1,862 research outputs found

    Temporal and spatial variations of the absolute reflectivity of Jupiter and Saturn from 0.38 to 1.7 μ\mum with PlanetCam-UPV/EHU

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    We provide measurements of the absolute reflectivity of Jupiter and Saturn along their central meridians in filters covering a wide range of visible and near-infrared wavelengths (from 0.38 to 1.7 μ\mum) that are not often presented in the literature. We also give measurements of the geometric albedo of both planets and discuss the limb-darkening behavior and temporal variability of their reflectivity values for a period of four years (2012-2016). This work is based on observations with the PlanetCam-UPV/EHU instrument at the 1.23 m and 2.2 m telescopes in Calar Alto Observatory (Spain). The instrument simultaneously observes in two channels: visible (VIS; 0.38-1.0 μ\mum) and short-wave infrared (SWIR; 1.0--1.7 μ\mum). We obtained high-resolution observations via the lucky-imaging method. We show that our calibration is consistent with previous independent determinations of reflectivity values of these planets and, for future reference, provide new data extended in the wavelength range and in the time. Our results have an uncertainty in absolute calibration of 10--20\%. We show that under the hypothesis of constant geometric albedo, we are able to detect absolute reflectivity changes related to planetary temporal evolution of about 5-10\%.Comment: 13 pages, 18 figures, (in press

    Carbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolution

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    We present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mkn 1271, NGC 3125, NGC 5408, POX 4, SDSS J1253-0312, Tol 1457-262, Tol 1924-416 and the HII region Hubble V in the Local Group dwarf irregular galaxy NGC 6822. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3100-10420 {\AA} range. We determine electron densities and temperatures of the ionized gas from several emission-line intensity ratios for all the objects. We derive the ionic abundances of C2+^{2+} and/or O2+^{2+} from faint pure recombination lines (RLs) in several of the objects, permitting to derive their C/H and C/O ratios. We have explored the chemical evolution at low metallicities analysing the C/O vs. O/H, C/O vs. N/O and C/N vs. O/H relations for Galactic and extragalactic HII regions and comparing with results for halo stars and DLAs. We find that HII regions in star-forming dwarf galaxies occupy a different locus in the C/O vs. O/H diagram than those belonging to the inner discs of spiral galaxies, indicating their different chemical evolution histories, and that the bulk of C in the most metal-poor extragalactic HII regions should have the same origin than in halo stars. The comparison between the C/O ratios in HII regions and in stars of the Galactic thick and thin discs seems to give arguments to support the merging scenario for the origin of the Galactic thick disc. Finally, we find an apparent coupling between C and N enrichment at the usual metallicities determined for HII regions and that this coupling breaks in very low-metallicity objects.Comment: 27 pages, 12 figures, Accepted for publication in Monthly Notices of the Royal Astronomical Societ

    Hipoplasia de la valva posterior de la válvula mitral y válvula aórtica bicúspide. Una muy rara asociación para encontrar en un paciente adulto

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    The congenital heart diseases are a diagnostic challenge for the clinician, particularly when they are presented in an adult. These types of anomalies that are observed in the mitral valve can be presented in isolated form or together with other heart defects. The case is presented of a patient with severe hypoplasia of the posterior mitral valve leaflet. This anomaly is, under normal conditions, fatal before birth or very symptomatic during childhood, and its delayed presentation is extremely rare and difficult to find in the adult. This the first case reported, not only in this country, but in the whole of South America. © 2018 Sociedad Colombiana de Cardiología y Cirugía Cardiovascula

    Photon path length distribution in random media from spectral speckle intensity correlations

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    We show that the spectral speckle intensity correlation (SSIC) technique can be profitably exploited to recover the path length distribution of photons scattered in a random turbid medium. We applied SSIC to the study of Teflon slabs of different thicknesses and were able to recover, via the use of the photon diffusion approximation theory, the characteristic transport mean free path ℓ∗ and absorption length s a of the medium. These results were compared and validated by means of complementary measurements performed on the same samples with standard pulsed laser time of flight technique

    A comparison of techniques for robust gender recognition

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    Reprinted, with permission, from [Rojas Bello, R.N., Lago Fernández, L.F., Martínez Muñoz, G., y Sánchez Montañés, M.A., A comparision of techniques for robust gender recognition, IEEE International Conference on Image Processing, ICIP 2011]. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the Universidad Autónoma de Madrid's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.Proceedings of 2011 18th IEEE International Conference on Image Processing (ICIP), 11-14 Sept. 2011, BrusselsAutomatic gender classification of face images is an area of growing interest with multiple applications. Appropriate classifiers should be robust against variations such as illumination, scale and orientation that occur in real world applications. This can be achieved by normalizing the images in order to reduce those variations (alignment, re-scaling, histogram-equalization, etc.), or by extracting features from the original images which are invariant respect to those variations. In this work we perform a robust comparison of eight different classifiers across 100 random partitions of a set of frontal face images. Four of them are state-of-the-art methods in automatic gender classification that use image normalization (SVMs, Neural Networks, ADABOOST and PCA+LDA). The other four strategies use invariant features extracted by SIFT (BOW, Evidence Random Trees, NBNN and Voted Nearest-Neighbor). The best strategies are SVM using normalized images and NBNN, the latter having the advantage that no strong image pre-processing is needed.This work has been supported by CDTI (project INTEGRA) and DGUICAM/UAM (project CCG10-UAM/TIC-5864

    Minimal invasive surgery in craniostenosis

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    En el presente trabajo se describe la experiencia en craneoestenosis con cirugía mínimamente invasiva, evaluando el diseño y eficacia de un nuevo craneotomo en cadáveres así como su aplicación clínica en un caso de sinostósis sagital con instrumentación endoscópica. Este procedimiento es sin duda un gran recurso en el tratamiento de las craneoestenosis brindando los beneficios de la cirugía mínimamente invasiva, eliminando la necesidad de grandes incisiones, disminuyendo el sangrado quirúrgico, reduciendo estancia hospitalaria y disminuyendo la morbilidad operatoria In this paper, we describe the experience with the use of endoscopic craniofacial procedures, evaluating the design and the efficacy of a new craniotome in cadavers and his clinical application in a case of sagittal synostosis for an endoscopic assisted cranioplasty. This procedure is a great option in the treatment of craniosynostosis, giving the benefits of minimal invasive surgery and eliminating the needing of big incisions, long hospital stay and reducing the postoperative morbidit

    Effects of carbohydrate–protein beverages on recovery of the exercise

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    Este artículo aporta una revisión del efecto de la coingesta de la proteína de suero de leche y proteína caseína administradas en bebidas carbohidratadas, sobre la recuperación y los parámetros del daño muscular en ejercicios de larga duración. La búsqueda se ha realizado en abril de 2013 en las bases de datos del ISI Web of Knowledge, SCOPUS, Sport Discuss, PubMed, Medline Sportdiscus, y en las bases de datos CINDOC en las redes CTI-CSIC, RESH, DICE y DIALNET cruzando los descriptores “Exercise”, “Resistance training” y “Recovery” con los términos “Ergogenic beverage”, “Casein Protein” y “Whey Protein”. La estrategia nutricional más respaldada es la ingesta de un preparado líquido carbohidratado en donde se combinan proteínas de diferentes fuentes sobre pruebas de esfuerzos prolongados similares a la competición tanto en deportes individuales como en colectivos, con resultados discrepantesThis manuscript shows a review about the effects of the whey and casein protein on recovery and parameters of muscle damage in long-term exercise. The search was conducted in April 2013 in the databases of ISI Web of Knowledge, SCOPUS, PubMed, Medline, SportDiscus, and databases on Spanish networks CINDOC CTI-CSIC, RESH, DICE, and DIALNET crossing the descriptors "Exercise", "Resistance training" and "Recovery" with the terms "Ergogenic Beverage", "Casein Protein" and "Whey Protein". The most used nutritional strategies are based in a carbohydrate beverage which combines different protein sources on prolonged exercise tests similar to sports competition, in both individual and collective sports, with discrepant result

    Características de cenizas volantes españolas

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    The purpose of this study is the characterization of fly ashes produced by Spanish thermoelectric power plants, according to sampling taken in 1981 and 1982. The study takes in the following characteristics: physical characteristics (size distribution of particles, ...); chemical ones (chemical analysis...); and mineralogical ones (application of instrumental techniques of X-ray diffraction and infrared absorption spectroscopy). From a general point of view, it can be said that the samples of Spanish fly ashes are similar to those produced in other countries. The results obtained are a contribution to the knowledge of Spanish fly ashes and form part of the antecedents of investigations carried out in subsequent years.Este trabajo tiene por objeto la caracterización de las cenizas volantes producidas en las Centrales Termoeléctricas españolas, según un muestreo realizado entre 1981 y 1982. El estudio comprende las siguientes características: físicas (distribución del tamaño de partículas,...); químicas (análisis químico, …); y mineralógicas (aplicación de las técnicas instrumentales de difracción de rayos X y espectroscopía de absorción infrarroja). Desde un punto de vista general, se puede afirmar que las muestras de ceniza volante estudiadas son semejantes a las producidas en otros países. Los resultados obtenidos son una aportación al conocimiento de las cenizas volantes españolas y forman parte de los antecedentes de las investigaciones llevadas a cabo en años posteriores
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