Shallow structure beneath the Central Volcanic Complex of Tenerife from new gravity data: implications for its evolution and recent reactivation

We present a new local Bouguer anomaly map of the Central Volcanic Complex (CVC) of Tenerife, Spain, constructed from the amalgamation of 323 new high precision gravity measurements with existing gravity data from 361 observations. The new anomaly map images the high-density core of the CVC and the pronounced gravity low centred in the Las Cañadas caldera in greater detail than previously available. Mathematical construction of a sub-surface model from the local anomaly data, employing a 3D inversion based on 'growing' the sub-surface density distribution via the aggregation of cells, enables mapping of the shallow structure beneath the complex, giving unprecedented insights into the sub-surface architecture. We find the resultant density distribution in agreement with geological and other geophysical data. The modelled sub-surface structure supports a vertical collapse origin of the caldera, and maps the headwall of the ca. 180 ka Icod landslide, which appears to lie buried beneath the Pico Viejo–Pico Teide stratovolcanic complex. The results allow us to put into context the recorded ground deformation and gravity changes at the CVC during its reactivation in spring 2004 in relation to its dominant structural building blocks. For example, the areas undergoing the most significant changes at depth in recent years are underlain by low-density material and are aligned along long-standing structural entities, which have shaped this volcanic ocean island over the past few million years

Monte Carlo simulations of post-common-envelope white dwarf + main sequence binaries: The effects of including recombination energy

Detached WD+MS PCEBs are perhaps the most suitable objects for testing predictions of close-compact binary-star evolution theories, in particular, CE evolution. The population of WD+MS PCEBs has been simulated by several authors in the past and compared with observations. However, most of those predictions did not take the possible contributions to the envelope ejection from additional sources of energy (mostly recombination energy) into account. Here we update existing binary population models of WD+MS PCEBs by assuming that a fraction of the recombination energy available within the envelope contributes to ejecting the envelope. We performed Monte Carlo simulations of 10^7 MS+MS binaries for 9 different models using standard assumptions for the initial primary mass function, binary separations, and initial-mass-ratio distribution and evolved these systems using the publicly available BSE code. Including a fraction of recombination energy leads to a clear prediction of a large number of long orbital period (>~10 days) systems mostly containing high-mass WDs. The fraction of systems with He-core WD primaries increases with the CE efficiency and the existence of very low-mass He WDs is only predicted for high values of the CE efficiency (>~0.5). All models predict on average longer orbital periods for PCEBs containing C/O-core WDs than for PCEBs containing He WDs. This effect increases with increasing values of both efficiencies. Longer periods after the CE phase are also predicted for systems containing more massive secondary stars. The initial-mass-ratio distribution affects the distribution of orbital periods, especially the distribution of secondary star masses. Our simulations, in combination with a large and homogeneous observational sample, can provide constraints on the values of the CE efficiencies, as well as on the initial-mass-ratio distribution for MS+MS binary stars.Comment: 11 pages, 10 figures, accepted for publication in A&

Comparative Analysis of Extrusion Processes by Finite Element Analysis

AbstractExtrusion processes are quite extended in the manufacturing of long products for a wide range of industrial applications. There are different approaches of extrusion processes, depending on either the final shape of the product to obtain or the maximum loading capacity of the equipment to be used. This work presents a comparative study of extrusion processes (solid and cup extrusion), considering both direct and indirect forming conditions and showing the most interesting differences between them. The comparison is realized by Finite Element simulation of the processes, using the code DEFORM F2. The material is a low carbon steel (AISI-1010) and the same extrusion ratio and ram displacement are considered in all cases. By comparing the required forces it can be concluded that required loads are higher in cup extrusion processes than in solid extrusion ones. Regarding the friction load, the maximum contribution due to the die-billet contact in cup extrusion is much higher than in the case of solid extrusion. On the contrary, the maximum friction load contribution due to the container wall is much higher in the case of solid extrusion than in cup extrusion

Monte Carlo simulations of post-common-envelope white dwarf + main sequence binaries: comparison with the SDSS DR7 observed sample

Detached white dwarf + main sequence (WD+MS) systems represent the simplest population of post-common envelope binaries (PCEBs). Since the ensemble properties of this population carries important information about the characteristics of the common-envelope (CE) phase, it deserves close scrutiny. However, most population synthesis studies do not fully take into account the effects of the observational selection biases of the samples used to compare with the theoretical simulations. Here we present the results of a set of detailed Monte Carlo simulations of the population of WD+MS binaries in the Sloan Digital Sky Survey (SDSS) Data Release 7. We used up-to-date stellar evolutionary models, a complete treatment of the Roche lobe overflow episode, and a full implementation of the orbital evolution of the binary systems. Moreover, in our treatment we took into account the selection criteria and all the known observational biases. Our population synthesis study allowed us to make a meaningful comparison with the available observational data. In particular, we examined the CE efficiency, the possible contribution of internal energy, and the initial mass ratio distribution (IMRD) of the binary systems. We found that our simulations correctly reproduce the properties of the observed distribution of WD+MS PCEBs. In particular, we found that once the observational biases are carefully taken into account, the distribution of orbital periods and of masses of the WD and MS stars can be correctly reproduced for several choices of the free parameters and different IMRDs, although models in which a moderate fraction (<=10%) of the internal energy is used to eject the CE and in which a low value of CE efficiency is used (<=0.3) seem to fit better the observational data. We also found that systems with He-core WDs are over-represented in the observed sample, due to selection effects.Comment: 15 pages, 7 figures, accepted for publication in A&

Salud e inmigración en el contexto de esta crisis económica y de valores:el ejemplo de España

Los principales determinantes de la salud de las personas y de las comunidades son sociales y por tanto así deberán ser sus soluciones. En el caso de la población inmigración existe una excepción a esta regla ya que a su llegada por diversos motivos (que pueden resumirse en el 'healthy migration effect') suelen presentar una salud superior a la población que los acoge. No obstante, con el transcurso de los años está salud tiende a deteriorarse. Los Sistemas Sanitarios Públicos de cobertura Universal han demostrado su capacidad de reducir las desigualdades sanitarias. La Unión Europea en diversos documentos ha enfatizado la importancia de garantizar una adecuada atención sanitaria a toda la población incluyendo la inmigrante. España era un referente mundial en este sentido al garantizar la accesibilidad al Sistema Sanitario de todos los inmigrantes independientemente de su situación administrativa. No obstante, a raíz del Real Decreto Ley 12/2012, el Gobierno Español ha excluido a unas 900.000 de este Derecho provocando un grave problema humano, ético y sanitario ante el que distintos colectivos sociales y profesionales han manifestado su oposición

A Study of Archiving Strategies in Multi-Objective PSO for Molecular Docking

Molecular docking is a complex optimization problem aimed at predicting the position of a ligand molecule in the active site of a receptor with the lowest binding energy. This problem can be formulated as a bi-objective optimization problem by minimizing the binding energy and the Root Mean Square Deviation (RMSD) difference in the coordinates of ligands. In this context, the SMPSO multi-objective swarm-intelligence algorithm has shown a remarkable performance. SMPSO is characterized by having an external archive used to store the non-dominated solutions and also as the basis of the leader selection strategy. In this paper, we analyze several SMPSO variants based on different archiving strategies in the scope of a benchmark of molecular docking instances. Our study reveals that the SMPSOhv, which uses an hypervolume contribution based archive, shows the overall best performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

La colección «Plantes De La Province De Grenada» de Pedro del Campo, en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial, Madrid (España)

CARRASCO, M. A., PEREA, D., ARAGÓN, C. F. & GARCÍA-CAMACHO, R. 2002. La Colección «Plantes de da Province de Grenada» de Pedro del Campo, en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial, Madrid (España). Bot. Complutensis 26: 93-103. En este trabajo presentamos una colección de plantas con interés histórico hallada en el herbario del Real Colegio Alfonso XII de San Lorenzo de El Escorial (Madrid). Fueron recolectadas en Granada por Pedro del Campo, distribuidas por E. Bourgeau en sus exsiccata de 1852 y utilizadas por Willkomm y Lange para establecer la distribución de las especies en la obra Prodromus florae hispanicae, según consta expresamente en ella. Además, muchos de estos materiales proceden de las localidades clásicas citadas por Boissier.CARRASCO, M. A., PEREA, D., ARAGÓN, C. F. & GARCÍA-CAMACHO, R. 2002. The sets «Plantes de la Province de Grenada» from Pedro del Campo, in the herbarium of Real Colegio Alfonso XII of San Lorenzo de El Escorial (Madrid, Spain). Bot. Complutensis 26: 93-103. This paper focuses on a set of plants, found in the Real Colegio Alfonso XII historical herbarium of San Lorenzo de El Escorial (Madrid). These plants which belonged to Pedro del Campo, were distributed in exsiccata by Bourgeau in 1852. The historical importance of these sheets is enhanced as they were used for Willkomm and Lange in order to establish the species corology in the classic Prodromus florae hispanicae, as clearly stated in that work. Furthermore, many of these sheets were collected in the localities cited by Boissier