Wave attenuation to clock sojourn times

The subject of time in quantum mechanics is of perennial interest especially because there is no observable for the time taken by a particle to transmit (or reflect) from a particular region. Several methods have been proposed based on scattering phase shifts and using different quantum clocks, where the time taken is clocked by some external input or indirectly from the phase of the scattering amplitudes. In this work we give a general method for calculating conditional sojourn times based on wave attenuation. In this approach clock mechanism does not couple to the Hamiltonian of the system. For simplicity, specific case of a delta dimer is considered in detail. Our analysis re-affirms recent results based on correcting quantum clocks using optical potential methods, albeit in a much simpler way.Comment: 4 pages, 5 figures. Minor corrections made and journal reference adde

Dephasing via stochastic absorption: A case study in Aharonov-Bohm oscillations

The Aharonov-Bohm ring has been the mainstay of mesoscopic physics research since its inception. In this paper we have dwelt on the problem of dephasing of AB oscillations using a phenomenological model based on stochastic absorption. To calculate the conductance in the presence of inelastic scattering we have used the method due to Brouwer and Beenakker. We have shown that conductance is symmetric under flux reversal and visibility of AB oscillations decay to zero as a function of the incoherence parameter thus signalling dephasing in the system. Some comments are made on the relative merits of stochastic absorption with respect to optical potential model, which have been used to mimic dephasing.Comment: 4 pages, 4 figures Minor corrections made and journal reference adde

Diseño de Metodologías Activas para Másteres

El objetivo de la Universidad de Burgos desde el Máster en Inspección, Restauración, Rehabilitación y Eficiencia Energética de Edificación (MIREE), es la implementación de metodologías docentes activas con el fin de la formación del alumnado, a través de casos concretos y reales que adicionalmente reportarán un beneficio social. Alguno de estos métodos pueden ser el estudio de casos, la resolución de ejercicios y problemas, el aprendizaje basado en problemas y orientado a proyectos, el aprendizaje cooperativo, etc. Lo que pretendemos con las metodologías activas de aprendizaje es, que los alumnos adquieran las competencias propuestas en el programa docente, desarrollando un aprendizaje profundo en cada una de ellas. Para ello debemos evitar que el profesorado monopolice la docencia, y es necesario comunicarles tanto al alumnado como al profesorado, que la docencia es una inversión en beneficio mutuo. La realización de este tipo de proyectos favorece notablemente a los alumnos ya que desarrollan la motivación de aprendizaje o puesta en práctica de las enseñanzas recibidas, pero lo que sin duda es motivador para ellos es el reconocimiento social al trabajo realizado. Esto se ve reflejado en la Estrategia Europea 2020 a nivel universitario que habla de reforzar la cooperación entre la Universidad, Investigación y Empresa

Desarrollo de la asertividad como instrumento de aprendizaje para alumnos universitarios

Uno de los éxitos de un buen proceso formativo es que el alumno sea capaz de manifestar con destreza sus habilidades comunicacionales, entendidas éstas como la capacidad para expresar abiertamente sus opiniones, dudas, sentimientos, actitudes y derechos, pero sin infringir los derechos de los demás. En este límite es donde el docente debe llevar a cabo técnicas que fomenten la comunicación, siempre bajo el respeto, fomentando el uso de un lenguaje asertivo el cual facilita de forma significativa el aprendizaje del alumno

Uso del Mapa Conceptual como Herramienta Docente para la Asignatura “Series Cronológicas”

Esta comunicación es fruto de un proyecto de innovación docente que está siendo desarrollado en la Universidad de Jaén. Los objetivos principales de dicho proyecto son el desarrollo de nuevos sistemas de evaluación basados en el reciente marco educativo EEES y el uso de las nuevas tecnologías TIC con el fin común de elaborar y desarrollar nuevos enfoques metodológicos docentes que faciliten el aprendizaje de los alumnos y mejoren la calidad docente.Concretamente, presentamos un mapa conceptual para la asignatura “Series Cronológicas” perteneciente a la Diplomatura en Estadística. Este mapa proporcionará al alumno una magnifica herramienta para asimilar mejor las diferentes técnicas que comprenden la modelización de procesos ARIMA

In Vivo insulin-dependent glucose uptake of specific tissues is decreased during aging of mature wistar rats

Copyright (1997) The Endocrine Society .The paper can be found at the following URL on the website http://endo.endojournals.org

Tree vigour influences secondary growth but not responsiveness to climatic variability in Holm oak

Many tree species from Mediterranean regions have started to show increased rates of crown defoliation, reduced groth, and dieback associated with the increase in temperatures and changes in the frequency and intensity of drought events experienced during the last decades. In this regard, Quercus ilex L. subsp. ballota (Desf.) (Holm oak), despite being a drought-tolerant species widely distributed in the Mediterranean basin, it has recently started to show acute signs of decline, extended areas from Spain being affected. However, few studies have assessed the role of climatic variability (i.e., temperature, precipitation, and drought) on the decline and resilience of Holm oak. Here, we measured secondary growth of seventy Holm oaks from a coppice stand located in central Spain. Sampled trees had different stages of decline, so they were classified into four vigour groups considering their crown foliar lost: healthy (0%), low defoliated (25%), highly defoliated (25 70%), and dying (70 100%). Our results showed that during the study period (1980 2009) the highly defoliated and dying Holm oaks grew significantly less than their healthy and low defoliated neighbours, suggesting permanent growth reduction in the less vigorous individuals. Despite these differences, all four vigour groups showed similar responses to climatic variations, especially during winter and late spring early summer seasons, and similar resilience after severe drought events, managing to significantly recover to pre-drought growth rates after only two years. Our findings, hence, illustrate that tree vigour influences secondary growth but not responsiveness to climatic variability in Holm oak. Still, as reduced growth rates are frequently associated with the process of tree mortality, we conclude that the less vigorous Holm oaks might not be able to cope with future water stress conditions, leading to increased mortality rates among this emblematic Mediterranean specie

ANGPTL3 gene variants in subjects with familial combined hyperlipidemia

Angiopoietin-like 3 (ANGPTL3) plays an important role in lipid metabolism in humans. Loss-of-function variants in ANGPTL3 cause a monogenic disease named familial combined hypolipidemia. However, the potential contribution of ANGPTL3 gene in subjects with familial combined hyperlipidemia (FCHL) has not been studied. For that reason, the aim of this work was to investigate the potential contribution of ANGPTL3 in the aetiology of FCHL by identifying gain-of-function (GOF) genetic variants in the ANGPTL3 gene in FCHL subjects. ANGPTL3 gene was sequenced in 162 unrelated subjects with severe FCHL and 165 normolipemic controls. Pathogenicity of genetic variants was predicted with PredictSNP2 and FruitFly. Frequency of identified variants in FCHL was compared with that of normolipemic controls and that described in the 1000 Genomes Project. No GOF mutations in ANGPTL3 were present in subjects with FCHL. Four variants were identified in FCHL subjects, showing a different frequency from that observed in normolipemic controls: c.607-109T>C, c.607-47_607-46delGT, c.835+41C>A and c.*52_*60del. This last variant, c.*52_*60del, is a microRNA associated sequence in the 3'UTR of ANGPTL3, and it was present 2.7 times more frequently in normolipemic controls than in FCHL subjects. Our research shows that no GOF mutations in ANGPTL3 were found in a large group of unrelated subjects with FCHL

Lateral absorption measurements of InAs/GaAs quantum dots stacks: Potential as intermediate band material for high efficiency solar cells

Prototypes based on InAs/GaAs QDs have been manufactured in order to realize the theoretically predicted high efficiency intermediate band solar cells (IBSCs). Unfortunately, until now, these prototypes have not yet demonstrated the expected increase in efficiency when compared with reference samples without IB material. One of the main arguments explaining this performance is the weak photon absorption in the QD-IB material, arising from a low density of QDs. In this work, we have analyzed the absorption coefficient of the IB material by developing a sample in an optical wave-guided configuration. This configuration allows us to illuminate the QDs laterally, increasing the path length for photon absorption. Using a multi-section metal contact device design, we were able to measure an absorption coefficient of ∼100 cm−1 around the band edge (∼1 eV ) defined by the transition in InAs/GaAs QD-IB materials. This figure, and its influence on the IBSC concept, is analyzed for this system