3,803 research outputs found
Low interface trap density in rapid thermally annealed Al/SiNx : H/InP metal-insulator-semiconductor devices
A minimum interface trap density of 10(12) eV(-1) cm(-2) was obtained on SiNx:H/InP metalinsulator-semiconductor structures without InP surface passivation. The SiNx:H gate insulator was obtained by the electron cyclotron resonance plasma method. This insulator was deposited in a single vacuum run and was composed of two layers with different nitrogen-to-silicon ratios. The first layer deposited onto the InP was grown with a nitrogen-to-silicon ratio of N/Si=1.55, whereas the second one was grown with a N/Si ratio of N/Si = 1.43. After the insulator deposition, rapid thermal annealing of the devices was performed at a constant annealing time of 30 s. The interface trap density minimum value was obtained at an optimum annealing temperature of 500 degrees C. Higher annealing temperatures promote thermal degradation of the interface and a sharp increase in the trap density
Performances of multi-gap timing RPCs for relativistic ions in the range Z=1-6
We present the performance of Multi-gap timing RPCs under irradiation by
fully stripped relativistic ions (gamma*beta=2.7, Z=1-6). A time resolution of
80 ps at high efficiency has been obtained by just using standard `off the
shelf' 4-gap timing RPCs from the new HADES ToF wall. The resolution worsened
to 100 ps for ~ 1 kHz/cm2 proton flux and for ~ 100 Hz/cm2 Carbon flux. The
chambers were operated at a standard field of E=100 kV/cm and showed a high
stability during the experiment, supporting the fact that RPCs are a convenient
choice when accommodating a very broad range of ionizing particles is needed.
The data provides insight in the region of very highly ionizing particles (up
to x 36 mips) and can be used to constrain the existing avalanche and
Space-Charge models far from the usual `mip valley'. The implications of these
results for the general case of detection based on secondary processes (n,
gamma) resulting in highly ionizing particles with characteristic energy
distributions will be discussed, together with the nature of the time-charge
correlation curve.Comment: 31 pages, 19 figures, submitted to JINS
High Energy Cosmic Rays from Neutrinos
We discuss recent models in which neutrinos, which are assumed to have mass
in the eV range, originate the highest energy cosmic rays by interaction with
the enhanced density in the galactic halo of the relic cosmic neutrino
background. We make an analytical calculation of the required neutrino fluxes
to show that the parameter space for these models is constrained by horizontal
air shower searches and by the total number of background neutrinos, so that
only models which have fairly unnatural halo sizes and enhanced densities are
allowed.Comment: 14 pages, 3 ps figures. To appear in Phys. Rev.
Releases of Asian houbara must respect genetic and geographic origin to preserve inherited migration behaviour:evidence from a translocation experiment
Maintaining appropriate migratory strategies is important in conservation; however, translocations of migratory animals may alter locally-evolved migration behaviours of recipient populations if these are different and heritable. We used satellite telemetry and experimental translocation to quantify differences and assess heritability in migration behaviours between three migratory Asian houbara (Chlamydotis macqueenii) breeding populations (640 km range across eastern, central and western Uzbekistan). Adults from the eastern population migrated twice as far (mean = 1,184 km ± 44 s.e.) as the western population (656 km ± 183 s.e.) and showed significantly less variation in migration distance than the central population (1,030 km ± 127 s.e.). The western and central populations wintered significantly further north (mean: +8.32°N ± 1.70 s.e. and +4.19°N ± 1.16 s.e., respectively) and the central population further west (-3.47°E ± 1.46 s.e.) than individuals from the eastern population.These differences could arise from differing innate drive, or through learnt facultative responses to topography, filtered by survival. Translocated birds from the eastern population (wild laid and captive-reared, n= 5) migrated further than adults from either western or central recipient populations, particularly in their second migration year. Translocated birds continued migrating south past suitable wintering grounds used by the recipient populations despite having to negotiate mountain obstacles. Together, this suggests a considerable conserved heritable migratory component with local adaptation at a fine geographic scale. Surviving translocated individuals returned to their release site, suggesting continued translocations would lead to introgression of the heritable component and risk altering recipient migration patterns. Conservation biologists considering translocation interventions for migratory populations should evaluate potential genetic components of migratory behaviour
Molecular Characteristics of Extraintestinal Pathogenic E. coli (ExPEC), Uropathogenic E. coli (UPEC), and Multidrug Resistant E. coli Isolated from Healthy Dogs in Spain. Whole Genome Sequencing of Canine ST372 Isolates and Comparison with Human Isolates Causing Extraintestinal Infections
Under a one health perspective and the worldwide antimicrobial resistance concern, we investigated extraintestinal pathogenic Escherichia coli (ExPEC), uropathogenic E. coli (UPEC), and multidrug resistant (MDR) E. coli from 197 isolates recovered from healthy dogs in Spain between 2013 and 2017. A total of 91 (46.2%) isolates were molecularly classified as ExPEC and/or UPEC, including 50 clones, among which (i) four clones were dominant (B2-CH14-180-ST127, B2-CH52-14-ST141, B2-CH103-9-ST372 and F-CH4-58-ST648) and (ii) 15 had been identified among isolates causing extraintestinal infections in Spanish and French humans in 2015 and 2016. A total of 28 (14.2%) isolates were classified as MDR, associated with B1, D, and E phylogroups, and included 24 clones, of which eight had also been identified among the human clinical isolates. We selected 23 ST372 strains, 21 from healthy dogs, and two from human clinical isolates for whole genome sequencing and built an SNP-tree with these 23 genomes and 174 genomes (128 from canine strains and 46 from human strains) obtained from public databases. These 197 genomes were segregated into six clusters. Cluster 1 comprised 74.6% of the strain genomes, mostly composed of canine strain genomes (p < 0.00001). Clusters 4 and 6 also included canine strain genomes, while clusters 2, 3, and 5 were significantly associated with human strain genomes. Finding several common clones and clone-related serotypes in dogs and humans suggests a potentially bidirectional clone transfer that argues for the one health perspective
Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy.
Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV
Subregión Playas y marismas de la Costa Patagónica e Islas del Atlántico Sur
Esta subregión se extiende a lo largo de más de 5.000 km. Debido a su extensión, se conjugan en ella diversas unidades ecológicas. La aridez del clima en el sector continental determina ambientes terrestres adaptados a las condiciones de escasez de agua, caracterizados por arbustos xerofíticos achaparrados, con hojas reducidas. La comunidad climáxica es la estepa arbustiva, aunque también se presentan estepas herbáceas y de caméfitos. En las zonas con mayor influencia marina y presencia de altos niveles de salinidad se observa una vegetación de tipo halófita con especies como Suaeda argentinensis y Atriplex sagittifolia.Fil: Blanco, Daniel E.. Fundación Humedales; Argentina. Secretaría de Ambiente y Desarrallo Sustentable de la Nación; ArgentinaFil: Gonzalez Trilla, Gabriela Liliana. Universidad Nacional de San Martin. Instituto de Investigacion E Ingenieria Ambiental. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Investigacion E Ingenieria Ambiental.; ArgentinaFil: Yorio, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentin
LFI 30 and 44 GHz receivers Back-End Modules
The 30 and 44 GHz Back End Modules (BEM) for the Planck Low Frequency
Instrument are broadband receivers (20% relative bandwidth) working at room
temperature. The signals coming from the Front End Module are amplified, band
pass filtered and finally converted to DC by a detector diode. Each receiver
has two identical branches following the differential scheme of the Planck
radiometers. The BEM design is based on MMIC Low Noise Amplifiers using GaAs
P-HEMT devices, microstrip filters and Schottky diode detectors. Their
manufacturing development has included elegant breadboard prototypes and
finally qualification and flight model units. Electrical, mechanical and
environmental tests were carried out for the characterization and verification
of the manufactured BEMs. A description of the 30 and 44 GHz Back End Modules
of Planck-LFI radiometers is given, with details of the tests done to determine
their electrical and environmental performances. The electrical performances of
the 30 and 44 GHz Back End Modules: frequency response, effective bandwidth,
equivalent noise temperature, 1/f noise and linearity are presented
Prediction of adverse neonatal outcome at admission for early-onset preeclampsia with severe features
Preeclampsia remains the leading cause of maternal morbidity and mortality. Consequently, research has focused on validating tools to predict maternal outcomes regarding clinical and biochemical features from the maternal compartment. However, preeclampsia also leads to neonatal complications due to placental insufficiency and prematurity, being the early-onset type associated with the poorest outcome. Hence, it is imperative to study whether these existing tools can predict adverse neonatal outcome.To assess the predictive value for adverse neonatal outcome of Doppler ultrasound, angiogenic factors and multi-parametric risk-score models in women with early-onset severe preeclampsia.This is a prospective cohort study of consecutive singleton pregnancies complicated by early-onset (developed before 34 week's gestation) severe preeclampsia.63 women with early-onset severe preeclampsia, 18 (28.6%) presented an adverse neonatal outcome. Placental growth factor (PlGF) showed the best discrimination between neonatal outcomes among angiogenic factors. PREP-L score is a multi-parametric risk-score for the prediction of complications in early-onset preeclampsia which includes maternal characteristics and clinical and analytical data obtained at admission. Good predictive values for the prediction of neonatal complications were found with the combination of PREP-L score with advanced Doppler (AUC ROC 0.9 95% CI 0.82-0.98]) and with PlGF levels (AUC ROC 0.91 [95% CI 0.84-0.98]).The combination of maternal risk scoring (PREP-L score) with angiogenic factors or fetal Doppler ultrasound at the time of diagnosis of early-onset preeclampsia with severe features performs well in predicting adverse neonatal outcome.Copyright © 2023 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved
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