48 research outputs found

    La fisiología: base de las ciencias médicas y biológicas

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    La Fisiología es una disciplina científica básica, de carácter integrador, cuyo objetivo último es entender el funcionamiento de los organismos vivos a todos sus niveles, desde el molecular hasta el sistémico-orgánico, en su estado de salud y considerando su interacción con el medio ambiente. Con esta finalidad, la Fisiología se constituye como una disciplina básica en las áreas de conocimiento de ciencias y ciencias de la salud y puede considerarse como la base de la patología y de la farmacología. En España, los profesionales de la Fisiología (investigadores y docentes) se reúnen en la Sociedad Española de Ciencias Fisiológicas (SECF). La SECF tiene como misión promover la Fisiología como ciencia y actividad profesional a todos los niveles, dando a conocer su importancia para el desarrollo del conocimiento y, en definitiva, su valor socia

    Galaxy clusters and groups in the ALHAMBRA Survey

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    We present a catalogue of 348 galaxy clusters and groups with 0.2<z<1.20.2<z<1.2 selected in the 2.78 deg2deg^2 ALHAMBRA Survey. The high precision of our photometric redshifts, close to 1%1\%, and the wide spread of the seven ALHAMBRA pointings ensure that this catalogue has better mass sensitivity and is less affected by cosmic variance than comparable samples. The detection has been carried out with the Bayesian Cluster Finder (BCF), whose performance has been checked in ALHAMBRA-like light-cone mock catalogues. Great care has been taken to ensure that the observable properties of the mocks photometry accurately correspond to those of real catalogues. From our simulations, we expect to detect galaxy clusters and groups with both 70%70\% completeness and purity down to dark matter halo masses of Mh3×1013MM_h\sim3\times10^{13}\rm M_{\odot} for z<0.85z<0.85. Cluster redshifts are expected to be recovered with 0.6%\sim0.6\% precision for z<1z<1. We also expect to measure cluster masses with σMhMCL0.250.35dex\sigma_{M_h|M^*_{CL}}\sim0.25-0.35\, dex precision down to 3×1013M\sim3\times10^{13}\rm M_{\odot}, masses which are 50%50\% smaller than those reached by similar work. We have compared these detections with previous optical, spectroscopic and X-rays work, finding an excellent agreement with the rates reported from the simulations. We have also explored the overall properties of these detections such as the presence of a colour-magnitude relation, the evolution of the photometric blue fraction and the clustering of these sources in the different ALHAMBRA fields. Despite the small numbers, we observe tentative evidence that, for a fixed stellar mass, the environment is playing a crucial role at lower redshifts (z<<0.5).Comment: Accepted for publication in MNRAS. Catalogues and figures available online and under the following link: http://bascaso.net46.net/ALHAMBRA_clusters.htm

    I. MUFFIT: A multi-filter fitting code for stellar population diagnostics

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    Numerical methods and codes.-- et al.[Aims]: We present MUFFIT, a new generic code optimized to retrieve the main stellar population parameters of galaxies in photometric multi-filter surveys, and check its reliability and feasibility with real galaxy data from the ALHAMBRA survey. [Methods]: Making use of an error-weighted X2-test, we compare the multi-filter fluxes of galaxies with the synthetic photometry of mixtures of two single stellar populations at different redshifts and extinctions, to provide the most likely range of stellar population parameters (mainly ages and metallicities), extinctions, redshifts, and stellar masses. To improve the diagnostic reliability, MUFFIT identifies and removes from the analysis those bands that are significantly affected by emission lines. The final parameters and their uncertainties are derived by a Monte Carlo method, using the individual photometric uncertainties in each band. Finally, we discuss the accuracies, degeneracies, and reliability of MUFFIT using both simulated and real galaxies from ALHAMBRA, comparing with results from the literature. [Results]: MUFFIT is a precise and reliable code to derive stellar population parameters of galaxies in ALHAMBRA. Using the results from photometric-redshift codes as input, MUFFIT improves the photometric-redshift accuracy by ∼10-20%. MUFFIT also detects nebular emissions in galaxies, providing physical information about their strengths. The stellar masses derived from MUFFIT show excellent agreement with the COSMOS and SDSS values. In addition, the retrieved age-metallicity locus for a sample of z ≤ 0.22 early-type galaxies in ALHAMBRA at different stellar mass bins are in very good agreement with the ones from SDSS spectroscopic diagnostics. Moreover, a one-to-one comparison between the redshifts, ages, metallicities, and stellar masses derived spectroscopically for SDSS and by MUFFIT for ALHAMBRA reveals good qualitative agreements in all the parameters, hence reinforcing the strengths of multi-filter galaxy data and optimized analysis techniques, like MUFFIT, to conduct reliable stellar population studies.L.A.D.G. acknowledges support from the "Caja Rural de Teruel" for developing this research. A.J.C. is a Ramon y Cajal Fellow of the Spanish Ministry of Science and Innovation. This work has been supported by the "Programa Nacional de Astronomia y Astrofisica" of the Spanish Ministry of Economy and Competitiveness (MINECO) under grant AYA2012-30789, as well as by FEDER funds and the Government of Aragon, through the Research Group E103. L.A.D.G. also thanks the Mullard Space Science Laboratory (MSSL) and Royal Astronomical Society (RAS) for offering the opportunity to support and develop part of this research in collaboration with I.F. MINECO grants AYA2010-15081, AYA2010-15169, AYA2010-22111-C03-01, AYA2010-22111-C03-02, AYA2011-29517-C03-01, AYA2013-40611-P, AYA2013-42227-P, AYA2013-43188-P, AYA2013-48623-C2-1, AYA2013-48623-C2-2, and AYA2014-58861-C3-1 are also acknowledged, together with Generalitat Valenciana projects Prometeo 2009/064 and PROMETEOII/2014/060, and Junta de Andalucia grants TIC114, JA2828, and P10-FQM-6444. MP acknowledges financial support from the JAE-Doc programme of the Spanish National Research Council (CSIC), co-funded by the European Social Fund.Peer Reviewe

    The use of interactive response systems as a tool to favor proactive learning in Engineering

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    El desarrollo de las tecnologías de la información y la comunicación (TIC) ha permitido el surgimiento de herramientas didácticas en el campo de la educación, proporcionando herramientas prácticas para apoyar a las clases presenciales. En este contexto, los sistemas electrónicos de respuesta estudiantil pueden ser útiles para introducir un elemento tecnológico motivador en las lecciones, así como una nueva metodología. En este estudio, además del uso de los sistemas de respuesta interactiva o clickers, se ha introducido la tecnología de aprendizaje móvil mediante la elaboración de una metodología de uso de las herramientas Kahoot y Telegram en la asignatura "Fundamentos Físicos en la Ingeniería II" del Grado en Ingeniería Electrónica Industrial. El Departamento de Física Aplicada de la Universidad de Córdoba tiene una amplia experiencia en el uso de Clickers en clases teóricas con grupos grandes para diferentes grados universitarios, pero ahora el uso de tecnologías móviles de aprendizaje se ha introducido en grupos de tamaño medio para clases prácticas. Usando esta nueva metodología, los estudiantes de grupos medianos realizan un cuestionario durante la lección de resolución de problemas, donde utilizaron sus conocimientos adquiridos durante la clase. La realización del cuestionario permite a los profesores evaluar en tiempo real el nivel del estudiante y utilizar la retroalimentación para abordar los problemas iniciales y los malentendidos. Los resultados muestran que los sistemas de respuesta interactiva son altamente valorados por los estudiantes, que lo perciben como una herramienta para mejorar el aprendizaje y aumentar la competencia en el aula.The development of information and communication technologies (ICT) has enabled the emergence of teaching tools in the education field, providing practical tools to support face-to-face classes. In this context, electronic student response systems can be useful for introducing a motivating technological element into the lessons, as well as a new methodology. In this study, in addition to the use of interactive response systems or clickers, mobile learning technology has been introduced by developing a methodology for using the Kahoot and Telegram tools in the subject “Physical Foundations of Engineering II” of Electronic Engineering Degree. Department of Applied Physics of University of Cordoba has a broad experience using Clickers in theory classes with large groups for different university degrees, but now the use of mobile learning technologies has been introduced in medium-sized groups for practical classes. Using this new methodology, students of medium-sized groups perform a quiz during the problem solving lesson, where they utilized their knowledge gained during the class. The completion of the quiz allows teachers to assess the student’s level in real time, and to use the feedback to address initial problems and misunderstandings. Results show the interactive response systems are highly valued by students, who perceive it as a tool to improve learning and increase competition in the classroom

    The ALHAMBRA survey: accurate merger fractions derived by PDF analysis of photometrically close pairs

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    [Aims]: Our goal is to develop and test a novel methodology to compute accurate close-pair fractions with photometric redshifts. [Methods]: We improved the currently used methodologies to estimate the merger fraction fm from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space; (ii) including the variation in the luminosity of the sources with z in both the sample selection and the luminosity ratio constrain; and (iii) splitting individual PDFs into red and blue spectral templates to reliably work with colour selections.We tested the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. [Results]: The merger fractions and rates from the ALHAMBRA survey agree excellently well with those from spectroscopic work for both the general population and red and blue galaxies. With the merger rate of bright (MB ≤ -20 - 1:1z) galaxies evolving as (1 + z)n, the power-law index n is higher for blue galaxies (n = 2:7 0:5) than for red galaxies (n = 1:3 0:4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is Nm red = 0:57 0:05 for red galaxies and Nm blue = 0:26 0:02 for blue galaxies. [Conclusions]: Our new methodology statistically exploits all the available information provided by photometric redshift codes and yields accurate measurements of the merger fraction by close pairs from using photometric redshifts alone. Current and future photometric surveys will benefit from this new methodology.This work has been mainly funded by the FITE (Fondos de Inversiones de Teruel) and the projects AYA2012-30789, AYA2006-14056, and CSD2007-00060. We also acknowledge financial support from the Spanish Government grants AYA2010-15169, AYA2010-22111-C03-01, AYA2010-22111-C03-02, and AYA2013-48623-C2-2, from the Aragón Government through the Research Group E103, from the Junta de Andalucía through TIC-114 and the Excellence Project P08-TIC-03531, and from the Generalitat Valenciana through the projects Prometeo/2009/064 and PrometeoII/2014/060. A.J.C. is Ramón y Cajal fellow of the Spanish government. M.P. acknowledges the financial support from JAE-Doc program of the Spanish National Research Council (CSIC), co-funded by the European Social Fund.Peer Reviewe

    The ALHAMBRA survey: Estimation of the clustering signal encoded in the cosmic variance

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    [Aims]: The relative cosmic variance (σv) is a fundamental source of uncertainty in pencil-beam surveys and, as a particular case of count-in-cell statistics, can be used to estimate the bias between galaxies and their underlying dark-matter distribution. Our goal is to test the significance of the clustering information encoded in the σv measured in the ALHAMBRA survey. [Methods]: We measure the cosmic variance of several galaxy populations selected with B-band luminosity at 0.35 ≤ z< 1.05 as the intrinsic dispersion in the number density distribution derived from the 48 ALHAMBRA subfields. We compare the observational σv with the cosmic variance of the dark matter expected from the theory, σv,dm. This provides an estimation of the galaxy bias b. [Results]: The galaxy bias from the cosmic variance is in excellent agreement with the bias estimated by two-point correlation function analysis in ALHAMBRA. This holds for different redshift bins, for red and blue subsamples, and for several B-band luminosity selections. We find that b increases with the B-band luminosity and the redshift, as expected from previous work. Moreover, red galaxies have a larger bias than blue galaxies, with a relative bias of brel = 1.4 ± 0.2. [Conclusions]: Our results demonstrate that the cosmic variance measured in ALHAMBRA is due to the clustering of galaxies and can be used to characterise the σv affecting pencil-beam surveys. In addition, it can also be used to estimate the galaxy bias b from a method independent of correlation functions.This work has been mainly funded by the FITE (Fondos de Inversiones de Teruel) and the projects AYA2012-30789, AYA2006-14056, and CSD2007-00060. We also acknowledge support from the Spanish Ministry for Economy and Competitiveness and FEDER funds through grants AYA2010-15081, AYA2010-15169, AYA2010-22111-C03-01, AYA2010-22111-C03-02, AYA2011-29517-C03-01, AYA2012-39620, AYA2013-40611-P, AYA2013-42227-P, AYA2013-43188-P, AYA2013-48623-C2-1, AYA2013-48623-C2-2, ESP2013-48274, AYA2014-58861-C3-1, Aragon Government Research Group E103, Generalitat Valenciana projects Prometeo 2009/064 and PROMETEOII/2014/060, Junta de Andalucia grants TIC114, JA2828, P10-FQM-6444, and Generalitat de Catalunya project SGR-1398. A.J.C. and C.H.-M. are Ramon y Cajal fellows of the Spanish government. A. M. acknowledges the financial support of the Brazilian funding agency FAPESP (Post-doc fellowship - process number 2014/11806-9). M.P. acknowledges financial support from JAE-Doc program of the Spanish National Research Council (CSIC), co-funded by the European Social Fund.Peer Reviewe

    Nuclear Activity In Isolated Galaxies

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    We present a spectroscopic study of the incidence of AGN nuclear activity in two samples of isolated galaxies (Karachentseva, V.E. & Varela, J.). Our results show that the incidence of non-thermal nuclear activity is about 43% and 31% for galaxies with emission lines and for the total sample 40% and 27% respectively. For the first time we have a large number of bona-fide isolated galaxies (513 objects), with statistically significant number of all types. We find a clear relation between bulge mass and the incidence of nuclear activity in the sample with emission lines. This relation becomes flatter when we take into account the complete sample with no emission line galaxies. A large fraction (~70%) of elliptical galaxies or early type spirals have an active galactic nucleus and ~70% of them are LINERs. Only 3% of the AGN show the presence of broad lines (a not a single one can be classified as type 1 AGN). This is a remarkable result which is completely at odds with the unified model even if we consider warped or clumpy tori. Finally, we interpret the large fraction of AGN in isolated galaxies as the result of secular evolution of their supermasive black holes.Comment: 7 figures, 7 table

    The impact from survey depth and resolution on the morphological classification of galaxies

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    We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) and Subaru/XMMNewton Deep Survey (SXDS, examples of deep ground-based surveys), and Cosmos Evolution Survey (COSMOS, deep space-based survey). We used a sample of 3000 local, visually classified galaxies, measuring their morphological parameters at their real redshifts (z ~ 0). Then we simulated them to match the redshift and magnitude distributions of galaxies in the non-local surveys. The comparisons of the two sets allow us to put constraints on the use of each parameter for morphological classification and evaluate the effectiveness of the commonly used morphological diagnostic diagrams. All analysed parameters suffer from biases related to spatial resolution and depth, the impact of the former being much stronger. When including asymmetry and smoothness in classification diagrams, the noise effects must be taken into account carefully, especially for ground-based surveys. M20 is significantly affected, changing both the shape and range of its distribution at all brightness levels. We suggest that diagnostic diagrams based on 2-3 parameters should be avoided when classifying galaxies in ground-based surveys, independently of their brightness; for COSMOS they should be avoided for galaxies fainter than F814 = 23.0. These results can be applied directly to surveys similar to ALHAMBRA, SXDS and COSMOS, and also can serve as an upper/lower limit for shallower/deeper ones.MP acknowledge financial support from JAE-Doc programme of the Spanish National Research Council (CSIC), co-funded by the European Social Fund. This research was supported by the Junta de Andalucia through project TIC114, and the Spanish Ministry of Economy and Competitiveness (MINECO) through projects AYA2010-15169, AYA2013-42227-P, and AYA2013-43188-P.Peer Reviewe

    The ALHAMBRA survey: Bayesian photometric redshifts with 23 bands for 3 deg2

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    A. Molino et al.The Advance Large Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey has observed eight different regions of the sky, including sections of the Cosmic Evolution Survey (COSMOS), DEEP2, European Large-Area Infrared Space Observatory Survey (ELAIS), Great Observatories Origins Deep Survey North (GOODS-N), Sloan Digital Sky Survey (SDSS) and Groth fields using a new photometric system with 20 optical, contiguous ~300-Å filters plus the JHKs bands. The filter system is designed to optimize the effective photometric redshift depth of the survey, while having enough wavelength resolution for the identification of faint emission lines. The observations, carried out with the Calar Alto 3.5-m telescope using the wide-field optical camera Large Area Imager for Calar Alto (LAICA) and the near-infrared (NIR) instrument Omega-2000, represent a total of ~700 h of on-target science images. Here we present multicolour point-spread function (PSF) corrected photometry and photometric redshifts for ~438 000 galaxies, detected in synthetic F814W images. The catalogues are complete down to a magnitude I~24.5AB and cover an effective area of 2.79 deg2. Photometric zero-points were calibrated using stellar transformation equations and refined internally, using a new technique based on the highly robust photometric redshifts measured for emission-line galaxies. We calculate Bayesian photometric redshifts with the Bayesian Photometric Redshift (BPZ)2.0 code, obtaining a precision of δz/(1+zs)=1 per cent for I<22.5 and δz/(1+zs)=1.4 per cent for 22.5<I<24.5. The global n(z) distribution shows a mean redshift 〈z〉=0.56 for I<22.5 AB and 〈z〉=0.86 for I<24.5 AB. Given its depth and small cosmic variance, ALHAMBRA is a unique data set for galaxy evolution studies. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.We acknowledge financial support from the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: First Science with the GTC. Part of this work was supported by Junta de Andalucía, through grant TIC-114 and the Excellence Project P08-TIC-3531, and by the Spanish Ministry for Science and Innovation through grants AYA2006-1456, AYA2010-15169, AYA2010-22111-C03-02, AYA2010-22111-C03-01 and Generalitat Valenciana project Prometeo 2009/064.Peer Reviewe

    The impact from survey depth and resolution on the morphological classification of galaxies

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    We consistently analyse for the first time the impact of survey depth and spatial resolution on the most used morphological parameters for classifying galaxies through non-parametric methods: Abraham and Conselice-Bershady concentration indices, Gini, M20moment of light, asymmetry, and smoothness. Three different non-local data sets are used, Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) and Subaru/XMMNewton Deep Survey (SXDS, examples of deep ground-based surveys), and Cosmos Evolution Survey (COSMOS, deep space-based survey). We used a sample of 3000 local, visually classified galaxies, measuring their morphological parameters at their real redshifts (z ~ 0). Then we simulated them to match the redshift and magnitude distributions of galaxies in the non-local surveys. The comparisons of the two sets allow us to put constraints on the use of each parameter for morphological classification and evaluate the effectiveness of the commonly used morphological diagnostic diagrams. All analysed parameters suffer from biases related to spatial resolution and depth, the impact of the former being much stronger. When including asymmetry and smoothness in classification diagrams, the noise effects must be taken into account carefully, especially for ground-based surveys. M20 is significantly affected, changing both the shape and range of its distribution at all brightness levels. We suggest that diagnostic diagrams based on 2-3 parameters should be avoided when classifying galaxies in ground-based surveys, independently of their brightness; for COSMOS they should be avoided for galaxies fainter than F814 = 23.0. These results can be applied directly to surveys similar to ALHAMBRA, SXDS and COSMOS, and also can serve as an upper/lower limit for shallower/deeper ones.Ministerio de Economía y Competitividad AYA2010-15169, AYA2013-42227-P, AYA2013-4318
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