723 research outputs found

    Plan de defensa contra incendios en la comarca Boedo - Ojeda.

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    El proyecto de defensa contra incendios de la comarca Boedo - Ojeda pretende realizar una planificación de la prevención y la defensa contra incendios en la comarca. La comarca es de especial interés debido a su situación de transición entre los campos y las montañas, lo que la hace especialmente variable en ecosistemas y con una gran diversidad de flora y fauna. Se trata además de una zona con campos de cultivo adyacentes a los montes, lo que configura una alta probabilidad de ocurrencia de incendios, debido a que el mayor número de incendios en la zona tienen inicio en terreno agrícola y un peligro de rápida propagación del mismo al monte.Grado en Ingeniería Forestal y del Medio Natura

    Control of V(D)J Recombination through Transcriptional Elongation and Changes in Locus Chromatin Structure and Nuclear Organization

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    V(D)J recombination is the assembly of gene segments at the antigen receptor loci to generate antigen receptor diversity in T and B lymphocytes. This process is regulated, according to defined developmental programs, by the action of a single specific recombinase complex formed by the recombination antigen gene (RAG-1/2) proteins that are expressed in immature lymphocytes. V(D)J recombination is strictly controlled by RAG-1/2 accessibility to specific recombination signal sequences in chromatin at several levels: cellular lineage, temporal regulation, gene segment order, and allelic exclusion. DNA cleavage by RAG-1/2 is regulated by the chromatin structure, transcriptional elongation, and three-dimensional architecture and position of the antigen receptor loci in the nucleus. Cis-elements specifically direct transcription and V(D)J recombination at these loci through interactions with transacting factors that form molecular machines that mediate a sequence of structural events. These events open chromatin to activate transcriptional elongation and to permit the access of RAG-1/2 to their recombination signal sequences to drive the juxtaposition of the V, D, and J segments and the recombination reaction itself. This chapter summarizes the advances in this area and the important role of the structure and position of antigen receptor loci within the nucleus to control this process

    Instrumento para la detección precoz de juego problemático en adolescentes

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    El objetivo de este trabajo fue la creación de un instrumento de detección precoz de juego problemático en la población española de 14 a 18 años. El diseño del instrumento se ha basado en cuestionarios anteriores de reconocido uso y eficacia, el instrumento desarrollado consta de dos partes, la primera de ellas más general con los ítems del cuestionario South Oaks Gambling Screen (SOGS), versión reducida, y la segunda más específica sobre las áreas de la vida del individuo sobre las que está afectando. Se ha elaborado una página web en la que está disponible este cuestionario además aparece información sobre el juego, cómo funcionan los juegos de azar, dónde acudir si se detecta juego problemático, consejos para una vida sana sin juego y enlaces a programas de actualidad que han investigado los efectos que está causando el juego en la sociedad, especialmente en la población joven.El desarrollo de esta intervención online se ha basado en las intervenciones que se están llevando a cabo en la actualidad, tanto por los servicios públicos de salud de algunas Comunidades Autónomas, como en Extremadura y Andalucía, como por la Federación Española de Jugadores de Azar Rehabilitados (FEJAR).<br /

    Study of non-uniform light profiles on high concentration III-V solar cells using quasi-3D distributed models

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    The quasi-3D models based on distributed circuit units are a powerful tool to analyse the performance of a solar cell from the point of view of its electrical behavior. Quite accurate models have been developed in the past that reproduce the experimental data of single-junction solar cells very closely. These models help in the determination of the origin of the peculiarities of the dark and one sun or high concentration experimental I-V curves. They also allow the design of the front grid, the analysis of the impact of the electrical parameters of the solar cell on the performance of the final device, etc. In this work, these models are used to study the effect of non-uniform profiles, generated by the concentrator optics, on the performance of a concentrator solar cell. The design of the front grid is then optimized to minimize the losses introduced by the light distribution, even taking into account the effect of the tracking system misalignment. As an introductory application example of multijunction solar cells analysis with this kind of modeling, the effect of the chromatic aberration on a double junction solar cell is presented

    Te doping of GaAs using metalorganic vapor phase epitaxy: volatile vs. non volatile

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    The incorporation of Te into the crystal lattice, when it is used as an n-type dopant for GaAs grown by metalorganic vapor phase epitaxy, is studied. For this purpose, several growth temperatures, total pressures, growth rates, and substrate misorientations have been analyzed, from which it is concluded that depending on the substrate misorientation and total pressure used, the Te behaves like a volatile dopant or a nonvolatile dopant as result of the enhancement or minimization of its adsorption onto the growth surface

    A GaAs metalorganic vapor phase epitaxy growth process o reduce Ge out-diffusion from the Ge substrate

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    A barrier based on GaAs for controlling the Ge out diffusion has been developed by metalorganic vapor phase epitaxy. It is based on a thin GaAs layer (50 nm) grown at a low temperature (≈500 °C) on top of a predeposition layer, showing that GaAs prevents the Ge diffusing when it is grown at a low temperature. Additionally, two different predeposition monolayers have been compared, concluding that when the Ga is deposited first, the diffusions across the GaAsGe heterointerface decrease

    Nanoscale electrical characterization of arrowhead defects in GalnP thin films grown on Ge

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    In this work the authors present an electrical characterization of the so called arrowhead defects (ADs) in GaInP thin films grown on Ge(100) substrates misoriented by 6° toward (111). The samples have been evaluated by means of conductive atomic force microscopy (C-AFM) and Kelvin probe force microscopy (KPFM). It is shown that the ADs have terminating planes which are composed from two alternating subplanes inclined 12° (close to {105} plane) and 6° (close to {109}) with respect to the (100) plane. The terminating planes of the arrowhead defects possess higher conductivity compared to their surrounding. The terminating planes differ also in their electrical behavior from each other, demonstrating different values of conductivity (C-AFM) and bucking voltages (KPFM). The difference in current densities between two terminating planes was found to be ∼ 170±35 μA/m2 at −3 V, and the difference in the bucking voltages was ∼ 70 mV at 5 V of the electrical excitation signal in the lift mode. It is suggested that the distinctive electrical behavior of the ADs is caused by an ordering effect which leads in this case to the degraded electrical properties of the ADs

    ARXPS analysis of a GaAs/GaInP heterointerface with application in III-V multijunction solar cells

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    In this contribution, angle-resolved X-ray photoelectron spectroscopy is used to explore the extension and nature of a GaAs/GaInP heterointerface. This bilayer structure constitutes a very common interface in a multilayered III-V solar cell. Our results show a wide indium penetration into the GaAs layer, while phosphorous diffusion is much less important. The physico-chemical nature of such interface and its depth could deleteriously impact the solar cell performance. Our results probe the formation of spurious phases which may profoundly affect the interface behavior

    Very long-term efficacy and safety of paclitaxel-eluting balloon after a bare-metal stent for the treatment of ST-elevation myocardial infarction: 8-year results of a randomized clinical trial (PEBSI study)

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    Drug-eluting stents; Drug-coated balloons; Myocardial infarctionStents alliberadors de fàrmacs; Globus recoberts de fàrmacs; Infart de miocardiStents liberadores de fármacos; Globos recubiertos de fármacos; Infarto de miocardioBackground: Drug-eluting stents (DES) are considered the therapy of choice in ST-segment elevation myocardial infarction (STEMI); however, a low persistent rate of revascularizations and stent thrombosis exist over the time. We have previously shown that a paclitaxel (PTX)-drug-coated balloon (DCB) after a bare-metal stent (BMS) implantation (DCB-combined strategy) yields superior angiographic and clinical results compared to BMS in the short term. However, the long-term safety and efficacy of this approach remain uncertain. Methods: An 8-year clinical follow-up was conducted on patients enrolled in the randomized PEBSI-1 trial (NCT01839890). The original trial included patients who suffered a STEMI, patients were randomly assigned to receive a DCB-combined strategy or BMS only and the primary endpoint was in-stent late luminal loss (LLL) at 9-month follow-up. After the completion of this study, death, myocardial re-infarction, ischemia-driven repeated revascularizations included target lesion revascularization (TLR) and target vessel revascularization (TVR), and stent thrombosis, were assessed by yearly contact by a clinical visit, telephone or by electronic records. These outcomes were adhered to ARC-2 criteria. Results: The rate of incomplete follow-up was very low, with only 3 out of 111 patients (2.7%) in the DCB-combined strategy group and 1 out of 112 patients (0.9%) in the BMS group. At 8 years there were a lower rate of TVR [3.7% vs. 14.3%; hazard ratio (HR): 0.243; 95% confidence interval (CI): 0.081–0.727; P=0.006], and a trend towards lower TLR (2.8% vs. 8.9%; HR: 0.300; 95% CI: 0.083–1.090; P=0.052) in the DCB-combined strategy group. No statistical difference between the DCB-combined strategy and BMS groups were found for all causes of death, deaths from cardiovascular disease, reinfarctions or stent thrombosis. Notably in the DCB-combined strategy group, no episode of stent thrombosis occurred after the first year. Similarly, there were no cardiovascular deaths, TVR and TLR in the DCB-combined strategy group after 5 years. In contrast, during the period from year 5 to 8, the BMS group experienced an additional cardiovascular death, as well as one case of TVR, one case of TLR, and one case of stent thrombosis. Conclusions: In STEMI patients, the DCB-combined strategy maintains its safety and clinical efficacy over time. Our rates of TVR, TLR, and very late stent thrombosis (VLST) at very long-term are the lowest ever found in a STEMI trial. Further studies are warranted to assess the potential superiority of this novel strategy as compared with new-generation DES to prevent very late events in these patients. Trial Registration: ClinicalTrials.gov; identifier: NCT01839890.This investigation has received the support of the Spanish Clinical Research Network (SCReN), financed by the ISCIII-Subdirección General de Evaluación y Fomento de la Investigación, under the project PT13/0002/0005 (Plan Estatal de I+D+I 2013-2016) and co-funded by the European Regional Development Fund (FEDER). An unrestricted research grant was received from Biotronik

    XPS as Characterization Tool for PV: From the Substrate to Complete III-V Multijunction Solar Cells

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    This contribution aims to illustrate the potential of the X-ray photoelectron spectroscopy (XPS) technique as a tool to analyze different parts of a solar cell (surface state, heterointerfaces, profile composition of ohmic contacts, etc). Here, the analysis is specifically applied to III-V multijunction solar cells used in concentrator systems. The information provided from such XPS analysis has helped to understand the physico-chemical nature of these surfaces and interfaces, and thus has guided the technological process in order to improve the solar cell performance
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