1,167 research outputs found

    Nucleon decay and atmospheric neutrinos in the Mont Blanc experiment

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    In the NUSEX experiment, during 2.8 years of operation, 31 fully contained events have been collected; 3 among them are nucleon decay candidates, while the others have been attributed to upsilon interactions. Limits on nucleon lifetime and determinations of upsilon interaction rates are presented

    An Experimentalist's View of Neutrino Oscillations

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    Neutrinos, and primarily neutrino oscillations, have undoubtedly been one of the most exciting topics in the field of high-energy physics over the past few years. The existence of neutrino oscillations would require an extension of the currently accepted description of sub-nuclear phenomena beyond the Standard Model. Compelling evidence of new physics, which seems to be pointing towards neutrino oscillations, is coming from the solar neutrino deficit and from the atmospheric neutrino anomaly. More controversial effects have been observed with artificially produced neutrinos. The present experimental status of neutrino oscillations is reviewed, as well as the planned future experimental programme, which, it is hoped, will solve most of the outstanding puzzles.Comment: 64 pages, 29 figures, to be published in Intern. J. Mod. Phys. A (2001

    PREVALENCE OF 'BORDERLINE' VALUES OF CARDIOVASCULAR RISK FACTORS IN THE CLINICAL PRACTICE OF GENERAL MEDICINE IN ITALY: RESULTS OF THE BORDERLINE STUDY.

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    INTRODUCTION: The prevalence of patients with 'borderline' levels of cardiovascular risk factors has been rarely investigated, being often reported in studies evaluating abnormal values of these parameters. The BORDERLINE study represents a pilot experience to primarily identify the prevalence of 'high-normal' conditions, such as pre-hypertension, lipid and glucose levels in the upper range of normality in the setting of general practice in Italy. AIM: The aim of this study was to evaluate the prevalence of patients with 'borderline' values of cardiovascular risk factors in Italy. METHODS: Involved physicians were asked to evaluate the first 20 outpatients, consecutively seen in June 2009. Data were collected in a study-designed case-report form, in which physicians identified thresholds rather than reported absolute values of several clinical parameters. High-normal values were defined as follows: blood pressure (BP) 130-140/85-90 mmHg; total cholesterol 180-200 mg/dL; low-density lipoprotein cholesterol (LDL-C) 130-150 mg/dL; high-density lipoprotein cholesterol (HDL-C) 30-40 mg/dL in males and 40-50 mg/dL in females; triglycerides 130-150 mg/dL and fasting glucose 100-110 mg/dL. RESULTS: Fifty-three Italian physicians provided valuable clinical data on 826 individual outpatients, among which 692 (83.7%, 377 women, mean age 60.9 ± 13.2 years, body mass index 26.6 ± 5.0 kg/m2) were included in the present analysis. Prevalence of borderline values of systolic BP and total cholesterol levels were at least comparable with those in the normal limits of the corresponding parameters, whereas prevalence of borderline diastolic BP, LDL-C, HDL-C, triglycerides and fasting glucose levels was significantly lower than that of normal values, but higher than that of abnormal values of the corresponding parameters. CONCLUSIONS: Using this sample of healthy subjects in the setting of general practice in Italy, our results demonstrated a relatively high prevalence of borderline values of cardiovascular risk factors, which was at least comparable with that of normal, but significantly higher than that of abnormal thresholds. These preliminary findings may prompt more extensive investigations in the area of 'borderline' cardiovascular risk. This information may, in fact, potentially enable the design of more effective prevention strategies in the future to limit the burden of cardiovascular disease in the general population in Italy

    A primer on machine learning techniques for genomic applications

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    High throughput sequencing technologies have enabled the study of complex biological aspects at single nucleotide resolution, opening the big data era. The analysis of large volumes of heterogeneous “omic” data, however, requires novel and efficient computational algorithms based on the paradigm of Artificial Intelligence. In the present review, we introduce and describe the most common machine learning methodologies, and lately deep learning, applied to a variety of genomics tasks, trying to emphasize capabilities, strengths and limitations through a simple and intuitive language. We highlight the power of the machine learning approach in handling big data by means of a real life example, and underline how described methods could be relevant in all cases in which large amounts of multimodal genomic data are available

    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

    Easy on that trigger dad: a study of long term family photo retrieval

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    We examine the effects of new technologies for digital photography on people's longer term storage and access to collections of personal photos. We report an empirical study of parents' ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants' organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants' false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings

    Measurement of the cosmic ray hadron spectrum up to 30 TeV at mountain altitude: the primary proton spectrum

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    The flux of cosmic ray hadrons at the atmospheric depth of 820 g/cm^2 has been measured by means of the EAS-TOP hadron calorimeter (Campo Imperatore, National Gran Sasso Laboratories, 2005 m a.s.l.). The hadron spectrum is well described by a single power law : S(E_h) = (2.25 +- 0.21 +- 0.34(sys)) 10^(-7)(E_h/1000)^(-2.79 +- 0.05) m^(-2) s^(-1) sr^(-1) GeV^(-1) over the energy range 30 GeV-30 TeV. The procedure and the accuracy of the measurement are discussed. The primary proton spectrum is derived from the data by using the CORSIKA/QGSJET code to compute the local hadron flux as a function of the primary proton spectrum and to calculate and subtract the heavy nuclei contribution (basing on direct measurements). Over a wide energy range E_0 = 0.5-50 TeV its best fit is given by a single power law : S(E_0) = (9.8 +- 1.1 +- 1.6(sys)) 10^(-5) (E_0/1000)^(-2.80 +- 0.06) m^(-2) s^(-1) sr^(-1) GeV^(-1). The validity of the CORSIKA/QGSJET code for such application has been checked using the EAS-TOP and KASCADE experimental data by reproducing the ratio of the measured hadron fluxes at the two experimental depths (820 and 1030 g/cm^2 respectively) at better than 10% in the considered energy range.Comment: 16 pages, 9 figures, accepted for publication in Astroparticle Physic

    The large-scale magnetic field of the M dwarf double-line spectroscopic binary FK Aqr

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    This work is part of the BinaMIcS project, the aim of which is to understand the interaction between binarity and magnetism in close binary systems. All the studied spectroscopic binaries targeted by the BinaMIcS project encompass hot massive and intermediate-mass stars on the main sequence, as well as cool stars over a wide range of evolutionary stages. The present paper focuses on the binary system FK Aqr, which is composed of two early M dwarfs. Both stars are already known to be magnetically active based on their light curves and detected flare activity. In addition, the two components have large convective envelopes with masses just above the fully convective limit, making the system an ideal target for studying effect of binarity on stellar dynamos. We use spectropolarimetric observations obtained with ESPaDOnS at CFHT in September 2014. Mean Stokes I and V line profiles are extracted using the least-squares deconvolution (LSD) method. The radial velocities of the two components are measured from the LSD Stokes I profiles and are combined with interferometric measurements in order to constrain the orbital parameters of the system. The longitudinal magnetic fields Bl and chromospheric activity indicators are measured from the LSD mean line profiles. The rotational modulation of the Stokes V profiles is used to reconstruct the surface magnetic field structures of both stars via the Zeeman Doppler imaging (ZDI) inversion technique. Maps of the surface magnetic field structures of both components of FK Aqr are presented for the first time. Our study shows that both components host similar large-scale magnetic fields of moderate intensity (Bmean ~ 0.25 kG); both are predominantly poloidal and feature a strong axisymmetric dipolar component. (abridged)Comment: 19 pages, 6 figures, 6 tables + appendices, accepted for publication in A&A, in pres

    Time dependence of the electron and positron components of the cosmic radiation measured by the PAMELA experiment between July 2006 and December 2015

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    Cosmic-ray electrons and positrons are a unique probe of the propagation of cosmic rays as well as of the nature and distribution of particle sources in our Galaxy. Recent measurements of these particles are challenging our basic understanding of the mechanisms of production, acceleration and propagation of cosmic rays. Particularly striking are the differences between the low energy results collected by the space-borne PAMELA and AMS-02 experiments and older measurements pointing to sign-charge dependence of the solar modulation of cosmic-ray spectra. The PAMELA experiment has been measuring the time variation of the positron and electron intensity at Earth from July 2006 to December 2015 covering the period for the minimum of solar cycle 23 (2006-2009) till the middle of the maximum of solar cycle 24, through the polarity reversal of the heliospheric magnetic field which took place between 2013 and 2014. The positron to electron ratio measured in this time period clearly shows a sign-charge dependence of the solar modulation introduced by particle drifts. These results provide the first clear and continuous observation of how drift effects on solar modulation have unfolded with time from solar minimum to solar maximum and their dependence on the particle rigidity and the cyclic polarity of the solar magnetic field.Comment: 11 pages, 2 figure
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