297 research outputs found

    Ultra-High Energy Neutrino Fluxes: New Constraints and Implications

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    We apply new upper limits on neutrino fluxes and the diffuse extragalactic component of the GeV gamma-ray flux to various scenarios for ultra high energy cosmic rays and neutrinos. As a result we find that extra-galactic top-down sources can not contribute significantly to the observed flux of highest energy cosmic rays. The Z-burst mechanism where ultra-high energy neutrinos produce cosmic rays via interactions with relic neutrinos is practically ruled out if cosmological limits on neutrino mass and clustering apply.Comment: 10 revtex pages, 9 postscript figure

    Physics at the LHC: a short overview

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    The CERN Large Hadron Collider (LHC) started operation a few months ago. The machine will deliver proton-proton and nucleus-nucleus collisions at energies as high as sqrt(s)=14 TeV and luminosities up to L~10^{34} cm^{-2}s^{-1}, never reached before. The main open scientific questions that the seven LHC experiments -- ATLAS, CMS, ALICE, LHCb, TOTEM, LHCf and MOEDAL -- aim to solve in the coming years are succinctly reviewed.Comment: 9 pages, 16 plots. Invited review talk Hot-Quarks 2010, La Londe-Les-Maures, July 2010. J. Phys. Conf. Ser. 270, 012001 (2011). Minor typos correcte

    Signatures of Quark-Gluon-Plasma formation in high energy heavy-ion collisions: A critical review

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    A critical review on signatures of Quark-Gluon-Plasma formation is given and the current (1998) experimental status is discussed. After giving an introduction to the properties of QCD matter in both, equilibrium- and non-equilibrium theories, we focus on observables which may yield experimental evidence for QGP formation. For each individual observable the discussion is divided into three sections: first the connection between the respective observable and QGP formation in terms of the underlying theoretical concepts is given, then the relevant experimental results are reviewed and finally the current status concerning the interpretation of both, theory and experiment, is discussed. A comprehensive summary including an outlook towards RHIC is given in the final section.Comment: Topical review, submitted to Journal of Physics G: 68 pages, including 39 figures (revised version: only minor modifications, some references added

    Alzheimer’s Disease and Other Dementias Workgroup: Alzheimer’s Disease and Other Dementias Report and Recommendations

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    Rates of Alzheimer’s disease and other dementias are expected to increase greatly over the next decades. Many practices lack guidelines on how to increase quality of diagnosing, treating, and supporting people with dementia and their family members and other caregivers. This workgroup met from January to November 2017, aligned with and built off the Alzheimer’s State Plan, and organized recommendations with the following focus areas: Early detection and appropriate diagnosis Ongoing care and support or management including for family members and caregivers Advance care planning and palliative care Assessment and planning for need for increased support and/or higher levels of care Preparing for potential hospitalization Screening for delirium risk during hospitalization for all patients over 6

    Interaction between integrin α9β1 and vascular cell adhesion molecule-1 (VCAM-1) inhibits neutrophil apoptosis

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    According to the prevailing paradigm, neutrophils are short-lived cells that undergo spontaneous apoptosis within 24 hours of their release from the bone marrow. However, neutrophil survival can be significantly prolonged within inflamed tissue by cytokines, inflammatory mediators, and hypoxia. During screening experiments aimed at identifying the effect of the adhesive microenvironment on neutrophil survival, we found that VCAM-1 (CD106) was able to delay both spontaneous and Fas-induced apoptosis. VCAM-1-mediated survival was as efficient as that induced by the cytokine IFN-β and provided an additive, increased delay in apoptosis when given in combination with IFN-β. VCAM-1 delivered its antiapoptotic effect through binding the integrin α9β1. The α9β 1 signaling pathway shares significant features with the IFN-β survival signaling pathway, requiring PI3 kinase, NF-κB activation, as well as de novo protein synthesis, but the kinetics of NF-κB activation by VCAM-1 were slower and more sustained compared with IFN-β. This study demonstrates a novel functional role for α9β1 in neutrophil biology and suggests that adhesive signaling pathways provide an important extrinsic checkpoint for the resolution of inflammatory responses in tissues
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