843 research outputs found

    Decays rates for S- and P-wave bottomonium

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    We use the Bodwin-Braaten-Lepage factorization scheme to separate the long- and short-distance factors that contribute to the decay rates of Υ\Upsilon, ηb\eta_b (S-wave) and χb\chi_b,hbh_b (P-wave). The long distance matrix elements are calculated on the lattice in the quenched approximation using a non-relativistic formulation of the bb quark dynamics.Comment: 3 pages Latex using espcrc2.sty and epsf.sty + 2 postscript figure

    Extinction of a conditioned response in rainbow trout selected for high or low responsiveness to stress

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    Two lines of rainbow trout (Oncorhynchus mykiss) that exhibit divergent endocrine responsiveness to stressors also display disparate behavioral traits. To investigate whether the high-responding (HR) and low-responding (LR) fish also differ in cognitive function the rate of extinction of a conditioned response was compared between the two lines. Groups of HR and LR fish were exposed to a paired conditioned stimulus (CS; water-off) and unconditioned stimulus (US; confinement stressor). After exposure to 18 CS-US pairings at least 70% of individuals of both lines acquired a conditioned response (CR), manifested as an elevation of blood cortisol levels on presentation of the CS only. Post-conditioning, the fish were tested by presentation of the CS at weekly intervals, for 4 weeks, with no further reinforcement and the extinction of the CR in the two lines was compared. The decline in mean plasma cortisol levels after exposure to the CS over successive tests suggested that the CR was retained for a shorter period among the HR (<14 days) than LR fish (<21 days). The frequency of individuals within each line whose plasma cortisol levels indicated a stress response when exposed to the CS was significantly greater among the LR than HR fish at 14 and 21 days with no HR fish falling into this category at 21 days. At 28 days post-conditioning, there were no HR fish and only three LR fish that were categorized as “stressed”. These results suggest that there are differences in cognitive function between the two lines. Possible mechanisms underlying these differences are discussed

    Confusing the extragalactic neutrino flux limit with a neutrino propagation limit

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    We study the possible suppression of the extragalactic neutrino flux due to a nonstandard interaction during its propagation. In particular, we study neutrino interaction with an ultra-light scalar field dark matter. It is shown that the extragalactic neutrino flux may be suppressed by such an interaction, leading to a new mechanism to reduce the ultra-high energy neutrino flux. We study both the cases of non-self-conjugate as well as self-conjugate dark matter. In the first case, the suppression is independent of the neutrino and dark matter masses. We conclude that care must be taken when explaining limits on the neutrino flux through source acceleration mechanisms only, since there could be other mechanisms for the reduction of the neutrino flux.Comment: 15 pages, 4 figures. Important changes implemented. Abstract modified. Conclusions remain. To be published in JCA

    Traversable Wormholes Construction in 2+1 Dimensions

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    We study traversable Lorentzian wormholes in the three-dimensional low energy string theory by adding some matter source involving a dilaton field. It will be shown that there are two-different types of wormhole solutions such as BTZ and black string wormholes depending on the dilaton backgrounds, respectively. We finally obtain the desirable solutions which confine exotic matter near the throat of wormhole by adjusting NS charge.Comment: 12 pages, 4 figures, JHEP style, one reference adde

    T Cells Bearing a Chimeric Antigen Receptor against Prostate-Specific Membrane Antigen Mediate Vascular Disruption and Result in Tumor Regression.

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    Aberrant blood vessels enable tumor growth, provide a barrier to immune infiltration, and serve as a source of protumorigenic signals. Targeting tumor blood vessels for destruction, or tumor vascular disruption therapy, can therefore provide significant therapeutic benefit. Here, we describe the ability of chimeric antigen receptor (CAR)-bearing T cells to recognize human prostate-specific membrane antigen (hPSMA) on endothelial targets in vitro as well as in vivo. CAR T cells were generated using the anti-PSMA scFv, J591, and the intracellular signaling domains: CD3ζ, CD28, and/or CD137/4-1BB. We found that all anti-hPSMA CAR T cells recognized and eliminated PSMA(+) endothelial targets in vitro, regardless of the signaling domain. T cells bearing the third-generation anti-hPSMA CAR, P28BBζ, were able to recognize and kill primary human endothelial cells isolated from gynecologic cancers. In addition, the P28BBζ CAR T cells mediated regression of hPSMA-expressing vascular neoplasms in mice. Finally, in murine models of ovarian cancers populated by murine vessels expressing hPSMA, the P28BBζ CAR T cells were able to ablate PSMA(+) vessels, cause secondary depletion of tumor cells, and reduce tumor burden. Taken together, these results provide a strong rationale for the use of CAR T cells as agents of tumor vascular disruption, specifically those targeting PSMA. Cancer Immunol Res; 3(1); 68-84. ©2014 AACR

    PP-wave Black holes and The Matrix Model

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    We discuss the sizes of a black hole in the M theory pp-wave background, and how the transverse size can be reproduced in the matrix model.Comment: 12 pages, harvmac. v2: final version to be published in JHEP, refs. adde

    Duality of Quasilocal Gravitational Energy and Charges with Non-orthogonal Boundaries

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    We study the duality of quasilocal energy and charges with non-orthogonal boundaries in the (2+1)-dimensional low-energy string theory. Quasilocal quantities shown in the previous work and some new variables arisen from considering the non-orthogonal boundaries as well are presented, and the boost relations between those quantities are discussed. Moreover, we show that the dual properties of quasilocal variables such as quasilocal energy density, momentum densities, surface stress densities, dilaton pressure densities, and Neuve-Schwarz(NS) charge density, are still valid in the moving observer's frame.Comment: 19pages, 1figure, RevTe

    Scalar wave propagation in topological black hole backgrounds

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    We consider the evolution of a scalar field coupled to curvature in topological black hole spacetimes. We solve numerically the scalar wave equation with different curvature-coupling constant ξ\xi and show that a rich spectrum of wave propagation is revealed when ξ\xi is introduced. Relations between quasinormal modes and the size of different topological black holes have also been investigated.Comment: 26 pages, 18 figure

    Higher codimension braneworlds from intersecting branes

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    We study the matching conditions of intersecting brane worlds in Lovelock gravity in arbitrary dimension. We show that intersecting various codimension 1 and/or codimension 2 branes one can find solutions that represent energy-momentum densities localized in the intersection, providing thus the first examples of infinitesimally thin higher codimension braneworlds that are free of singularities and where the backreaction of the brane in the background is fully taken into account.Comment: 20 pages; v2. references and comments added to match the published versio

    Understanding museum vacationers’ eco-friendly decision-making process: Strengthening the VBN framework

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    In the present research, the process of vacationers’ pro-environmental decision formation for environmentally responsible museums was examined. This research employed and broadened the value-belief-norm theory, using satisfaction with green product use, green trust, and frequency of past behavior for green product use as predictors. A structural equation modeling was utilized for modeling comparisons and hypothesis testing. A measurement model tested using the data gathered at museums was found to satisfactorily fit to the data. Newly integrated constructs significantly improved the prediction power of the theory. In addition, results of the structural equation modeling generally supported the proposed relationships. Moreover, a salient role of moral norm was identified. As expected, new environmental paradigm, awareness of consequences, ascribed responsibility, and moral norm played an important mediating role. A parsimonious model with greater prediction power than the original value-belief-norm theory was produced through modeling comparisons and the process of testing relationships among research variables. Our results offer a sufficient understanding of vacationers’ pro-environmental intention for eco-friendly museums
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