185 research outputs found
External Load Demands and Positional Differences in Elite Futsal Using UWB Technology
Las exigencias condicionales a las que están sometidos los deportistas profesionales en competiciĂłn han sido objeto de estudio durante las Ăşltimas dĂ©cadas. El presente estudio tiene como primer objetivo describir las demandas de carga externa a las que están sometidos los jugadores de Ă©lite de fĂştbol sala para posteriormente comprobar si existen diferencias entre las posiciones especĂficas de juego. 14 jugadores profesionales de primera divisiĂłn de la Liga Nacional de FĂştbol Sala española fueron categorizados en tres grupos de acuerdo con su posiciĂłn especĂfica en el campo: cierre (C), ala (A) y pĂvot (P). Los porteros no fueron incluidos en el estudio. Durante la temporada 2017-2018, se registraron un total de 15 partidos oficiales de la liga mediante la tecnologĂa de banda ultraancha (ultra wideband, UWB), con los dispositivos WIMU PRO. Las variables analizadas fueron las siguientes: distancia total recorrida (DT); distancia total recorrida por encima de 18 km·h-1 (DTAI: > 18 km·h-1); carga del jugador (CJ); nĂşmero de aceleraciones y desaceleraciones de alta intensidad (> / < 2 m·s-²). C, A y P no presentaron diferencias substanciales en DT y CJ, pero sĂ en DTAI, donde A y C recorren más metros a alta intensidad (A = 274 ± 118 m; C = 249 ± 85 m) que los P (P = 195 ± 60 m), en nĂşmero de aceleraciones de alta intensidad (A = 134 ± 46; C = 139 ± 40; P = 118 ± 21) y nĂşmero de desaceleraciones de alta intensidad (A = 128 ± 46; C = 131 ± 36; P = 116 ± 23). Los resultados obtenidos en este estudio podrĂan servir de apoyo a entrenadores, tĂ©cnicos y preparadores fĂsicos para planificar, diseñar y ajustar las cargas de entrenamiento de sus jugadores
A Multi-APD readout for EL detectors
Detectors with an electroluminesence readout show an excellence performance
in respect of energy resolution making them interesting for various
applications as X-ray detection, double beta and dark matter experiments,
Compton and gamma cameras, etc. In the following the study of a readout based
on avalanche photo diodes to detect directly the VUV photons is presented.
Results of measurements with 5 APDs in xenon at pressures between 1 and 1.65
bar are shown indicating that such a readout can provide excellent energy and a
moderate position resolution.Comment: Talk given at the 5th Symposium on Large TPCs for Low Energy Rare
Events. Submitted to JPCS (Journal of Physics: Conference Series) for
publication. 8 pages, 17 figure
Avalanches in compressed porous SiO2-based materials
The failure dynamics in SiO2-based porous materials under compression, namely the synthetic glass Gelsil and three natural sandstones, has been studied for slowly increasing compressive uniaxial stress with rates between 0.2 and 2.8 kPa/s. The measured collapsed dynamics is similar to Vycor, which is another synthetic porous SiO2 glass similar to Gelsil but with a different porous mesostructure. Compression occurs by jerks of strain release and a major collapse at the failure point. The acoustic emission and shrinking of the samples during jerks are measured and analyzed. The energy of acoustic emission events, its duration, and waiting times between events show that the failure process follows avalanche criticality with power law statistics over ca. 4 decades with a power law exponent ε 1.4 for the energy distribution. This exponent is consistent with the mean-field value for the collapse of granular media. Besides the absence of length, energy, and time scales, we demonstrate the existence of aftershock correlations during the failure process
Measurement of the Stray Light in the Advanced Virgo Input Mode Cleaner Cavity using an instrumented baffle
A new instrumented baffle was installed in Spring 2021 at Virgo surrounding
the suspended mirror in the input mode cleaner triangular cavity. It serves as
a demonstrator of the technology designed to instrument the baffles in the main
arms in the near future. We present, for the first time, results on the
measured scattered light distribution inside the cavity as determined by the
new device using data collected between May and July 2021, with Virgo in
commissioning phase and operating with an input laser power in the cavity of
28.5~W. The sensitivity of the baffle is discussed and the data is compared to
scattered light simulations.Comment: 4 pages, 5 figures, 1 tabl
ProtoDESI: First On-Sky Technology Demonstration for the Dark Energy Spectroscopic Instrument
The Dark Energy Spectroscopic Instrument (DESI) is under construction to
measure the expansion history of the universe using the baryon acoustic
oscillations technique. The spectra of 35 million galaxies and quasars over
14,000 square degrees will be measured during a 5-year survey. A new prime
focus corrector for the Mayall telescope at Kitt Peak National Observatory will
deliver light to 5,000 individually targeted fiber-fed robotic positioners. The
fibers in turn feed ten broadband multi-object spectrographs. We describe the
ProtoDESI experiment, that was installed and commissioned on the 4-m Mayall
telescope from August 14 to September 30, 2016. ProtoDESI was an on-sky
technology demonstration with the goal to reduce technical risks associated
with aligning optical fibers with targets using robotic fiber positioners and
maintaining the stability required to operate DESI. The ProtoDESI prime focus
instrument, consisting of three fiber positioners, illuminated fiducials, and a
guide camera, was installed behind the existing Mosaic corrector on the Mayall
telescope. A Fiber View Camera was mounted in the Cassegrain cage of the
telescope and provided feedback metrology for positioning the fibers. ProtoDESI
also provided a platform for early integration of hardware with the DESI
Instrument Control System that controls the subsystems, provides communication
with the Telescope Control System, and collects instrument telemetry data.
Lacking a spectrograph, ProtoDESI monitored the output of the fibers using a
Fiber Photometry Camera mounted on the prime focus instrument. ProtoDESI was
successful in acquiring targets with the robotically positioned fibers and
demonstrated that the DESI guiding requirements can be met.Comment: Accepted versio
An instrumented baffle for the Advanced Virgo Input Mode Cleaner End Mirror
A novel instrumented baffle surrounding the suspended end mirror in the input
mode cleaner cavity of the Virgo interferometer was installed in spring 2021.
Since then, the device has been regularly operated in the experiment and the
obtained results indicate a good agreement with simulations of the stray light
inside the optical cavity. The baffle will operate in the upcoming O4
observation run, serving as a demonstrator of the technology designed to
instrument the baffles in front of the main mirrors in time for O5. In this
paper we present a detailed description of the baffle design, including
mechanics, front-end electronics, data acquisition, as well as optical and
vacuum tests, calibration and installation procedures, and performance results.Comment: 12 pages, 21 figures, 3 tables, to be submitted to PR
Behavioral and cognitive interventions to improve treatment adherence and access to HIV care among older adults in sub-Saharan Africa: an updated systematic review
BACKGROUND: Approximately 14% of Africans infected with HIV are over the age of 50, yet few intervention studies
focus on improving access to care, retention in care, and adherence to antiretroviral therapy (ART) in this
population. A review of the published literature until 2012, found no relevant ART management and care interventions
for older people living with HIV (OPLHIV) in sub-Saharan Africa. The aim of this systematic review is to update the
original systematic review of intervention studies on OPLHIV, with a focus on evidence from sub-Saharan Africa.
METHODS: We conducted a systematic review of the available published literature from 2012 to 2017 to explore
behavioral and cognitive interventions addressing access to ART, retention in HIV care and adherence to ART in
sub-Saharan Africa that include older adults (50+). We searched three databases (MEDLINE, EMBASE, and Education
Resources Information Center) using relevant Medical Subject Headings (MeSH) terms as well as a manual search of the
reference lists. No language restrictions were placed. We identified eight articles which were analyzed using content
analysis with additional information obtained directly from the corresponding authors.
RESULTS AND DISCUSSION: There were no studies that exclusively focused on OPLHIV. Three studies referred only to
participants being over 18 years and did not specify age categories. Therefore, it is unclear whether these studies
actively considered people living with HIV over the age of 50. Although the studies sampled older adults, they lacked
sufficient data to draw conclusions about the relevance of the outcomes of this group.
CONCLUSIONS: These findings underscore the need to increase the evidence-base of which interventions will work for
older Africans on ART
Linkage map saturation, construction, and comparison in four populations of Prunus
One of the objectives of the ISAFRUIT Project was to perform genetic analyses in four populations of Prunus, two of peach (P. persica) and two of apricot (P. armeniaca), in order to identify major genes and quantitative trait loci (QTLs) for characters related to fruit quality. This required the construction of saturated marker maps in each of these populations. Marker maps were available for an intra-specific peach × peach F2, a BC2 peach × P. davidiana (using peach as the recurrent parent), and an apricot × apricot F1. We have further saturated these maps mainly with SSR (simple sequence repeat) markers. A new map, constructed uniquely from SSRs was prepared for a fourth apricot × apricot F1 population. Using anchor markers, we compared these four maps with the reference Prunus map, constructed using an almond × peach F2 population. As previously observed, conservation of synteny and co-linearity were the general rule, providing additional evidence of the high level of similarity between all Prunus genomes. Comparisons of genetic distances between the maps suggested that those involving similar genomes had higher levels of recombination than those with more distant genomes, particularly the inter-specific crosses.The ISAFRUIT Project is funded by the European Commission under Thematic Priority 5 – Food Quality and Safety of the 6th Framework Programme of RTD (Contract No. FP6-FOOD-CT-2006-016279).Peer reviewe
The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in
the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent
a series of upgrades, involving the exchange of the MAGIC-I camera and its
trigger system, as well as the upgrade of the readout system of both
telescopes. We use observations of the Crab Nebula taken at low and medium
zenith angles to assess the key performance parameters of the MAGIC stereo
system. For low zenith angle observations, the standard trigger threshold of
the MAGIC telescopes is ~50GeV. The integral sensitivity for point-like sources
with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula
flux in 50 h of observations. The angular resolution, defined as the sigma of a
2-dimensional Gaussian distribution, at those energies is < 0.07 degree, while
the energy resolution is 16%. We also re-evaluate the effect of the systematic
uncertainty on the data taken with the MAGIC telescopes after the upgrade. We
estimate that the systematic uncertainties can be divided in the following
components: < 15% in energy scale, 11-18% in flux normalization and +/-0.15 for
the energy spectrum power-law slope.Comment: 21 pages, 25 figures, accepted for publication in Astroparticle
Physic
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