10,137 research outputs found
MACRO results on atmospheric neutrinos
We discuss the final results of the MACRO experiment on atmospheric neutrino
oscillations. The data concern event topologies with average neutrino energies
of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons was
used to estimate the neutrino energy event by event. The angular distributions,
the L/E_nu distribution, the particle ratios and the absolute fluxes all favor
nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 ~0.0023 eV^2.
Emphasis is given to measured ratios which are not affected by Monte Carlo (MC)
absolute normalization; a discussion is made on MC uncertainties. A preliminary
search for possible Lorentz invariance violation contributions to atmospheric
neutrino oscillations is presented and discussed.Comment: 4 pages, 6 figures. Paper presented at the NOW 2004 Workshop, Conca
Specchiulla, Otranto, Italy, September 200
Neutrino physics and astrophysics with the MACRO detector
After a brief presentation of the MACRO detector we discuss the data on
atmospheric neutrinos and neutrino oscillations, on high energy (E> 1 GeV)
neutrino astronomy, on indirect searches for WIMPs and low energy (E >7 MeV)
stellar collapse neutrinos.Comment: 8 pages, 7 figures. Invited paper at the Chacaltaya Meeting on Cosmic
Ray Physics, La Paz, 23-27 July, 200
Nuclear Track Detectors for Environmental Studies and Radiation Monitoring
Several improvements were made for Nuclear Track Detectors (NTDs) used for
environmental studies and for particle searches. A new method was used to
determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the
simultaneous measurement of the diameter and of the height of etch-pit cones
caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and
their fragments. The use of alcohol in the etching solution improves the
surface quality of NTDs and it raises their thresholds. The detectors were used
for the determination of nuclear fragmentation cross sections of Iron and
Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for
the determination of doses in hadron therapy and for doses received by
astronauts. The detectors were also used in the search of massive particles in
the cosmic radiation, for the determination of the mass spectrum of cosmic rays
and for the evaluation of Po(210) alpha decay and of natural radon
concentrations.Comment: 7 pages, 5 EPS figures. Presented at the 10th Topical Seminar on
Innovative Particle and Radiation Detectors, 1-5 October 2006, Siena, Ital
New results on the limit for the width of the exotic Theta^+ resonance
We investigate the impact of the \Theta^+(1540) resonance on differential and
integrated cross sections for the reaction K^+d{\to}K^0pp, where experimental
information is available at kaon momenta below 640 MeV/c. The calculation
utilizes the J\"ulich KN model and extensions of it that include contributions
from a \Theta^+(1540) state with different widths. The evaluation of the
reaction K^+d{\to}K^0pp takes into account effects due to the Fermi motion of
the nucleons within the deuteron and the final three-body kinematics. We
conclude that the available data constrain the width of the \Theta^+(1540) to
be less than 1 MeV.Comment: 5 pages, 5 figures, updated version, accepted for publication in
Phys. Lett.
A higher Angiogenin expression is associated with a non-nuclear Maspin location in laryngeal carcinoma
Objectives. In numerous malignancies, angiogenin (ANG) and Maspin are important proangiogenic and antiangiogenic regulators, respectively. The aim of this study was to identify potential relationships between the biological roles of these two proteins in laryngeal squamous cell carcinoma (LSCC).
Methods. Immunohistochemical staining for ANG and Maspin was performed on specimens from 76 consecutive LSCC patients treated with surgery alone, considering the subcellular pattern of Maspin expression. Univariate and multivariate statistical models were used for prognostic purposes.
Results. On univariate analysis, a different level of ANG expression was seen for patients stratified by subcellular Maspin expression pattern: the mean ANG expression was higher in cases with a nonnuclear MASPIN expression than in those with a nuclear pattern (P=0.002). Disease-free survival (DFS; in months) differed significantly when patients were stratified by N stage (P=0.01). Patients whose Maspin expression was nonnuclear (i.e., it was cytoplasmic or there was none) had a significantly higher recurrence rate (P<0.001), and shorter DFS (P=0.01) than those with a nuclear Maspin pattern. The mean ANG expression was significantly higher in cases with loco-regional recurrent disease (P=0.007); and patients with an ANG expression 655.0% had a significantly shorter DFS than those with an ANG expression <5.0% (P=0.007). On multivariate analysis, ANG expression 655.0% was a significant, independent, negative prognostic factor in terms of DFS (P=0.041).
Conclusion. Our results support the hypothesis that a higher ANG expression is associated with a nonnuclear Maspin expression pattern in patients with LSCC. Further studies are needed to clarify the relationship between the ANG and Maspin pathways, and their potential diagnostic and therapeutic role in LSCC
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