1,176 research outputs found

    ICT-based applications to improve social health and social participation in older adults with dementia. A systematic literature review

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    OBJECTIVES: Information and communication technologies (ICT) developers, together with dementia experts have created several technological solutions to improve and facilitate social health and social participation and quality of life of older adults living with dementia. However, there is a need to carry out a systematic literature review that focuses on the validity and efficacy of these new technologies assessing their utility to promote ‘social health’ and ‘active ageing’ in people with dementia. METHOD: Searches in electronic databases identified 3824 articles of which 6 met the inclusion criteria and were coded according to their methodological approach, sample sizes, type of outcomes and results. RESULTS: Six papers were identified reporting the use of 10 different interventions with people with dementia. Qualitative studies (four) showed a benefit of the use of technologies to foster social participation in people with dementia. At the same time, barriers to a widespread use of these technologies in this population were identified. A quantitative study and a mixed-method study with quantitative outcomes showed that ICT-based interventions promote more social behaviours than non-technology-based interventions. CONCLUSIONS: In the last years, several technological devices for living independently and fostering social health and social participation in people with dementia have been developed. However, specific outcome measures to assess social health and social participation are needed. Even though the analysed studies provided some evidence-base for the use of technology in this field, there is an urge to develop high quality studies and specific outcome measures

    Effectiveness of rotavirus vaccination in Spain

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    With the aim of determining rotavirus vaccine effectiveness (RVVE) in Spain, from Oct-2008/Jun-2009, 467 consecutive children below 2 years old with acute gastroenteritis (AGE) were recruited using a pediatric research network (ReGALIP-www.regalip.org) that includes primary, emergency and hospital care settings. Of 467 enrolled children, 32.3% were rotavirus positive and 35.0% had received at least one dose of any rotavirus vaccine. RRVE to prevent any episode of rotavirus AGE was 91.5% (95% CI: 83.7%-95.6%). RVVE to prevent hospitalization by rotavirus AGE was 95.6% (85.6-98.6%). No differences in RVVE were found regarding the vaccine used. Rotavirus vaccines have showed an outstanding effectiveness in Spain

    Cosmic-Ray Anisotropies in Right Ascension Measured by the Pierre Auger Observatory

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    We present measurements of the large-scale cosmic-ray (CR) anisotropies in R.A., using data collected by the surface detector array of the Pierre Auger Observatory over more than 14 yr. We determine the equatorial dipole component, through a Fourier analysis in R.A. that includes weights for each event so as to account for the main detector-induced systematic effects. For the energies at which the trigger efficiency of the array is small, the east-west method is employed. Besides using the data from the array with detectors separated by 1500 m, we also include data from the smaller but denser subarray of detectors with 750 m separation, which allows us to extend the analysis down to ∼0.03 EeV. The most significant equatorial dipole amplitude obtained is that in the cumulative bin above 8 EeV, %, which is inconsistent with isotropy at the 6σ level. In the bins below 8 EeV, we obtain 99% CL upper bounds on d ⊥ at the level of 1%-3%. At energies below 1 EeV, even though the amplitudes are not significant, the phases determined in most of the bins are not far from the R.A. of the Galactic center, at GC =-94°, suggesting a predominantly Galactic origin for anisotropies at these energies. The reconstructed dipole phases in the energy bins above 4 EeV point instead to R.A. that are almost opposite to the Galactic center one, indicative of an extragalactic CR origin

    Status and performance of the underground muon detector of the Pierre Auger Observatory

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    The Auger Muons and Infill for the Ground Array (AMIGA) is an enhancement of the Pierre Auger Observatory, whose purpose is to lower the energy threshold of the observatory down to 1016.5 eV, and to measure the muonic content of air showers directly. These measurements will significantly contribute to the determination of primary particle masses in the range between the second knee and the ankle, to the study of hadronic interaction models with air showers, and, in turn, to the understanding of the muon puzzle. The underground muon detector of AMIGA is concomitant to two triangular grids of water-Cherenkov stations with spacings of 433 and 750 m; each grid position is equipped with a 30 m2 plastic scintillator buried at 2.3 m depth. After the engineering array completion in early 2018 and general improvements to the design, the production phase commenced. In this work, we report on the status of the underground muon detector, the progress of its deployment, and the performance achieved after two years of operation. The detector construction is foreseen to finish by mid-2022

    Deep-learning based reconstruction of the shower maximum Xmax using the water-Cherenkov detectors of the Pierre Auger Observatory

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    The atmospheric depth of the air shower maximum Xmax is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of Xmax are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of Xmax from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of Xmax. The reconstruction relies on the signals induced by shower particles in the ground based water-Cherenkov detectors of the Pierre Auger Observatory. The network architecture features recurrent long short-term memory layers to process the temporal structure of signals and hexagonal convolutions to exploit the symmetry of the surface detector array. We evaluate the performance of the network using air showers simulated with three different hadronic interaction models. Thereafter, we account for long-term detector effects and calibrate the reconstructed Xmax using fluorescence measurements. Finally, we show that the event-by-event resolution in the reconstruction of the shower maximum improves with increasing shower energy and reaches less than 25 g/cm2 at energies above 2×1019 eV

    A combined fit of energy spectrum, shower depth distribution and arrival directions to constrain astrophysical models of UHECR sources

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    The combined fit of the measured energy spectrum and distribution of depths of shower maximum of ultra-high-energy cosmic rays is known to constrain the parameters of astrophysical scenarios with homogeneous source distributions. Further measurements show that the cosmic-ray arrival directions agree better with the directions and fluxes of catalogs of starburst galaxies and active galactic nuclei than with isotropy. Here, we present a novel combination of both analyses. For that, a three-dimensional universe model containing a nearby source population and a homogeneous background source distribution is built, and its parameters are adapted using a combined fit of the energy spectrum, depth of shower maximum distribution and energy-dependent arrival directions. The model takes into account a symmetric magnetic field blurring, source evolution and interactions during propagation. We use simulated data, which resemble measurements of the Pierre Auger Observatory, to evaluate the method’s sensitivity. With this, we are able to verify that the source parameters as well as the fraction of events from the nearby source population and the size of the magnetic field blurring are determined correctly, and that the data is described by the fitted model including the catalog sources with their respective fluxes and three-dimensional positions. We demonstrate that by combining all three measurements we reach the sensitivity necessary to discriminate between the catalogs of starburst galaxies and active galactic nuclei

    The XY Scanner – A Versatile Method of the Absolute End-to-End Calibration of Fluorescence Detectors

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    One of the crucial detector systems of the Pierre Auger Observatory is the fluorescence detector composed of 27 large-aperture wide-angle Schmidt telescopes. In the past, these telescopes were absolutely calibrated by illuminating the whole aperture with a uniform large-diameter light source. This absolute calibration was performed roughly once every three years, while a relative calibration was performed on a nightly basis. In this contribution, a new technique for an absolute end-to-end calibration of the fluorescence telescopes is presented. For this technique, a portable, calibrated light source mounted on a rail system is moved across the aperture of each telescope instead of illuminating the whole aperture at once. A dedicated setup using a combination of NIST traceable photodiodes to measure the mean intensity and a PMT for pulse-to-pulse stability tracking has been built for the absolute calibration of the light source. As a result of these complementary measurements, the pulse-to-pulse light source intensity can be known to the 3.5% uncertainty level. The analysis of the readout of the PMT camera at each position of the light source together with the knowledge of the light source emission provides an absolute end-to-end calibration of the telescope. We will give a brief overview of this novel calibration method and its current status as well as show preliminary results from the measurement campaigns performed so far

    Combined Search for UHE Neutrinos from Binary Black Hole Mergers with the Pierre Auger Observatory

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    We present searches for ultra-high energy (UHE) neutrinos (> 0.1 EeV) with the Pierre Auger Observatory, following up binary black hole (BBH) mergers detected by the LIGO and Virgo detectors via gravitational waves (GWs). In this work, the so-far published BBH mergers are combined as standard candles with a hypothetical isotropic UHE neutrino luminosity L(t − t0) as a function of the time after the respective merger, t − t0. The UHE neutrino emission spectrum is assumed to follow a power law distribution ∝ Ev−2. Using these assumptions, L(t − t0) is probed, taking into account the instantaneous effective area of the Pierre Auger Observatory to UHE neutrinos and the 3D sky localizations of the sources. No UHE neutrino candidates have been found and upper limits on L(t − t0) are obtained for the hypothetical cases of emissions lasting 24 hours and 60 days after the merger, respectively. The corresponding upper limit on the total energy per source emitted in UHE neutrinos does not depend on the emission duration and demonstrates the competitiveness of the Pierre Auger Observatory with dedicated neutrino telescopes

    Search for upward-going showers with the Fluorescence Detector of the Pierre Auger Observatory

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    Given its operation time and wide field of view, the Fluorescence Detector (FD) of the Pierre Auger Observatory is sufficiently sensitive to detect upward-going events when used in monocular mode. Upward-going air showers are a possible interpretation of the recent events reported by the ANITA Collaboration in the energy range above 1017 eV. The Pierre Auger FD data can be used to support or constrain this interpretation. If confirmed, it would require either new phenomena or significant modifications to the standard model of particle physics. To prepare this search, a set of quality selection criteria was defined by using 10% of the available FD data from 14 years of operation. This subset was mainly used to clean the data from improperly labelled laser events that had been used to monitor the quality of the atmosphere. The potential background for this search consists of cosmic-ray induced air showers with specific geometric configurations which, in a monocular reconstruction, can be reconstructed erroneously as upward-going events. To distinguish candidates from these false positives, to calculate the exposure, and to estimate the expected background, dedicated simulations for signal (upward-going events) and background (downward-going events) have been performed. The detector exposure is large enough to strongly constrain the interpretation of ANITA anomalous events. Preliminary results of the analysis after unblinding the data set are presented
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