71 research outputs found
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Red âUniversidad, gĂ©nero, docencia e igualdadâ
La Red de investigaciĂłn en docencia universitaria âUniversidad, docencia, genero e igualdadâ persigue avanzar en la calidad e innovaciĂłn de las enseñanzas universitarias a partir de la inclusiĂłn de la perspectiva de gĂ©nero. Se busca dar cumplimiento a las directrices generales de los nuevos planes de estudio respecto del principio de igualdad de oportunidades entre hombres y mujeres en la formaciĂłn universitaria (Real Decreto 1393/2007. BOE nÂș 260, 30 de octubre de 2007). En la quinta ediciĂłn de la Red, y dada su composiciĂłn multidisciplinar, se ha trabajado en tres lĂneas de investigaciĂłn: 1) mantenimiento del âPortal web con recursos docentes con perspectiva de gĂ©neroâ, proyecto financiado por el Instituto de la Mujer (PACUI, 2012) e iniciado en el curso 2012-2013; 2) desarrollo de la primera versiĂłn de âiLengUAâ, una herramienta informĂĄtica para un discurso inclusivo e igualitario; y 3) diseño de una GuĂa de recomendaciones para la inclusiĂłn de la perspectiva de gĂ©nero en la docencia universitaria
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Invariability of the residual structure with respect to perfect matching
International audienceThis paper discusses some issues associated to the generation of the residual structure for fault detection and isolation using graph theory tools. In particular, the residual structure is shown invariant with respect to a reduced number of complete matchings of the graph. The knowledge of cause and eÂźect variables allows a reduction of matchings to span the residual structure which can be robust to speciÂŻc constraints. Moreover, the paper shows that a dynamic graph obtained from a state space realization generates a causal residual structure as well, and then no additional conditions are required in the matching process to get causal residuals
Influence of the operating conditions and kinetic analysis of the selective hydrogenation of oleic acid on Ru-Sn-B/Al2O3 catalysts
International audienceThe influence of the operating conditions on the selectivity and activity of Ru-Sn-B/Al2O3 catalysts for the hydrogenation of oleic acid to oleyl alcohol was studied. It was found that the Ru-Sn-B/Al2O3 catalyst is selective to oleyl alcohol while Ru or Ru-B/Al2O3 catalysts are not selective to produce oleyl alcohol. The electronic and catalytic properties of Ru are modified by the strong interaction between Sn and B. The incorporation of Sn leads to catalysts capable of producing oleyl alcohol. The experiments of oleic acid hydrogenation showed that an increase in reaction temperature leads to an increase in activity while the selectivity to oleyl alcohol goes through a maximum. This is because the reactions of hydrogenation of C=C double bond have lower activation energies than hydrogenolytic reactions. The increase in operating pressure has a positive effect on conversion and a more important effect on selectivity. A very simple first order kinetic model is proposed and reasonably represents the results obtained. This model can be useful to compare catalyst performance more rationally
Adipose-derived mesenchymal stromal cells for the treatment of patients with severe SARS-CoV-2 pneumonia requiring mechanical ventilation. A proof of concept study
Background: Identification of effective treatments in severe cases of COVID-19 requiring mechanical ventilation represents an unmet medical need. Our aim was to determine whether the administration of adiposetissue derived mesenchymal stromal cells (AT-MSC) is safe and potentially useful in these patients.
Methods: Thirteen COVID-19 adult patients under invasive mechanical ventilation who had received previous
antiviral and/or anti-inflammatory treatments (including steroids, lopinavir/ritonavir, hydroxychloroquine
and/or tocilizumab, among others) were treated with allogeneic AT-MSC. Ten patients received two doses,
with the second dose administered a median of 3 days (interquartile range-IQR- 1 day) after the first one.
Two patients received a single dose and another patient received 3 doses. Median number of cells per dose
was 0.98 ÂŁ 106 (IQR 0.50 ÂŁ 106
) AT-MSC/kg of recipientâs body weight. Potential adverse effects related to
cell infusion and clinical outcome were assessed. Additional parameters analyzed included changes in imaging, analytical and inflammatory parameters
- âŠ