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Necrotic and apoptotic neuronal cell death can be found in pneumococcal meningitis. We have investigated the role of Bcl-2 as an anti-apoptotic gene-product in pneumococcal meningitis using ...Bcl-2-knockout (Bcl-2 -/-) mice. Using a model of pneumococcal meningitis and cerebritis induced by intracerebral infection, Bcl-2-deficient mice and control littermates were assessed by clinical score and tight rope test (TRT) at 0, 12, 24, 32 and 36h after intracerebral injection of pneumococci (104 CFU/25µl saline) or 25µl normal saline. Then, mice were sacrificed, bacterial titers in blood, spleen and cerebellar homogenates were determined, and the brain and spleen were evaluated histologically. Infected Bcl-2-deficient mice developed more severe clinical illness than infected controls with significant differences in clinical score at 24, 32 and 36h and in TRT at 12 and 32h. Bacterial titers were increased in blood in Bcl-2-deficient mice (mean±SD, 7.46±1.93 logCFU/ml vs. 5.16± 0.96 logCFU/ml, p<0.01). Neuronal damage was most prominent in the hippocampal formation. It did not differ significantly between groups. In-situ-tailing identified only few apoptotic neurons in the brain. The spleen, however, showed significantly more apoptotic leukocytes in Bcl-2-deficient mice than in controls (mean±SD, 5148±3406/mm2 vs. 1070±395/mm2, p<0.005). In uninfected animals there were significantly less apoptotic leukocytes in the spleen. Again, the rate of apoptotic leukocytes in the spleen was higher in Bcl-2-deficient mice than in controls (mean±SD, 118±42 vs. 36±23/mm2, p=0.02). Bcl-2 expression in the spleen of infected control mice after 36 hours determined by Western blot analysis did not differ from uninfected controls. In conclusion, Bcl-2 appears to counteract sepsis-induced apoptosis of splenic lymphocytes thereby enhancing clearance of bacteria from the blood.
The RPC system for the CMS experiment Pugliese, G.
2006 IEEE Nuclear Science Symposium Conference Record,
2006-Oct., Volume:
2
Conference Proceeding
The CMS experiment at the CERN Large Hadron Collider (LHC) is equipped with a redundant muon trigger system based on drift tubes chambers (DT) and cathode strip chamber (CSC), for the precise ...position measurement, and resistive plate chambers (RPC), for the bunch crossing identification and a preliminary fast measurement of the muon transverse momentum. The CMS RPC system is constituted by 480 chambers in the barrel and 756 chambers in the forward corresponding to a total surface of about 3500 m 2 . The design and construction has involved many laboratories scattered all over the word. An accurate quality control procedure has been established at different levels of the production to achieve final detectors with operation parameters well inside the CMS specifications. In the summer 2006 a preliminary slice test involving a fraction of the CMS detector was performed. The performance of the RPC system with cosmic rays was studied versus the magnetic field using final running hardware and software protocols. Results on the RPC main working parameters are reported.
The proacrosin gene is transcribed in diploid spermatogenic cells and translated in haploid round spermatids. In order to evaluate sequences which are involved in proacrosin gene transcription, ...DNA-protein interactions were analyzed in 1.2 kb of the 5'flanking region of the rat gene. 13 protein binding sites were identified by DNase I footprinting using nuclear extracts from rat testis and brain, respectively. Five footprints (F1, F3, F7, TS2, TS3) which suggest an interaction with testis specific nuclear factors were further examined by gel retardation assays. Three testis specific binding sites (F1, F7, TS2, located 472bp, 697bp and 1004bp upstream of ATG, respectively) could be identified with both methods. The binding site F1 contains a motif which is similar to a testis specific footprint found in mouse protamine 1 gene. The nucleotide sequence of F7 contains the recognition motif of an isoform of the transcription factor GATA1, which is expressed in testis. Furthermore F1 and F7 are located in that part of the 5'flanking region of the proacrosin gene, which can direct proacrosin gene expression in germ cells of male transgenic mice.
The CMS GEM collaboration is considering Gas Electron Multipliers (GEMs) for upgrading the CMS forward muon system in the 1.5<|eta|<2.4 endcap region. GEM detectors can provide precision tracking and ...fast trigger information. They would improve the CMS muon trigger and muon momentum resolution and provide missing redundancy in the high-eta region. Employing a new faster construction and assembly technique, we built four full-scale Triple-GEM muon detectors for the inner ring of the first muon endcap station. We plan to install these or further improved versions in CMS during the first long LHC shutdown in 2013/14 for continued testing. These detectors are designed for the stringent rate and resolution requirements in the increasingly hostile environments expected at CMS after the second long LHC shutdown in 2018/19. The new prototypes were studied in muon/pion beams at the CERN SPS. We discuss our experience with constructing the new full-scale production prototypes and present preliminary performance results from the beam test. We also tested smaller Triple-GEM prototypes with zigzag readout strips with 2 mm pitch in these beams and measured a spatial resolution of 73 microns. This readout offers a potential reduction of channel count and consequently electronics cost for this system while maintaining high spatial resolution.
At present, part of the forward RPC muon system of the CMS detector at the CERN LHC remains uninstrumented in the high-\eta region. An international collaboration is investigating the possibility of ...covering the 1.6 < |\eta| < 2.4 region of the muon endcaps with large-area triple-GEM detectors. Given their good spatial resolution, high rate capability, and radiation hardness, these micro-pattern gas detectors are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in a future upgrade of the CMS detector. A general overview of this feasibility study will be presented. The design and construction of small (10\times10 cm2) and full-size trapezoidal (1\times0.5 m2) triple-GEM prototypes will be described. During detector assembly, different techniques for stretching the GEM foils were tested. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown for the small and large prototypes. Preliminary simulation studies on the expected muon reconstruction and trigger performances of this proposed upgraded muon system will be reported.
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 $1.6<| \eta |<2.4$ 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.
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 \(1.6<| \eta |<2.4\) 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.
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