Binarity in Cool Asymptotic Giant Branch Stars: A Galex Search for Ultraviolet Excesse

The search for binarity in AGB stars is of critical importance for our understanding of how planetary nebulae acquire the dazzling variety of aspherical shapes which characterises this class. However, detecting binary companions in such stars has been severely hampered due to their extreme luminosities and pulsations. We have carried out a small imaging survey of AGB stars in ultraviolet light (using GALEX) where these cool objects are very faint, in order to search for hotter companions. We report the discovery of significant far-ultraviolet excesses towards nine of these stars. The far-ultraviolet excess most likely results either directly from the presence of a hot binary companion, or indirectly from a hot accretion disk around the companion.Comment: revised for Astrophysical Journa

Identification of a fibronectin-like molecule from a marine bivalve Pecten maximus (L., 1758) and its hyperaccumulation in the female compartment of the gonad

The present paper is the first report on the existence in marine scallops of a protein with properties similar to those of mammalian fibronectin (FN), henceforth called a scallop fibronectinlike polypeptide (sFN-LP). We describe the results of the biochemical and immunochemical identification of sFN-LP in mature gonad tissue of the simultaneous hermaphroditic species Pecten maximus (L., 1758). sFN-LP is similar to mammalian FN in the following respects: (1) it is a dimeric polypeptide with subunits of approx. 200 kDa; (2) it is recognised by antibodies against human FN on Western-blots; and (3) it is located in the basement membranes of follicles, the connective-tissue matrix, and the integument of the gonad. In the P. maximus female gonad compartment, sFN-LP is highly accumulated in the connective-tissue fibrilar network but is not detected in oocytes. In the male gonad tissue, only trace amounts of sFN-LP were detected.ésta es la primera demostración de la existencia en los pectínidos marinos de una proteína con propiedades similares a la fibronectina humana, a la que se ha denominado scallop fibronectin-like polypeptide (sFN-LP). Se describen los resultados obtenidos de la identificación bioquímica e inmunoquímica de sFN-LP en el tejido gonadal maduro de la especie hermafrodita simultánea Pecten maximus (L., 1758). sFN-LP es similar a la FN humana en los siguientes aspectos: (1) es un polipéptido dimérico con subunidades y peso molecular de alrededor de 200 kDa; (2) en Western-blot es reconocido por anticuerpos contra la FN humana; (3) se localiza en la membrana basal de los folículos, en la matriz del tejido conectivo y en el tegumento de la gónada. En el compartimento gonadal femenino de P. maximus, sFN-LP se acumula en gran cantidad en la red fibrilar de tejido conectivo, pero no se detecta en los oocitos. En el tejido gonadal masculino se detectaron cantidades traza de sFN-LP.Instituto Español de Oceanografí

Good-bye email, welcome Slack

[EN] Email is the standard in communication with university students; as a one-to-one communication device, students repeat their doubts along multiple messages, multiplying the teacher's work and preventing the participation and learning of other students. The topic forums on virtual campuses allow better a management of doubts but require the active participation of all the students to achieve a final outcome. We propose to abandon the email and traditional forums of the campuses and enter tools with a higher professional profile to manage communication with the students. The results of this first experience, carried out with more than 90 postgraduate students, encourage its mass employment in both undergraduate and postgraduate. The survey conducted over 102 students in three different subjects of two different MSc shows how Slack, the tool we used, has been highly valued, with differences depending on the studies but neither on the gender nor on the intensity of use of the social networks.Lopez-Zafra, JM.; De Paz-Cobo, S.; Queralt Sánchez, RA. (2020). Good-bye email, welcome Slack. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):635-642. https://doi.org/10.4995/HEAd20.2020.11119OCS63564230-05-202

Search for blue compact dwarf galaxies during quiescence II: metallicities of gas and stars, ages, and star-formation rates

We examine the metallicity and age of a large set of SDSS/DR6 galaxies that may be Blue Compact Dwarf (BCD) galaxies during quiescence (QBCDs).The individual spectra are first classified and then averaged to reduce noise. The metallicity inferred from emission lines (tracing ionized gas) exceeds by ~0.35 dex the metallicity inferred from absorption lines (tracing stars). Such a small difference is significant according to our error budget estimate. The same procedure was applied to a reference sample of BCDs, and in this case the two metallicities agree, being also consistent with the stellar metallicity in QBCDs. Chemical evolution models indicate that the gas metallicity of QBCDs is too high to be representative of the galaxy as a whole, but it can represent a small fraction of the galactic gas, self enriched by previous starbursts. The luminosity weighted stellar age of QBCDs spans the whole range between 1 and 10 Gyr, whereas it is always smaller than 1 Gyr for BCDs. Our stellar ages and metallicities rely on a single stellar population spectrum fitting procedure, which we have specifically developed for this work using the stellar library MILES.Comment: Accepted for publication in ApJ. 20 pages. 16 figures (corrected typos

PINGS: the PPAK IFS Nearby Galaxies Survey

We present the PPAK Integral Field Spectroscopy (IFS) Nearby Galaxies Survey: PINGS, a 2-dimensional spectroscopic mosaicking of 17 nearby disk galaxies in the optical wavelength range. This project represents the first attempt to obtain continuous coverage spectra of the whole surface of a galaxy in the nearby universe. The final data set comprises more than 50000 individual spectra, covering in total an observed area of nearly 80 arcmin^2. In this paper we describe the main astrophysical issues to be addressed by the PINGS project, we present the galaxy sample and explain the observing strategy, the data reduction process and all uncertainties involved. Additionally, we give some scientific highlights extracted from the first analysis of the PINGS sample.Comment: Accepted for publication in MNRAS, 26 pages, 14 figures (some in low resolution), 3 table

Relaciones entre riqueza de plantas vasculares y tipos funcionales: Modelos riqueza-área y especies-tipos funcionales

La relación riqueza de especies – área es considerada una de leyes generales en ecología. A través de la riqueza de tipos funcionales se amplía el alcance de la riqueza de especies hacia enfoques de evaluación de la redundancia funcional de la vegetación en plantas vasculares. El objetivo de la investigación fue desarrollar y evaluar de un modelo de la relación riqueza-área y riqueza-especies y tipos funcionales. Para la relación riqueza-área en la literatura abundan los modelos empíricos, donde sobresalen el potencial y el logarítmico. Estos modelos, además de un modelo polinómico de segundo orden, pueden ser utilizados para definir la relación riqueza de especies (S) y de tipos funcionales (Sg). Un modelo propuesto por los autores se basa en la cinética de orden n, en el cual el modelo logarítmico y el potencial son casos particulares. En el análisis de los ajustes estadísticos de los modelos considerados, se utilizó una base de datos de la relación riqueza de especies y de tipos funcionales con relación al área de muestreo (A). Los resultados de la aplicación de regresiones no lineales muestran que el modelo de cinética de orden n resultó ser el modelo con mejor ajuste experimental, aunque los modelos potencial y logarítmico se consideran viables

CO^(12) mapping of the low-metallicity blue compact dwarf galaxy Markarian 86

We have mapped the CO^12 J = 1-0 and J = 2-1 line emission in Markarian 86, one of the most metal-deficient blue compact dwarf galaxies so far detected in CO^12. The CO^12 emission is distributed in a horseshoe-like structure that follows the locus of the most recent star formation regions. The minimum in molecular line emission corresponds to the position of an older, massive nuclear starburst. The H_2 mass of the galaxy [in the range of (0.4-5) x 10^7 M_⨀] and its morphology have been compared with the predictions of hydrodynamic simulations of the evolution of the interstellar medium surrounding a nuclear starburst. These simulations suggest that the physical conditions in the gas swept out by the starburst could have led to the formation of the ring of molecular gas reported here. This result provides an attractive scenario for explaining the propagation (in a galactic scale) of the star formation in dwarf galaxies