1,377 research outputs found

    Non-equilibrium phase behavior of confined molecular films at low shear rates

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    In a recent publication [Maćkowiak et al., J. Chem. Phys. 145, 164704 (2016)] the results of Non-Equilibrium Molecular Dynamics (NEMD) simulations of confined sheared Lennard-Jones molecular films have been presented. The present work builds on that study by focusing on the low wall speed (shear rate) regime. Maps are given of the steady-state structures and corresponding friction coefficients in the region where a transition from static to kinetic friction is observed. The boundary between static and kinetic friction regions is determined as a function of wall speed and applied pressure, which is located for wall speeds up to about 0.8 m s−1. It was found that stick-slip behavior extends to pressures as high as 1000 MPa. The NEMD equations of motion are shown to be consistent with the Prandtl–Tomlinson model in the ‘soft spring’ limit, which leads to a new expression for the friction coefficient. This study provides new details and insights into the nature of anomalous friction behavior in the so-called Plug-Slip part of the nonquilibrium phase diagram regime

    Why are Prices Sticky? Evidence from Business Survey Data

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    This paper offers new insights on the price setting behaviour of German retail firms using a novel dataset that consists of a large panel of monthly business surveys from 1991-2006. The firm-level data allows matching changes in firms' prices to several other firm-characteristics. Moreover, information on price expectations allow analyzing the determinants of price updating. Using univariate and bivariate ordered probit specifications, empirical menu cost models are estimated relating the probability of price adjustment and price updating, respectively, to both time- and state- dependent variables. First, results suggest an important role for state-dependence; changes in the macroeconomic and institutional environment as well as firm-specific factors are significantly related to the timing of price adjustment. These findings imply that price setting models should endogenize the timing of price adjustment in order to generate realistic predictions concerning the transmission of monetary policy. Second, an analysis of price expectations yields similar results providing evidence in favour of state-dependent sticky plan models. Third, intermediate input cost changes are among the most important determinants of price adjustment suggesting that pricing models should explicitly incorporate price setting at different production stages. However, the results show that adjustment to input cost changes takes time indicating "additional stickiness" at the last stage of processing

    PCD13: PATIENT BENEFIT QUESTIONNAIRE (PBQ) FOR XEROSTOMIA: DEVELOPMENT AND VALIDATION REPORT

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    Approaches toward Sustainable Forage-Livestock Systems: Strip-Planting a Legume into a Warm-Season Perennial Grass Pasture

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    Despite the demonstrated potential of rhizoma peanut (Arachis glabrata Benth.; RP) for grazing in the southeastern USA (Ortega-S. et al. 1992), high establishment cost and removal of land from production during establishment have limited its use to primarily hay production systems. The premise of this experiment is that strip-planting RP in existing bahiagrass (Paspalum notatum FlĂŒgge) pastures offers the opportunity to use grass forage during the legume establishment phase so that land need not be totally removed from grazing, while allowing successful establishment of the legume

    Expressão e distribuição da conexina 32 em fígados de ratos com fibrose induzida experimentalmente

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    The connexin 32 (Cx32) is a protein that forms the channels that promote the gap junction intercellular communication (GJIC) in the liver, allowing the diffusion of small molecules through cytosol from cell-to-cell. Hepatic fibrosis is characterized by a disruption of normal tissue architeture by cellular lesions, and may alter the GJIC. This work aimed to study the expression and distribution of Cx32 in liver fibrosis induced by the oral administration of dimethylnitrosamine in female Wistar rats. The necropsy of the rats was carried out after five weeks of drug administration. They presented a hepatic fibrosis state. Sections from livers with fibrosis and from control livers were submitted to immunohistochemical, Real Time-PCR and Western-Blot analysis to Cx32. In fibrotic livers the Cxs were diffusely scattered in the cytoplasm, contrasting with the control livers, where the Cx32 formed junction plaques at the cell membrane. Also it was found a decrease in the gene expression of Cx32 without reduction in the protein quantity when compared with controls. These results suggest that there the mechanism of intercellular communication between hepatocytes was reduced by the fibrotic process, which may predispose to the occurrence of a neoplastic process, taken in account that connexins are considered tumor suppressing genes.A conexina 32 (Cx32) Ă© uma proteĂ­na que constitui os canais que promovem as comunicaçÔes intercelulares via junçÔes comunicantes (CIJC) no fĂ­gado, permitindo difusĂŁo de pequenas molĂ©culas citoplasmĂĄticas de uma cĂ©lula Ă  outra. A fibrose hepĂĄtica caracteriza-se pela alteração da arquitetura normal do fĂ­gado e podem alterar as CIJCs. O objetivo deste trabalho foi estudar a expressĂŁo e distribuição de Cx32 na fibrose hepĂĄtica. O objetivo do presente trabalho foi estudar a expressĂŁo e distribuição da Cx32 em fĂ­gados com fibrose induzida pela administração oral de dimetilnitrosamina em fĂȘmeas de ratos Wistar. A necropsia foi realizada apĂłs cinco semanas da Ășltima administração da droga e observou-se um quadro de fibrose hepĂĄtica. Amostras dos fĂ­gados com fibrose e de animais controle foram submetidas Ă  anĂĄlise imunoistoquĂ­mica, por Real Time-PCR e por Western-Blot verificando-se a presença de Cx32 difusa e dispersa no citoplasma dos fĂ­gados com fibrose. No grupo controle a Cx32 localizou-se na membrana citoplasmĂĄtica com a formação de placas juncionais. O fĂ­gado com fibrose tambĂ©m revelou diminuição da expressĂŁo gĂȘnica de Cx32, embora sem a redução da quantidade do produto protĂ©ico, quando comparado ao grupo controle. Estes resultados sugerem que o mecanismo de comunicação intercelular entre os hepatĂłcitos reduziu-se durante o processo fibrĂłtico, o que pode predispor a ocorrĂȘncia de processos neoplĂĄsicos, uma vez que as conexinas sĂŁo consideradas genes supressores de tumores.FAPESPCNP

    Pricing in inflationary times: The penny drops

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    How does the frequency and magnitude of micro-price rises and falls relate to macroeconomic crisis, as well as moderation? Weekly micropricing behaviour in British groceries was investigated across three leading retailers over the moderation period 2004–7 and the crisis period 2008–10. We find significant price flexibility sharply distinguished from behaviour observed in most previous works. Downward price flexibility increased markedly in 2008. Overall basket prices rise, but significantly more individual prices fall than rise in the latter period. Tests of obfuscation in price setting suggested that large numbers of small price falls were used to disguise the basket price rises

    The Ultimate Fate of Supercooled Liquids

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    In recent years it has become widely accepted that a dynamical length scale {\xi}_{\alpha} plays an important role in supercooled liquids near the glass transition. We examine the implications of the interplay between the growing {\xi}_{\alpha} and the size of the crystal nucleus, {\xi}_M, which shrinks on cooling. We argue that at low temperatures where {\xi}_{\alpha} > {\xi}_M a new crystallization mechanism emerges enabling rapid development of a large scale web of sparsely connected crystallinity. Though we predict this web percolates the system at too low a temperature to be easily seen in the laboratory, there are noticeable residual effects near the glass transition that can account for several previously observed unexplained phenomena of deeply supercooled liquids including Fischer clusters, and anomalous crystal growth near T_g

    Cognitive impairment after lacunar stroke: systematic review and meta-analysis of incidence, prevalence and comparison with other stroke subtypes

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    Funding SDJM is supported by a Wellcome Trust Project Grant (WT088134/Z/09/A). JMW is supported by the Scottish Funding Council through the Scottish Imaging Network, A Platform for Scientific Excellence (SINAPSE) Initiative (http://www. sinapse.ac.uk). The study was independent of the funders.Peer reviewedPublisher PD

    Multiplicity and transverse momentum fluctuations in inelastic proton-proton interactions at the CERN Super Proton Synchrotron

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    Measurements of multiplicity and transverse momentum fluctuations of charged particles were performed in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the scaled variance of the multiplicity distribution and for three strongly intensive measures of multiplicity and transverse momentum fluctuations \$\Delta[P_{T},N]\$, \$\Sigma[P_{T},N]\$ and \$\Phi_{p_T}\$ are presented. For the first time the results on fluctuations are fully corrected for experimental biases. The results on multiplicity and transverse momentum fluctuations significantly deviate from expectations for the independent particle production. They also depend on charges of selected hadrons. The string-resonance Monte Carlo models EPOS and UrQMD do not describe the data. The scaled variance of multiplicity fluctuations is significantly higher in inelastic p+p interactions than in central Pb+Pb collisions measured by NA49 at the same energy per nucleon. This is in qualitative disagreement with the predictions of the Wounded Nucleon Model. Within the statistical framework the enhanced multiplicity fluctuations in inelastic p+p interactions can be interpreted as due to event-by-event fluctuations of the fireball energy and/or volume.Comment: 18 pages, 12 figure
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