3,989 research outputs found

    Widening the prostacyclin paradigm: tissue fibroblasts are a critical site of production and 2 anti-thrombotic protection

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    Prostacyclin is a fundamental signaling pathway traditionally associated with the cardiovascular system and protection against thrombosis but which also has regulatory functions in fibrosis, proliferation, and immunity. Prevailing dogma states that prostacyclin is principally derived from vascular endothelium, although it is known that other cells can also synthesize it. However, the role of nonendothelial sources in prostacyclin production has not been systematically evaluated resulting in an underappreciation of their importance relative to better characterized endothelial sources..

    Spin rotons and supersolids in binary antidipolar condensates

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    We present a theoretical study of a mixture of antidipolar and nondipolar Bose-Einstein condensates confined to an infinite tube. We predict the presence of a spin roton and its associated instability, which triggers a continuous unmodulated--to--supersolid phase transition. We characterize the phase diagram of the binary system, ranging from the quasi-1D to the radial Thomas-Fermi (elongated 3D) regimes. We also present the dynamic formation of supersolids following a quench from the uniform miscible phase, which maintains phase coherence across the system.Comment: 13 pages main text, 5 figures, submission to SciPost Physics Cor

    Peatland hydrology and carbon release: why small-scale process matters

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    Peatlands cover over 400 million hectares of the Earth's surface and store between one-third and one-half of the world's soil carbon pool. The long-term ability of peatlands to absorb carbon dioxide from the atmosphere means that they play a major role in moderating global climate. Peatlands can also either attenuate or accentuate flooding. Changing climate or management can alter peatland hydrological processes and pathways for water movement across and below the peat surface. It is the movement of water in peats that drives carbon storage and flux. These small-scale processes can have global impacts through exacerbated terrestrial carbon release. This paper will describe advances in understanding environmental processes operating in peatlands. Recent (and future) advances in high-resolution topographic data collection and hydrological modelling provide an insight into the spatial impacts of land management and climate change in peatlands. Nevertheless, there are still some major challenges for future research. These include the problem that impacts of disturbance in peat can be irreversible, at least on human time-scales. This has implications for the perceived success and understanding of peatland restoration strategies. In some circumstances, peatland restoration may lead to exacerbated carbon loss. This will also be important if we decide to start to create peatlands in order to counter the threat from enhanced atmospheric carbon

    Evaluation of an online youth ambassador program to promote mental health

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    To evaluate an online Youth Ambassador (YA) program designed to promote internet resources for mental health in an adolescent population, 56 YAs and 357 of their Year 10 peers from 11 Tasmanian schools completed e-mental health questionnaires before and after the YAs attended a single workshop session. The workshops, which were delivered in the high school setting, were either facilitated or self-directed. Self-reported awareness of e-mental health resources increased among both YAs and their peers. The peer group also showed increased frequency of recommending help-seeking to others. There were no differences in outcomes for facilitated or self-directed workshop formats. The results suggest that an online YA program delivered in school is useful in improving mental health awareness for workshop participants. While their Year 10 peer groups also showed increased awareness, this could not necessarily be attributed to the participation of all 11 schools in the YA program

    Hadronic Transitions among Quarkonium States in a Soft-Exchange-Approximation. Chiral Breaking and Spin Symmetry Breaking Processes

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    Although no asymptotic heavy quark spin symmetry, and even more no flavor symmetry, are expected for systems such as quarkonium, a numerical discussion shows that for some processes and in a preasymptotic region which may roughly include charmonium and bottomonium, the use of the spin-symmetry may be useful in conjunction with chiral symmetry for light hadrons (soft-exchange- approximation regime, SEA). We continue our discussion of hadronic transitions in the SEA-regime by studying in particular chiral breaking transitions such as  3P′→ 3Pπ0~^3P' \to ~^3P\pi^0,  3Pη~^3P\eta, level splittings and transitions which break both chiral and spin symmetry, such as ψ′→J/ψπ0\psi ' \to J/\psi \pi^0, J/ψηJ/\psi \eta, and  1P1→J/ψπ0~^1P_1 \to J/\psi \pi^0.Comment: LaTeX (style article) 19 pages, UGVA-DPT 12-80

    Impact of D0-D0bar mixing on the experimental determination of gamma

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    Several methods have been devised to measure the weak phase gamma using decays of the type B+- --> D K+-, where it is assumed that there is no mixing in the D0-D0bar system. However, when using these methods to uncover new physics, one must entertain the real possibility that the measurements are affected by new physics effects in the D0-D0bar system. We show that even values of x_D and/or y_D around 10^{-2} can have a significant impact in the measurement of sin^2{gamma}. We discuss the errors incurred in neglecting this effect, how the effect can be checked, and how to include it in the analysis.Comment: 18 pages, Latex with epsfig, 8 figure

    Endothelial cyclooxygenase-1 paradoxically drives local vasoconstriction and atherogenesis despite underpinning prostacyclin generation

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    Endothelial cyclooxygenase-1–derived prostanoids, including prostacyclin, have clear cardioprotective roles associated with their anti-thrombotic potential but have also been suggested to have paradoxical pathological activities within arteries. To date it has not been possible to test the importance of this because no models have been available that separate vascular cyclooxygenase-1 products from those generated elsewhere. Here, we have used unique endothelial-specific cyclooxygenase-1 knockout mice to show that endothelial cyclooxygenase-1 produces both protective and pathological products. Functionally, however, the overall effect of these was to drive pathological responses in the context of both vasoconstriction in vitro and the development of atherosclerosis and vascular inflammation in vivo. These data provide the first demonstration of a pathological role for the vascular cyclooxygenase-1 pathway, highlighting its potential as a therapeutic target. They also emphasize that, across biology, the role of prostanoids is not always predictable due to unique balances of context, products, and receptors
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