347 research outputs found

    Quark cluster signatures in deuteron electromagnetic interactions

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    A suggestion is made for distinguishing 2N and 6q short range correlations within the deuteron. The suggestion depends upon observing high momentum backward nucleons emerging from inelastic electromagnetic scattering from a deuteron target. A simple model is worked out to see the size of effects that may be expected.Comment: 18 pages (3 figures available as hard copy), WM-94-10

    Splitting the voter criticality

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    Recently some two-dimensional models with double symmetric absorbing states were shown to share the same critical behaviour that was called the voter universality class. We show, that for an absorbing-states Potts model with finite but further than nearest neighbour range of interactions the critical point is splitted into two critical points: one of the Ising type, and the other of the directed percolation universality class. Similar splitting takes place in the three-dimensional nearest-neighbour model.Comment: 4 pages, eps figures include

    Identification and characterization of two novel mutations in the LPL gene causing type I hyperlipoproteinemia

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    Background Type 1 hyperlipoproteinemia is a rare autosomal recessive disorder most often caused by mutations in the lipoprotein lipase (LPL) gene resulting in severe hypertriglyceridemia and pancreatitis. Objectives The aim of this study was to identify novel mutations in the LPL gene causing type 1 hyperlipoproteinemia and to understand the molecular mechanisms underlying the severe hypertriglyceridemia. Methods Three patients presenting classical features of type 1 hyperlipoproteinemia were recruited for DNA sequencing of the LPL gene. Pre-heparin and post-heparin plasma of patients were used for protein detection analysis and functional test. Furthermore, in\ua0vitro experiments were performed in HEK293\ua0cells. Protein synthesis and secretion were analyzed in lysate and medium fraction, respectively, whereas medium fraction was used for functional assay. Results We identified two novel mutations in the LPL gene causing type 1 hyperlipoproteinemia: a two base pair deletion (c.765_766delAG) resulting in a frameshift at position 256 of the protein (p.G256TfsX26) and a nucleotide substitution (c.1211\ua0T\ua0>\ua0G) resulting in a methionine to arginine substitution (p.M404\ua0R). LPL protein and activity were not detected in pre-heparin or post-heparin plasma of the patient with p.G256TfsX26 mutation or in the medium of HEK293\ua0cells over-expressing recombinant p.G256TfsX26 LPL. A relatively small amount of LPL p.M404\ua0R was detected in both pre-heparin and post-heparin plasma and in the medium of the cells, whereas no LPL activity was detected. Conclusions We conclude that these two novel mutations cause type 1 hyperlipoproteinemia by inducing a loss or reduction in LPL secretion accompanied by a loss of LPL enzymatic activity

    Outcomes After Major Surgical Procedures in Octogenarians:A Nationwide Cohort Study

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    Introduction: Aging of the worldwide population has been observed, and postoperative outcomes could be worse in elderly patients. This nationwide study assessed trends in number of surgical resections in octogenarians regarding various major surgical procedures and associated postoperative outcomes. Methods: All patients who underwent surgery between 2014 and 2018 were included from Dutch nationwide quality registries regarding esophageal, stomach, pancreas, colorectal liver metastases, colorectal cancer, lung cancer and abdominal aortic aneurysms (AAA). For each quality registry, the number of patients who were 80 years or older (octogenarians) was calculated per year. Postoperative outcomes were length of stay (LOS), 30 day major morbidity and 30 day mortality between octogenarians and younger patients. Results: No increase in absolute number and proportion of octogenarians that underwent surgery was observed. Median LOS was higher in octogenarians who underwent surgery for colorectal cancer, colorectal liver metastases, lung cancer, pancreatic disease and esophageal cancer. 30 day major morbidity was higher in octogenarians who underwent surgery for colon cancer, esophageal cancer and elective AAA-repair. 30 day mortality was higher in octogenarians who underwent surgery for colorectal cancer, lung cancer, stomach cancer, pancreatic disease, esophageal cancer and elective AAA-repair. Median LOS decreased between 2014 and 2018 in octogenarians who underwent surgery for stomach cancer and colorectal cancer. 30 day major morbidity decreased between 2014 and 2018 in octogenarians who underwent surgery for colon cancer. No trends were observed in octogenarians regarding 30 day mortality between 2014 and 2018. Conclusion: No increase over time in absolute number and proportion of octogenarians that underwent major surgery was observed in the Netherlands. Postoperative outcomes were worse in octogenarians

    Inclusive production of ρ0(770),f0(980)\rho^{0}(770), f_0(980) and f2(1270)f_2(1270) mesons in νμ\nu_{\mu} charged current interactions

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    The inclusive production of the meson resonances ρ0(770)\rho^{0}(770), f0(980)f_0(980) and f2(1270)f_2(1270) in neutrino-nucleus charged current interactions has been studied with the NOMAD detector exposed to the wide band neutrino beam generated by 450 GeV protons at the CERN SPS. For the first time the f0(980)f_{0}(980) meson is observed in neutrino interactions. The statistical significance of its observation is 6 standard deviations. The presence of f2(1270)f_{2}(1270) in neutrino interactions is reliably established. The average multiplicity of these three resonances is measured as a function of several kinematic variables. The experimental results are compared to the multiplicities obtained from a simulation based on the Lund model. In addition, the average multiplicity of ρ0(770)\rho^{0}(770) in antineutrino - nucleus interactions is measured.Comment: 23 pages, 14 figures, 8 tables. To appear in Nucl. Phys.

    A Precise Measurement of the Muon Neutrino-Nucleon Inclusive Charged Current Cross-Section off an Isoscalar Target in the Energy Range 2.5 < E_\nu < 40 GeV by NOMAD

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    We present a measurement of the muon neutrino-nucleon inclusive charged current cross-section, off an isoscalar target, in the neutrino energy range 2.5Eν402.5 \leq E_\nu \leq 40 GeV. The significance of this measurement is its precision, ±4\pm 4% in 2.5Eν102.5 \leq E_\nu \leq 10 GeV, and ±2.6\pm 2.6% in 10Eν4010 \leq E_\nu \leq 40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.Comment: 14 pages, 3 figures, submitted to Phys.Lett.

    A study of backward going pp and π\pi^{-} in νμCC\nu_{\mu}CC interactions with the NOMAD detector

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    Backward proton and π\pi^- production has been studied in νμCC\nu_{\mu}CC interactions with carbon nuclei. Detailed analyses of the momentum distributions, of the production rates, and of the general features of events with a backward going particle, have been carried out in order to understand the mechanism producing these particles. The backward proton data have been compared with the predictions of the reinteraction and the short range correlation models.Comment: 29 pages, 14 figures, submitted to Nucl. Phys.

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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