IAA : Información y actualidad astronómica (44)

Sumario : La importancia de los cometas.-- Gamow, Alpher y el ylem.-- DECONSTRUCCIÓN Y otros ENSAYOS. El universo molecular.-- EL “MOBY DICK” DE... Alberto Molino (IAG).-- CIENCIA EN HISTORIAS...Tras la estela de Plateau.-- ACTUALIDAD.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Explosiones de rayos gamma.N

Adding plant oils to dairy goat diets: Effect on fatty acid content of milk fat

[ES]: El objetivo del presente trabajo fue investigar el efecto de la adición de aceites vegetales de diferente grado de insaturación a la dieta de cabras lecheras sobre el perfil de ácidos grasos de la grasa láctea. Doce cabras de raza Malagueña fueron asignadas al azar a uno de cuatro tratamientos: dieta basal sin aceite añadido y la misma dieta basal adicionada con 48 g/d de aceite de girasol alto oleico, aceite de girasol normal o aceite de lino. La dieta estuvo compuesta por heno de alfalfa (30%) y un concentrado granulado (70%) en el que se incluyó el aceite correspondiente. Todos los aceites redujeron el contenido de ácidos grasos saturados de cadena media de la grasa láctea (P 0,05). El aceite de girasol normal incrementó el contenido de los ácidos C18:1t10, vaccénico y ruménico y aumentó el valor de la ratio linoleico/α-linolénico (P 0,05). Los resultados obtenidos permiten concluir que la adición de aceite de lino a la dieta de cabras en lactación, en comparación con la de los aceites de girasol alto oleico y normal, modifica el perfil de ácidos grasos de la grasa láctea en un sentido más favorable desde el punto de vista de la salud humana.[EN]: The aim of this study was to investigate the effects of adding differently unsaturated vegetable oils to a dairy goat diet on fatty acid content of milk fat. Twelve Malagueña goats were randomly allocated to one of four treatments: no oil basal diet and the same basal diet supplemented with 48 g/d of high oleic sunflower oil, regular sunflower oil or linseed oil. The basal diet was made of alfalfa hay and a pelleted concentrate (30:70 w/w). The concentrate included the respective oils. Supplemented diets decreased medium chain saturated fatty acid content in milk fat (P 0.05). Regular sunflower oil increased C18:1t10, vaccenic and rumenic acid contents as well as linoleic to α-linolenic acid ratio (P 0.05). It was concluded that compared to high oleic o regular sunflower oils, adding linseed oil in dairy goat diets modifies milk fat fatty acid content more favourably from the point of view of human health.Peer Reviewe

The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83

The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are $\sim$5 $\times$ 10$^{-19}$ erg s$^{-1}$ cm$^{2}$ and $\sim$6 \AA, respectively. We are able to constrain the faint-end slope ($\alpha = -1.03\pm0.08$) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M$_\star$ $<$ 10$^{10}$ M$_{\odot}$.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadat

Genetic susceptibility, residential radon, and lung cancer in a radon prone area

INTRODUCTION: Radon exposure has been classified as the second cause of lung cancer, after tobacco, and the first in never smokers. GSTM1 and GSTT1 genes deletion increase the risk of lung cancer. We aim to know whether the risk of lung cancer because of residential radon is modulated by these genetic polymorphisms. METHODS: Hospital-based, case-control study where cases had confirmed lung cancer. Cases and controls did not have previous neoplasm and were older than 30. Controls attended hospital for noncomplex surgery. We analyzed the results for the whole sample and separately for never/light smokers and moderate/heavy smokers. RESULTS: Seven-hundred and ninety-two participants were analyzed. GSTM1 and GSTT1 deletion conferred an odds ratio (OR) of 1.38 (95% confidence interval [CI] 0.93-2.04) and 1.13 (95% CI 0.70-1.82), respectively. Individuals with GSTM1 present and residential radon concentrations higher than 148 Bq/m had an OR of 1.48 (95% CI 0.73-3.00), whereas those with GSTM1 deleted had an OR of 2.64 (95% CI 1.18-5.91) when compared with participants with GSTM1 present and radon concentrations below 50 Bq/m3. Similar results were observed for GSTT1 deletion. These results were basically the same for the moderate/heavy smokers' subgroup. CONCLUSIONS: The absence of GSTM1 and GSTT1 genes increases the risk of lung cancer because of radon exposure. These genes might modulate the carcinogenic pathway of alpha radiation. Further studies are warranted analyzing this association in never smokers

Quail eggs in artificial nests change their coloration when exposed to ambient conditions: implication for studies on nest predation

Quail eggs have been widely used in field experiments, mainly to study factors associated with the risk of nest predation. Some shortcomings of using quail eggs in this type of study have been previously addressed (e.g., these eggs might be too big for some predators of eggs of small birds). Here, we show experimental evidence of another shortcoming of the use of these eggs in field experiments. Quail eggs exposed to sunlight rapidly faded in colour after three days, both in the visible and UV spectra, and this change was related to the amount of solar radiation received. This caused changes in the camouflage of the eggs, which may be perceived by predators with different visual systems (dichromatic, trichromatic, and tetrachromatic (for both violet- and UV-sensitive species)). Therefore, the results of field studies of nest predation using quail eggs might be questioned in those cases in which the camouflage has been altered due to the rapid changes in coloration, as this can affect the resulting predation rates. We recommend that researchers planning to use quail eggs should perform a prospective assessment of changes in coloration of eggs exposed to environmental conditions in the nest sites used by the target species.This study was funded by grant CGL2017-83518-P from Ministerio de Economia, Industria y Competitividad, Spain, with EU-ERDF financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

San Pedro Mártir observations of microvariability in obscured quasars

Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei (AGN). These variations are called microvariability or intra-night variability, and this phenomenon has been monitored in samples of blazars and unobscured AGNs. Detecting optical microvariations in targets hidden by the obscuring torus is a challenging task because the region responsible for the variations is hidden from our sight. However, there have been reports of fast variations in obscured Seyfert galaxies in X-rays, which rises the question whether microvariations can also be detected in obscured AGNs in the optical regime. Because the expected variations are very small and can easily be lost within the noise, the analysis requires a statistical approach. We report the use of a one-way analysis of variance, ANOVA, with which we searched for microvariability. ANOVA was successfully employed in previous studies of unobscured AGNs. As a result, we found microvariable events during three observing blocks: in two we observed the same object (Mrk 477), and in another, J0759+5050. The results on Mrk 477 confirm previous findings. However, since Mrk 477 is quite a peculiar target with hidden broad-line regions, we cannot rule out the possibility that we have serendipitously chosen a target prone to variations.This research has been supported by the Spanish Ministerio de Economía y Competitividad (MINECO) under the grant AYA2014-58861-C3-1. I.O. acknowledges support from the European Research Council (ERC) in the form of Advanced Grant, COSMICISM. J.A.D. is grateful for the support from the grant UNAM-DGAPA-PAPIIT IN110013 Program and the Canary islands CIE: Tricontinental Atlantic Campus. A.E. acknowledges support by the grant AYA2012-30789. J. I. González-Serrano is grateful for the support from AYA2011-29517-C03-02.Peer Reviewe

Lyman break and ultraviolet-selected galaxies at z ̃ 1-I. Stellar populations from the ALHAMBRA survey

We take advantage of the exceptional photometric coverage provided by the combination of GALEX data in the ultraviolet (UV) and the ALHAMBRA survey in the optical and near-infrared to analyse the physical properties of a sample of 1225 GALEX-selected Lyman break galaxies (LBGs) at 0.8 ≲ z ≲ 1.2 that are located in the COSMOS field. This is the largest sample of LBGs studied in this redshift range to date. According to a spectral energy distribution (SED) fitting with synthetic stellar population templates, we find that LBGs at z ̃ 1 are mostly young galaxies with a median age of 341 Myr and have intermediate dust attenuation, (Es(B - V)) ̃ 0.20. Owing to the selection criterion, LBGs at z ̃ 1 are UV-bright galaxies and have a high dust-corrected total star formation rate (SFR), with a median value of 16.9M⊙ yr-1. Their median stellar mass is log (M*/M⊙) = 9.74. We find that the dustcorrected total SFR of LBGs increases with stellar mass and that the specific SFR is lower for more massive galaxies (downsizing scenario). Only 2 per cent of the galaxies selected through the Lyman break criterion have an active galactic nucleus nature. LBGs at z ̃ 1 are located mostly over the blue cloud of the colour-magnitude diagram of galaxies at their redshift, with only the oldest and/or the dustiest deviating towards the green valley and red sequence. Morphologically, 69 per cent of LBGs are disc-like galaxies, with the fractions of interacting, compact, or irregular systems being much lower, below 12 per cent. LBGs have a median effective radius of 2.5 kpc, and larger galaxies have a higher total SFR and stellar mass. Compared with their high-redshift analogues, we find evidence that LBGs at lower redshifts are larger, redder in the UV continuum, and have a major presence of older stellar populations in their SEDs. However, we do not find significant differences in the distributions of stellar mass or dust attenuation.NASA NAS5-26555NASA Office of Space Science NNX09AF08GEuropean Southern Observatory LP175.A-0839.Junta de Andalucia TIC-114, P08-TIC03531Ministerio de Economía y Competitividad AYA2011-29517-C03- 01, AYA2010-1516

Galaxy classification: deep learning on the OTELO and COSMOS databases

Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press

IAA : Información y actualidad astronómica (13)

Sumario : Las galaxias anfitrionas de los GRBs.-- Marte: una historia de descubrimientos.-- Programa Ramón y Cajal: ¿recuperación o catapulta de cerebros?.-- CHARLAS CON...Fernando Cornet.-- El problema de la distancia a las Pléyades.-- Un bólido sobre nuestras cabezas.-- Actividades IAA.-- Agenda.Esta revista se publica con la ayuda de la Acción Especial DIS 2003-10261-E del Programa Nacional de Difusión y divulgación de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.N

La integración de los stakeholders en la empresa: identificación de sus principales dimensiones

La importancia de los Stakeholders en el mundo empresarial actual hace que las empresas estén obligadas a tenerlos en cuenta, y les provoca la necesidad de realizar esfuerzos en integrar las demandas de sus grupos de interés (GI) en las políticas y prioridades de la firma para conseguir su satisfacción. Tras analizar los distintos aspectos que se han tenido en cuenta para analizar las relaciones con los Stakeholders, y utilizando tanto el enfoque descriptivo como normativo de la teoría, identificamos tres dimensiones en el proceso de integración de los GI: el conocimiento de los GI, su implicación en la empresa a través de la consulta y la participación y la modificación de políticas y objetivos para adaptarse a sus demandas. Estas dimensiones se identifican especialmente relevantes para conseguir la satisfacción de los grupos de interés.The importance of Stakeholders in the current managerial world is forcing companies to keep them continually in mind. In addition, it causes the necessity of carrying out efforts aimed at integrating stakeholders’ demands into their politics and priorities in order to achieve their satisfaction. After analyzing the different aspects considered in the study of relationships with Stakeholders, and using both a descriptive and normative theory scope, we identify three dimensions in the process of stakeholders´ integration: the knowledge about them, their implication in the company through consulting and participation, and finally, the modification of enterprises’ politics and objectives in order to adapt to their demands. These dimensions are considered to be of special importance in ensuring Stakeholders’ satisfaction