2,431 research outputs found

    Vortex Lattice Structural Transitions: a Ginzburg-Landau Model Approach

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    We analyze the rhombic to square vortex lattice phase transition in anisotropic superconductors using a variant of Ginzburg-Landau (GL) theory. The mean-field phase diagram is determined to second order in the anisotropy parameter, and shows a reorientation transition of the square vortex lattice with respect to the crystal lattice. We then derive the long-wavelength elastic moduli of the lattices, and use them to show that thermal fluctuations produce a reentrant rhombic to square lattice transition line, similar to recent studies which used a nonlocal London model.Comment: 4 pages, 3 figures, final version with various referee suggested modifications, scheduled to appear in PR

    Tunneling between bilayer quantum Hall structures in a strong magnetic field

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    We calculate the tunneling current in a quantum Hall bilayer system in the strong magnetic field limit. We model the bilayer electron system as two Wigner crystals coupled through interlayer Coulomb interactions, treated in the continuum limit. We generalized the Johansson and Kinaret (JK) model and were able to study the effect of the low energy out-of-phase magnetophonon modes produced as a result of tunneling events. We find the same scaling behavior of the tunneling current peak with the magnetic field as found by JK but were able to find the tunneling current scaling behavior with interlayer distance as well.Comment: 4 pages, 1 figure, SemiMag16 conference paper to be published in International Journal of Modern Physics

    The Effects of Variable Capital Utilization on the Measurement and Properties of Sectoral Productivity: Some International Evidence

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    This paper explores how accounting for variations in factor utilization rates alters the empirical characteristics of productivity residuals in the United States and Canada. Using data on 19 manufacturing industries, we study the behavior of productivity using three proxies for capital services. We find that adjusting for cyclical movements in capital utilization alters many of the empirical characteristics of productivity, both within and across countries.

    Neuregulin 1-Beta cytoprotective role in AML 12 mouse hepatocytes exposed to pentachlorophenol.

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    Neuregulins are a family of growth factor domain proteins that are structurally related to the epidermal growth factor. Accumulating evidence has shown that neuregulins have cyto- and neuroprotective properties in various cell types. In particular, the neuregulin-1 Beta (NRG1-Beta) isoform is well documented for its antiinflammatory properties in rat brain after acute stroke episodes. Pentachlorophenol (PCP) is an organochlorine compound that has been widely used as a biocide in several industrial, agricultural, and domestic applications. Previous investigations from our laboratory have demonstrated that PCP exerts both cytotoxic and mitogenic effects in human liver carcinoma (HepG2) cells, primary catfish hepatocytes and AML 12 mouse hepatocytes. We have also shown that in HepG2 cells, PCP has the ability to induce stress genes that may play a role in the molecular events leading to toxicity and tumorigenesis. In the present study, we hypothesize that NRG1-Beta will exert its cytoprotective effects in PCP-treated AML 12 mouse hepatocytes by its ability to suppress the toxic effects of PCP. To test this hypothesis, we performed the MTT-cell respiration assay to assess cell viability, and Western-blot analysis to assess stress-related proteins as a consequence of PCP exposure. Data obtained from 48 h-viability studies demonstrated a biphasic response; showing a dose-dependent increase in cell viability within the range of 0 to 3.87 microg/mL, and a gradual decrease within the concentration range of 7.75 to 31.0 microg/mL in concomitant treatments of NRG1-Beta+PCP and PCP. Cell viability percentages indicated that NRG1-Beta+PCPtreated cells were not significantly impaired, while PCP-treated cells were appreciably affected; suggesting that NRG1-Beta has the ability to suppress the toxic effects of PCP. Western Blot analysis demonstrated the potential of PCP to induce oxidative stress and inflammatory response (c-fos), growth arrest and DNA damage (GADD153), proteotoxic effects (HSP70), cell cycle arrest as consequence of DNA damage (p53), mitogenic response (cyclin- D1), and apoptosis (caspase-3). NRG1-Beta exposure attenuated stress-related protein expression in PCP-treated AML 12 mouse hepatocytes. Here we provide clear evidence that NRG1-Beta exerts cytoprotective effects in AML 12 mouse hepatocytes exposed to PCP

    Viscoelastic Behavior of Solid 4^4He

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    Over the last five years several experimental groups have reported anomalies in the temperature dependence of the period and amplitude of a torsional oscillator containing solid 4^4He. We model these experiments by assuming that 4^4He is a viscoelastic solid--a solid with frequency dependent internal friction. We find that while our model can provide a quantitative account of the dissipation observed in the torsional oscillator experiments, it only accounts for about 10% of the observed period shift, leaving open the possibility that the remaining period shift is due to the onset of superfluidity in the sample.Comment: 4 pages, 3 figure

    Financial Decision Making, Price, and Consumer Financial Well-being: A Multiple Methodology Inquiry of the Cognitions, Emotional Coping Responses, and Brand Measures in the Healthcare Service Industry

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    Article 1: Financial bankruptcy, particularly those as a result of healthcare expenses, has become a pervasive issue in the United States. This article examines a basic premise for the research, that healthcare is not viewed, by consumers, consistently with other exchanges, leading to detachment and disengagement within the purchase experience (e.g., a lack of price searching and price comparison behaviors) and disadvantageous consequences for financial well-being. Subsequently, the studies test cognitive (i.e., knowledge structures) and emotional constructs (i.e., emotion regulation), with a between-subjects experimental methodology (three studies), that may further unfurl the decision process for healthcare consumers. Contributions to the marketing, psychology, and public policy literatures yield implications for marketers and public policy makers, which are discussed subsequently.;Article 2: A qualitative exploration of mindfulness and emotion regulation is proffered, in an effort to identify and understand the cognitive processes used by consumers during healthcare financial decision making. Two complementary methodologies (i.e., stimulated recall, think-aloud protocol) are used for data collection, and two rounds of coding analysis offer themes which inform the literatures of psychology and marketing. Data from 16 participants supports the proposal of a preliminary framework. Implications for marketers and public policy makers are discussed.;Article 3: Healthcare organizations (HCO) are a critical portion of the continually burgeoning healthcare industry. Recent revenue estimates for the industry now exceed {dollar}3 trillion in the U.S. (Phillips 2015). As such, HCOs, embedded within a unique service context, have turned their attention and resources towards managing, cultivating, and promoting their brands. Brand equity and brand image are examined for their impact on price (i.e., average charge price ), a dependent variable derived from data from the Centers for Medicare & Medicaid Services, and price premiums within the healthcare industry. Implications for the theory of services marketing and healthcare marketing are discussed, as well as for managers

    Analysis of Transit Oriented Development Compatibility for Light Rail Station Areas adjacent to U.S. Interstate Freeways

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    In 2006, the city of Denver completed a major phase of the T-REX project that included expanding a Light Rail Transit (LRT) system, building 13 stations along the corridors of Interstates 25 and 225. The expansion brought mixed concerns about whether locating the system alongside interstate freeways would produce transit-oriented developments (TOD), or if it intended to have stations that serve multiple purposes, some functioning as destinations and others serving as feeder stations to generate ridership for the system. This prompted a study to (1) create a typology of station areas and determine what type of station areas are located near an interstate freeway and (2) to quantify what aspects of station areas promote ridership within the system, again with a particular focus on those stations adjacent to freeways. We identified numerous geographic variables considered to impact ridership such as land use, socio-economic population features, the street network, and features of LRT stations. We then used factor and cluster analysis on street network and land use data to create typologies of station areas based on these criteria. Of specific interest was whether stations located adjacent to interstate freeways had a unique built environment. We then used multiple regression analysis to estimate potential ridership relating to the built environment as well as the socio-economic and rail station characteristics as independent variables for each station. The overall results provided evidence that station areas near interstate freeways presented a built environment that could limit their ability to transition into a TOD compatible neighborhood
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