Characterizing stellar populations in spiral disks

It is now possible to measure detailed spectral indices for stellar populations in spiral disks. We propose to interpret these data using evolutionary synthesis models computed from the Star Formation Histories obtained from chemical evolutionary models. We find that this technique is a powerful tool to discriminate between old and young stellar populations. We show an example of the power of Integral Field spectroscopy in unveiling the spatial distribution of populations in a barred galaxy.Comment: 5 pages, to be published in "Science Perspectives for 3D Spectroscopy", Eds. M. Kissler-Patig, M.M. Roth and J.R. Walsh (Springer-Verlag, ESO astrophysics symposia series

Oxygen and nitrogen abundances in Virgo and field spirals

The oxygen and nitrogen abundances in the HII regions of the nine Virgo spirals of the sample from Skillman et al (1996) and in nine field spiral galaxies are re-determined with the recently suggested P - method. We confirm that there is an abundance segregation in the sample of Virgo spirals in the sense that the HI deficient Virgo spirals near the core of the cluster have higher oxygen abundances in comparison to the spirals at the periphery of the Virgo cluster. At the same time both the Virgo periphery and core spirals have counterparts among field spirals. We conclude that if there is a difference in the abundance properties of the Virgo and field spirals, this difference appears to be small and masked by the observational errors.Comment: 16 pages, 10 figures, accepted for publication in Astronomy and Astrophysic

The Nitrogen-to-Oxygen evolution in galaxies: the role of the star formation rate

The main objective of the present work is to ckeck if the star formation efficiency plays a relevant role in the evolution of the relative abundance N/O. We analyze the evolution of the nitrogen-to-oxygen ratio as predicted by a set of computed theoretical models of simulated galaxies with different total masses which are evolved assuming different collapse time scales and different star formation efficiencies, thus producing different star formation histories. The stellar yield set we use for all of them (Gavil\'{a}n et al. 2005) have an important contribution of primary nitrogen proceeding from low and intermediate mass stars. It allows to obtain a dispersion of results in the N/O-O/H plane, when star formation efficiencies vary, in general agreement with observations. The model results for the N/O abundance ratio are in good agreement with most observational data trends: the extragalactic H{\sc ii} regions is well reproduced with present time resulting abundances and the low N/O values estimated for high-redshift objects, as well as the higher and constant values of N/O observed for irregular and dwarf galaxies or halo stars, can be simultaneously obtained with our models at the same low oxygen abundances. We conclude that differences in the star formation history of galaxies and regions within them are a key factor to explain the data in the N/O-O/H plane.Comment: 13 pages, 10 figures, accepted in MNRA

Ortesis para la prevención de la subluxación y luxación de rodilla en alargamientos femorales complejos

Se describe una ortesis para uso en la prevención de la subluxación y luxación de rodilla en los casos de alargamientos femorales en los que se considera posible la presentación de este problemaWe present an orthesis to prevent dislocation of the knee during femoral lengtheing when this problem can presumably occur

Utilización de fijadores externos como tratamiento de urgencias en las fracturas pélvicas del politraumatizado

La importancia de la inestabilidad pélvica en el pronóstico vital del paciente politraumatizado obliga a actuar con rapidez sobre estas lesiones. Presentamos nuestra casuística de 10 pacientes politraumatizados con fracturas inestables de pelvis tratados de urgencia mediante fijación externa. Los buenos resultados obtenidos confirman la utilidad de este sistema como tratamiento inicial en un servicio de urgencias, que en la gran mayoría de los casos será el tratamiento definitivo.The importance of pelvis instability for life prognosis in multiple trauma patients implies a rapid treatment action in these lesions. We report 10 patients with multiple trauma and unstable pelvis fractures treated as emergency by external fixation. The good results obtained confirm the utility of this method as both the initial and definitive treatment of pelvis fractures in cases of emergency

Analysis of instabilities in the Basque Coast Geopark coastal cliffs for its environmentally friendly management (Basque-Cantabrian basin, northern Spain)

Coastal cliffs provide a high landscape value to many natural sites around the world. This means that an ever-increasing number of people are attracted to them. At this point, there is a growing need to manage these spaces from the safety of visitors, but with a view to preserving the environment. With this aim, this paper presents an approach to analyze and manage instabilities in these environments, particularly those subjected to significant anthropic activity, which has been implemented in the cliffs of the Basque Coast Geopark. The starting point is a detailed topographic information, obtained from UAV flights, and the identification on site of unstable elements, including their typology, active source areas, dynamics and reach. From this information, the simulation of rockfall processes, which basically correspond to toppling and infinite slope instabilities favored by differential erosion along the coastline, is approached in two and three dimensions. Results allow the design of precise actions by sectors, according to the energy, height and reach of the detached blocks, including barriers, middle slope actions, ditches and information strategies, depending on the different uses of the sectors. Therefore, this approach leads to a more detailed and environmentally friendly management of these environments. © 2021This study has been carried out by the UPV/EHU Research GroupIT-1029/16 (Government of the Basque Country) in the framework of the strategic project ?Analysis of instabilities in coastal environments of the Basque Country? PES-18/97 (University of the Basque Country) and the collaboration of the Basque Coast Geopark (Geoparkea). Finally, the authors are grateful to the reviewers and the handling editor, for the valuable comments that highly improved the paper