Implementación del càlculo de polinomios zonales y aplicaciones en análisis multivariante

En este trabajo se describe la implementación de un algoritmo para el cálculo de polinomios zonales, así como dos aplicaciones explícitas de éstos en el ámbito del análisis multivariante. Concretamente, esta implementación permite obtener resultados de sumación aproximados para funciones hipergeométricas de argumento matricial que, a su vez, pueden utilizarse en la génesis de distribuciones multivariantes discretas con frecuencias simétricas. De igual forma, se pone en práctica un conocido resultado teórico que caracteriza la distribución de la menor raíz característica de una matriz aleatoria con distribución de Wishart

攻读韦尔瓦大学本科教育学位的新生学习动机

Several variables inherent to the profile of new university students affect their likelihood of achieving optimal adaptation and finishing the studies they embark upon. A cornerstone of this is the vocational factor as, to some extent, it influences the commitment and willingness of students to tackle the learning process with ambition and enthusiasm. The main aim of the present work was to identify student profiles based on their reasons for undertaking Early Childhood Education, Primary Education and Social Education degrees. The present study adopts a survey-type methodology and follows a cross-sectional, descriptive and associative design, in which the set of individuals that make up the sample are grouped using a hierarchical approach. To this end, data are processed according to multivariate statistical methods (clustering). The sample was selected incidentally and is composed of 376 first year students undertaking one of three degrees within the Faculty of Education, Psychology and Sports Sciences at Huelva University. Findings reveal the existence of three possible groupings in terms of the profile of students enrolled on degrees. Two of these groups pertain to variables that are linked with vocational aspects, although a smaller group also exists in which this is not the case. Moreover, degrees in Early Childhood Education (ECE) and Social Education continue to be feminised, whilst the “wild card” entry option continues to be applied to Primary Education degrees.Existen diversas variables asociadas al perfil del alumnado universitario de nuevo ingreso que inciden en el logro de una óptima adaptación y continuidad en los estudios que estos inician. El factor vocacional emerge como uno de los pilares fundamentales puesto que, en cierta medida, es garante de encontrar un alumnado universitario más comprometido y receptivo a afrontar un proceso de aprendizaje con ambición y energías. El objetivo principal de este trabajo consiste en identificar perfiles de estudiantes en base a los motivos de ingreso en los grados de Educación Infantil, Educación Primaria y Educación Social. El estudio parte de una metodología tipo encuesta, con un diseño transversal de tipo descriptivo y asociativo, desde el que se persigue hacer una agrupación jerarquizada con el conjunto de individuos que conforma la muestra. Para ello, los datos se tratarán con métodos estadísticos multivariantes (conglomerados o cluster). La muestra ha sido seleccionada de manera incidental y está compuesta por 376 estudiantes de primer curso de los tres grados de la Facultad de Educación, Psicología y Ciencias del Deporte de la Universidad de Huelva. Los resultados revelan la existencia de tres posibles agrupamientos en cuanto al perfil de los estudiantes que acceden a los grados, en dos de los cuales se atisban variables ligadas a lo vocacional, mientras que hay un grupo minoritario en el que esto no ocurre; además, sigue presente la feminización en los grados Grado de Educación Infantil y educación social o la atribución de “comodín” al Grado de Educación Primaria.Existem várias variáveis associadas ao perfil dos novos estudantes universitários que afetam a obtenção de uma adaptação e continuidade ótimas nos estudos que iniciam. O fator vocacional emerge como um dos pilares fundamentais uma vez que, até certo ponto, é uma garantia de encontrar estudantes universitários mais comprometidos e recetivos para enfrentar um processo de aprendizagem com ambição e energias. O principal objetivo deste trabalho é identificar os perfis de estudantes com base nas razões de admissão aos graus de Ensino Infantil, Ensino Primário e Ensino Social. O estudo baseia-se numa metodologia de tipo topográfico, com um desenho descritivo e associativo transversal, a partir do qual se pretende fazer um agrupamento hierárquico do conjunto de indivíduos que compõem a amostra. Para este fim, os dados serão processados utilizando métodos estatísticos multivariantes (conglomerados ou clusters). A amostra foi selecionada de forma incidental e é composta por 376 estudantes do primeiro ano dos três graus da Faculdade de Educação, Psicologia e Ciências do Desporto da Universidade de Huelva. Os resultados revelam a existência de três agrupamentos possíveis em termos do perfil dos estudantes que entram nos graus, em duas das quais é possível discernir variáveis ligadas a aspetos profissionais, enquanto existe um grupo minoritário em que isso não acontece; além disso, a feminização ainda está presente nos graus de Ensino Infantil e Ensino Social ou na atribuição de “joker” ao Grau de Ensino Primário.Existem várias variáveis associadas ao perfil dos novos estudantes universitários que afetam a obtenção de uma adaptação e continuidade ótimas nos estudos que iniciam. O fator vocacional emerge como um dos pilares fundamentais uma vez que, até certo ponto, é uma garantia de encontrar estudantes universitários mais comprometidos e recetivos para enfrentar um processo de aprendizagem com ambição e energias. O principal objetivo deste trabalho é identificar os perfis de estudantes com base nas razões de admissão aos graus de Ensino Infantil, Ensino Primário e Ensino Social. O estudo baseia-se numa metodologia de tipo topográfico, com um desenho descritivo e associativo transversal, a partir do qual se pretende fazer um agrupamento hierárquico do conjunto de indivíduos que compõem a amostra. Para este fim, os dados serão processados utilizando métodos estatísticos multivariantes (conglomerados ou clusters). A amostra foi selecionada de forma incidental e é composta por 376 estudantes do primeiro ano dos três graus da Faculdade de Educação, Psicologia e Ciências do Desporto da Universidade de Huelva. Os resultados revelam a existência de três agrupamentos possíveis em termos do perfil dos estudantes que entram nos graus, em duas das quais é possível discernir variáveis ligadas a aspetos profissionais, enquanto existe um grupo minoritário em que isso não acontece; além disso, a feminização ainda está presente nos graus de Ensino Infantil e Ensino Social ou na atribuição de “joker” ao Grau de Ensino Primário.存在众多与大学新生个人情况相关的变量用来反映他们在学业适应及连续性方面的成就。在这其中，最为重要的一项因素就是兴趣热爱。在一定程度上可以确定，对学业持有兴趣的大学新生对学习有更多的承诺，也更愿意付出精力，用野心面对学习过程中的种种挑战。该研究的主要目的是根据幼儿教育、小学教育和社会教育本科新生的入学动机确定学生的情况。该研究采用问卷研究法和描述性及关联性的横断设计，对样本群体进行等级分组。因此，我们使用多种统计学方法（整群抽样或聚类分析）处理数据。通过偶遇抽样得到韦尔瓦大学教育系、心理系和体育科学系的376名大一新生样本。研究结果显示根据大学新生的入学情况，有可能将其分为三大组。其中两组可以观察到跟兴趣紧密相关的变量，而另外的一组少数样本则没有观察到相同的结果。研究还表明本科幼儿教育和社会教育系仍然存在女多男少的情况，同时把小学教育学位当做“保底”专业的态度屡见不鲜

Influence of Wood Properties and Building Construction on Energy Demand, Thermal Comfort and Start-Up Lag Time of Radiant Floor Heating Systems

Radiant floor heating is becoming increasingly popular in cold climates because it delivers higher comfort levels more efficiently than conventional systems. Wood is one of the surface coverings most frequently used in radiant flooring, despite the widely held belief that in terms of thermal performance it is no match for higher conductivity materials if a high energy performance is intended. Given that the highest admissible thermal resistance for flooring finishes or coverings is generally accepted to be 0.15 m(2)K/W, wood would appear to be a scantly appropriate choice. Nonetheless, the evaluation of the thermal performance of wooden radiant floor heating systems in conjunction with the building in terms of energy demand, thermal comfort, and start-up period, has been insufficiently explored in research. This has led to the present knowledge gap around its potential to deliver lower energy consumption and higher thermal comfort than high-thermal-conductivity materials, depending on building characteristics. This article studies the thermal performance of wood radiant floors in terms of three parameters: energy demand, thermal comfort, and start-up lag time, analysing the effect of wood properties in conjunction with building construction on each. An experimentally validated radiant floor model was coupled to a simplified building thermal model to simulate the performance of 60 wood coverings and one reference granite covering in 216 urban dwellings differing in construction features. The average energy demand was observed to be lower in the wood than in the granite coverings in 25% of the dwellings simulated. Similarly, on average, wood lagged behind granite in thermal comfort by less than 1 h/day in 50% of the dwellings. The energy demand was minimised in a significant 18% and thermal comfort maximised in 14% of the simulations at the lowest thermal conductivity value. The vast majority of the wooden floors lengthened the start-up lag time relative to granite in only 30 min or less in all the dwellings. Wood flooring with the highest thermal resistance (even over the 0.15 m(2)K/W cited in standard EN 1264-2) did not significantly affect the energy demand or thermal comfort. On average, wood flooring lowered energy demand by 6.4% and daily hours of thermal comfort by a mere 1.6% relative to granite coverings. The findings showed that wood-finished flooring may deliver comparable or, in some cases, higher thermal performance than high-conductivity material coverings, even when their thermal resistance is over 0.15 m(2)K/W. The suggestion is that the aforementioned value, presently deemed the maximum admissible thermal resistance, may need to be revised

Effect of Wood Properties and Building Construction on Thermal Performance of Radiant Floor Heating Worldwide

Due to its relatively lower thermal conductivity, the suitability of wood is called into question when selecting the flooring material best suited to radiant heating systems. The European standard EN 1264 considers floorings with a thermal resistance over 0.15 m2 K/W to be out of scope. This belief was partially disproved in a previous article that studied wooden floors for Madrid’s climate. However, the effect of climate still needs to be addressed. The present study extends the previous research to worldwide climates and aimed to answer the following questions: (1) Do the lowest thermal conductivity woods present good thermal performance when used in radiant floors? (2) Should the flooring have a maximum thermal resistance value? (3) Is the standard thermal resistance limit of 0.15 m2 K/W objectively justified? And (4) Do the answers of the preceding questions depend on the climate and the construction characteristics? To answer these questions, 28 cities were selected according to the Köppen–Geiger climate classification. In each city, 216 different dwellings were simulated with 60 wood floorings and one of low thermal resistance as a reference, comprising a total of 368,928 cases. Thermal performance was evaluated in terms of three parameters: energy demand, thermal comfort, and start-up lag time. Consequently, the answers to the previous questions were: (1) The lowest thermal conductivity woods can be used efficiently worldwide in radiant floor heating systems with start-up lag times close to that of the reference flooring; (2) There is no limit value for thermal resistance for floorings that can be applied to all dwellings and climates; (3) No objective justification was found for establishing a thermal resistance limit for flooring of 0.15 m2 K/W; and (4) Climate and construction characteristics can play an important role in the correct selection of flooring properties, especially in severe winters and dwellings with the greatest outdoor-exposed envelope and the worst insulation

Application of Particle Induced X-ray Emision (PIXE) technique to the non-destructive characterization of a burial-sample object (S.I. a.C.) coming from an archaeological excavation (formerly Hospital de las Cinco Llagas, Sevilla)

En el presente trabajo se ha realizado la caracterización de una pieza de ajuar funerario del Siglo I d.C. (anillo con pieza incrustada y grabada), encontrado en una excavación arqueológica en el antiguo Hospital de las Cinco Llagas de Sevilla, de la que inicialmente se desconocía su naturaleza cerámica o vítrea, utilizando las posibilidades que brindan una serie de técnicas instrumentales no destructivas ampliamente conocidas, como son microscopía óptica convencional, MEB-EDX, DRX y FRX. En este caso concreto se ha aplicado, además, la técnica de Emisión de Rayos X inducidos por partículas (Particle Induced X-ray Emision, PIXE). Dicha técnica permite extraer información de la composición química de una muestra para un análisis rápido de múltiples elementos traza. El estudio de esta interesante pieza pone de manifiesto la extrema calidad y precisión de la talla de las figuras o motivos, en particular algunos de ellos (garza y palma) a pesar del tamaño reducido de la misma, con efectos de relieve en el tallado del material aprovechando su propia constitución. El análisis de fases por DRX indica que la única fase cristalina constituyente del material es cuarzo y puede considerarse la pieza estudiada como una gema: cuarzo azul. La composición química de la gema determinada por FRX ha permitido comprobar que además de los elementos mayoritarios (Si y O), existen otros minoritarios, como son Ca y Fe (< 1,5 %), Na y Al (próximos al 0,3 %); otros elementos como Cl, K y P aparecen en porcentajes similares (0.2-0,25 %), además de Mg y S en porcentajes inferiores (ca. 0,08 %). Sin embargo, la aplicación de la técnica PIXE basada en haces de iones ha permitido determinar la presencia de Ti y V en la gema, lo que explicaría su coloración azul. Estos elementos deben encontrarse en forma iónica formando parte de la estructura cristalina del cuarzo. En consecuencia, esta técnica no destructiva permite encontrar una diferencia química importante entre zonas de una misma pieza, que no se aprecian mediante la aplicación de técnicas convencionales, con la ventaja añadida de utilizar directamente el objeto del análisis.In this work, a non-destructive characterization of a burial-sample object dated S.I. a.C. (ring with an incrusted material) coming from an archaeological excavation (former Hospital de las Cinco Llagas, Sevilla) has been carried out. The glass or ceramic nature of this sample was unknown. Several non-destructive techniques have been applied: optical microscopy, SEM-EDX, XRD and XRF. In this particular case, the technique Particle Induced X-ray Emision (PIXE) has been also applied. PIXE allows to obtain a fast information concerning chemical composition of trace elements using the object directly. The study of this interesting object indicates the extreme quality and accurance of the engrave observed on its surface, for instance a long-legged bird and a palm leaf despite their reduced size. Relief effects have been observed in the engrave using the own constitution of this particular material. The XRD phase analysis demonstrates that crystalline quartz as single phase constitutes the incrusted material of the ring considered as a gem: blue quartz. The chemical composition obtained from XRF analysis confirm the XRD result, with Si and O as main elements, although there are minoritary elements such as Ca and Fe (< 1,5 %), Na and Al (ca. 0,3 %). Other elements, such as Cl, K and P were detected in similar percentages (0.2-0,25 %), besides Mg and S (less than 0,08 %). However, the application of the PIXE technique based on ion beam analysis to this material allowed to demonstrate the presence of Ti and V, probably as ions in the quartz crystal structure which constitutes the gem. This experimental fact would then explain the blue colour observed in the gem. Consequently, PIXE as a non-destructive technique allows to find an important chemical difference between zones of the same object. There are some advantages, first of all that these chemical differences can not be accurately observed using other conventional techniques and secondly, the analysis is performed directly on the object, which is very interesting in studies on glass and ceramics samples of the Cultural Heritage.Junta de Andalucía TEP 20

An instrumental puzzle: the modular integration of AOLI

The Adaptive Optics Lucky Imager, AOLI, is an instrument developed to deliver the highest spatial resolution ever obtained in the visible, 20 mas, from ground-based telescopes. In AOLI a new philosophy of instrumental prototyping has been applied, based on the modularization of the subsystems. This modular concept offers maximum flexibility regarding the instrument, telescope or the addition of future developments.Comment: 10 pages, 8 figures, Proc. SPIE 9908, Ground-based and Airborne Instrumentation for Astronomy VI, 99082Z (August 9, 2016

Laboratory and telescope demonstration of the TP3-WFS for the adaptive optics segment of AOLI

AOLI (Adaptive Optics Lucky Imager) is a state-of-art instrument that combines adaptive optics (AO) and lucky imaging (LI) with the objective of obtaining diffraction limited images in visible wavelength at mid- and big-size ground-based telescopes. The key innovation of AOLI is the development and use of the new TP3-WFS (Two Pupil Plane PositionsWavefront Sensor). The TP3-WFS, working in visible band, represents an advance over classical wavefront sensors such as the Shack-Hartmann WFS (SH-WFS) because it can theoretically use fainter natural reference stars, which would ultimately provide better sky coverages to AO instruments using this newer sensor. This paper describes the software, algorithms and procedures that enabled AOLI to become the first astronomical instrument performing real-time adaptive optics corrections in a telescope with this new type of WFS, including the first control-related results at the William Herschel Telescope (WHT)This work was supported by the Spanish Ministry of Economy under the projects AYA2011-29024, ESP2014-56869-C2-2-P, ESP2015-69020-C2-2-R and DPI2015-66458-C2-2-R, by project 15345/PI/10 from the Fundación Séneca, by the Spanish Ministry of Education under the grant FPU12/05573, by project ST/K002368/1 from the Science and Technology Facilities Council and by ERDF funds from the European Commission. The results presented in this paper are based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Special thanks go to Lara Monteagudo and Marcos Pellejero for their timely contributions

Compositional, structural and functional properties of discrete coexisting complexes within bronchoalveolar pulmonary surfactant

Lung surfactant (LS) stabilizes the respiratory surface by forming a film at the alveolar air-liquid interface that reduces surface tension and minimizes the work of breathing. Typically, this surface-active agent has been isolated from animal lungs both for research and biomedical applications. However, these materials are constituted by complex membranous architectures including surface-active and inactive lipid/protein assemblies. In this work, we describe the composition, structure and surface activity of discrete membranous entities that are part of a LS preparation isolated from bronchoalveolar lavages of porcine lungs. Seven different fractions could be resolved from whole surfactant subjected to sucrose density gradient centrifugation. Detailed compositional characterization revealed differences in protein and cholesterol content but no distinct saturated:unsaturated phosphatidylcholine ratios. Moreover, no significant differences were detected regarding apparent hydration at the headgroup region of membranes, as reported by the probe Laurdan, and lipid chain mobility analysed by electron spin resonance (ESR) in spite of the variety of membranous assemblies observed by transmission electron microscopy. In addition, six of the seven separated LS subfractions formed similar, essentially disordered-like, interfacial films and performed efficient surface activity, under physiologically relevant conditions. Altogether, our work show that a LS isolated from porcine lungs is comprised by a heterogenous population of membranous assemblies lacking freshly secreted unused LS complexes sustaining highly dehydrated and ordered membranous assemblies as previously reported. We propose that surfactant subfractions may illustrate intermediates in sequential structural steps within the structural transformations occurring along the respiratory compression-expansion cycles

Oral administration of melatonin counteracts several of the effects of chronic stress in rainbow trout

To assess a possible antistress role of melatonin in fish, we orally administered melatonin to rainbow trout for 10 d and then kept the fish under normal or high stocking density conditions during the last 4 d. Food intake; biochemical parameters in plasma (cortisol, glucose, and lactate concentrations); liver (glucose and glycogen concentrations, and glycogen synthase activity); enzyme activities of amylase, lipase, and protease in foregut and midgut; and content of the hypothalamic neurotransmitters dopamine and serotonin, as well as their oxidized metabolites, 3,4-dihydroxyphenylacetic acid and 5-hydroxy-3-indoleacetic acid, were evaluated under those conditions. High stocking density conditions alone induced changes indicative of stress conditions in plasma cortisol concentrations, liver glycogenolytic potential, the activities of some digestive enzymes, and the 3,4-dihydroxyphenylacetic acid-to-dopamine and 5-hydroxy-3-indoleacetic acid-to-serotonin ratios in the hypothalamus. Melatonin treatment in nonstressed fish induced an increase in liver glycogenolytic potential, increased the activity of some digestive enzymes, and enhanced serotoninergic and dopaminergic metabolism in hypothalamus. The presence of melatonin in stressed fish resulted in a significant interaction with cortisol concentrations in plasma, glycogen content, and glycogen synthase activity in liver and dopaminergic and serotoninergic metabolism in the hypothalamus. In general, the presence of melatonin mitigated several of the effects induced by stress, supporting an antistress role for melatonin in rainbow trout.Ministerio de Ciencia e Innovación | Ref. AGL2010-22247-C03-03Xunta de Galicia | Ref. CN2012/ 00