293 research outputs found

    Genetic risk factors for ischaemic stroke and its subtypes (the METASTROKE Collaboration): a meta-analysis of genome-wide association studies

    Get PDF
    <p>Background - Various genome-wide association studies (GWAS) have been done in ischaemic stroke, identifying a few loci associated with the disease, but sample sizes have been 3500 cases or less. We established the METASTROKE collaboration with the aim of validating associations from previous GWAS and identifying novel genetic associations through meta-analysis of GWAS datasets for ischaemic stroke and its subtypes.</p> <p>Methods - We meta-analysed data from 15 ischaemic stroke cohorts with a total of 12 389 individuals with ischaemic stroke and 62 004 controls, all of European ancestry. For the associations reaching genome-wide significance in METASTROKE, we did a further analysis, conditioning on the lead single nucleotide polymorphism in every associated region. Replication of novel suggestive signals was done in 13 347 cases and 29 083 controls.</p> <p>Findings - We verified previous associations for cardioembolic stroke near PITX2 (p=2·8×10−16) and ZFHX3 (p=2·28×10−8), and for large-vessel stroke at a 9p21 locus (p=3·32×10−5) and HDAC9 (p=2·03×10−12). Additionally, we verified that all associations were subtype specific. Conditional analysis in the three regions for which the associations reached genome-wide significance (PITX2, ZFHX3, and HDAC9) indicated that all the signal in each region could be attributed to one risk haplotype. We also identified 12 potentially novel loci at p<5×10−6. However, we were unable to replicate any of these novel associations in the replication cohort.</p> <p>Interpretation - Our results show that, although genetic variants can be detected in patients with ischaemic stroke when compared with controls, all associations we were able to confirm are specific to a stroke subtype. This finding has two implications. First, to maximise success of genetic studies in ischaemic stroke, detailed stroke subtyping is required. Second, different genetic pathophysiological mechanisms seem to be associated with different stroke subtypes.</p&gt

    Experimental study of the atmospheric neutrino backgrounds for proton decay to positron and neutral pion searches in water Cherenkov detectors

    Get PDF
    The atmospheric neutrino background for proton decay to positron and neutral pion in ring imaging water Cherenkov detectors is studied with an artificial accelerator neutrino beam for the first time. In total, about 314,000 neutrino events corresponding to about 10 megaton-years of atmospheric neutrino interactions were collected by a 1,000 ton water Cherenkov detector (KT). The KT charged-current single neutral pion production data are well reproduced by simulation programs of neutrino and secondary hadronic interactions used in the Super-Kamiokande (SK) proton decay search. The obtained proton to positron and neutral pion background rate by the KT data for SK from the atmospheric neutrinos whose energies are below 3 GeV is about two per megaton-year. This result is also relevant to possible future, megaton-scale water Cherenkov detectors.Comment: 13 pages, 16 figure

    Measurement of single charged pion production in the charged-current interactions of neutrinos in a 1.3 GeV wide band beam

    Full text link
    Single charged pion production in charged-current muon neutrino interactions with carbon is studied using data collected in the K2K long-baseline neutrino experiment. The mean energy of the incident muon neutrinos is 1.3 GeV. The data used in this analysis are mainly from a fully active scintillator detector, SciBar. The cross section for single π+\pi^{+} production in the resonance region (W<2W<2 GeV/c2c^2) relative to the charged-current quasi-elastic cross section is found to be 0.734 0.153+0.140^{+0.140}_{-0.153}. The energy-dependent cross section ratio is also measured. The results are consistent with a previous experiment and the prediction of our model.Comment: 15 pages, 12 figures, 7 tables. Uses revtex4. Minor revisions to match version accepted for publication in Physical Review

    Interim Design Report

    Get PDF
    The International Design Study for the Neutrino Factory (the IDS-NF) was established by the community at the ninth "International Workshop on Neutrino Factories, super-beams, and beta- beams" which was held in Okayama in August 2007. The IDS-NF mandate is to deliver the Reference Design Report (RDR) for the facility on the timescale of 2012/13. In addition, the mandate for the study [3] requires an Interim Design Report to be delivered midway through the project as a step on the way to the RDR. This document, the IDR, has two functions: it marks the point in the IDS-NF at which the emphasis turns to the engineering studies required to deliver the RDR and it documents baseline concepts for the accelerator complex, the neutrino detectors, and the instrumentation systems. The IDS-NF is, in essence, a site-independent study. Example sites, CERN, FNAL, and RAL, have been identified to allow site-specific issues to be addressed in the cost analysis that will be presented in the RDR. The choice of example sites should not be interpreted as implying a preferred choice of site for the facility

    Risk factors and outcome of COVID-19 in patients with hematological malignancies

    Get PDF
    Background: Prognostic factors of poor outcome in patients with hematological malignancies and COVID-19 are poorly defned. Patients and methods: This was a Spanish transplant group and cell therapy (GETH) multicenter retrospective observational study, which included a large cohort of blood cancer patients with laboratory-confrmed SARS-CoV-2 infection through PCR assays from March 1st 2020 to May 15th 2020. Results: We included 367 pediatric and adult patients with hematological malignancies, including recipients of autologous (ASCT) (n=58) or allogeneic stem cell transplantation (allo-SCT) (n=65) from 41 hospitals in Spain. Median age of patients was 64 years (range 1-93.8). Recipients of ASCT and allo-SCT showed lower mortality rates (17% and 18%, respectively) compared to non-SCT patients (31%) (p=0.02). Prognostic factors identifed for day 45 overall mortality (OM) by logistic regression multivariate analysis included age>70 years [odds ratio (OR) 2.1, 95% con‑ fdence interval (CI) 1.2-3.8, p=0.011]; uncontrolled hematological malignancy (OR 2.9, 95% CI 1.6-5.2, p20 mg/dL (OR 3.3, 95% CI 1.7-6.4, p<0.0001). In multivariate analysis of 216 patients with very severe COVID-19, treatment with azithromycin or low dose corticosteroids was associated with lower OM (OR 0.42, 95% CI 0.2-0.89 and OR 0.31, 95% CI 0.11-0.87, respectively, p=0.02) whereas the use of hidroxycloroquine did not show signifcant improvement in OM (OR 0.64, 95% CI 0.37-1.1, P=0.1). Conclusions: In most patients with hematological malignancies COVID-19 mortality was directly driven by older age, disease status, performance status, as well as by immune (neutropenia) parameters and level of infammation (high CRP). Use of azithromycin and low dose corticosteroids may be of value in very severe COVID-19

    Genome-wide association trans-ethnic meta-analyses identifies novel associations regulating coagulation Factor VIII and von Willebrand Factor plasma levels

    Get PDF
    BACKGROUND: Factor VIII (FVIII) and its carrier protein von Willebrand factor (VWF) are associated with risk of arterial and venous thrombosis and with hemorrhagic disorders. We aimed to identify and functionally test novel genetic associations regulating plasma FVIII and VWF. METHODS: We meta-analyzed genome-wide association results from 46 354 individuals of European, African, East Asian, and Hispanic ancestry. All studies performed linear regression analysis using an additive genetic model and associated ≈35 million imputed variants with natural log-transformed phenotype levels. In vitro gene silencing in cultured endothelial cells was performed for candidate genes to provide additional evidence on association and function. Two-sample Mendelian randomization analyses were applied to test the causal role of FVIII and VWF plasma levels on the risk of arterial and venous thrombotic events. RESULTS: We identified 13 novel genome-wide significant ( P≤2.5×10-8) associations, 7 with FVIII levels ( FCHO2/TMEM171/TNPO1, HLA, SOX17/RP1, LINC00583/NFIB, RAB5C-KAT2A, RPL3/TAB1/SYNGR1, and ARSA) and 11 with VWF levels ( PDHB/PXK/KCTD6, SLC39A8, FCHO2/TMEM171/TNPO1, HLA, GIMAP7/GIMAP4, OR13C5/NIPSNAP, DAB2IP, C2CD4B, RAB5C-KAT2A, TAB1/SYNGR1, and ARSA), beyond 10 previously reported associations with these phenotypes. Functional validation provided further evidence of association for all loci on VWF except ARSA and DAB2IP. Mendelian randomization suggested causal effects of plasma FVIII activity levels on venous thrombosis and coronary artery disease risk and plasma VWF levels on ischemic stroke risk. CONCLUSIONS: The meta-analysis identified 13 novel genetic loci regulating FVIII and VWF plasma levels, 10 of which we validated functionally. We provide some evidence for a causal role of these proteins in thrombotic events

    Measurement of inclusive π0\pi^0 production in the Charged-Current Interactions of Neutrinos in a 1.3-GeV wide band beam

    Get PDF
    In this paper we report on the measurement of the rate of inclusive π0\pi^0 production induced by charged-current neutrino interactions in a C8_8H8_8 target at a mean energy of 1.3 GeV in the K2K near detector. Out of a sample of 11,606 charged current neutrino interactions, we select 479 π0\pi^0 events with two reconstructed photons. We find that the cross section for the inclusive π0\pi^0 production relative to the charged-current quasi-elastic cross section is σCCπ0σCCQE=0.426±0.032(stat.)±0.035(syst.)\frac{\sigma_{CC\pi^0}}{\sigma_{CCQE}}=0.426\pm0.032(stat.)\pm0.035(syst.) The energy dependent cross section ratio is also measured. The results are consistent with previous experiments for exclusive channels on different targets.Comment: 18 pages, 11 figures, submitted to PR

    Improved search for νμνe\nu_\mu \to \nu_e oscillation in a long-baseline accelerator experiment

    Get PDF
    We performed an improved search for νμνe\nu_\mu \to \nu_e oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2×10199.2 \times 10^{19}\xspace protons on target. No evidence for a νe\nu_e appearance signal was found, and we set bounds on the νμνe\nu_\mu \to \nu_e oscillation parameters. At Δm2\Delta m^2 = 2.8×103eV22.8 \times 10^{-3} \mathrm{eV}^2, the best fit value of the K2K νμ\nu_\mu disappearance analysis, we set an upper limit of sin22θμe\sin^2 2\theta_{\mu e} << 0.13 at 90% confidence level.Comment: 5 pages, 2 figure

    Measurement of neutrino oscillation by the K2K experiment

    Get PDF
    We present measurements of nu(mu) disappearance in K2K, the KEK to Kamioka long-baseline neutrino oscillation experiment. One-hundred and twelve beam-originated neutrino events are observed in the fiducial volume of Super-Kamiokande with an expectation of 158.1(-8.6)(+9.2) events without oscillation. A distortion of the energy spectrum is also seen in 58 single-ring muonlike events with reconstructed energies. The probability that the observations are explained by the expectation for no neutrino oscillation is 0.0015% (4.3 sigma). In a two-flavor oscillation scenario, the allowed Delta m(2) region at sin(2)2 theta=1 is between 1.9 and 3.5x10(-3) eV(2) at the 90% C.L. with a best-fit value of 2.8x10(-3) eV(2)
    corecore