4,686 research outputs found

    Detection of Hepatitis E Virus in Shellfish Harvesting Areas from Galicia (Northwestern Spain)

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    The hepatitis E virus (HEV) affects almost 20 million individuals annually, causing approximately 3.3 million acute liver injuries, 56,600 deaths, and huge healthcare-associated economic losses. Shellfish produced close to urban and livestock areas can bioaccumulate this virus and transmit it to the human population. The aim of this study was to evaluate the presence of HEV in molluscan shellfish, in order to deepen the knowledge about HEV prevalence in Galicia (northwestern Spain), and to investigate this as a possible route of HEV transmission to humans. A total of 168 shellfish samples was obtained from two different Galician rías (Ría de Ares-Betanzos and Ría de Vigo). The samples were analyzed by reverse transcription-quantitative PCR (RT-qPCR). RT-nested PCR and sequencing were used for further genotyping and phylogenetic analysis of positive samples. HEV was detected in 41 (24.4%) samples, at quantification levels ranging from non-quantifiable (<102 copies of the RNA genome (RNAc)/g tissue) to 1.1 × 105 RNAc/g tissue. Phylogenetic analysis based on the open reading frame (ORF)2 region showed that all sequenced isolates belonged to genotype 3, and were closely related to strains of sub-genotype e, which is of swine origin. The obtained results demonstrate a significant prevalence of HEV in bivalve molluscs from Galician rías, reinforcing the hypothesis that shellfish may be a potential route for HEV transmission to humans.The authors gratefully acknowledge Ms. Cristina Álvarez from the INTECMAR (Galicia, Spain) for her help in obtaining the samples included in the analysis. E.R. acknowledges the IACOBUS Program from the European Strategic Group of Territorial Cooperation Galicia/North of Portugal for a research fellowship

    Extraction-Separation Performance and Dynamic Modeling of Orion Test Vehicles with Adams Simulation: 2nd Edition

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    NASA's Orion Capsule Parachute Assembly System (CPAS) project has advanced into the third generation of its parachute test campaign and requires technically comprehensive modeling capabilities to simulate multi-body dynamics (MBD) of test articles released from a C-17. Safely extracting a 30,000 lbm mated test article from a C-17 and performing stable mid-air separation maneuvers requires an understanding of the interaction between elements in the test configuration and how they are influenced by extraction parachute performance, aircraft dynamics, aerodynamics, separation dynamics, and kinetic energy experienced by the system. During the real-time extraction and deployment sequences, these influences can be highly unsteady and difficult to bound. An avionics logic window based on time, pitch, and pitch rate is used to account for these effects and target a favorable separation state in real time. The Adams simulation has been employed to fine-tune this window, as well as predict and reconstruct the coupled dynamics of the Parachute Test Vehicle (PTV) and Cradle Platform Separation System (CPSS) from aircraft extraction through the mid-air separation event. The test-technique for the extraction of CPAS test articles has evolved with increased complexity and requires new modeling concepts to ensure the test article is delivered to a stable test condition for the programmer phase. Prompted by unexpected dynamics and hardware malfunctions in drop tests, these modeling improvements provide a more accurate loads prediction by incorporating a spring-damper line-model derived from the material properties. The qualification phase of CPAS testing is on the horizon and modeling increasingly complex test-techniques with Adams is vital to successfully qualify the Orion parachute system for human spaceflight

    Correlation entropy of synaptic input-output dynamics

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    The responses of synapses in the neocortex show highly stochastic and nonlinear behavior. The microscopic dynamics underlying this behavior, and its computational consequences during natural patterns of synaptic input, are not explained by conventional macroscopic models of deterministic ensemble mean dynamics. Here, we introduce the correlation entropy of the synaptic input-output map as a measure of synaptic reliability which explicitly includes the microscopic dynamics. Applying this to experimental data, we find that cortical synapses show a low-dimensional chaos driven by the natural input pattern.Comment: 7 pages, 6 Figures (7 figure files

    Galaxy properties from J-PAS narrow-band photometry

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    We study the consistency of the physical properties of galaxies retrieved from SED-fitting as a function of spectral resolution and signal-to-noise ratio (SNR). Using a selection of physically motivated star formation histories, we set up a control sample of mock galaxy spectra representing observations of the local universe in high-resolution spectroscopy, and in 56 narrow-band and 5 broad-band photometry. We fit the SEDs at these spectral resolutions and compute their corresponding the stellar mass, the mass- and luminosity-weighted age and metallicity, and the dust extinction. We study the biases, correlations, and degeneracies affecting the retrieved parameters and explore the r\^ole of the spectral resolution and the SNR in regulating these degeneracies. We find that narrow-band photometry and spectroscopy yield similar trends in the physical properties derived, the former being considerably more precise. Using a galaxy sample from the SDSS, we compare more realistically the results obtained from high-resolution and narrow-band SEDs (synthesized from the same SDSS spectra) following the same spectral fitting procedures. We use results from the literature as a benchmark to our spectroscopic estimates and show that the prior PDFs, commonly adopted in parametric methods, may introduce biases not accounted for in a Bayesian framework. We conclude that narrow-band photometry yields the same trend in the age-metallicity relation in the literature, provided it is affected by the same biases as spectroscopy; albeit the precision achieved with the latter is generally twice as large as with the narrow-band, at SNR values typical of the different kinds of data.Comment: 26 pages, 15 figures. Accepted for publication in MNRA

    JPCam: A 1.2Gpixel camera for the J-PAS survey

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    JPCam is a 14-CCD mosaic camera, using the new e2v 9k-by-9k 10microm-pixel 16-channel detectors, to be deployed on a dedicated 2.55m wide-field telescope at the OAJ (Observatorio Astrofisico de Javalambre) in Aragon, Spain. The camera is designed to perform a Baryon Acoustic Oscillations (BAO) survey of the northern sky. The J-PAS survey strategy will use 54 relatively narrow-band (~13.8nm) filters equi-spaced between 370 and 920nm plus 3 broad-band filters to achieve unprecedented photometric red-shift accuracies for faint galaxies over ~8000 square degrees of sky. The cryostat, detector mosaic and read electronics is being supplied by e2v under contract to J-PAS while the mechanical structure, housing the shutter and filter assembly, is being designed and constructed by a Brazilian consortium led by INPE (Instituto Nacional de Pesquisas Espaciais). Four sets of 14 filters are placed in the ambient environment, just above the dewar window but directly in line with the detectors, leading to a mosaic having ~10mm gaps between each CCD. The massive 500mm aperture shutter is expected to be supplied by the Argelander-Institut fur Astronomie, Bonn. We will present an overview of JPCam, from the filter configuration through to the CCD mosaic camera. A brief outline of the main J-PAS science projects will be included.Comment: 11 pages and 9 figure

    The monzonitic rocks of the eastern sector of the Cacheuta Pluton, Precordillera of Mendoza: geochemical signature and U/Pb age (LA-ICP-MS)

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    En el sur de la Precordillera mendocina, aflora el plutón de Cacheuta formado por un borde de tipo monzonítico a granodiorítico (Boca del Río) gris-verdoso y otro posterior de mayor superficie aflorante de composición granítica y tonos rosadosrojizos. Se ofrecen en este trabajo nuevos datos geoquímicos sobre las rocas monzoníticas y el análisis geocronológico por el método U/Pb (LA-ICP-MS) sobre 25 cristales de circones extraídos de tres muestras. Las rocas monzoníticas analizadas son de características subalcalinas, metaaluminosas y presentan enriquecimiento en LREE, diseño plano o ligeramente inclinado de HREE y leve anomalía negativa de Eu. La signatura geoquímica es de rocas calco-alcalinas de arco magmático. El análisis geocronológico por U/Pb permitió definir un histograma con una moda principal de edades entre 253 - 258 Ma correspondiente al Pérmico Tardío. Luego los datos isotópicos se extienden entre el Carbonífero Tardío con 302 Ma para un circón de una de las muestras como registro más antiguo y otra que presenta la edad de 249 Ma correspondiendo ya al Triásico más bajo. Con estos datos se confirma que el magmatismo del plutón de Cacheuta pertenece al ciclo gondwánico, resultando coetáneo con parte de la actividad volcánica del Grupo Choiyoi.In the south of the Precordillera of Mendoza crops out the Cacheuta Pluton formed with an eastern belt of gray-green monzonite to granodiorite type rocks (Boca del Rio) and a subsequent larger surface outcrop of pink granitic rocks. In this work are offered new whole rock geochemical and geochronological U/Pb (LA-ICP-MS) data on 25 zircon crystals extracted from three monzonitic rock samples. These rocks have subalkaline and metaaluminous signature, with enrichment in light REE with less negative Eu anomaly. The analyses of zircon crystals by U/Pb geochronology show that a main mode of ages is 253 -258 Ma that represent the Late Permian. Then the isotopic data span between the Carboniferous with 302 Ma as the oldest zircon record and other one that presents the age of 249 Ma corresponding to the Early Triassic. With these data, the composed Cacheuta Pluton belongs entirely to the Gondwanian orogenic cycle and is coeval with the Permian-Triassic volcanic activity of the Choiyoi Group.Centro de Investigaciones GeológicasFacultad de Ciencias Naturales y Muse

    J-PLUS: analysis of the intracluster light in the Coma cluster

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    The intracluster light (ICL) is a luminous component of galaxy clusters composed of stars that are gravitationally bound to the cluster potential but do not belong to the individual galaxies. Previous studies of the ICL have shown that its formation and evolution are intimately linked to the evolutionary stage of the cluster. Thus, the analysis of the ICL in the Coma cluster will give insights into the main processes driving the dynamics in this highly complex system. Using a recently developed technique, we measure the ICL fraction in Coma at several wavelengths, using the J-PLUS unique filter system. The combination of narrow- and broadband filters provides valuable information on the dynamical state of the cluster, the ICL stellar types, and the morphology of the diffuse light. We use the Chebyshev-Fourier Intracluster Light Estimator (CICLE) to disentangle the ICL from the light of the galaxies, and to robustly measure the ICL fraction in seven J-PLUS filters. We obtain the ICL fraction distribution of the Coma cluster at different optical wavelengths, which varies from 7%21%\sim 7\%-21\%, showing the highest values in the narrowband filters J0395, J0410, and J0430. This ICL fraction excess is distinctive pattern recently observed in dynamically active clusters (mergers), indicating a higher amount of bluer stars in the ICL compared to the cluster galaxies. Both the high ICL fractions and the excess in the bluer filters are indicative of a merging state. The presence of younger/lower-metallicity stars the ICL suggests that the main mechanism of ICL formation for the Coma cluster is the stripping of the stars in the outskirts of infalling galaxies and, possibly, the disruption of dwarf galaxies during past/ongoing mergers.Comment: 10 pages, 3 figures, 1 table. Accepted for publication in A&

    MANEJO DA FLORESTA OMBRÓFILA MISTA A PARTIR DA DISTRIBUIÇÃO DIAMÉTRICA: UMA REVISÃO BIBLIOGRÁFICA

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    A diminuição expressiva da área de ocorrência da Floresta Ombrófila Mista (FOM) ocorreu principalmente devido à intensa exploração madeireira de espécies, como a Araucaria angustifolia. A avaliação dos fragmentos submetidos a distúrbios antrópicos de diferentes intensidades e natureza, identificou fortes diferenciações florísticas e estruturais na vegetação. O conhecimento das características estruturais, como a projeção da distribuição diamétrica no tempo, é de real importância para o manejo das florestas naturais, definindo intervenções que assegurem a sustentabilidade. Com o objetivo de apresentar formas de se obter a distribuição diamétrica, a presente revisão baseou-se em mais de 20 referências, após seleção do levantamento de publicações científicas. A elaboração dos resultados da pesquisa foi dividida em duas partes, mostrando inicialmente cada método e posteriormente seus respectivos resultados. No geral, fragmentos da FOM submetidos ao corte seletivo podem recuperar suas variáveis estruturais em poucas décadas. No entanto, nota-se que todos os parâmetros apresentam baixo incremento, podendo estar relacionado à falta de condução das florestas nativas ou exploração desordenada. Quanto a A. angustifolia, essa vem diminuindo sua participação na floresta, com a tendência de as folhosas aumentarem. Conclui-se que há diversos métodos para se obter a distribuição diamétrica de uma floresta, tendo a necessidade da continuação dos estudos para que no futuro seja possível a determinação de um ciclo de manejo sustentável que priorize a valorização dessa formação florestal e do bioma como um todo

    Middle Proterozoic and Lower Paleozoic of the Sierra de Umango, Andean Foreland (29°S), Argentina: U-Pb ages and isotopic characteristics

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    En el basamento cristalino de la sierra de Umango se han distinguido varias unidades ígneo-metamórficas, formadas principalmente entre el Proterozoico medio y el Paleozoico inferior. Incluye ortogneises graníticos, una sucesión de esquistos y mármoles, anfibolitas, y tres plutones graníticos de reducido tamaño. Se han realizado análisis químicos de granitoides y anfibolitas, y determinaciones de edad por los métodos U-Pb y K-Ar. La edad U-Pb en circón del Ortogneis Juchi (1108±13 Ma) ratifica la asignación al Proterozoico medio por anterior datación Rb-Sr (1030±30 Ma). La edad U-Pb en circón del Granito El Peñón (473±17 Ma) es ligeramente mayor que la obtenida por el método Rb-Sr (469±9 Ma), aunque concordante si se tiene en cuenta el error de las determinaciones. Las edades K-Ar sobre muscovitas del Granito El Peñón (409±14 y 381±11 Ma) son relacionadas a deformación y metamorfismo ocurridos en el Devónico. Los isótopos de Nd y Sr permitieron establecer diferencias entre un conjunto de unidades relacionadas con el Ciclo Grenvilliano y otro con los Ciclos Pampeano-Famatiniano. Los datos obtenidos en la sierra de Umango indican que en las Sierras Pampeanas Occidentales hay núcleos de un basamento del Proterozoico medio (Ciclo Grenvilliano), más una sucesión de esquistos y mármoles con anfibolitas, y plutones graníticos de reducido tamaño, formados en el lapso Proterozoico superior-Devónico (Ciclos Pampeano-Famatiniano). La estructura interna de mayor relevancia, formada en el Ordovícico-Devónico muestra clara vergencia tectónica occidental y estaría relacionada con láminas de corrimiento (nappes) de una tectónica colisional. Las mismas se proyectarían desde el interior orogénico (Sierras Pampeanas Orientales) hacia el contiguo antepaís de una de las placas interactuantes. Las sedimentitas clásticas del Ordovícico superior-Devónico en Precordillera (cuenca de antepaís) completan el escenario geodinámico.Igneous and metamorphic units formed mainly during the Middle Proterozoic and Early Paleozoic times have been distinguished in the Sierra de Umango crystalline basement. These include granitic orthogneisses, a sequence of schists and marbles, amphibolites, and three small granitic plutons. Geochemical analyses of granitoids and amphibolites, as well as age determinations using U-Pb and K-Ar methods were carried out. The U-Pb age in zircón of the Juchi Orthogneiss (1108 ± 13 Ma) confirms the previous Rb-Sr Mesoproterozoic dating (1030 ± 30 Ma). The U-Pb in zircón age of El Peñón Granite (473 ± 17 Ma) is slighty older than the Rb-Sr age (469 ± 9 Ma). The K-Ar mouscovite dates from El Peñón Granite (409 ± 14 and 381 ± 11 Ma) are related to a Devonian deformation and metamorphism. On the basis of Nd and Sr isotopic characteristics, two different sets of units can be identified, one related to the Grenvillian cycle and the second to the Pampean-Famatinian cycles. According to the data obtained for the Sierra de Umango, we interpret that in this part of the Western Sierras Pampeanas there are relics of a Mesoproterozoic basement (Grenville cycle), together with more important exposures of a schists and marble succession, with amphibolites and small granitic plutons, that were formed during Late Proterozoic to Devonian times (Pampean and Famatinian cycles). The major basement structure, formed during Ordovician to Devonian, shows a clear tectonic vergence toward the west, and consists of thrust sheets (nappes) typical of collisional tectonics. These sheets are transported from the inner parts of the orogen (Sierras Pampeanas Orientales) toward the contiguous foreland of the interacting terrane. The Upper Ordovician to Devonian sedimentary rocks of the Precordillera (foreland basin) could complete the geodynamic environment.Centro de Investigaciones Geológica
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