101 research outputs found

    IDENTIFICACIÓN MOLECULAR y FILOGENÉTICA DE ROTAVIRUS., EN CONEJOS DE LA ZONA SUR ORIENTE DEL ESTADO DE MÉXICO

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    Rotavirus es reconocido como el agente etiológico de gastroenteritis más importante tanto en niños como en animales neonatos en todo el mundo, con una morbilidad y mortalidad de gran impacto social y económico (Dodet et al., 1997; Estes et al., 2001; Matthijinssens et al., 2008). El género Rotavirus está clasificado dentro de la familia Reoviridae, subfamilia Sedoreovirinae (Nakagomi y Nakagomi, 2002). El genoma del virus está compuesto por 11 segmentos de doble cadena de RNA, seis de ellos codifican para seis proteínas estructurales (VP1-VP4, VP6 y VP7) y cinco para seis proteínas no estructurales (NSP1-NSP6). El genoma está protegido por una cápside constituida por tres capas (Martella et al., 2005). La capa intermedia está conformada en su totalidad por la proteína VP6, esta proteína permite la clasificación antigénica de rotavirus en siete grupos (A-G), aunque Matthijnssens et al., 2012, han añadido el grupo H. En conejos se ha identificado el grupo A de Rotavirus, las cepas que pertenecen a este grupo, se clasifican en subgrupos (SG), mediante la amplificación de la región que codifica para sus determinantes antigénicos, ubicada dentro del fragmento VP6En otros países, Rotavirus es considerado la principal etiología de gastroenteritis aguda en conejos. En México, en las unidades de producción cunícola los cuadros entéricos repercuten en alta mortalidad y fuertes pérdidas económicas. La proteína VP6 de la capa intermedia de la cápside del virus, es utilizada para clasificar antigénicamente el Rotavirus en grupos (A-H). Utilizando la técnica de Reverso Transcriptasa-Reacción en Cadena de la Polimerasa, se probaron 19 muestras de intestino de conejos sanos y con cuadro clínico entérico, provenientes de la región suroriente del Estado de México, De las muestras probada el 31.5% (6), amplificaron un fragmento de 380pb utilizando los primers específicos para el fragmento VP6. Es el primer reporte de detección molecular de Rotavirus en conejos en Méxic

    Novel Multiplierless Wideband Comb Compensator with High Compensation Capability

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    This paper proposes a novel multiplierless comb compensation filter, which has the absolute passband deviation less than 0.1 dB in the wide passband. The compensator consists of a cascade of two simple filter sections, both operating at a low rate. The magnitude characteristics of the two-component filters are synthesized as sinewave functions, in which the main design parameters correspond to the amplitudes of sinewave functions. A systematic procedure is followed to select synthesis parameters, which depend only on the number of cascaded comb filters. In particular, they are independent of the decimation factor. Comparisons with comb compensators from the literature illustrate the benefits of the proposed design.Consejo Nacional de Ciencia y TecnologĂ­a 17958

    DROM: Enabling Efficient and Effortless Malleability for Resource Managers

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    In the design of future HPC systems, research in resource management is showing an increasing interest in a more dynamic control of the available resources. It has been proven that enabling the jobs to change the number of computing resources at run time, i.e. their malleability, can significantly improve HPC system performance. However, job schedulers and applications typically do not support malleability due to the common belief that it introduces additional programming complexity and performance impact. This paper presents DROM, an interface that provides efficient malleability with no effort for program developers. The running application is enabled to adapt the number of threads to the number of assigned computing resources in a completely transparent way to the user through the integration of DROM with standard programming models, such as OpenMP/OmpSs, and MPI. We designed the APIs to be easily used by any programming model, application and job scheduler or resource manager. Our experimental results from two realistic use cases analysis, based on malleability by reducing the number of cores a job is using per node and jobs co-allocation, show the potential of DROM for improving the performance of HPC systems. In particular, the workload of two MPI+OpenMP neuro-simulators are tested, reporting improvement in system metrics, such as total run time and average response time, up to 8% and 48%, respectively.This work is partially supported by the Span- ish Government through Programa Severo Ochoa (SEV-2015-0493), by the Spanish Ministry of Science and Technology through TIN2015-65316-P project, by the Generalitat de Catalunya (contract 2017-SGR-1414) and from the European Union’s Horizon 2020 under grant agreement No 785907 (HBP SGA2)Peer ReviewedPostprint (author's final draft

    Circulación local y ascenso de aire en un sitio costero y tropical al pie de la montaña

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    Ponencia presentada en: IV Congreso de la Asociación Española de Climatología "El Clima entre el Mar y la Montaña", celebrado en Santander del 2 al 5 de noviembre de 2004.[ES]La zona tropical centrada en Laguna Verde (19,3° a 20,0°N; 96,4° a 96,6° W; cero a 1.000 m) se localiza sobre un terreno complejo, en la costa central del estado de Veracruz (México) en el Golfo de México. A partir de la información climatológica de superficie y mediciones esporádicas enfocadas al comportamiento de la capa límite superficial (datos de anemómetro sónico, sodar y radiosondeos), esta comunicación revisa el campo de viento y algunas características de la capa de mezcla, en términos del acoplamiento entre el flujo local, la circulación sinóptica, las propiedades convectivas de la capa de mezcla, y el balance de calor en la interfaz suelo atmósfera. Destaca un bajo acoplamiento entre el flujo local y la circulación sinóptica; la altura de la capa de mezcla es prácticamente independiente del balance calórico superficial, y frecuentemente se sobreponen dos capas límites superficiales: una inducida por la brisa marina y otra por la brisa terral.[EN]The tropical Mexican zone centered at Laguna Verde (19,3° to 20,0°N; 96,4° to 96,6° W; zero to 1.000 m) is located on a complex terrain of the State of Veracruz on the coast of the Gulf of Mexico. From superficial meteorological information and sporadic measurement campaigns focused on the behavior of the surface boundary layer (data from sodar, sonic anemometer and radiosonde balloons), this paper shows a review of the wind field and some characteristics of the atmospheric mixed layer in terms of coupling between local flow and synoptic circulation, the convective properties of the mixed layer, and soil-atmosphere energy budget. It is evident a relatively low degree of coupling between the local flow and the synoptic circulation; the height of the mixture layer is almost independent of the surface radiative energy budget, and superposition of two boundary layers (one due to the advection of marine air and other one to the land breeze) often is present

    Posibles causas de flujos diurnos negativos de vapor de agua en el verano en Barcelona

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    Ponencia presentada en: III Congreso de la Asociación Española de Climatología “El agua y el clima”, celebrado en Palma de Mallorca del 16 al 19 de junio de 2002.[ES]Del 16 al 21 de junio del 2001 se realizaron mediciones de balance energético atmosférico en el centro de la ciudad de Barcelona. Los flujos de calor latente y de calor sensible se obtuvieron con el método de covarianza turbulenta a partir de datos instantáneos tomados a 20 Hz y procesados cada media hora. Los comportamientos del balance responden a lo esperado bajo estabilidad atmosférica. Sin embargo, se presentaron casos de flujos turbulentos de calor latente de evaporación (QE) negativos (hacia abajo) a mitad del día. Aquí se discute el tratamiento de esos casos bajo dos hipótesis: a) Eventuales fallas del equipo de medición, b) Se analizan casos de QE negativo para una situación meteorológica similar en la ciudad de México, con datos instantáneos tomados cada segundo. Aún para el día se encontraron rachas de subsidencia, que pueden generar flujos netos negativos de vapor de agua.[EN]Atmospheric energy balance measurements were made from 06/16/2001 to 06/21/2001 in downtown Barcelona, Spain. The latent and sensible turbulent heat fluxes were obtained using eddycovariance method. The data were taken at 20 Hz and processed every 30 minutes. Actually, the behavior of energy balance components was as expected to an urban zone with oceanic influence under atmospheric stability conditions. However, negative latent heat fluxes (down direction) were presented in some times around midday. This paper shows the analysis of these cases according to two hypotheses: a) If there were instrumental errors, b) For similar meteorological situation in Mexico City, the QE negative values were analyzed, but from instantaneous data from vertical wind and specific humidity sensed each second. It was found that subsidence cases were presented during day- time, too

    Direct constraint on the distance of y2 Velorum from AMBER/VLTI observations

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    In this work, we present the first AMBER observations, of the Wolf-Rayet and O (WR+O) star binary system y2 Velorum. The AMBER instrument was used with the telescopes UT2, UT3, and UT4 on baselines ranging from 46m to 85m. It delivered spectrally dispersed visibilities, as well as differential and closure phases, with a resolution R = 1500 in the spectral band 1.95-2.17 micron. We interpret these data in the context of a binary system with unresolved components, neglecting in a first approximation the wind-wind collision zone flux contribution. We show that the AMBER observables result primarily from the contribution of the individual components of the WR+O binary system. We discuss several interpretations of the residuals, and speculate on the detection of an additional continuum component, originating from the free-free emission associated with the wind-wind collision zone (WWCZ), and contributing at most to the observed K-band flux at the 5% level. The expected absolute separation and position angle at the time of observations were 5.1±0.9mas and 66±15° respectively. However, we infer a separation of 3.62+0.11-0.30 mas and a position angle of 73+9-11°. Our analysis thus implies that the binary system lies at a distance of 368+38-13 pc, in agreement with recent spectrophotometric estimates, but significantly larger than the Hipparcos value of 258+41-31 pc

    Near-Infrared interferometry of Eta Carinae with high spatial and spectral resolution using the VLTI and the AMBER instrument

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    We present the first NIR spectro-interferometry of the LBV Eta Carinae. The K band observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer using three 8.2m Unit Telescopes with baselines from 42 to 89m. The aim of this work is to study the wavelength dependence of Eta Car's optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution. The medium spectral resolution observations (R=1,500) were performed in the wavelength range around both the HeI 2.059 micron and the Br gamma 2.166 micron emission lines, the high spectral resolution observations (R=12,000) only in the Br gamma line region. In the K-band continuum, a diameter of 4.0 +/-0.2 mas (Gaussian FWHM, fit range 28-89m) was measured for Eta Car's optically thick wind region. If we fit Hillier et al. (2001) model visibilities to the observed AMBER visibilities, we obtain 50 % encircled-energy diameters of 4.2, 6.5 and 9.6mas in the 2.17 micron continuum, the HeI, and the Br gamma emission lines, respectively. In the continuum near the Br gamma line, an elongation along a position angle of 120+/-15 degrees was found, consistent with previous VLTI/VINCI measurements by van Boekel et al. (2003). We compare the measured visibilities with predictions of the radiative transfer model of Hillier et al. (2001), finding good agreement. Furthermore, we discuss the detectability of the hypothetical hot binary companion. For the interpretation of the non-zero differential and closure phases measured within the Br gamma line, we present a simple geometric model of an inclined, latitude-dependent wind zone. Our observations support theoretical models of anisotropic winds from fast-rotating, luminous hot stars with enhanced high-velocity mass loss near the polar regions.Comment: 22 pages, 14 figures, 2 tables; A&A in pres

    Constraining the wind launching region in Herbig Ae stars: AMBER/VLTI spectroscopy of HD 104237

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    This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Aims. We investigate the origin of the Brγ emission of the Herbig Ae star HD 104237 on Astronomical Unit (AU) scales. Methods. Using AMBER/VLTI at a spectral resolution R = 1500 we spatially resolve the emission in both the Brγ line and the adjacent continuum. Results. The visibility does not vary between the continuum and the Brγ line, even though the line is strongly detected in the spectrum, with a peak intensity 35% above the continuum. This demonstrates that the line and continuum emission have similar size scales. We assume that the K-band continuum excess originates in a “puffed-up” inner rim of the circumstellar disk, and discuss the likely origin of Brγ. Conclusions. We conclude that this emission most likely arises from a compact disk wind, launched from a region 0.2–0.5 AU from the star, with a spatial extent similar to that of the near infrared continuum emission region, i.e., very close to the inner rim location.This work has been partly supported by the MIUR COFIN grant 2003/027003-001 and 025227/2004 to the INAFOsservatorio Astrofisico di Arcetri. This project has benefited from funding from the French Centre National de la Recherche Scientifique (CNRS) through the Institut National des Sciences de l’Univers (INSU) and its Programmes Nationaux (ASHRA, PNPS). The authors from the French laboratories would like to thank the successive directors of the INSU/CNRS directors. C. Gil work was supported in part by the Fundac¸˜ao para a Ciˆencia e a Tecnologia through project POCTI/CTE-AST/55691/2004 from POCTI,with funds from the European program FEDER

    Interferometric data reduction with AMBER/VLTI. Principle, estimators, and illustration

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    This is the author accepted manuscript. The final version is available from EDP Sciences via the DOI in this record.Aims. In this paper, we present an innovative data reduction method for single-mode interferometry. It has been specifically developed for the AMBER instrument, the three-beam combiner of the Very Large Telescope Interferometer, but it can be derived for any single-mode interferometer. Methods. The algorithm is based on a direct modelling of the fringes in the detector plane. As such, it requires a preliminary calibration of the instrument in order to obtain the calibration matrix that builds the linear relationship between the interferogram and the interferometric observable, which is the complex visibility. Once the calibration procedure has been performed, the signal processing appears to be a classical least-square determination of a linear inverse problem. From the estimated complex visibility, we derive the squared visibility, the closure phase, and the spectral differential phase. Results. The data reduction procedures have been gathered into the so-called amdlib software, now available for the community, and are presented in this paper. Furthermore, each step in this original algorithm is illustrated and discussed from various on-sky observations conducted with the VLTI, with a focus on the control of the data quality and the effective execution of the data reduction procedures. We point out the present limited performances of the instrument due to VLTI instrumental vibrations which are difficult to calibrate.The AMBER project4 was founded by the French Centre National de la Recherche Scientifique (CNRS), the Max Planck Institute für Radioastronomie (MPIfR) in Bonn, the Osservatorio Astrofisico di Arcetri (OAA) in Firenze, the French Region “Provence Alpes Côte D’Azur” and the European Southern Observatory (ESO). The CNRS funding has been made through the Institut National des Sciences de l’Univers (INSU) and its Programmes Nationaux (ASHRA, PNPS, PNP). The OAA co-authors acknowledge partial support from MIUR grants to the Arcetri Observatory: A LBT interferometric arm, and analysis of VLTI interferometric data and From Stars to Planets: accretion, disk evolution and planet formation and from INAF grants to the Arcetri Observatory Stellar and Extragalactic Astrophysics with Optical Interferometry. C. Gil work was supported in part by the Fundação para a Ciência e a Tecnologia through project POCTI/CTE-AST/55691/2004 from POCTI, with funds from the European program FEDER
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