57 research outputs found

    Is Large Lepton Mixing Excluded?

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    The original \bnum -(or νˉτ\bar{\nu}_{\tau}-) energy spectrum from the gravitational collapse of a star has a larger average energy than the spectrum for \bnue since the opacity of \bnue exeeds that of \bnum (or ντ\nu_{\tau}). Flavor neutrino conversion, \bnue \leftrightarrow \bnum, induced by lepton mixing results in partial permutation of the original \bnue and \bnum spectra. An upper bound on the permutation factor, p0.35p \leq 0.35 (99%\% CL) is derived using the data from SN1987A and the different models of the neutrino burst. The relation between the permutation factor and the vacuum mixing angle is established, which leads to the upper bound on this angle. The excluded region, sin22θ>0.70.9\sin^2 2\theta > 0.7 - 0.9, covers the regions of large mixing angle solutions of the solar neutrino problem: ``just-so" and, partly, MSW, as well as part of region of νeνμ\nu_{e} - \nu_{\mu} oscillation space which could be responsible for the atmospheric muon neutrino deficit. These limits are sensitive to the predicted neutrino spectrum and can be strengthened as supernova models improve.Comment: 20 pages, TeX file. For hardcopy with figures contact [email protected]. Institute for Advanced Study number AST 93/1

    The Central Temperature of the Sun can be Measured via the 7^7Be Solar Neutrino Line

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    A precise test of the theory of stellar evolution can be performed by measuring the difference in average energy between the neutrino line produced by 7Be{\rm ^7Be} electron capture in the solar interior and the corresponding neutrino line produced in a terrestrial laboratory. The high temperatures in the center of the sun broaden the line asymmetrically, FWHM = 1.6~keV, and cause an average energy shift of 1.3~keV. The width of the 7^7Be neutrino line should be taken into account in calculations of vacuum neutrino oscillations.Comment: RevTeX file, 9 pages. For hardcopy with figure, send to [email protected]. Institute for Advanced Study number AST 93/4

    A Review of the Scientific Rigor, Reproducibility, and Transparency Studies Conducted by the ABRF Research Groups.

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    Shared research resource facilities, also known as core laboratories (Cores), are responsible for generating a significant and growing portion of the research data in academic biomedical research institutions. Cores represent a central repository for institutional knowledge management, with deep expertise in the strengths and limitations of technology and its applications. They inherently support transparency and scientific reproducibility by protecting against cognitive bias in research design and data analysis, and thedy have institutional responsibility for the conduct of research (research ethics, regulatory compliance, and financial accountability) performed in their Cores. The Association of Biomolecular Resource Facilities (ABRF) is a FASEB-member scientific society whose members are scientists and administrators that manage or support Cores. The ABRF Research Groups (RGs), representing expertise for an array of cutting-edge and established technology platforms, perform multicenter research studies to determine and communicate best practices and community-based standards. This review provides a summary of the contributions of the ABRF RGs to promote scientific rigor and reproducibility in Cores from the published literature, ABRF meetings, and ABRF RGs communications

    Dietary reference values for chloride

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    This publication is linked to the following EFSA Supporting Publications articles: http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2019.EN-1679/full, http://onlinelibrary.wiley.com/doi/10.2903/sp.efsa.2017.e15121/full This publication is linked to the following EFSA Journal article: http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2019.5778/fullPeer reviewedPublisher PD

    Safety of phenylcapsaicin as a novel food pursuant to Regulation (EU) 2015/2283

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    Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on phenylcapsaicin as a novel food (NF) pursuant to Regulation (EU) 2015/2283. Phenylcapsaicin is a chemically synthesised analogue of capsaicin intended to be marketed in food supplements and in foods for special medical purposes to the general population above the age of 11 years old at a maximum level of 2.5 mg/day. The highest intake of the NF is 2.5 mg/day which corresponds to 36 \u3bcg/kg body weight (bw) per day for adults, and 58 \u3bcg/kg bw per day for adolescents (10\u201314 years). The Panel considers that there is no concern with respect to genotoxicity of the NF. The reference point derived based on a 13-week rat study was the lowest of the model averaged BMDL20 values of 37.2 mg/kg bw per day in females for increased plasma alanine aminotransferase (ALAT) levels. The Panel concludes that the NF, phenylcapsaicin, is safe under the proposed uses and use levels

    Neopterin is a cerebrospinal fluid marker for treatment outcome evaluation in patients affected by Trypanosoma brucei gambiense sleeping sickness.

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    BACKGROUND: Post-therapeutic follow-up is essential to confirm cure and to detect early treatment failures in patients affected by sleeping sickness (HAT). Current methods, based on finding of parasites in blood and cerebrospinal fluid (CSF) and counting of white blood cells (WBC) in CSF, are imperfect. New markers for treatment outcome evaluation are needed. We hypothesized that alternative CSF markers, able to diagnose the meningo-encephalitic stage of the disease, could also be useful for the evaluation of treatment outcome. METHODOLOGY/PRINCIPAL FINDINGS: Cerebrospinal fluid from patients affected by Trypanosoma brucei gambiense HAT and followed for two years after treatment was investigated. The population comprised stage 2 (S2) patients either cured or experiencing treatment failure during the follow-up. IgM, neopterin, B2MG, MMP-9, ICAM-1, VCAM-1, CXCL10 and CXCL13 were first screened on a small number of HAT patients (n = 97). Neopterin and CXCL13 showed the highest accuracy in discriminating between S2 cured and S2 relapsed patients (AUC 99% and 94%, respectively). When verified on a larger cohort (n = 242), neopterin resulted to be the most efficient predictor of outcome. High levels of this molecule before treatment were already associated with an increased risk of treatment failure. At six months after treatment, neopterin discriminated between cured and relapsed S2 patients with 87% specificity and 92% sensitivity, showing a higher accuracy than white blood cell numbers. CONCLUSIONS/SIGNIFICANCE: In the present study, neopterin was highlighted as a useful marker for the evaluation of the post-therapeutic outcome in patients suffering from sleeping sickness. Detectable levels of this marker in the CSF have the potential to shorten the follow-up for HAT patients to six months after the end of the treatment

    Cerebrospinal fluid neopterin as marker of the meningo-encephalitic stage of Trypanosoma brucei gambiense sleeping sickness.

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    BACKGROUND: Sleeping sickness, or human African trypanosomiasis (HAT), is a protozoan disease that affects rural communities in sub-Saharan Africa. Determination of the disease stage, essential for correct treatment, represents a key issue in the management of patients. In the present study we evaluated the potential of CXCL10, CXCL13, ICAM-1, VCAM-1, MMP-9, B2MG, neopterin and IgM to complement current methods for staging Trypanosoma brucei gambiense patients. METHODS AND FINDINGS: Five hundred and twelve T. b. gambiense HAT patients originated from Angola, Chad and the Democratic Republic of the Congo (D.R.C.). Their classification as stage 2 (S2) was based on the number of white blood cells (WBC) (>5/µL) or presence of parasites in the cerebrospinal fluid (CSF). The CSF concentration of the eight markers was first measured on a training cohort encompassing 100 patients (44 S1 and 56 S2). IgM and neopterin were the best in discriminating between the two stages of disease with 86.4% and 84.1% specificity respectively, at 100% sensitivity. When a validation cohort (412 patients) was tested, neopterin (14.3 nmol/L) correctly classified 88% of S1 and S2 patients, confirming its high staging power. On this second cohort, neopterin also predicted both the presence of parasites, and of neurological signs, with the same ability as IgM and WBC, the current reference for staging. CONCLUSIONS: This study has demonstrated that neopterin is an excellent biomarker for staging T. b. gambiense HAT patients. A rapid diagnostic test for detecting this metabolite in CSF could help in more accurate stage determination
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