712 research outputs found

    Three-Flavour Neutrino-Mixing Implications of the LSND Result

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    The LSND result is shown to fit into a minimal three-flavour neutrino-mixing scenario capable of describing all known experimental facts provided the large Delta M^2 = m_3^2 - m_2^2 \sim m_3^2 - m_1^2 lies in the range 2.5 x 10^{-1} < Delta M^2 < 3.0 eV^2. In this range the value of P_{\mu\tau} is expected to be about 5% or larger.Comment: 10 pages, 2 eps figures, LaTeX 2.09, revised for Physics Letters

    Steady Combustion Waves Driven by a Recombination Reaction in a Gas Mixture

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    Effect of task failure on intermuscular coherence measures in synergistic muscles

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    The term "task failure" describes the point when a person is not able to maintain the level of force required by a task. As task failure approaches, the corticospinal command to the muscles increases to maintain the required level of force in the face of a decreased mechanical efficacy. Nevertheless, most motor tasks require the synergistic recruitment of several muscles. How this recruitment is affected by approaching task failure is still not clear. The increase in the corticospinal drive could be due to an increase in synergistic recruitment or to overlapping commands sent to the muscles individually. Herein, we investigated these possibilities by combining intermuscular coherence and synergy analysis on signals recorded from three muscles of the quadriceps during dynamic leg extension tasks. We employed muscle synergy analysis to investigate changes in the coactivation of the muscles. Three different measures of coherence were used. Pooled coherence was used to estimate the command synchronous to all three muscles, pairwise coherence the command shared across muscle pairs and residual coherence the command peculiar to each couple of muscles. Our analysis highlights an overall decrease in synergistic command at task failure and an intensification of the contribution of the nonsynergistic shared command

    Testing the performance of a blind burst statistic

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    In this work we estimate the performance of a method for the detection of burst events in the data produced by interferometric gravitational wave detectors. We compute the receiver operating characteristics in the specific case of a simulated noise having the spectral density expected for Virgo, using test signals taken from a library of possible waveforms emitted during the collapse of the core of Type II Supernovae.Comment: 8 pages, 6 figures, Talk given at the GWDAW2002 worksho

    Educational interventions on pregnancy vaccinations during childbirth classes improves vaccine coverages among pregnant women in Palermo’s province

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    Maternal immunization is considered the best intervention in order to prevent influenza infection of pregnant women and influenza and pertussis infection of newborns. Despite the existing recommendations, vaccination coverage rates in Italy remain very low. Starting from August 2018, maternal immunization against influenza and diphtheria-tetanus-pertussis were strongly recommended by the Italian Ministry of Health. We conducted a cross sectional study to estimate the effectiveness of an educational intervention, conducted during childbirth classes in three general hospitals in the Palermo metropolitan area, Italy, on vaccination adherence during pregnancy. To this end, a questionnaire on knowledge, attitudes, and immunization practices was structured and self-administered to a sample of pregnant women attending childbirth classes. Then, an educational intervention on maternal immunization, followed by a counseling, was conducted by a Public Health medical doctor. After 30 days following the interventions, the adherence to the recommended vaccinations (influenza and pertussis) was evaluated. At the end of the study 326 women were enrolled and 201 responded to the follow-up survey. After the intervention, among the responding pregnant women 47.8% received influenza vaccination (+44.8%), 57.7% diphtheria-tetanus-pertussis vaccination (+50.7%) and 64.2% both the recommended vaccinations (+54.8%). A significant association was found between pregnant women that received at least one vaccination during pregnancy and higher educational level (graduation degree/master’s degree), employment status (employed part/full-time) and influenza vaccination adherence during past seasons (at least one during last five years). The implementation of vaccination educational interventions, including counseling by healthcare professionals (HCPs), on maternal immunization during childbirth courses improved considerably the vaccination adherence during pregnancy

    A complete solution to neutrino mixing

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    Deviations from expectations have been claimed for solar, atmospheric and high energy prompt neutrinos from charm decay. This information, supplemented only by the existing very good upper limits for oscillations of the νμ\nu_{\mu} at accelerator energies, is used as input to a phenomenological three-flavour analysis of neutrino mixing. The solution found is unique and completely determines the mass eigenstates as well as the mixing matrix relating mass and flavour eigenstates. Assuming the mass eigenstates to follow the hierarchy m1m2m3m_{1} \ll m_{2} \ll m_{3}, their values are found to be m1102m_{1} \ll 10^{-2} eV, m2=(0.18±0.06)m_{2} = (0.18 \pm 0.06) eV, m3=(19.4±0.7)m_{3} = (19.4 \pm 0.7) eV. These masses are in agreement with the leptonic quadratic hierarchy of the see-saw model and large enough to render energy-independent any oscillation-induced phenomenon in solar neutrino physics observable on Earth. This possibility is not excluded by the present knowledge of solar neutrino physics. The mixing angles are determined to be θ12=0.55±0.08\theta_{12} = 0.55 \pm 0.08, θ13=0.38±0.06\theta_{13} = 0.38 \pm 0.06, θ23<0.03\theta_{23} < 0.03. Small values of θ23\theta_{23} are typical of any solution in which m3m_{3} lies in the cosmological interesting region. The solution found is not in serious contradiction with any of the present limits to the existence of neutrino oscillations. The most relevant implications in particle physics, astrophysics and cosmology are discussed.Comment: 17 pages, 3 figures, to be published in Astroparticle Physic

    Abnormal sensory integration affects balance control in hemiparetic patients within the first year after stroke

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    OBJECTIVE: Impairments in balance can be a consequence of changes in the motor, sensory, and integrative aspects of motor control. Abnormal sensory reweighting, i.e., the ability to select the most appropriate sensory information to achieve postural stability, may contribute to balance impairment. The Sensory Organization Test is a component of Computerized Dynamic Posturography that evaluates the impact of visual, vestibular, and somatosensory inputs, as well as sensory reweighting, under conditions of sensory conflict. The aim of this study is to compare balance control in hemiparetic patients during the first year post-stroke and in age-matched neurologically normal subjects using the Berg Balance Scale and Computerized Dynamic Posturography. METHODS: We compared the Berg Balance Scale and Sensory Organization Test scores in 21 patients with hemiparesis after first-ever ischemic stroke and in 21 age-matched, neurologically normal subjects. An equilibrium score was defined for each Sensory Organization Test condition. RESULTS: Berg Balance Scale scores were significantly lower in the patients than in the neurologically normal subjects. Equilibrium scores were significantly lower in the patients than in the neurologically normal subjects for those Sensory Organization Test conditions that did not provide appropriate somatosensory information and under conditions of sensory conflict. A history of falls was more frequent in patients with lower equilibrium scores. CONCLUSION: During the first year after a stroke, defective sensory reweighting significantly impacts balance control in hemiparetic patients. These results are important for the planning of effective rehabilitation interventions
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