12 research outputs found
New hadrons as ultra-high energy cosmic rays
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
On the dynamics of predator-prey models with the Beddington–De Angelis functional response, under Robin boundary conditions
A inclusão da criança com Síndrome de Down na rede regular de ensino: desafios e possibilidades
Hypertonic saline resuscitation reduces apoptosis of intestinal mucosa in a rat model of hemorrhagic shock
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
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 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 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
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
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