849 research outputs found

    Exploring mobility in Italian Neolithic and Copper Age communities

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    As a means for investigating human mobility during late the Neolithic to the Copper Age in central and southern Italy, this study presents a novel dataset of enamel oxygen and carbon isotope values (delta (18)Oca and delta (13)Cca) from the carbonate fraction of biogenic apatite for one hundred and twenty-six individual teeth coming from two Neolithic and eight Copper Age communities. The measured delta (18)Oca values suggest a significant role of local sources in the water inputs to the body water, whereas delta (13)Cca values indicate food resources, principally based on C-3 plants. Both delta (13)Cca and delta (18)Oca ranges vary substantially when samples are broken down into local populations. Statistically defined thresholds, accounting for intra-site variability, allow the identification of only a few outliers in the eight Copper Age communities, suggesting that sedentary lifestyle rather than extensive mobility characterized the investigated populations. This seems to be also typical of the two studied Neolithic communities. Overall, this research shows that the investigated periods in peninsular Italy differed in mobility pattern from the following Bronze Age communities from more northern areas

    Precise mirror alignment and basic performance of the RICH detector of the NA62 experiment at CERN

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    The Ring Imaging Cherenkov detector is crucial for the identification of charged particles in the NA62 experiment at the CERN SPS. The detector commissioning was completed in 2016 by the precise alignment of mirrors using reconstructed tracks. The alignment procedure and measurement of the basic performance are described. Ring radius resolution, ring centre resolution, single hit resolution and mean number of hits per ring are evaluated for positron tracks. The contribution of the residual mirror misalignment to the performance is calculated.Comment: 13 pages, 10 figure

    Natalizumab affects T-cell phenotype in multiple sclerosis: implications for JCV reactivation

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    The anti-CD49d monoclonal antibody natalizumab is currently an effective therapy against the relapsing-remitting form of multiple sclerosis (RRMS). Natalizumab therapeutic efficacy is limited by the reactivation of the John Cunningham polyomavirus (JCV) and development of progressive multifocal leukoencephalopathy (PML). To correlate natalizumab-induced phenotypic modifications of peripheral blood T-lymphocytes with JCV reactivation, JCV-specific antibodies (serum), JCV-DNA (blood and urine), CD49d expression and relative abundance of peripheral blood T-lymphocyte subsets were longitudinally assessed in 26 natalizumab-treated RRMS patients. Statistical analyses were performed using GraphPad Prism and R. Natalizumab treatment reduced CD49d expression on memory and effector subsets of peripheral blood T-lymphocytes. Moreover, accumulation of peripheral blood CD8+ memory and effector cells was observed after 12 and 24 months of treatment. CD4+ and CD8+ T-lymphocyte immune-activation was increased after 24 months of treatment. Higher percentages of CD8+ effectors were observed in subjects with detectable JCV-DNA. Natalizumab reduces CD49d expression on CD8+ T-lymphocyte memory and effector subsets, limiting their migration to the central nervous system and determining their accumulation in peripheral blood. Impairment of central nervous system immune surveillance and reactivation of latent JCV, can explain the increased risk of PML development in natalizumab-treated RRMS subjects

    Light Detection System and Time Resolution of the NA62 RICH

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    A large RICH detector is used in NA62 to suppress the muon contamination in the charged pion sample by a factor of 100 in the momentum range between 15 and 35 GeV/c. Cherenkov light is collected by 1952 photomultipliers placed at the upstream end. In this paper the characterization of the photomultipliers and the dedicated Frontend and Data Acquisition electronics are described, the time resolution and the light detection efficiency measurement are presented.Comment: 15 pages, 11 figure

    Quartz fiber calorimetry

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    The fundamentals of a new electromagnetic and hadronic sampling calorimetry based on the detection of Cherenkov light generated in quartz optical fibers are presented. Optical fibers transport light only in a selected angular range which results in a non-obvious and absolutely unique characteristic for this new technique: showers of very narrow visible energy. In addition, the technique is characterized by radiation resistance measured in Gigarads and nanosecond signal duration. Combined, these properties make quartz fiber calorimetry a very promising technique for high intensity heavy ion experiments and for the high pseudorapidity regions of high intensity collider experiments. The results of beam tests and simulations are used to illustrate the basic properties and peculiar characteristics of this recent development

    Prospects for K+→π+ννˉK^+ \to \pi^+ \nu \bar{ \nu } at CERN in NA62

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    The NA62 experiment will begin taking data in 2015. Its primary purpose is a 10% measurement of the branching ratio of the ultrarare kaon decay K+→π+ννˉK^+ \to \pi^+ \nu \bar{ \nu }, using the decay in flight of kaons in an unseparated beam with momentum 75 GeV/c.The detector and analysis technique are described here.Comment: 8 pages for proceedings of 50 Years of CP

    Mirror system of the RICH detector of the NA62 experiment

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    A large RICH detector is used in NA62 to suppress the muon contamination in the charged pion selection by a factor 100 in the momentum range between 15 and 35 GeV/c. The detector consists of a 17 m long tank (vessel), filled with neon gas at atmospheric pressure. Cherenkov light is reflected by a mosaic of 20 spherical mirrors with 17 m focal length, placed at the downstream end, and collected by 1952 photomultipliers (PMTs) placed at the upstream end. In this paper the characterization of the mirrors before installation and the mirror support system are described. The mirror installation procedure and the laser alignment are also illustrated

    First observation of the KS->pi0 gamma gamma decay

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    Using the NA48 detector at the CERN SPS, 31 KS->pi0 gamma gamma candidates with an estimated background of 13.7 +- 3.2 events have been observed. This first observation leads to a branching ratio of BR(KS->pi0 gamma gamma) = (4.9 +- 1.6(stat) +- 0.9(syst)) x 10^-8 in agreement with Chiral Perturbation theory predictions.Comment: 10 pages, 4 figures submitted to Phys. Lett.

    Observation of the rare decay K_S -> pi^0mu^+mu^-

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    A search for the decay K_S -> pi^0mu^+mu^- has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity K_S beam. Six events were found with a background expectation of 0.22^+0.18_-0.11 event. Using a vector matrix element and unit form factor, the measured branching ratio is B(K_S -> pi^0mu^+mu^-)=[2.9^+1.5_-1.2(stat)+/-0.2(syst)]x10^{-9}.Comment: 19 pages, 8 figures, 4 tables. To be published in Physics Letters
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