44 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
Perfil dos bolsistas de produtividade do Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) na área de Medicina Veterinária
Impacto da vitimação juvenil na resiliência e na empatia : um estudo com jovens delinquentes
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas MonizEnquadramento: Vários estudos apontam para o facto de a vitimação e da delinquência
estarem relacionados, uma vez que, jovens vítimas de acontecimentos adversos,
apresentam maior probabilidade de enveredar pelo caminho da delinquência. No que
concerne à resiliência e à empatia, segundo os estudos, tendem a ser mais baixos neste
grupo de jovens. Objetivo: Verificar a relação entre a vitimação, empatia e resiliência
numa amostra de jovens delinquentes e, analisar se existem diferenças relativamente à
faixa etária, ao sexo e à vitimação e polivítimação relativamente à resiliência e à empatia.
Método: A amostra foi composta por 41 jovens, 23 do sexo masculino (54.8%) e 18 do
sexo feminino (42.9%), dos quais 36 são vítimas (85.7%) e 23 polivítimas (54.8%).
Resultados: Este estudo confirma existir uma relação negativa entre a resiliência e a
vitimação, uma relação positiva entre a empatia e a resiliência e diferenças entre os sexos na resiliência. Conclusão: As análises deste estudo forneceram uma importante
contribuição para o estudo da vitimação, resiliência e empatia em jovens delinquentes. É
uma mais valia na promoção de resiliência, a empatia na prevenção da delinquência neste grupo de jovens.Background: Different studies point that victimization and delinquency are related since
young victims of adverse events are most likely to take the delinquency path. Regarding
resilience and empathy, according to studies, they tend to be lower in this group of young
people. Objectives: Verify the relationship between victimization, empathy, and
resilience in a sample of young delinquents and analyze if there are differences regarding
the age group, sex and victimization, and poly-vitimization regarding resilience and
empathy. Method: The sample consisted of 41 young people, 23 males (54.8%) and 18
females (42.9%), of whom 36 are victims (85.7%) and 23 poly-victims (54.8%). Results:
This study confirms that there is a negative relationship between resilience and
victimization, a positive relationship between empathy and resilience and differences
between genders in resilience. Conclusion: The analysis of this study provided an
important contribution to the study of victimization, resilience and empathy in young
offenders. It is an asset in promoting resilience, empathy in preventing delinquency in
this group of young people
Evaluation of the Clinical Sensitivities of Three Viral Load Assays with Plasma Samples from a Pediatric Population Predominantly Infected with Human Immunodeficiency Virus Type 1 Subtype G and BG Recombinant Forms
The viral load assays AMPLICOR HIV-1 Monitor Test 1.5, Nuclisens HIV-1 QT, and Quantiplex HIV RNA 3.0 (bDNA) were evaluated for their abilities to quantify human immunodeficiency virus type 1 (HIV-1) RNA in 64 plasma samples from 21 children infected in Portugal. The children were infected with HIV-1 subtypes A1, B, F1, G, and BG recombinant virus. AMPLICOR v1.5 and Quantiplex v3.0 detected all samples, and there was a good correlation of results between the two kits. Thirty-eight specimens containing HIV-1 subtype B, G, or recombinant BG, could not be detected by Nuclisens HIV-1 QT. We also evaluated the new Retina HIV-1 assay on 21 samples that were HIV-1 positive; Retina HIV-1 failed to detect 5 of 11 subtype G specimens. AMPLICOR v1.5 and Quantiplex v3.0 assays may be used for HIV-1 RNA quantification in Portugal, whereas an improvement in sensitivity for subtype G and recombinant BG is required for Nuclisens HIV-1 QT and Retina HIV-1
C2V3C3-specific IgG response is associated with disease progression
Objective: To examine the unspecific and envelope-specific IgA and IgG responses in acute and chronic HIV-2 infection. Methods: Twenty-eight chronically infected adults and two children with perinatal infection were studied. Total plasma concentrations of. - Fundacao para a Ciencia e Tecnologia [POCTI/ESP/48045]. - The present work was supported by Fundacao para a Ciencia e Tecnologia (project POCTI/ESP/48045). Jose Marcelino is the recipient of a PhD scholarship from Fundacao para a Ciencia e Tecnologia (FCT), Portugal. The Instituto Portugues do Sangue (IPS), Por