3,420 research outputs found

    Occurrence of Blastocystis-subtypes in patients from Italy revealed association of ST3 with a healthy gut microbiota

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    An epidemiological survey on Blastocystis was carried out enrolling a total of 2524 subjects referred to the Umberto I Academic Hospital in Rome, for the routine parasitological exams, during 2017–2018. The studied population included a sample of immunocompromised individuals (N = 130) followed at the same hospital. DNA sequencing of the small subunit rRNA gene (SSU rDNA) locus was performed on samples positive to the coproparasitological analysis to molecular characterize the Blastocystis-subtypes. Microscopical analysis detected Blastocystis in 192/2524 (7.6%) of the enrolled subjects. It was the organism most frequently identified in the analysed faecal samples diagnosed in single infection (5.6%) or in co-infection with other enteric protozoa (2%). Furthermore, it was found mainly in immunocompromised patients (22.3%) compared to immunocompetent ones (6.8%). As expected, ST3 was the most occurring subtype identified in 40% of the subjects, followed by ST1 (29%), ST2 (16%), ST4 (12%), and ST7 (3%). Next-generation sequencing (NGS) of the 16S rDNA was performed on a sub-sample of Blastocystis-ST3-carriers, homogenous by age and gender, as well as on Blastocystis-free subjects, to profile and compare their gut bacterial composition. A higher bacterial diversity was found in ST3-Blastocystis-carriers, which exhibited a high abundance of Prevotella, Methanobrevibacter and Ruminococcus while, a high percentage of Bacteroides was found in Blastocystis-free subjects. This study evidenced the presence of Blastocystis in 7.6% of faecal samples in Italy and a high circulation of the protist among immunocompromised patients (22.3%). Molecular characterization of positive samples evidenced the occurrence of five different subtypes, including zoonotic ST such as the ST7, highlighting the risk of transmission from animals. Study of the gut microbiota composition confirms previous evidences according to which, the colonisation by Blastocystis would be linked with an eubiotic gut characterized by potentially beneficial species such as Prevotella and Ruminococcus, rather than with a dysbiotic state, with a high abundance of Enterobacteriaceae, and corroborated the role of the protist as “an old friend” of the human gut

    Extreme Energy Cosmic Rays (EECR) Observation Capabilities of an "Airwatch from Space'' Mission

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    The longitudinal development and other characteristics of the EECR induced atmospheric showers can be studied from space by detecting the fluorescence light induced in the atmospheric nitrogen. According to the Airwatch concept a single fast detector can be used for measuring both intensity and time development of the streak of fluorescence light produced by the atmospheric shower induced by an EECR. In the present communication the detection capabilities for the EECR observation from space are discussed.Comment: 3 pages (LaTeX). To appear in the Proceedings of TAUP'9

    Generic and Layered Framework Components for the Control of a Large Scale Data Acquisition System

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    The complexity of today's experiments in High Energy Physics results in a large amount of readout channels which can count up to a million and above. The experiments in general consist of various subsystems which themselves comprise a large amount of detectors requiring sophisticated DAQ and readout electronics. We report here on the structured software layers to control such a data acquisition system for the case of LHCb which is one of the four experiments for LHC. Additional focus is given on the protocols in use as well as the required hardware. An abstraction layer was implemented to allow access on the different and distinct hardware types in a coherent and generic manner. The hierarchical structure which allows propagating commands down to the subsystems is explained. Via finite state machines an expert system with auto-recovery abilities can be modeled

    Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

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    An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

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    The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

    Search for CP violation in D+KK+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

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    A model-independent search for direct CP violation in the Cabibbo suppressed decay D+KK+π+D^+ \to K^- K^+\pi^+ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb1^{-1}. The normalized Dalitz plot distributions for D+D^+ and DD^- are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

    Hadronization properties of b quarks compared to light quarks in e+e- -> q qbar from 183 to 200 GeV

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    The DELPHI detector at LEP has collected 54 pb^{-1} of data at a centre-of-mass energy around 183 GeV during 1997, 158 pb^{-1} around 189 GeV during 1998, and 187 pb^{-1} between 192 and 200 GeV during 1999. These data were used to measure the average charged particle multiplicity in e+e- -> b bbar events, _{bb}, and the difference delta_{bl} between _{bb} and the multiplicity, _{ll}, in generic light quark (u,d,s) events: delta_{bl}(183 GeV) = 4.55 +/- 1.31 (stat) +/- 0.73 (syst) delta_{bl}(189 GeV) = 4.43 +/- 0.85 (stat) +/- 0.61 (syst) delta_{bl}(200 GeV) = 3.39 +/- 0.89 (stat) +/- 1.01 (syst). This result is consistent with QCD predictions, while it is inconsistent with calculations assuming that the multiplicity accompanying the decay of a heavy quark is independent of the mass of the quark itself.Comment: 13 pages, 2 figure

    Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

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    Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.Comment: 31 pages, 14 figure

    Search for composite and exotic fermions at LEP 2

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    A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio
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