quantity, standard parameter adjustment theory can be brought to bear on HR diagram analysis. Here we use the method of differential corrections with a least-squares fitting criterion, but any of the many known fitting methods should be applicable to comparison of observed and theoretical distributions. Diverse numerical schemes were developed to make the overall algorithm workable, including two that improve differentiability of by rendering point distributions effectively equivalent to continuous distributions in certain respects. Statistics of distributions are handled not via Monte Carlo methods but by the Functional Statistics Algorithm (hereafter FSA), a statistical algorithm that has been developed for HR diagram fitting but should serve as an alternative to Monte Carlo in many other applications. FSA accomplishes the aims of Monte Carlo with orders of magnitude less computation. Analysis of luminosity functions is included within the HR diagram algorithm as a special case. Areal density analysis of HR diagrams is acceptably fast because we handle stellar evolution via approximation functions, whose output also is more precisely differentiable than that of a full stellar evolution program. Evolution by approximation functions is roughly a million times as fast as full evolution and has virtually no numerical noise. The algorithmic ideas that lead to objective solutions can be applied to many kinds of HR diagram analysis that are now done subjectively. The present solution program is limited by speed considerations to use of one evolution

  4. 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. PMID:25751047

  5. Influence of long-range interactions on the critical behavior of systems with a negative Fisher exponent

    NASA Astrophysics Data System (ADS)

    Janssen, H. K.

    1998-09-01

    The influence of long-range interactions decaying in d dimensions as 1/Rd+σ on the critical behavior of systems with negativeFisher's correlation-function exponent for short-range interactions, ηSR<0, is reexamined. Such systems, typically described by φ3-field theories, are, e.g., the Potts model in the percolation limit, the Edwards-Anderson spin-glass model, and the Yang-Lee edge singularity. In contrast to preceding studies, it is shown by means of Wilson's momentum-shell renormalization-group recursion relations that the long-range interactions dominate as long as σ<2-ηSR. Exponents change continuously to their short-range values at the boundary of this region.

  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. Genetic basis for genotype-environment interactions influencing flavonoid gene expression in Capsicum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorophylls, carotenoids, flavonoids and betalains contribute to color in economically important vegetables, fruits and floral crops. The flavonoids can be subdivided into anthocyanins and co-pigments. Anthocyanin production is markedly influenced by numerous environmental factors including tempe...

  8. Graphical Synthesis of Colloid Transport Results on Quirk-Schofield Diagrams

    NASA Astrophysics Data System (ADS)

    Mays, D. C.

    2008-05-01

    The degree of colloid dispersion, or conversely the degree of flocculation, is crucial for understanding colloid transport in natural porous media, since it determines whether colloids are mobile or immobile. Additionally, in porous media containing more than a few percent fines, the degree of colloid dispersion also influences the permeability, and consequently the practicality of fluid extraction or injection. Colloid dispersion is largely determined by the aqueous chemistry, specifically pH, ionic strength, and sodium adsorption ratio (SAR). In the soil science literature, the effects of these three variables on colloid dispersion are commonly illustrated on Quirk-Schofield diagrams. In contrast, Quirk-Schofield diagrams appear to have been overlooked in the contaminant hydrology literature. This presentation will demonstrate the usefulness of Quirk-Schofield diagrams for presenting and interpreting a diversity of published colloid transport results, ranging from microbial pathogens to engineered nanoparticles to colloid-facilitated transport of metals. In particular, a quantitative analysis of published findings is presented using new Quirk-Schofield diagrams for kaolinite, illite, and montmorillonite, three clay minerals that are common in natural porous media. Additionally, because there is a relationship between colloid dispersion and permeability, this presentation will also show how Quirk-Schofield diagrams can provide insight into permeability changes, with applications to aquifer hydraulics and reservoir damage. The common aspects of all these results will be apparent, demonstrating that Quirk-Schofield diagrams are a simple, graphical technique that can be used to synthesize findings across the diverse applications where colloids play a central role. This study also suggests a framework for consistent reporting of colloid transport results: (1) measure the effects of pH, ionic strength, and SAR on colloid dispersion; (2) report results on Quirk

  9. 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.

  10. Influence of salt bridge interactions on the gas-phase stability of DNA/peptide complexes

    NASA Astrophysics Data System (ADS)

    Alves, Sandra; Woods, Amina; Delvolvé, Alice; Tabet, Jean Claude

    2008-12-01

    Negative ion mode electrospray ionization mass spectrometry was used to study DNA duplexes-peptide interaction. In the present study, we show that peptides that contain two adjacent basic residues interact noncovalently with DNA single strand or duplex. Fragmentation of the complexes between peptides containing basic residues and DNA were studied under collisions and showed unexpected dissociation pathways, as previously reported for peptide-peptide interactions. The binary complexes are dissociated either along fragmentation of the covalent bonds of the peptide backbone and/or along the single DNA strand backbone cleavage without disruption of noncovalent interaction, which demonstrates the strong binding of peptide to the DNA strand. Sequential MS/MS and MSn were further performed on ternary complexes formed between duplexes and peptides to investigate the nature of interaction. The CID spectra showed as major pathway the disruption of the noncovalent interactions and the formation of binary complexes and single-strand ions, directed by the nucleic acid gas-phase acidity. Indeed, a preferential formation of complexes with thymidine containing single strands is observed. An alternative pathway is also detected, in which complexes are dissociated along the covalent bond of the peptide and/or DNA according to the basicity. Our experimental data suggest the presence of strong salt bridge interactions between DNA and peptides containing basic residues.

  11. 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. PMID:25660708

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Effects of aspect ratio on the phase diagram of spheroidal particles

    NASA Astrophysics Data System (ADS)

    Kutlu, Songul; Haaga, Jason; Rickman, Jeffrey; Gunton, James

    Ellipsoidal particles occur in both colloidal and protein science. Models of protein phase transitions based on interacting spheroidal particles can often be more realistic than those based on spherical molecules. One of the interesting questions is how the aspect ratio of spheroidal particles affects the phase diagram. Some results have been obtained in an earlier study by Odriozola (J. Chem. Phys. 136:134505 (2012)). In this poster we present results for the phase diagram of hard spheroids interacting via a quasi-square-well potential, for different aspect ratios. These results are obtained from Monte Carlo simulations using the replica exchange method. We find that the phase diagram, including the crystal phase transition, is sensitive to the choice of aspect ratio. G. Harold and Leila Y. Mathers Foundation.

  17. Search the Foot and Ankle: Interactive Foot Diagram

    MedlinePlus

    ... Text Size Print Bookmark Search the Foot and Ankle Foot conditions in this region: Bunions (Hallux Valgus) » ... Injuries » Posterior Tibial Tendon Dysfunction (PTTD) » Tarsal Coalition » Ankle Fractures » Ankle Sprain » Chronic Ankle Instability » Equinus » Gout » ...

  18. NITROGEN: DEFINING LIMITS TO ECOSYSTEM RESTORATION; THE INFLUENCE OF SUCCESSION AND TROPHIC INTERACTIONS

    EPA Science Inventory

    A goal of this research is to investigate the interacting characteristics of biota and abiotic conditions relative to nitrogen cycling in the ecosystem. The research will support development of nitrogen cycling models with an ultimate application directed towards identification ...

  19. The influence of strong field vacuum polarization on gravitational-electromagnetic wave interaction

    NASA Astrophysics Data System (ADS)

    Papadopoulos, D.

    2012-01-01

    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 quantum electrodynamical (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.

  20. 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.

  1. Stellar evolution at low metallicity under the influence of binary interaction and rotation

    NASA Astrophysics Data System (ADS)

    de Mink, S. E.

    2010-04-01

    The chapters of this thesis have been published in the following journals. Ch. 2: "Fluorine in carbon-enhanced metal-poor stars: a binary scenario", Astronomy and Astrophysics Letters, 484, 27, 2008, M. Lugaro, S.E. de Mink, R.G. Izzard, S.W. Campbell, A. I. Karakas, S. Cristallo, O.R. Pols, J.C. Lattanzio, O. Straniero, R. Gallino, and T.C. Beers Ch. 3: "Efficiency of mass transfer in massive close binaries. Tests from double-lined eclipsing binaries in the SMC", Astronomy and Astrophysics, 467, 1181, 2007, S.E. de Mink, O.R. Pols, and R.W. Hilditch Ch. 4: "Rotational mixing in massive binaries: detached short-period systems", Astronomy and Astrophysics 497, 243, 2009, S.E. de Mink, M. Cantiello, N. Langer and O.R. Pols, I. Brott and S.-Ch Yoon Ch. 5: "Massive binaries as the source of globular cluster abundance patterns", Astronomy and Astrophysics Letters, 507, 1, 2009, S.E. de Mink, O.R. Pols, N. Langer, R.G. Izzard Ch. 6: "The Effect of Stellar Rotation on Colour-Magnitude Diagrams: On the apparent presence of multiple populations in intermediate age stellar clusters", Monthly Notices of the Royal Astronomical Society Letters 398, 11, 2009, N. Bastian and S.E. de Mink Ch. 7: "The evolution of runaway stellar collision products", Astronomy and Astrophysics, 497, 255, 2009. E. Glebbeek, E. Gaburov, S.E. de Mink, O.R. Pols, and S.F. Portegies Zwart

  2. 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.

  3. Linking the Budyko framework and the Dunne diagram

    NASA Astrophysics Data System (ADS)

    Trancoso, Ralph; Larsen, Joshua R.; McAlpine, Clive; McVicar, Tim R.; Phinn, Stuart

    2016-04-01

    The spatial and temporal heterogeneity of climate, soils, topography and vegetation control the water and energy balances among catchments. Two well-known hydrological theories underpinning these processes are the Budyko framework and the Dunne diagram. Relating the scaling of water-energy balances (Budyko) and runoff generation mechanisms (Dunne) raises some important catchment comparison questions, namely: (i) how do streamflow characteristics vary according to the annual water and energy balances?; (ii) to what extent do biophysical drivers of runoff explain the observed streamflow variability?; and (iii) are there quantifiable process overlaps between these two approaches, and can they offer insights into the mechanics of catchment co-evolution? This study addresses these questions by analysing daily streamflow and precipitation time series data to quantify hydrological similarity across 355 catchments located along a tropical-temperate climatic gradient in eastern Australia. We used eight hydrological metrics to describe the hydrological response over a 33-year period (1980-2013). Hierarchical cluster, ordination analysis, the Budyko framework, and generalized additive models were used to evaluate hydrological similarity, extract the dominant response, and examine how the landscape and climatic characteristics of catchments influence the dominant streamflow response. The catchments were classified into five clusters based on the analysis of their hydrological characteristics and similarity, which vary along the annual water and energy balances gradient in the Budyko framework. Furthermore, we show that the streamflow similarity is explained by six catchment-specific biophysical factors that overlap with those described by the Dunne diagram for runoff generation, which in this case have the following order of relative importance: (i) Dryness Index; (ii) Fraction of Photosynthetically Active Radiation; (iii) Saturated Hydraulic Conductivity; (iv) Soil Depth; (v

  4. 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…

  5. Influence of cations on noncovalent interactions between 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and dissolved fulvic and humic acids.

    PubMed

    Gadad, Praveen; Nanny, Mark A

    2008-12-01

    The influence of cations (Na(+), Ca(2+) and Mg(2+)) on noncovalent interactions between 6-propionyl-2-dimethylaminonaphthalene (PRODAN) and dissolved fulvic acids (FAs) (Norman landfill leachate fulvic acid (NLFA) and Suwannee River fulvic acid (SRFA)) and dissolved humic acids (HAs) (Suwannee River humic acid (SRHA) and Leonardite humic acid (LHA)) was examined using steady-state fluorescence spectroscopy at pH 4, 7 and 10 as a function of cation concentration (up to 25-100mM). Regardless of pH and cation concentration, PRODAN quenching by FA was unaffected by cations. However, interactions between PRODAN and HA decreased in the presence of cations at pH 7 and 10. Cation concentrations below the HA charge density resulted in the greatest decrease of PRODAN quenching, while very little additional decrease in PRODAN quenching occurred at cation concentrations above the HA charge density. This suggests that as the HA carboxylic acid functional groups form inner sphere complexes with divalent cations, intramolecular interactions result in a contraction of the HA molecular structure, thereby preventing PRODAN from associating with the condensed aromatic, electron accepting moieties inherent within HA molecules and responsible for PRODAN quenching. However, once the HA carboxylic acid functional groups are fully titrated with divalent cations, PRODAN quenching is no longer significantly influenced by the further addition of cations, even though these additional cations facilitate intermolecular interactions between the HA molecules to form supramolecular HA aggregates that can continue to increase in size. Regardless of FA and HA type, pH, cation type and concentration, the lack of blue-shifted fluorescence emission spectra indicated that micelle-like hydrophobic regions, amenable to PRODAN partitioning, were not formed by intra- and intermolecular interactions of FA and HA. PMID:18849058

  6. 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. PMID:23981229

  7. Interactions Between Bacteria and the Gut Mucosa: Do Enteric Neurotransmitters Acting on the Mucosal Epithelium Influence Intestinal Colonization or Infection?

    PubMed

    Green, Benedict T; Brown, David R

    2016-01-01

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include enteric neurons, whose activity is influenced by bacterial pathogens, and their secreted products. Neurotransmitters appear to influence epithelial associations with bacteria in the intestinal lumen. For example, internalization of Salmonella enterica and Escherichia coli O157:H7 into the Peyer's patch mucosa of the small intestine is altered after the inhibition of neural activity with saxitoxin, a neuronal sodium channel blocker. Catecholamine neurotransmitters, such as dopamine and norepinephrine, also alter bacterial internalization in Peyer's patches. In the large intestine, norepinephrine increases the mucosal adherence of E. coli. These neurotransmitter actions are mediated by well-defined catecholamine receptors situated on the basolateral membranes of epithelial cells rather than through direct interactions with luminal bacteria. Investigations of the involvement of neuroepithelial communication in the regulation of interactions between the intestinal mucosa and luminal bacteria will provide novel insights into the mechanisms underlying bacterial colonization and pathogenesis at mucosal surfaces. PMID:26589216

  8. 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. PMID:25961305

  9. 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

  10. Ehrlichia chaffeensis TRP32 Interacts with Host Cell Targets That Influence Intracellular Survival

    PubMed Central

    Luo, Tian

    2012-01-01

    Ehrlichia chaffeensis is an obligately intracellular bacterium that exhibits tropism for mononuclear phagocytes and survives by evading host cell defense mechanisms. Recently, molecular interactions of E. chaffeensis tandem repeat proteins 47 and 120 (TRP47 and -120) and the eukaryotic host cell have been described. In this investigation, yeast two-hybrid analysis demonstrated that an E. chaffeensis type 1 secretion system substrate, TRP32, interacts with a diverse group of human proteins associated with major biological processes of the host cell, including protein synthesis, trafficking, degradation, immune signaling, cell signaling, iron metabolism, and apoptosis. Eight target proteins, including translation elongation factor 1 alpha 1 (EF1A1), deleted in azoospermia (DAZ)-associated protein 2 (DAZAP2), ferritin light polypeptide (FTL), CD63, CD14, proteasome subunit beta type 1 (PSMB1), ring finger and CCCH-type domain 1 (RC3H1), and tumor protein p53-inducible protein 11 (TP53I11) interacted with TRP32 as determined by coimmunoprecipitation assays, colocalization with TRP32 in HeLa and THP-1 cells, and/or RNA interference. Interactions between TRP32 and host targets localized to the E. chaffeensis morulae or in the host cell cytoplasm adjacent to morulae. Common or closely related interacting partners of E. chaffeensis TRP32, TRP47, and TRP120 demonstrate a molecular convergence on common cellular processes and molecular cross talk between Ehrlichia TRPs and host targets. These findings further support the role of TRPs as effectors that promote intracellular survival. PMID:22547548

  11. Influence of the dipole interaction on the direction of the magnetization in thin ferromagnetic films

    NASA Astrophysics Data System (ADS)

    Moschel, A.; Usadel, K. D.

    1994-11-01

    The magnetization of thin films depends in a very sensitive way on surface anisotropy fields which often favor a perpendicular orientation and on the dipole interaction which favors an in-plane magnetization. A temperature driven transition from one to the other orientation has been observed experimentally. In order to understand this behavior theoretically we performed detailed calculations of the magnetization of very thin films (thickness of up to 5 layers) within a quantum mechanical mean field approach. A surface anisotropy that favors a perpendicular orientation and a long range dipole interaction were taken into account. It is shown that these competing interactions for certain values of the parameters may result in a temperature driven switching transition from an out-of plane to an in-plane ordered state. Varying the strength of the dipole interaction we found that the switching temperature is a very sensitive function of the ratio of these two competing interactions. A perpendicular ground state magnetization of the firm is only found for values of the surface anisotropy which are larger than a critical surface anisotropy value. The reorientation of the magnetization vector has its physical origin in an entropy increase of the system when going from a perpendicular to an in-plan ordered state.

  12. 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.

  13. Environmental influences on maize-Aspergillus flavus interactions and aflatoxin production.

    PubMed

    Fountain, Jake C; Scully, Brian T; Ni, Xinzhi; Kemerait, Robert C; Lee, Robert D; Chen, Zhi-Yuan; Guo, Baozhu

    2014-01-01

    Since the early 1960s, the fungal pathogen Aspergillus flavus (Link ex Fr.) has been the focus of intensive research due to the production of carcinogenic and highly toxic secondary metabolites collectively known as aflatoxins following pre-harvest colonization of crops. Given this recurrent problem and the occurrence of a severe aflatoxin outbreak in maize (Zea mays L.), particularly in the Southeast U.S. in the 1977 growing season, a significant research effort has been put forth to determine the nature of the interaction occurring between aflatoxin production, A. flavus, environment and its various hosts before harvest. Many studies have investigated this interaction at the genetic, transcript, and protein levels, and in terms of fungal biology at either pre- or post-harvest time points. Later experiments have indicated that the interaction and overall resistance phenotype of the host is a quantitative trait with a relatively low heritability. In addition, a high degree of environmental interaction has been noted, particularly with sources of abiotic stress for either the host or the fungus such as drought or heat stresses. Here, we review the history of research into this complex interaction and propose future directions for elucidating the relationship between resistance and susceptibility to A. flavus colonization, abiotic stress, and its relationship to oxidative stress in which aflatoxin production may function as a form of antioxidant protection to the producing fungus. PMID:24550905

  14. Gene--gene interaction among cytokine polymorphisms influence susceptibility to aggressive periodontitis.

    PubMed

    Scapoli, C; Mamolini, E; Carrieri, A; Guarnelli, M E; Annunziata, M; Guida, L; Romano, F; Aimetti, M; Trombelli, L

    2011-09-01

    Aggressive periodontitis (AgP) is a multifactorial disease. The distinctive aspect of periodontitis is that this disease must deal with a large number of genes interacting with one another and forming complex networks. Thus, it is reasonable to expect that gene-gene interaction may have a crucial role. Therefore, we carried out a pilot case-control study to identify the association of candidate epistatic interactions between genetic risk factors and susceptibility to AgP, by using both conventional parametric analyses and a higher order interactions model, based on the nonparametric Multifactor Dimensionality Reduction algorithm. We analyzed 122 AgP patients and 246 appropriate periodontally healthy individuals, and genotyped 28 polymorphisms, located within 14 candidate genes, chosen among the principal genetic variants pointed out from literature and having a role in inflammation and immunity. Our analyses provided significant evidence for gene--gene interactions in the development of AgP, in particular, present results: (a) indicate a possible role of two new polymorphisms, within SEPS1 and TNFRSF1B genes, in determining host individual susceptibility to AgP; (b) confirm the potential association between of IL-6 and Fc γ- receptor polymorphisms and the disease; (c) exclude an essential contribution of IL-1 cluster gene polymorphisms to AgP in our Caucasian-Italian population. PMID:21593780

  15. 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.

  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. Direct Measurement of the Fluid Phase Diagram.

    PubMed

    Bao, Bo; Riordon, Jason; Xu, Yi; Li, Huawei; Sinton, David

    2016-07-19

    The thermodynamic phase of a fluid (liquid, vapor or supercritical) is fundamental to all chemical processes, and the critical point is particularly important for supercritical chemical extraction. Conventional phase measurement methods require hours to obtain a single datum on the pressure and temperature diagram. Here, we present the direct measurement of the full pressure-temperature phase diagram, with 10 000 microwells. Orthogonal, linear, pressure and temperature gradients are obtained with 100 parallel microchannels (spanning the pressure range), each with 100 microwells (spanning the temperature range). The phase-mapping approach is demonstrated with both a pure substance (CO2) and a mixture (95% CO2 + 5% N2). Liquid, vapor, and supercritical regions are clearly differentiated, and the critical pressure is measured at 1.2% error with respect to the NIST standard. This approach provides over 100-fold improvement in measurement speed over conventional methods. PMID:27331613

  19. Krajewski diagrams and the standard model

    SciTech Connect

    Stephan, Christoph A.

    2009-04-15

    This paper provides a complete list of Krajewski diagrams representing the standard model of particle physics. We will give the possible representations of the algebra and the anomaly free lifts which provide the representation of the standard model gauge group on the fermionic Hilbert space. The algebra representations following from the Krajewski diagrams are not complete in the sense that the corresponding spectral triples do not necessarily obey to the axiom of Poincare duality. This defect may be repaired by adding new particles to the model, i.e., by building models beyond the standard model. The aim of this list of finite spectral triples (up to Poincare duality) is therefore to provide a basis for model building beyond the standard model.

  20. MHV diagrams in momentum twistor space

    NASA Astrophysics Data System (ADS)

    Bullimore, Mathew; Mason, Lionel; Skinner, David

    2010-12-01

    We show that there are remarkable simplifications when the MHV diagram formalism for mathcal{N} = 4 super Yang-Mills is reformulated in momentum twistor space. The vertices are replaced by unity while each propagator becomes a dual superconformal `R-invariant' whose arguments may be read off from the diagram, and include an arbitrarily chosen reference twistor. The momentum twistor MHV rules generate a formula for the full, all-loop planar integrand for the super Yang-Mills S-matrix that is manifestly dual superconformally invariant up to the choice of a reference twistor. We give a general proof of this reformulation and illustrate its use by computing the momentum twistor NMHV and N2MHV tree amplitudes and the integrands of the MHV and NMHV 1-loop and the MHV 2-loop planar amplitudes.

  1. Ring-Diagram Analysis: Status and Perspectives

    NASA Astrophysics Data System (ADS)

    Hill, F.

    Ring diagram analysis is now more than a decade old. While the details of the technique are still evolving, the application of the method to MDI, TON, Mt. Wilson, HLH, and GONG data is providing intriguing results. Thanks to the work of many people, it is now becoming possible to observationally infer the complicated dynamics in the outer 15 Mm of the solar convection zone, investigate the depth dependence of meridional flow, and get a closer look at zonal jet-stream structures in the mid-latitudes. We may soon be able to similarly investigate the spatio-temporal distribution of scalar fields. As ring diagrams and other local helioseismology methods such as time-distance and acoustic imaging continue to mature, the comparison of results from different techniques on common data sets will provide a useful reality check.

  2. Persistence diagrams of cortical surface data.

    PubMed

    Chung, Moo K; Bubenik, Peter; Kim, Peter T

    2009-01-01

    We present a novel framework for characterizing signals in images using techniques from computational algebraic topology. This technique is general enough for dealing with noisy multivariate data including geometric noise. The main tool is persistent homology which can be encoded in persistence diagrams. These diagrams visually show how the number of connected components of the sublevel sets of the signal changes. The use of local critical values of a function differs from the usual statistical parametric mapping framework, which mainly uses the mean signal in quantifying imaging data. Our proposed method uses all the local critical values in characterizing the signal and by doing so offers a completely new data reduction and analysis framework for quantifying the signal. As an illustration, we apply this method to a 1D simulated signal and 2D cortical thickness data. In case of the latter, extra homological structures are evident in an control group over the autistic group. PMID:19694279

  3. Extracting parameters from colour-magnitude diagrams

    NASA Astrophysics Data System (ADS)

    Bonatto, C.; Campos, F.; Kepler, S. O.; Bica, E.

    2015-07-01

    We present a simple approach for obtaining robust values of astrophysical parameters from the observed colour-magnitude diagrams (CMDs) of star clusters. The basic inputs are the Hess diagram built with the photometric measurements of a star cluster and a set of isochrones covering wide ranges of age and metallicity. In short, each isochrone is shifted in apparent distance modulus and colour excess until it crosses over the maximum possible Hess density. Repeating this step for all available isochrones leads to the construction of the solution map, in which the optimum values of age and metallicity - as well as foreground/background reddening and distance from the Sun - can be searched for. Controlled tests with simulated CMDs show that the approach is efficient in recovering the input values. We apply the approach to the open clusters M 67, NGC 6791 and NGC 2635, which are characterized by different ages, metallicities and distances from the Sun.

  4. Phase Coexistence in a Dynamic Phase Diagram.

    PubMed

    Gentile, Luigi; Coppola, Luigi; Balog, Sandor; Mortensen, Kell; Ranieri, Giuseppe A; Olsson, Ulf

    2015-08-01

    Metastability and phase coexistence are important concepts in colloidal science. Typically, the phase diagram of colloidal systems is considered at the equilibrium without the presence of an external field. However, several studies have reported phase transition under mechanical deformation. The reason behind phase coexistence under shear flow is not fully understood. Here, multilamellar vesicle (MLV)-to-sponge (L3 ) and MLV-to-Lα transitions upon increasing temperature are detected using flow small-angle neutron scattering techniques. Coexistence of Lα and MLV phases at 40 °C under shear flow is detected by using flow NMR spectroscopy. The unusual rheological behavior observed by studying the lamellar phase of a non-ionic surfactant is explained using (2) H NMR and diffusion flow NMR spectroscopy with the coexistence of planar lamellar-multilamellar vesicles. Moreover, a dynamic phase diagram over a wide range of temperatures is proposed. PMID:26083451

  5. Influence of spurious resonances on the interaction force in dynamic AFM.

    PubMed

    Costa, Luca; Rodrigues, Mario S

    2015-01-01

    The quantification of the tip-sample interaction in amplitude modulation atomic force microscopy is challenging, especially when measuring in liquid media. Here, we derive formulas for the tip-sample interactions and investigate the effect of spurious resonances on the measured interaction. Highlighting the differences between measuring directly the tip position or the cantilever deflection, and considering both direct and acoustic excitation, we show that the cantilever behavior is insensitive to spurious resonances as long as the measured signal corresponds to the tip position, or if the excitation force is correctly considered. Since the effective excitation force may depend on the presence of such spurious resonances, only the case in which the frequency is kept constant during the measurement is considered. Finally, we show the advantages that result from the use of a calibration method based on the acquisition of approach-retract curves. PMID:25821682

  6. Influence of homology and node age on the growth of protein-protein interaction networks

    NASA Astrophysics Data System (ADS)

    Bottinelli, Arianna; Bassetti, Bruno; Lagomarsino, Marco Cosentino; Gherardi, Marco

    2012-10-01

    Proteins participating in a protein-protein interaction network can be grouped into homology classes following their common ancestry. Proteins added to the network correspond to genes added to the classes, so the dynamics of the two objects are intrinsically linked. Here we first introduce a statistical model describing the joint growth of the network and the partitioning of nodes into classes, which is studied through a combined mean-field and simulation approach. We then employ this unified framework to address the specific issue of the age dependence of protein interactions through the definition of three different node wiring or divergence schemes. A comparison with empirical data indicates that an age-dependent divergence move is necessary in order to reproduce the basic topological observables together with the age correlation between interacting nodes visible in empirical data. We also discuss the possibility of nontrivial joint partition and topology observables.

  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. Mutual touch during mother-infant face-to-face still-face interactions: influences of interaction period and infant birth status.

    PubMed

    Mantis, Irene; Stack, Dale M; Ng, Laura; Serbin, Lisa A; Schwartzman, Alex E

    2014-08-01

    Contact behaviours such as touch, have been shown to be influential channels of nonverbal communication between mothers and infants. While existing research has examined the communicative roles of maternal or infant touch in isolation, mutual touch, whereby touching behaviours occur simultaneously between mothers and their infants, has yet to be examined. The present study was designed to investigate mutual touch during face-to-face interactions between mothers and their 5½-month-old fullterm (n=40), very low birth weight/preterm (VLBW/preterm; n=40) infants, and infants at psychosocial risk (n=41). Objectives were to examine: (1) how the quantitative and qualitative aspects of touch employed by mothers and their infants varied across the normal periods of the still-face (SF) procedure, and (2) how these were associated with risk status. Mutual touch was systematically coded using the mother-infant touch scale. Interactions were found to largely consist of mutual touch and one-sided touch plus movement, highlighting that active touching is pervasive during mother-infant interactions. Consistent with the literature, while the SF period did not negatively affect the amount of mutual touch engaged in for mothers and their fullterm infants and mothers and their infants at psychosocial risk, it did for mothers and their VLBW/preterm infants. Together, results illuminate how both mothers and infants participate in shaping and co-regulating their interactions through the use of touch and underscore the contribution of examining the influence of birth status on mutual touch. PMID:24793734

  9. Intramembrane Aromatic Interactions Influence the Lipid Sensitivities of Pentameric Ligand-gated Ion Channels*

    PubMed Central

    Carswell, Casey L.; Sun, Jiayin; Baenziger, John E.

    2015-01-01

    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. PMID:25519904

  10. 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…

  11. Pulling the River: The Interactions of Local and Global Influences in Chinese Early Childhood Music Education

    ERIC Educational Resources Information Center

    Chen-Hafteck, Lily; Zhuoya, X. U.

    2008-01-01

    Educators in China are facing challenges as a tug-of-war between local culture and global influences in Chinese early childhood music educations plays out. By exploring the situations of Hong Kong and Nanjing, the authors demonstrate a wide gap between policy and practice. The top-down policy from government officials is based on global views of…

  12. 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…

  13. 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…

  14. A generic framework for the parcellation of the cortical surface into gyri using geodesic Voronoï diagrams.

    PubMed

    Cachia, A; Mangin, J-F; Rivière, D; Papadopoulos-Orfanos, D; Kherif, F; Bloch, I; Régis, J

    2003-12-01

    In this paper we propose a generic automatic approach for the parcellation of the cortical surface into labeled gyri. These gyri are defined from a set of pairs of sulci selected by the user. The selected sulci are first automatically identified in the data, then projected onto the cortical surface. The parcellation stems from two nested Voronoï diagrams computed geodesically to the cortical surface. The first diagram provides the zones of influence of the sulci. The boundary between the two zones of influence of each selected pair of sulci stands for a gyrus seed. A second diagram yields the gyrus parcellation. The distance underlying the Voronoï diagram allows the method to interpolate the gyrus boundaries where the limiting sulci are interrupted. The method is illustrated with 12 different hemispheres. PMID:14561546

  15. 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.

  16. 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…

  17. 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…

  18. Phase diagram of superconductor-ferromagnet superlattices

    SciTech Connect

    Radovic, Z.; Dobrosavljevic-Grujic, L.

    1994-12-31

    Recent progress in the proximity effect theory of superconductor-ferromagnet superlattices is reviewed. The phase diagram calculations, transition temperature {Tc} and upper critical fields H{sub c2}, are presented. Characteristic features in {Tc} and H{sub c2}(T) dependence on layers thicknesses, including the predicted unusual oscillatory variations and new inhomogeneous superconducting state with nontrivial phase difference between neighboring superconducting layers, are discussed and compared with experimental data for V/Fe and Nb/Gd superlattices.

  19. 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).

  20. 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.

  1. 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.

  2. Regime Diagrams for K-Theory Dispersion

    NASA Astrophysics Data System (ADS)

    Smith, Ronald B.

    2011-06-01

    In atmospheric dispersion, the "non-Gaussian" effects of gravitational settling, the vertical gradient in diffusivity and the surface deposition do not enter uniformly but rather break up parameter space into several discrete regimes. Here, we describe regime diagrams that are constructed for K-theory dispersion of effluent from a surface line source in unsheared inhomogeneous turbulence, using a previously derived Fourier-Hankel method. This K-theory formulation differs from the traditional one by keeping a non-zero diffusivity at the ground. This change allows for turbulent exchange between the canopy and the atmosphere and allows new natural length scales to emerge. The axes on the regime diagrams are non-dimensional distance defined as the ratio of downwind distance to the characteristic length scale for each effect. For each value of the ratio of settling speed to the K gradient, two to four regimes are found. Concentration formulae are given for each regime. The regime diagrams allow real dispersion problems to be categorized and the validity of end-state concentration formulae to be judged.

  3. Recognition and processing of logic diagrams

    NASA Astrophysics Data System (ADS)

    Darwish, Ahmed M.; Bashandy, Ahmed R.

    1996-03-01

    In this paper we present a vision system that is capable of interpreting schematic logic diagrams, i.e. determine the output as a logic function of the inputs. The system is composed of a number of modules each designed to perform a specific subtask. Each module bears a minor contribution in the form of a new mixture of known algorithms or extensions to handle actual real life image imperfections which researchers tend to ignore when they develop their theoretical foundations. The main contribution, thus, is not in any individual module, it is rather in their integration to achieve the target job. The system is organized more or less in a classical fashion. Aside from the image acquisition and preprocessing modules, interesting modules include: the segmenter, the identifier, the connector and the grapher. A good segmentation output is one reason for the success of the presented system. Several novelties exist in the presented approach. Following segmentation the type of each logic gate is determined and its topological connectivity. The logic diagram is then transformed to a directed acyclic graph in which the final node is the output logic gate. The logic function is then determined by backtracking techniques. The system is not only aimed at recognition applications. In fact its main usage may be to target other processing applications such as storage compression and graphics modification and manipulation of the diagram as is explained.

  4. 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.

  5. 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…

  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. 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…

  8. 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…

  9. Influence of dynamic soil-pile raft-structure interaction: an experimental approach

    NASA Astrophysics Data System (ADS)

    Saha, Rajib; Haldar, Sumanta; Dutta, Sekhar Chandra

    2015-12-01

    Traditionally seismic design of structures supported on piled raft foundation is performed by considering fixed base conditions, while the pile head is also considered to be fixed for the design of the pile foundation. Major drawback of this assumption is that it cannot capture soil-foundation-structure interaction due to flexibility of soil or the inertial interaction involving heavy foundation masses. Previous studies on this subject addressed mainly the intricacy in modelling of dynamic soil structure interaction (DSSI) but not the implication of such interaction on the distribution of forces at various elements of the pile foundation and supported structure. A recent numerical study by the authors showed significant change in response at different elements of the piled raft supported structure when DSSI effects are considered. The present study is a limited attempt in this direction, and it examines such observations through shake table tests. The effect of DSSI is examined by comparing dynamic responses from fixed base scaled down model structures and the overall systems. This study indicates the possibility of significant underestimation in design forces for both the column and pile if designed under fixed base assumption. Such underestimation in the design forces may have serious implication in the design of a foundation or structural element.

  10. Children's Preliteracy Skills: Influence of Mothers' Education and Beliefs about Shared-Reading Interactions

    ERIC Educational Resources Information Center

    Curenton, Stephanie M.; Justice, Laura M.

    2008-01-01

    Research Findings: This research investigated the associations among children's preliteracy skills, mothers' education, and mothers' beliefs about shared-reading interactions for 45 Appalachian families. These variables were studied for lower income, primarily European American, families residing in a geographically isolated, small, rural…

  11. PAM in irrigated agriculture: Processes and soil-PAM interactions influencing canal sealing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To identify or develop alternative polymers, which may successfully replace PAM as an irrigation reservoir or canal sealant, it is important to understand the nature of the sealing processes in these unlined, earthen irrigation structures and how PAM interacts with those processes to alter water see...

  12. Influence of the Virus LbFV and of Wolbachia in a Host-Parasitoid Interaction

    PubMed Central

    Woolfit, Megan; Vavre, Fabrice; O'Neill, Scott L.; Varaldi, Julien

    2012-01-01

    Symbionts are widespread and might have a substantial effect on the outcome of interactions between species, such as in host-parasitoid systems. Here, we studied the effects of symbionts on the outcome of host-parasitoid interactions in a four-partner system, consisting of the parasitoid wasp Leptopilina boulardi, its two hosts Drosophila melanogaster and D. simulans, the wasp virus LbFV, and the endosymbiotic bacterium Wolbachia. The virus is known to manipulate the superparasitism behavior of the parasitoid whereas some Wolbachia strains can reproductively manipulate and/or confer pathogen protection to Drosophila hosts. We used two nuclear backgrounds for both Drosophila species, infected with or cured of their respective Wolbachia strains, and offered them to L. boulardi of one nuclear background, either infected or uninfected by the virus. The main defence mechanism against parasitoids, i.e. encapsulation, and other important traits of the interaction were measured. The results showed that virus-infected parasitoids are less frequently encapsulated than uninfected ones. Further experiments showed that this viral effect involved both a direct protective effect against encapsulation and an indirect effect of superparasitism. Additionally, the Wolbachia strain wAu affected the encapsulation ability of its Drosophila host but the direction of this effect was strongly dependent on the presence/absence of LbFV. Our results confirmed the importance of heritable symbionts in the outcome of antagonistic interactions. PMID:22558118

  13. 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…

  14. 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. PMID:19094035

  15. Interactions between HERC2, OCA2 and MC1R may influence human pigmentation phenotype.

    PubMed

    Branicki, Wojciech; Brudnik, Urszula; Wojas-Pelc, Anna

    2009-03-01

    Human pigmentation is a polygenic trait which may be shaped by different kinds of gene-gene interactions. Recent studies have revealed that interactive effects between HERC2 and OCA2 may be responsible for blue eye colour determination in humans. Here we performed a population association study, examining important polymorphisms within the HERC2 and OCA2 genes. Furthermore, pooling these results with genotyping data for MC1R, ASIP and SLC45A2 obtained for the same population sample we also analysed potential genetic interactions affecting variation in eye, hair and skin colour. Our results confirmed the association of HERC2 rs12913832 with eye colour and showed that this SNP is also significantly associated with skin and hair colouration. It is also concluded that OCA2 rs1800407 is independently associated with eye colour. Finally, using various approaches we were able to show that there is an interaction between MC1R and HERC2 in determination of skin and hair colour in the studied population sample. PMID:19208107

  16. Influence of Deacetylation on the Rheological Properties of Xanthan-Guar Interactions in Dilute Aqueous Solutions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An oscillating capillary rheometer was used to investigate the effects of xanthan deacetylation on the viscoelastic properties and intrinsic viscosity of xanthan and guar mixtures in dilute aqueous solutions. Deacetylated xanthan exhibited a stronger synergistic interaction with guar than native xan...

  17. The Play Interactions of Young Children with and without Disabilities: Individual and Environmental Influences.

    ERIC Educational Resources Information Center

    Hestenes, Linda L.; Carroll, Deborah E.

    2000-01-01

    Examined young children's play interactions and beliefs in inclusive preschool settings. Found a tendency for children without disabilities to engage in more cooperative play and less solitary play and on-looking behavior than their peer with disabilities. Found a high level of similarity between the two groups in choice of free play activities.…

  18. Interacting and Learning Together: Factors Influencing Preservice Teachers' Perceptions of Academic Wiki Use

    ERIC Educational Resources Information Center

    Israel, Maya; Moshirnia, Andrew

    2012-01-01

    Academic wikis hold promise in supporting preservice teachers' collaborative interactions in online contexts. Nonetheless, little is written in either technology or teacher education literature about facilitating wiki use and instruction within teacher education. This study investigated the use of an academic wiki within a technology teacher…

  19. 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…

  20. 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…