108 research outputs found

    First Observation of Coherent π0\pi^0 Production in Neutrino Nucleus Interactions with EÎœ<E_{\nu}< 2 GeV

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    The MiniBooNE experiment at Fermilab has amassed the largest sample to date of π0\pi^0s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of π0\pi^0s produced in mineral oil (CH2_2) and the first observation of coherent π0\pi^0 production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 ±\pm1.1 (stat) ±\pm2.5 (sys))% of all exclusive NC π0\pi^0 production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for ΜΌ→Μe\nu_{\mu} \to \nu_e oscillations.Comment: Submitted to Phys. Lett.

    Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses

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    The sidereal time dependence of MiniBooNE electron neutrino and anti-electron neutrino appearance data are analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino and anti-electron neutrino appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the electron neutrino appearance data prefer a sidereal time-independent solution, and the anti-electron neutrino appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10E-20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for muon neutrino to electron neutrino and anti-muon neutrino to anti-electron neutrino oscillations. The fit values and limits of combinations of SME coefficients are provided.Comment: 14 pages, 3 figures, and 2 tables, submitted to Physics Letters

    A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

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    This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≄3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

    Ação do cepa e do åcido giberélico na frutificação da videira 'niagara rosada'

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    Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the JundiaĂ­ Research Station, Agronomic Institute State of SĂŁo Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersĂŁo, do CEPA (ĂĄcido 2-cloroetil fosfĂŽnico) e do ĂĄcido giberĂ©lico, 14 dias antes do florescimento, nas caracterĂ­sticas morfolĂłgicas da panĂ­cula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ĂĄcido giberĂ©lico foram concluĂ­dos com nova aplicação 10 dias apĂłs o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panĂ­culas com a maioria de caracterĂ­sticas indesejĂĄveis. o tratamento misto CEPA 100 ppm + ĂĄcido giberĂ©lico 100 ppm tambĂ©m promoveu o aparecimento de panĂ­culas subdesenvolvidas. Aplicação de ĂĄcido giberĂ©lico na concentração de 100 ppm em prĂ© e pĂłs-Ă­lorescimento, resultou mĂ©dias mais elevadas, com relação ao peso da panĂ­cula, comprimento da panĂ­cula, peso das bagas e comprimento da rĂĄquis. Ácido giberĂ©lico na concentração de 100 ppm aplicado em pĂłs-Ă­lorescimento, promoveu uma tendĂȘncia de aumento nas mĂ©dias do tratamento quanto ao comprimento mĂ©dio das bagas, largura mĂ©dia das bagas, largura do engaço e comprimento da rĂĄquila. Devemos considerar porĂ©m, que os resultados obtidos nĂŁo apresentaram diferenças significativas com relação ao controle, quanto Ă s caracterĂ­sticas das frutificaçÔes, nas condiçÔes de estudo

    Genetic determinants of telomere length from 109,122 ancestrally diverse whole-genome sequences in TOPMed

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    Genetic studies on telomere length are important for understanding age-related diseases. Prior GWASs for leukocyte TL have been limited to European and Asian populations. Here, we report the first sequencing-based association study for TL across ancestrally diverse individuals (European, African, Asian, and Hispanic/Latino) from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. We used whole-genome sequencing (WGS) of whole blood for variant genotype calling and the bioinformatic estimation of telomere length in n = 109,122 individuals. We identified 59 sentinel variants (p &lt; 5 × 10−9) in 36 loci associated with telomere length, including 20 newly associated loci (13 were replicated in external datasets). There was little evidence of effect size heterogeneity across populations. Fine-mapping at OBFC1 indicated that the independent signals colocalized with cell-type-specific eQTLs for OBFC1 (STN1). Using a multi-variant gene-based approach, we identified two genes newly implicated in telomere length, DCLRE1B (SNM1B) and PARN. In PheWAS, we demonstrated that our TL polygenic trait scores (PTSs) were associated with an increased risk of cancer-related phenotypes
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