1,342 research outputs found

    Solar neutrino measurements using the full data period of Super-Kamiokande-IV

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    International audienceAn analysis of solar neutrino data from the fourth phase of Super-Kamiokande~(SK-IV) from October 2008 to May 2018 is performed and the results are presented. The observation time of the data set of SK-IV corresponds to 29702970~days and the total live time for all four phases is 58055805~days. For more precise solar neutrino measurements, several improvements are applied in this analysis: lowering the data acquisition threshold in May 2015, further reduction of the spallation background using neutron clustering events, precise energy reconstruction considering the time variation of the PMT gain. The observed number of solar neutrino events in 3.493.49--19.4919.49~MeV electron kinetic energy region during SK-IV is 65,443388+390(stat.)±925(syst.)65,443^{+390}_{-388}\,(\mathrm{stat.})\pm 925\,(\mathrm{syst.}) events. Corresponding 8B\mathrm{^{8}B} solar neutrino flux is (2.314±0.014(stat.)±0.040(syst.))×106 cm2s1(2.314 \pm 0.014\, \rm{(stat.)} \pm 0.040 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}, assuming a pure electron-neutrino flavor component without neutrino oscillations. The flux combined with all SK phases up to SK-IV is (2.336±0.011(stat.)±0.043(syst.))×106 cm2s1(2.336 \pm 0.011\, \rm{(stat.)} \pm 0.043 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}. Based on the neutrino oscillation analysis from all solar experiments, including the SK 58055805~days data set, the best-fit neutrino oscillation parameters are sin2θ12,solar=0.306±0.013\rm{sin^{2} \theta_{12,\,solar}} = 0.306 \pm 0.013 and Δm21,solar2=(6.100.81+0.95)×105 eV2\Delta m^{2}_{21,\,\mathrm{solar}} = (6.10^{+ 0.95}_{-0.81}) \times 10^{-5}~\rm{eV}^{2}, with a deviation of about 1.5σ\sigma from the Δm212\Delta m^{2}_{21} parameter obtained by KamLAND. The best-fit neutrino oscillation parameters obtained from all solar experiments and KamLAND are sin2θ12,global=0.307±0.012\sin^{2} \theta_{12,\,\mathrm{global}} = 0.307 \pm 0.012 and Δm21,global2=(7.500.18+0.19)×105 eV2\Delta m^{2}_{21,\,\mathrm{global}} = (7.50^{+ 0.19}_{-0.18}) \times 10^{-5}~\rm{eV}^{2}

    Solar neutrino measurements using the full data period of Super-Kamiokande-IV

    No full text
    International audienceAn analysis of solar neutrino data from the fourth phase of Super-Kamiokande~(SK-IV) from October 2008 to May 2018 is performed and the results are presented. The observation time of the data set of SK-IV corresponds to 29702970~days and the total live time for all four phases is 58055805~days. For more precise solar neutrino measurements, several improvements are applied in this analysis: lowering the data acquisition threshold in May 2015, further reduction of the spallation background using neutron clustering events, precise energy reconstruction considering the time variation of the PMT gain. The observed number of solar neutrino events in 3.493.49--19.4919.49~MeV electron kinetic energy region during SK-IV is 65,443388+390(stat.)±925(syst.)65,443^{+390}_{-388}\,(\mathrm{stat.})\pm 925\,(\mathrm{syst.}) events. Corresponding 8B\mathrm{^{8}B} solar neutrino flux is (2.314±0.014(stat.)±0.040(syst.))×106 cm2s1(2.314 \pm 0.014\, \rm{(stat.)} \pm 0.040 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}, assuming a pure electron-neutrino flavor component without neutrino oscillations. The flux combined with all SK phases up to SK-IV is (2.336±0.011(stat.)±0.043(syst.))×106 cm2s1(2.336 \pm 0.011\, \rm{(stat.)} \pm 0.043 \, \rm{(syst.)}) \times 10^{6}~\mathrm{cm^{-2}\,s^{-1}}. Based on the neutrino oscillation analysis from all solar experiments, including the SK 58055805~days data set, the best-fit neutrino oscillation parameters are sin2θ12,solar=0.306±0.013\rm{sin^{2} \theta_{12,\,solar}} = 0.306 \pm 0.013 and Δm21,solar2=(6.100.81+0.95)×105 eV2\Delta m^{2}_{21,\,\mathrm{solar}} = (6.10^{+ 0.95}_{-0.81}) \times 10^{-5}~\rm{eV}^{2}, with a deviation of about 1.5σ\sigma from the Δm212\Delta m^{2}_{21} parameter obtained by KamLAND. The best-fit neutrino oscillation parameters obtained from all solar experiments and KamLAND are sin2θ12,global=0.307±0.012\sin^{2} \theta_{12,\,\mathrm{global}} = 0.307 \pm 0.012 and Δm21,global2=(7.500.18+0.19)×105 eV2\Delta m^{2}_{21,\,\mathrm{global}} = (7.50^{+ 0.19}_{-0.18}) \times 10^{-5}~\rm{eV}^{2}

    Identified charged-hadron production in pp++Al, 3^3He++Au, and Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and in U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV

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    International audienceThe PHENIX experiment has performed a systematic study of identified charged-hadron (π±\pi^\pm, K±K^\pm, pp, pˉ\bar{p}) production at midrapidity in pp++Al, 3^3He++Au, Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV. Identified charged-hadron invariant transverse-momentum (pTp_T) and transverse-mass (mTm_T) spectra are presented and interpreted in terms of radially expanding thermalized systems. The particle ratios of K/πK/\pi and p/πp/\pi have been measured in different centrality ranges of large (Cu++Au, U++U) and small (pp++Al, 3^3He++Au) collision systems. The values of K/πK/\pi ratios measured in all considered collision systems were found to be consistent with those measured in pp++pp collisions. However the values of p/πp/\pi ratios measured in large collision systems reach the values of 0.6\approx0.6, which is 2\approx2 times larger than in pp++pp collisions. These results can be qualitatively understood in terms of the baryon enhancement expected from hadronization by recombination. Identified charged-hadron nuclear-modification factors (RABR_{AB}) are also presented. Enhancement of proton RABR_{AB} values over meson RABR_{AB} values was observed in central 3^3He++Au, Cu++Au, and U++U collisions. The proton RABR_{AB} values measured in pp++Al collision system were found to be consistent with RABR_{AB} values of ϕ\phi, π±\pi^\pm, K±K^\pm, and π0\pi^0 mesons, which may indicate that the size of the system produced in pp++Al collisions is too small for recombination to cause a noticeable increase in proton production

    Accelarated immune ageing is associated with COVID-19 disease severity

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    Background The striking increase in COVID-19 severity in older adults provides a clear example of immunesenescence, the age-related remodelling of the immune system. To better characterise the association between convalescent immunesenescence and acute disease severity, we determined the immune phenotype of COVID-19 survivors and non-infected controls. Results We performed detailed immune phenotyping of peripheral blood mononuclear cells isolated from 103 COVID-19 survivors 3–5 months post recovery who were classified as having had severe (n = 56; age 53.12 ± 11.30 years), moderate (n = 32; age 52.28 ± 11.43 years) or mild (n = 15; age 49.67 ± 7.30 years) disease and compared with age and sex-matched healthy adults (n = 59; age 50.49 ± 10.68 years). We assessed a broad range of immune cell phenotypes to generate a composite score, IMM-AGE, to determine the degree of immune senescence. We found increased immunesenescence features in severe COVID-19 survivors compared to controls including: a reduced frequency and number of naïve CD4 and CD8 T cells (p < 0.0001); increased frequency of EMRA CD4 (p < 0.003) and CD8 T cells (p < 0.001); a higher frequency (p < 0.0001) and absolute numbers (p < 0.001) of CD28−ve CD57+ve senescent CD4 and CD8 T cells; higher frequency (p < 0.003) and absolute numbers (p < 0.02) of PD-1 expressing exhausted CD8 T cells; a two-fold increase in Th17 polarisation (p < 0.0001); higher frequency of memory B cells (p < 0.001) and increased frequency (p < 0.0001) and numbers (p < 0.001) of CD57+ve senescent NK cells. As a result, the IMM-AGE score was significantly higher in severe COVID-19 survivors than in controls (p < 0.001). Few differences were seen for those with moderate disease and none for mild disease. Regression analysis revealed the only pre-existing variable influencing the IMM-AGE score was South Asian ethnicity ( = 0.174, p = 0.043), with a major influence being disease severity ( = 0.188, p = 0.01). Conclusions Our analyses reveal a state of enhanced immune ageing in survivors of severe COVID-19 and suggest this could be related to SARS-Cov-2 infection. Our data support the rationale for trials of anti-immune ageing interventions for improving clinical outcomes in these patients with severe disease

    The artificial intelligence-based model ANORAK improves histopathological grading of lung adenocarcinoma

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    The introduction of the International Association for the Study of Lung Cancer grading system has furthered interest in histopathological grading for risk stratification in lung adenocarcinoma. Complex morphology and high intratumoral heterogeneity present challenges to pathologists, prompting the development of artificial intelligence (AI) methods. Here we developed ANORAK (pyrAmid pooliNg crOss stReam Attention networK), encoding multiresolution inputs with an attention mechanism, to delineate growth patterns from hematoxylin and eosin-stained slides. In 1,372 lung adenocarcinomas across four independent cohorts, AI-based grading was prognostic of disease-free survival, and further assisted pathologists by consistently improving prognostication in stage I tumors. Tumors with discrepant patterns between AI and pathologists had notably higher intratumoral heterogeneity. Furthermore, ANORAK facilitates the morphological and spatial assessment of the acinar pattern, capturing acinus variations with pattern transition. Collectively, our AI method enabled the precision quantification and morphology investigation of growth patterns, reflecting intratumoral histological transitions in lung adenocarcinoma

    Identified charged-hadron production in pp++Al, 3^3He++Au, and Cu++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV and in U++U collisions at sNN=193\sqrt{s_{_{NN}}}=193 GeV