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Framboidal chalcopyrite and bornite constrain redox conditions during formation of their host rocks in the copper stratabound mineralization of Picachos, north-central Chile
Get PDFThe Picachos Project is a copper deposit that occurs in manto-type orebodies in north-central Chile and it exhibits
common features of Chilean stratabound or manto-type copper deposits: (1) an increase of copper contents
from the margins to the centre of the orebodies; (2) sodic and potassic hydrothermal alteration of host rocks with
subsequent chloritization and sericite alteration; and (3) its occurrence in sequences of limestones that are
intercalated with volcanic rocks. The most salient characteristic of the Picachos Project is the presence of pervasive
framboidal pyrite in both the non-mineralized limestones and the host rocks of the copper mineralization.
These framboidal pyrites are well preserved, probably due to their close relationship with organic matter, and
have no evident textures of overgrowth, recrystallization or dissolution. Moreover, framboidal chalcopyrite and
bornite are formed in the external and internal areas, respectively, of the orebodies, sharing common morphological
characteristics with framboidal pyrite, and are formed by the replacement of the original pyrite
framboids, without changing their shape and size distribution. Representative size distributions of framboidal
pyrite, chalcopyrite and bornite are determined using high-resolution X-ray tomography (micro-CT). This study
highlights the effectiveness of these analytical techniques to obtain the representative size distribution of
framboids in mineralized rocks. The preservation of the original framboidal texture of pyrite makes it possible to
infer anoxic to near-dysoxic conditions. The size distributions of framboidal chalcopyrite and bornite are hypothesized
to be additional potential paleo-redox indicators, referring to the same formation dynamic as typical
framboidal pyrites.Spanish Ministry of Economy and
Competitiveness, project PETROSIS PA-18-ACB17-1
Check list del uso de oxitocina. Hospital Universitario Central de Asturias
Get PDFProtocolo del Servicio de Obstetricia y Ginecología el HUCA. Área Sanitaria I
El papel del Comité Nacional para la Prevención del Tabaquismo
Get PDFTobacco use is a serious public health problem because of the serious health impact on morbidity and premature mortality of both those who use it directly and those who are involuntarily exposed to tobacco smoke; and by reducing their consumption to the most disadvantaged sectors of the population. It therefore requires a multidisciplinary approach. The tobacco epidemic can be reversed if the guidelines of the WHO Framework Convention on Tobacco Control, ratified in 2005, are implemented. 37 scientific, health, professional and
professional societies join forces with the National Tobacco Prevention Committee to promote the implementation of the strategies of the International Convention Nursing is actively represented in this Committee since 2001.El consumo de tabaco es un grave problema de salud pública por las graves repercusiones sanitarias en morbilidad y mortalidad
prematura, tanto de quienes ejercen un consumo directo, como de quienes son expuestos involuntariamente al humo de tabaco; y por la regresión de su consumo a los sectores de la población más desfavorecidos. Por ello precisa un abordaje multidisciplinar.
La epidemia de tabaquismo se puede revertir si se aplican las directrices del convenio
Marco para el control del tabaquismo de la
OMS, ratificado en 2005.
Treinta y siete sociedades científicas, sanitarias, profesionales y consejos profesionales aglutinan sus esfuerzos en el Comité Nacional de Prevención del Tabaquismo para impulsar la implementación de las estrategias de dicho Convenio internacional. En este Comité está representada la enfermería de forma activa desde 2001
Comparison Between Analytic Derivative and the Technique of Differential Contributions in Reflectarray Phase-Only Synthesis
Get PDFMany algorithms for the optimization of array antennas need the calculation of a gradient to minimize a cost function. Usually, the best approach is to compute analytically the derivatives, since that way computations are faster. However, sometimes the derivatives are cumbersome to obtain or they cannot be calculated, such as when directly optimizing the layout in reflectarrays for cross-polarization improvement. In those cases, derivatives are evaluated using numerical techniques such as finite differences. In this work, we present the numerical technique of differential contributions (DFC) to accelerate gradient-based algorithms when the derivatives are calculated with finite differences, achieving a complexity time scaling of the same order as the analytical derivatives. The technique is applied to a far field phase-only synthesis for reflectarray antennas using the generalized Intersection Approach, and it is compared with the analytic derivatives and the use of finite differences with the FFT. The DFC technique shows superior performance in all cases, even than the analytic derivative.This work was supported in part by the European Space Agency (ESA) under contract ESTEC/AO/1-7064/12/NL/MH; by the Ministerio de Ciencia, Innovación y Universidades under project TEC2017-86619-R (ARTEINE); by the Ministerio de Economía, Industria y Competitividad under project TEC2016-75103-C2-1-R (MYRADA); and by the Gobierno del Principado de Asturias through Programa "Clarín" de Ayudas Postdoctorales / Marie Curie-Cofund under project ACA17-09.13th European Conference on Antennas and Propagation (EuCAP
Support Vector Regression to Accelerate Design and Crosspolar Optimization of Shaped-Beam Reflectarray Antennas for Space Applications
Get PDFA machine learning technique is applied to the design and optimization of reflectarray antennas to considerably accelerate computing time without compromising accuracy. In particular, Support Vector Machines (SVMs), automatic learning structures that are able to deal with regression problems, are employed to obtain surrogate models of the reflectarray element to substitute the full-wave analysis tool for the characterization of the unit cell in the design and optimization algorithms. The analysis, design and optimization of a very large reflectarray antenna for Direct Broadcast Satellite applications are accelerated up to three orders of magnitude. This is here demonstrated with three examples: one showing the design of a reflectarray; and two for the crosspolar optimization, one with one coverage for each linear polarization (Europe and the Middle East) and another with a Middle East coverage working in dual-linear polarization. The accuracy of the proposed approach is validated by means of a comparison of the final designs with full-wave simulations based on local periodicity obtaining good agreement. The crosspolar dicrimination and crosspolar isolation are greatly improved using the SVMs while considerably reducing computing time.This work was supported in part by the European Space Agency (ESA) under contract ESTEC/AO/1-7064/12/NL/MH; by the Ministerio de Ciencia, Innovación y Universidades under projects TEC2017-86619-R (ARTEINE); by the Ministerio de Economía, Industria y Competitividad under project TEC2016-75103-C2-1-R (MYRADA); and by the Gobierno del Principado de Asturias through Programa "Clarín" de Ayudas Postdoctorales / Marie Curie-Cofund under project ACA17-09
Gambling Motives Questionnaire validation in adolescents: Differences based on gambling severity and activities
Get PDFSelf-reported reasons for gambling have been highlighted as crucial to
understanding why adults develop problems with gambling. However, research
on motives among adolescents remains scarce. The aim of this study is to
explore the factorial structure of the Gambling Motives Questionnaire (GMQ)
and to analyze differences in motives among adolescents, depending on the
gambling activity and level of gambling severity. A total of 698 adolescent
gamblers (M = 15.24, SD = .76) were assessed. As well as the GMQ, the South
Oaks Gambling Screen (SOGS-RA) questionnaire was used. Gamblers were
classified into three categories (strategic, non-strategic, and mixed) according
to the activities engaged in during the last year. An Exploratory Factor Analysis
was conducted followed by a Confirmatory Factor Analysis in order to explore
the internal structure of the GMQ. Three two-way between-groups Analyses of
Variance (ANOVA) were conducted to explore differences in motives
according to the type of activity and the gambling severity levels. According to
the factorial structure of the GMQ, three main groups of motivations were
found: enhancement, coping and social. Compared to non-problem gamblers,
problem gamblers scored higher on all motives. Moreover, gamblers seeking
enhancement prefer strategic games, those gambling to cope with stress use
non-strategic games more frequently, while social gamblers do not show a
preference for either strategic or non-strategic games. In conclusion, gambling
motives are related to gambling severity and structural characteristics of
gambling. These findings may be useful from a prevention standpoint
Visible-Light-Driven Intermolecular Reductive Ene–Yne Coupling by Iridium/Cobalt Dual Catalysis for C(sp3)-C(sp2) Bond Formation
Get PDFA new methodology to form C(sp3)-C(sp2) bonds by visible-light-driven intermolecular reductive ene–yne coupling has been successfully developed. The process relies on the ability of the Hantzsch ester to contribute in both SET and HAT processes through a unified cobalt and iridium catalytic system. This procedure avoids the use of stoichiometric amounts of reducing metallic reagents, which is translated into high functional-group tolerance and atom economy.Marie Curie Clarín-COFUND postdoctoral grant (ACA-1712
Quantifying the Variability in Flow Competence and Streambed Mobility with Water Discharge in a Gravel-Bed Channel: River Esva, NW Spain
Get PDFStreambed mobility in gravel-bed rivers is largely controlled by the rate at which particles with different grain sizes are recruited from the riverbed into the bed load. In this paper, we present a study case in which we explored this question, based on combining field observations using painted plots and the grain size analysis of a large flood sediment deposit in the River Esva, northwest Spain, and the generalized threshold model (GTM) competence model developed by Recking. The main aim was to accomplish a complete characterization of streambed mobility in this river. The obtained results suggest the large potential of the GTM model compared to previous competence models when searching for the quantitative description of particle entrainment and streambed mobility in the River Esva. We observed how the grain size of the bed load in the River Esva tended to be closer to that of the sub-armour bed material during large floods, while moderate magnitude flows tended to carry a relatively fine bed load. Additionally, we compared our results with previously published field observations on flow competence. This comparison outlined the large degree of site specificity in the links between grain size of the bed load and that of the bed material.Ayuda post-doctoral ACB17-44, co-financiada por el programa “Clarín”-FICYT (Principado de Asturias)/ Marie Curie Co-Fund.
También, ayuda del proyecto RIVERCHANGES-CGL2015-68824-R (MINECO/FEDER, UE