190 research outputs found

    Features of the immune profile and microbiota in persons whose immune status is susceptible or resistant to chronic stress

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    Background. The presence of influence both sympathetic and vagus links of the autonomic nervous system to the immune system is generally recognized, but the data on their specific immunotropic effects are ambiguous. This includes, in particular, immune responses to the stress-induced shift of sympatho-vagal balance. The purpose of this study is to identify the characteristics of the immune profile, as well as the microbiota associated with it, in persons whose immune status is susceptible or resistant to chronic stress. Materials and Methods. The object of observation were 32 men and 8 women with chronic pyelonephritis in remission. The criterion for inclusion was the magnitude of the sympatho-vagal balance index LF/HF (recorded by "CardioLab+HRV"), which exceeded the age norm by 0,5 σ. Immune status evaluated on a set of I and II levels recommended by the WHO. The observed contingent by pair matching of persons with the same values of LF/HF ratio was retrospectively divided into two groups, almost identical to the average value of LF/HF and its dispersion, but with opposite deviations from the norm of the immune status index. Results. Immune profiles constructed on Z-scores can be divided into three networks. The first set contains 8 parameters (Killing Index vs E. coli and Staph. aur., IL-6, Entropy of LCG, Popovych’s Strain Index of LCG, Igg G and M as well as Microbial Count E. coli) that are not significantly different from persons who are stress-sensitive and stress-resistant. 18 parameters of the second set (Leukocytes, Phagocytose Index vs E. coli and Staph. aur.(PhIA), B-Lymphocytes, Segmented Neutrophils, Microbial Count Staph. aur., T-active (Ta), T-cytolytic and Natural Killers Lymphocytes (NK), IgA, Bactericidity vs E. coli and Staph. aur. (BCA), Bifidobacterium and Lactobacillus feces, Stub Neutrophils, T-helpers, Popovych’s Adaptation Index of LCG (PAI) as well as CIC) to a greater or lesser degree higher in stress-resistant persons. Instead, the 8 parameters of the third set (Lymphocytes, Monocytes and Eosinophils (E), TNF-α, IL-1 as well as Popovych’s Strain Index of LCG, 0-Lymphocytes and Hemolytica E. coli HEC) are higher in stress-sensitive persons. The method of discriminant analysis revealed 9 parameters (ranked by criterion Λ: 0-Lym, BCA, HEC, Ta, CIC, E, PhIA, PAI, NK) that characterize the features of immune profile of stress-susceptible and stress-resistant persons

    Recent Borexino results and prospects for the near future

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    The Borexino experiment, located in the Gran Sasso National Laboratory, is an organic liquid scintillator detector conceived for the real time spectroscopy of low energy solar neutrinos. The data taking campaign phase I (2007 - 2010) has allowed the first independent measurements of 7Be, 8B and pep fluxes as well as the first measurement of anti-neutrinos from the earth. After a purification of the scintillator, Borexino is now in phase II since 2011. We review here the recent results achieved during 2013, concerning the seasonal modulation in the 7Be signal, the study of cosmogenic backgrounds and the updated measurement of geo-neutrinos. We also review the upcoming measurements from phase II data (pp, pep, CNO) and the project SOX devoted to the study of sterile neutrinos via the use of a 51Cr neutrino source and a 144Ce-144Pr antineutrino source placed in close proximity of the active material.Comment: 8 pages, 11 figures. To be published as proceedings of Rencontres de Moriond EW 201

    Final results of Borexino Phase-I on low energy solar neutrino spectroscopy

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    Borexino has been running since May 2007 at the LNGS with the primary goal of detecting solar neutrinos. The detector, a large, unsegmented liquid scintillator calorimeter characterized by unprecedented low levels of intrinsic radioactivity, is optimized for the study of the lower energy part of the spectrum. During the Phase-I (2007-2010) Borexino first detected and then precisely measured the flux of the 7Be solar neutrinos, ruled out any significant day-night asymmetry of their interaction rate, made the first direct observation of the pep neutrinos, and set the tightest upper limit on the flux of CNO neutrinos. In this paper we discuss the signal signature and provide a comprehensive description of the backgrounds, quantify their event rates, describe the methods for their identification, selection or subtraction, and describe data analysis. Key features are an extensive in situ calibration program using radioactive sources, the detailed modeling of the detector response, the ability to define an innermost fiducial volume with extremely low background via software cuts, and the excellent pulse-shape discrimination capability of the scintillator that allows particle identification. We report a measurement of the annual modulation of the 7 Be neutrino interaction rate. The period, the amplitude, and the phase of the observed modulation are consistent with the solar origin of these events, and the absence of their annual modulation is rejected with higher than 99% C.L. The physics implications of phase-I results in the context of the neutrino oscillation physics and solar models are presented

    New limits on heavy sterile neutrino mixing in 8B{^{8}\rm{B}}-decay obtained with the Borexino detector

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    If heavy neutrinos with mass mνHm_{\nu_{H}}\geq2me m_e are produced in the Sun via the decay 8B8Be+e++νH{^8\rm{B}} \rightarrow {^8\rm{Be}} + e^+ + \nu_H in a side branch of pp-chain, they would undergo the observable decay into an electron, a positron and a light neutrino νHνL+e++e\nu_{H}\rightarrow\nu_{L}+e^++e^-. In the present work Borexino data are used to set a bound on the existence of such decays. We constrain the mixing of a heavy neutrino with mass 1.5 MeV mνH\leq m_{\nu_{H}} \le 14 MeV to be UeH2(1034×106)|U_{eH}|^2\leq (10^{-3}-4\times10^{-6}) respectively. These are tighter limits on the mixing parameters than obtained in previous experiments at nuclear reactors and accelerators.Comment: 7 pages, 6 figure

    The Main Results of the Borexino Experiment

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    The main physical results on the registration of solar neutrinos and the search for rare processes obtained by the Borexino collaboration to date are presented.Comment: 8 pages, 8 figgures, To be published as Proceedings of the Third Annual Large Hadron Collider Physics Conference, St. Petersburg, Russia, 201

    Measurement of neutrino flux from the primary proton--proton fusion process in the Sun with Borexino detector

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    Neutrino produced in a chain of nuclear reactions in the Sun starting from the fusion of two protons, for the first time has been detected in a real-time detector in spectrometric mode. The unique properties of the Borexino detector provided an oppurtunity to disentangle pp-neutrino spectrum from the background components. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 105^{5} years time scale, and sets a strong limit on the power production in the unknown energy sources in the Sun of no more than 4\% of the total energy production at 90\% C.L.Comment: 15 pages, 2 tables, 3 figure

    Identification of the cosmogenic 11C background in large volumes of liquid scintillators with Borexino

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    Cosmogenic radio-nuclei are an important source of background for low-energy neutrino experiments. In Borexino, cosmogenic 11C decays outnumber solar pep and CNO neutrino events by about ten to one. In order to extract the flux of these two neutrino species, a highly efficient identification of this background is mandatory. We present here the details of the most consolidated strategy, used throughout Borexino solar neutrino measurements. It hinges upon finding the space-time correlations between 11C decays, the preceding parent muons and the accompanying neutrons. This article describes the working principles and evaluates the performance of this Three-Fold Coincidence (TFC) technique in its two current implementations: a hard-cut and a likelihood-based approach. Both show stable performances throughout Borexino Phases II (2012–2016) and III (2016–2020) data sets, with a 11C tagging efficiency of ∼90 % and ∼ 63–66 % of the exposure surviving the tagging. We present also a novel technique that targets specifically 11C produced in high-multiplicity during major spallation events. Such 11C appear as a burst of events, whose space-time correlation can be exploited. Burst identification can be combined with the TFC to obtain about the same tagging efficiency of ∼90% but with a higher fraction of the exposure surviving, in the range of ∼ 66–68 %
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