12 research outputs found

    New hadrons as ultra-high energy cosmic rays

    Get PDF
    Ultra-high energy cosmic ray (UHECR) protons produced by uniformly distributed astrophysical sources contradict the energy spectrum measured by both the AGASA and HiRes experiments, assuming the small scale clustering of UHECR observed by AGASA is caused by point-like sources. In that case, the small number of sources leads to a sharp exponential cutoff at the energy E<10^{20} eV in the UHECR spectrum. New hadrons with mass 1.5-3 GeV can solve this cutoff problem. For the first time we discuss the production of such hadrons in proton collisions with infrared/optical photons in astrophysical sources. This production mechanism, in contrast to proton-proton collisions, requires the acceleration of protons only to energies E<10^{21} eV. The diffuse gamma-ray and neutrino fluxes in this model obey all existing experimental limits. We predict large UHE neutrino fluxes well above the sensitivity of the next generation of high-energy neutrino experiments. As an example we study hadrons containing a light bottom squark. These models can be tested by accelerator experiments, UHECR observatories and neutrino telescopes.Comment: 17 pages, revtex style; v2: shortened, as to appear in PR

    Detection of disability worsening in relapsing-remitting multiple sclerosis patients: a real-world roving Expanded Disability Status Scale reference analysis from the Italian Multiple Sclerosis Register

    No full text
    Background and purpose: In relapsing-remitting multiple sclerosis patients (RRMS) disability progressively accumulates over time. To compare the cumulative probability of 6-month confirmed disability-worsening events using a fixed baseline or a roving Expanded Disability Status Scale (EDSS) reference, in a real-world setting. Methods: A cohort of 7964 RRMS patients followed for 2 or more years, with EDSS scores recorded every 6&nbsp;months, was selected from the Italian Multiple Sclerosis Register. The overall probability of confirmed disability-worsening events and of confirmed disability-worsening events unrelated to relapse was evaluated using as reference a fixed baseline EDSS score or a roving EDSS score in which the increase had to be separated from the last EDSS assessment by at least 6 or 12&nbsp;months. Results: Using a fixed baseline EDSS reference, the cumulative probability of 6-year overall confirmed disability-worsening events was 33.2%, and that of events unrelated to relapse was 10.9% (33% of overall confirmed disability-worsening events). Using a roving EDSS, the proportions were respectively 35.2% and 21.3% (61% of overall confirmed disability-worsening events). Conclusions: In a real-world setting, roving EDSS reference scores appear to be more sensitive for detecting confirmed disability-worsening events unrelated to relapse in RRMS patients

    Determinants of Erectile Dysfunction Risk in a Large Series of Italian Men Attending Andrology Clinics

    No full text
    Objective: To assess determinants of ED in men who asked for a free of charge andrologic consultation during a week focused on andrologic prevention in Italy. Methods: Men were invited to attend 178 participating andrology centers for a free of charge visit for counselling about urologic or andrologic conditions. Data were recorded with a simple questionnaire used by all centers. Results: 2499 (19.9%) were diagnosed having ED. The frequency of ED increased with age, ranging from 4.6% in men under 25 years, to 37.6% in men over 74. In comparison with men with primary education the OR of ED was 0.8 (95% CI 0.7-0.9) in men with secondary education and 0.7 (95% CI 0.6-0.9) in those with university degree. After adjusting for age, the risk of ED was significantly higher in men consuming more than 3 glasses/day of alcoholic drinking (OR 1.4, 95% CI 1.1-2.0), in subjects smoking more than 10 cigarettes/day (OR 1.2, CI 95% 1.1-1.4) and in former smokers (OR 1.2, CI 95% 1.1-1.4). Men performing at least two hours per week of physical activity had a decreased risk of ED (OR 0.8, CI 95% 0.7-0.9). We found an increased risk of ED in men with diabetes (OR 1.2, 95% CI 1.1-1.4), hypertension (OR 1.3, 95% CI 1.1-1.4), cardiopathy (OR 1.5, 95% CI 1.3-1.8) and hypercholesterolemia (OR 1.4, 95% CI 1.2-1.6). Conclusions: This study provides further data on determinants of ED risk in a large data set and underlines the relationship between ED and cardiovascular diseases. \ua9 2003 Elsevier B.V. All rights reserved

    High-energy astrophysics with neutrino telescopes

    No full text
    Neutrino astrophysics offers new perspectives on the Universe investigation: high energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos with respect to photons. While the small interaction cross section of neutrinos allows them to come from the core of astrophysical objects, it is also a drawback, as their detection requires a large target mass. This is why it is convenient put huge cosmic neutrino detectors in natural locations, like deep underwater or under-ice sites. In order to supply for such extremely hostile environmental conditions, new frontiers technologies are under development. The aim of this work is to review the motivations for high energy neutrino astrophysics, the present status of experimental results and the technologies used in underwater/ice Cherenkov experiments, with a special focus on the efforts for the construction of a km3 scale detector in the Mediterranean Sea.Comment: 88 pages and 41 figure

    Density waves in strongly correlated quantum chains

    No full text
    corecore