57 research outputs found

    Expected performance of the ASTRI-SST-2M telescope prototype

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    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is an Italian flagship project pursued by INAF (Istituto Nazionale di Astrofisica) strictly linked to the development of the Cherenkov Telescope Array, CTA. Primary goal of the ASTRI program is the design and production of an end-to-end prototype of a Small Size Telescope for the CTA sub-array devoted to the highest gamma-ray energy region. The prototype, named ASTRI SST-2M, will be tested on field in Italy during 2014. This telescope will be the first Cherenkov telescope adopting the double reflection layout in a Schwarzschild-Couder configuration with a tessellated primary mirror and a monolithic secondary mirror. The collected light will be focused on a compact and light-weight camera based on silicon photo-multipliers covering a 9.6 deg full field of view. Detailed Monte Carlo simulations have been performed to estimate the performance of the planned telescope. The results regarding its energy threshold, sensitivity and angular resolution are shown and discussed.Comment: In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All CTA contributions at arXiv:1307.223

    The Software Architecture and development approach for the ASTRI Mini-Array gamma-ray air-Cherenkov experiment at the Observatorio del Teide

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    The ASTRI Mini-Array is an international collaboration led by the Italian National Institute for Astrophysics (INAF) and devoted to the imaging of atmospheric Cherenkov light for very-high gamma-ray astronomy. The project is deploying an array of 9 telescopes sensitive above 1 TeV. In this contribution, we present the architecture of the software that covers the entire life cycle of the observatory, from scheduling to remote operations and data dissemination. The high-speed networking connection available between the observatory site, at the Canary Islands, and the Data Center in Rome allows for ready data availability for stereo triggering and data processing

    ASTRI Mini-Array core science at the Observatorio del Teide

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    The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few tera-electronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics

    Recent advances in amyotrophic lateral sclerosis

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    Activation of guinea pig alveolar macrophages by endothelin-1.

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    International audienceEndothelin-1 (ET-1) induced a concentration- and time-dependent increase in arachidonic acid release from guinea pig alveolar macrophages, a maximum being reached at 1 nM ET-1. Regarding the time-course study, maximal release of arachidonic acid was observed after 30 s of incubation with ET-1 and then followed by a marked decrease, suggesting a reuptake of free arachidonic acid. ET-1 (0.1-10 nM) induced a concentration- and time-dependent release of TXB2, the stable metabolite of TXA2, evaluated by an ELISA technique. Maximum release was also obtained with 1 nM ET-1 but only after a 1-min incubation period. By contrast, ET-1 (1 pM-1 microM) did not stimulate the release of superoxide anion at any time point of the kinetic study. These results suggests that ET-1 may activate guinea pig alveolar macrophages, probably through a mechanism involving the arachidonic acid pathway

    Outcome measures and prognostic indicators in patients with amyotrophic lateral sclerosis

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    The purpose of the study was to assess frequency and predictors of disability measures in ALS. One hundred and fourteen newly diagnosed patients resident in eight administrative districts of Lombardy, Italy (population 4,947,554), included in a population-based registry, were followed for 2570 person-months (mean 22.5 months). The cumulative time-dependent risk of wheelchair, percutaneous endoscopic gastrostomy, and assisted ventilation was estimated according to the Kaplan-Meier method. Predictors of disability (age, sex, disease duration at diagnosis, type of onset, El-Escorial diagnosis) were assessed with the Cox proportional hazard function. During follow-up, 29 patients (25.4%) became wheelchair bound, 51 (44.7%) received gastrostomy, and 47 (41.2%) received assisted ventilation. The median time to loss of ambulation was 46.7 months (95% CI 36.5-56.8). The median time to gastrostomy and assisted ventilation was 31.1 months (95% CI 26.8-35.4) and 34.6 months (95% CI 29.6-39.6), respectively. Spinal onset ALS was the only predictor of loss of ambulation. Predictors of gastrostomy were older age, definite ALS, and shorter disease duration. Shorter disease duration was the only predictor of assisted ventilation. In conclusion, patients with ALS differ in terms of measures and predictors of disability. These factors are sources of bias and confounding in randomized clinical trials

    Incidence of ALS in Lombardy, Italy

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    Objective: To assess the incidence and trends of ALS in a large population at risk. Methods: This study was performed in nine provinces of Lombardy in Northern Italy (population 4,947,554). Patients with newly diagnosed ALS were enrolled during the period 1998 to 2002 through a prospective regional register. For each patient, the main demographic and clinical information was collected by the caring physicians and reviewed by a panel of experts according to the original and revised El Escorial diagnostic criteria. Overall, age- and sex-specific and standardized annual incidence rates were calculated for the entire population and for each year and province separately. Results: We studied 517 patients (M:F ratio 1.3) aged 18 to 92 years (mean 63.6). Onset of symptoms was bulbar in 29% of cases. ALS was definite in 45%, probable in 27%, probable laboratory supported in 3.5%, possible in 15%, and suspected in 10%. Mean disease duration at diagnosis was 10.6 months. The standardized incidence rate was 2.09 per 100,000/year (95% CI: 1.17 to 3.18). The rate, which was 2.43 in men and 1.76 in women, tended to increase up to ages 65 to 74 and to decrease thereafter. The rate was unchanged over time and presented moderate variations across provinces. The incidence rate of definite ALS was 0.93 (spinal-onset ALS 1.35; bulbar-onset ALS 0.74) and was consistently higher in men with spinal-onset ALS vs men with bulbar-onset ALS and women. Conclusions: The incidence of ALS varied according to age, sex, and site of onset. No temporal and geographic clusters were detected over a 5-year period

    Validity of hospital discharge diagnoses for the assessment of the prevalence and incidence of Amyotrophic Lateral Sclerosis

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    INTRODUCTION: As amyotrophic lateral sclerosis (ALS) is a rare neurological disorder, many sources must be investigated for complete case ascertainment. Hospital discharge diagnoses (HDDs) are a source of administrative data for patients hospitalized for a given disease. The accuracy of HDDs was tested, to assess whether they could be used to trace patients with amyotrophic lateral sclerosis (ALS). METHODS: All the HDDs referring to patients with motor neuron disease (MND) (ICD-9 code 335.2) were identified from primary hospital discharge diagnoses made during the years 1994-95 in six target provinces of the Lombardy region in Northern Italy (total population 2922920). The medical records of the patients were reviewed and each patient was then accepted or rejected according to whether he/she did or did not satisfy the El Escorial criteria for the diagnosis of ALS. The ALS discharge diagnoses filed in the study period in the neurology departments of all the regional hospitals were the 'gold standard'. Newly diagnosed patients registered during the year 1998 in the same provinces served for the calculation of the incidence of the disease. Sensitivity, specificity and positive predictive value were calculated. Data were presented separately for all the patients and those who were indicated as first hospital admissions. RESULTS: During the study period a total of 1012122 hospital discharge records were coded in the six index provinces. The ICD-9 code 335.2 was reported in 408 of these (0.04%). These discharge diagnoses were made in 267 patients, 245 of whom were resident in Lombardy at the time of hospital admission. The hospital records of 237 cases were examined. In 95 of these the medical records showed a diagnosis other than ALS. Other motor neuron diseases were listed for 50 patients. Thirteen additional cases were traced through neurology department files. The sensitivity of the HDDs was 91.6%, the specificity 99.9%, the positive predictive value 65.4%. The corresponding values for first-hospitalized patients were 97.7, 99.9, and 37.3. The overall ALS incidence rate obtained from the HDDs was 2.1 per 100000 (95% CI 1.3-3.3). he corresponding rate calculated after exclusion of the false positives and inclusion of the false negatives was 0.8 (95% CI 0.1-2.1) and that obtained using the 1998 cases registered in the same areas was 1.6 (95% CI 0.7-2.7). CONCLUSIONS: The incidence of ALS is overestimated when HDDs are used for the estimate. Nevertheless, with improved quality, administrative data could be useful for the estimate of prevalence and incidence
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