118 research outputs found

    An overview of the design, construction and performance of large area triple-GEM prototypes for future upgrades of the CMS forward muon system

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    GEM detectors are used in high energy physics experiments given their good spatial resolution, high rate capability and radiation hardness. An international collaboration is investigating the possibility of covering the 1.6 < vertical bar eta vertical bar < 2.4 region of the CMS muon endcaps with large-area triple-GEM detectors. The CMS high-eta area is actually not fully instrumented, only Cathode Strip Chamber (CSC) are installed. The vacant area presents an opportunity for a detector technology able to to cope with the harsh radiation environment; these micropattern gas detectors are an appealing option to simultaneously enhance muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study is presented. Design and construction of small (10cm x 10cm) and full-size trapezoidal (1m x 0.5m) triple-GEM prototypes is described. Results from measurements with x-rays and from test beam campaigns at the CERN SPS is shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system are reported

    Low bone mass in microscopic colitis

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    <p>Abstract</p> <p>Background</p> <p>Microscopic colitis presents with similar symptoms to classic inflammatory bowel diseases. Osteoporosis is a common complication of Crohn's disease but there are no data concerning bone metabolism in microscopic colitis.</p> <p>Aims</p> <p>The aim of the present study was to evaluate bone density and metabolism in patients with microscopic colitis.</p> <p>Methods</p> <p>Fourteen patients microscopic colitis were included in the study, and 28 healthy persons and 28 age and gender matched Crohn's disease patients were enrolled as controls. Bone mineral density was measured using dual x-ray absorptiometry at the lumbar spine, femoral neck and the radius. Serum bone formation and bone resorption markers (osteocalcin and beta-crosslaps, respectively) were measured using immunoassays.</p> <p>Results</p> <p>Low bone mass was measured in 57.14% patients with microscopic colitis. Bone mineral density at the femoral neck in patients suffering from microscopic colitis and Crohn's disease was lower than in healthy controls (0.852 Âą 0.165 and 0.807 Âą 0.136 vs. 1.056 Âą 0.126 g/cm<sup>2</sup>; p < 0.01). Bone mineral density at the non-dominant radius was decreased in microscopic colitis patients (0.565 Âą 0.093 vs. 0.667 Âą 0.072 g/cm<sup>2</sup>; p < 0.05) but unaffected in Crohn's disease patients (0.672 Âą 0.056 g/cm<sup>2</sup>). Mean beta-crosslaps concentration was higher in microscopic colitis and Crohn's disease patients than controls (417.714 Âą 250.37 and 466.071 Âą 249.96 vs. 264.75 Âą 138.65 pg/ml; p < 0.05). A negative correlation between beta-crosslaps concentration and the femoral and radius t-scores was evident in microscopic colitis patients.</p> <p>Conclusions</p> <p>Low bone mass is frequent in microscopic colitis, and alterations to bone metabolism are similar to those present in Crohn's disease. Therefore, microscopic colitis-associated osteopenia could be a significant problem in such patients.</p

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    An operative case of hepatic pseudolymphoma difficult to differentiate from primary hepatic marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue

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    Hepatic pseudolymphoma (HPL) and primary hepatic marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are rare diseases and the differential diagnosis between these two entities is sometimes difficult. We herein report a 56-year-old Japanese woman who was pointed out to have a space occupying lesion in the left lateral segment of the liver. Hepatitis viral-associated antigen/antibody was negative and liver function tests including lactic dehydrogenase, peripheral blood count, tumor markers and soluble interleukin-2 receptor were all within normal limit. Imaging study using computed tomography and magnetic resonance imaging were not typical for hepatocellular carcinoma, cholangiocarcinoma, or other metastatic cancer. Fluorodeoxyglucose-positron emission tomography examination integrated with computed tomography scanning showed high standardized uptake value in the solitary lesion in the liver. Under a diagnosis of primary liver neoplasm, laparoscopic-assisted lateral segmentectomy was performed. Liver tumor of maximal 1.0 cm in diameter was consisted of aggregation of lymphocytes of predominantly B-cell, containing multiple lymphocyte follicles positive for CD10 and bcl-2, consistent with a diagnosis of HPL rather than MALT lymphoma, although a definitive differentiation was pending. The background liver showed non-alcoholic fatty liver disease/early non-alcoholic steatohepatitis. The patient is currently doing well with no sign of relapse 13 months after the surgery. Since the accurate diagnosis is difficult, laparoscopic approach would provide a reasonable procedure of diagnostic and therapeutic advantage with minimal invasiveness for patients. Considering that the real nature of this entity remains unclear, vigilant follow-up of patient is essential

    Test beam results of the GE1/1 prototype for a future upgrade of the CMS high-Ρ muon system

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    Gas Electron Multipliers (GEM) are an interesting technology under consideration for the future upgrade of the forward region of the CMS muon system, specifically in the 1.6 < vertical bar eta vertical bar < 2.4 endcap region. With a sufficiently fine segmentation GEMs can provide precision tracking as well as fast trigger information. The main objective is to contribute to the improvement of the CMS muon trigger. The construction of large-area GEM detectors is challenging both from the technological and production aspects. In view of the CMS upgrade we have designed and built the largest full-size Triple-GEM muon detector, which is able to meet the stringent requirements given the hostile environment at the high-luminosity LHC. Measurements were performed during several test beam campaigns at the CERN SPS in 2010 and 2011. The main issues under study are efficiency, spatial resolution and timing performance with different inter-electrode gap configurations and gas mixtures. In this paper results of the performance of the prototypes at the beam tests will be discussed

    Latin American Consensus: Children Born Small for Gestational Age

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    72-87Cuatrimestra

    CMS Data Processing Workflows during an Extended Cosmic Ray Run

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    Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run

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    Peer reviewe

    Commissioning of the CMS high-level trigger with cosmic rays

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    This is the Pre-print version of the Article. The official published version of the paper can be accessed from the link below - Copyright @ 2010 IOPThe CMS High-Level Trigger (HLT) is responsible for ensuring that data samples with potentially interesting events are recorded with high efficiency and good quality. This paper gives an overview of the HLT and focuses on its commissioning using cosmic rays. The selection of triggers that were deployed is presented and the online grouping of triggered events into streams and primary datasets is discussed. Tools for online and offline data quality monitoring for the HLT are described, and the operational performance of the muon HLT algorithms is reviewed. The average time taken for the HLT selection and its dependence on detector and operating conditions are presented. The HLT performed reliably and helped provide a large dataset. This dataset has proven to be invaluable for understanding the performance of the trigger and the CMS experiment as a whole.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
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