Los procesos estables como generalización del movimiento Brownianoel Ibex35

El movimiento browniano, caracterizado por la independencia y la normalidad de la distribución de sus incrementos, es uno de los modelos más utilizados para describir el precio de una acción. Sin embargo, su distribución empírica difiere de la distribución normal. En los años sesenta Benoît B. Mandelbrot (1924-) propuso como generalización del movimiento browniano los procesos estables como modelo de la evolución de los precios de un activo financiero manteniendo la independencia de los incrementos del proceso. En este trabajo se analiza algunas de las aportaciones de esta generalización tomando como modelo la serie de los cierres diarios del índice Ibex35 durante la década de los noventa.Browniam motion, whose increments are Gaussian and independent, is one of the most used models to describe stock prices. However, its empirical distribution differs from the Gaussian one. During the sixties Benoit B. Mandelbrot (1924-) suggested stable processes, which generalize Brownian motion, as a model of price variation. In this paper is analyzed some features of stable processes taking the Ibex35 series as a model

Selection of nature-based solutions to improve comfort in schools during heat waves

Climate change impacts particularly affect vulnerable populations such as children. Therefore, addressing the adaptation of educational buildings is crucial in avoiding these negative effects on school performance. In this paper, three educational buildings, located in Badajoz (Spain), Evora (Portugal) and Porto (Portugal), serve as pilot samples to study the suitability of nature-based solutions (NBS), chosen for each one of three climatic zones. The NBS selected include green roofs, vertical structures with vegetation to shade holes, outdoor trees and free-cooling ventilation. The scenarios of the different NBS implemented in the three models were simulated with the software EnergyPlus, which allows optimising the appropriate decision before renovation operations begin. The results obtained from the simulations suggest energy performance improvements after applying the most adequate NBS selection to each one of the three buildings tested. Particularly, a reduction in radiation on both roofs and facades is required in the case of Evora and Badajoz, where both climate zones have similar features, that is, warm and dry. While in Porto, milder and more humid than the former ones, it is very effective to operate mainly on the roof, complemented by small ventilation operations.The authors gratefully acknowledge the support of this work by the LIFE+ Programme under the responsibility of the Directorate General for the Environment of the European Commission through the agreement LIFE17 CCA/ES/00088, LIFE myBUILDINGisGREEN

Explorando saberes: la etnobotánica a través del registro audiovisual como instrumento de innovación docente para el aprendizaje significativo y la acción social del desarrollo sostenible

Memoria ID-170. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2019-2020

Fabrication effects in the optical performance of DOEs engraved with femtosecond lasers

The development of DOEs fabrication techniques is continuously growing due to the wide range of industrial applications, such as beam manipulation or optical position encoders. In this work, we use Femtosecond laser direct writing to manufacture DOEs, which uses a simpler and more efficient way to fabricate amplitude binary masks. Also, we have analyzed the performance of the DOEs. The fabrication technique is validated since the experimental results are in accordance to numerical simulations

Percepción, valores y actitudes sobre el medio ambiente y el tratamiento de la problemática ambiental en los medios de comunicación

Memoria ID-0142. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Gold-coated split laser-induced periodic surface structures as refractometric sensors

The generation of surface plasmon resonances (SPR) in laser-induced periodic surface structures (LIPSS) allows their application in the field of optical sensing, such as the detection of refractive index variations in gases and liquids. We have fabricated gold-coated LIPSS nanostructures on stainless steel substrates by using femtosecond laser nano-ablation. This technique is a low-cost and high-throughput fabrication method applicable to fast and large-scale manufacturing. The depth profile of the fabricated LIPSS shows a central dip at the top of each ripple that split the geometry. The actual topography is modeled and included in a computational electromagnetism package to obtain the expected optical response under the experimental conditions. The measured and simulated spectral reflectances are compared, and the differences are explained by the departure of the fabricated LIPSS from the ideal topography. The experiments and simulations showed excellent agreement for the main spectral characteristics, like the Fano-like lineshapes of the spectral reflectance. This fitting provides the values used to determine the refractometric performance of the fabricated device, that shows a sensitivity of 518 nm/RIU and a figure of merit of 32 RIU−1 for an aqueous analyte. Our experimental results show that the fabricated devices are competitive in terms of cost and simplicity when compared to existing devices with similar performance

Etnobotánica, aprovechamiento tradicional de plantas y patrimonio cultural como instrumento de innovación para el desarrollo sostenible

Memoria ID-0147. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2017-2018

Cribado de la depresión mayor en la infancia y adolescencia (Parte 2)

El síndrome depresivo que aparece durante la infancia o la adolescencia tiende a seguir un curso crónico, con alta probabilidad de permanecer en la edad adulta. Su sintomatología repercute en la vida diaria del menor y, en el caso de la depresión mayor, supone un riesgo para la aparición de conducta suicida. Dada la variabilidad de sus manifestaciones clínicas y las dificultades en el diagnóstico, se plantea la posible utilidad del uso de cuestionarios de cribado en la población infantil y adolescente, a partir de un análisis del rendimiento de estos y de la eficacia de las medidas terapéuticas actuales. El presente trabajo se ha dividido en dos partes, y al final de este se recopilan las recomendaciones de distintos grupos de trabajo y tras el análisis de la evidencia, las recomendaciones que el grupo PrevInfad ha consensuado para la consulta de los pediatras en Atención Primaria

Morbid liver manifestations are intrinsically bound to metabolic syndrome and nutrient intake based on a machine-learning cluster analysis

Metabolic syndrome (MetS) is one of the most important medical problems around the world. Identification of patient ' s singular characteristic could help to reduce the clinical impact and facilitate individualized management. This study aimed to categorize MetS patients using phenotypical and clinical variables habitually collected during health check-ups of individuals considered to have high cardiovascular risk. The selected markers to categorize MetS participants included anthropometric variables as well as clinical data, biochemical parameters and prescribed pharmacological treatment. An exploratory factor analysis was carried out with a subsequent hierarchical cluster analysis using the z-scores from factor analysis. The first step identified three different factors. The first was determined by hypercholesterolemia and associated treatments, the second factor exhibited glycemic disorders and accompanying treatments and the third factor was characterized by hepatic enzymes. Subsequently four clusters of patients were identified, where cluster 1 was characterized by glucose disorders and treatments, cluster 2 presented mild MetS, cluster 3 presented exacerbated levels of hepatic enzymes and cluster 4 highlighted cholesterol and its associated treatments Interestingly, the liver status related cluster was characterized by higher protein consumption and cluster 4 with low polyunsaturated fatty acid intake. This research emphasized the potential clinical relevance of hepatic impairments in addition to MetS traditional characterization for precision and personalized management of MetS patients