169 research outputs found

    Adaptive transfer functions: improved multiresolution visualization of medical models

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s00371-016-1253-9Medical datasets are continuously increasing in size. Although larger models may be available for certain research purposes, in the common clinical practice the models are usually of up to 512x512x2000 voxels. These resolutions exceed the capabilities of conventional GPUs, the ones usually found in the medical doctors’ desktop PCs. Commercial solutions typically reduce the data by downsampling the dataset iteratively until it fits the available target specifications. The data loss reduces the visualization quality and this is not commonly compensated with other actions that might alleviate its effects. In this paper, we propose adaptive transfer functions, an algorithm that improves the transfer function in downsampled multiresolution models so that the quality of renderings is highly improved. The technique is simple and lightweight, and it is suitable, not only to visualize huge models that would not fit in a GPU, but also to render not-so-large models in mobile GPUs, which are less capable than their desktop counterparts. Moreover, it can also be used to accelerate rendering frame rates using lower levels of the multiresolution hierarchy while still maintaining high-quality results in a focus and context approach. We also show an evaluation of these results based on perceptual metrics.Peer ReviewedPostprint (author's final draft

    Análisis de las operaciones en la carga aérea. Estudio de tecnologías avanzadas y nuevos procedimientos operativos, y su implantación

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    El objetivo del trabajo es el desarrollo de una metodología que permita crear herramientas decálculo para el estudio de los tiempos en los procesos de handling aeroportuario y a partir deaquí investigar las nuevas tecnologías que incrementen la productividad de dichos procesos.En primer lugar, se ha definido paso a paso el proceso de carga de una aeronave en función delos productos que se transportan, haciendo hincapié en dos canales logísticos concretos, comoson, el de la exportación de producto textil y el de la importación de pescado. Se hadesarrollado una metodología que consiste en realizar una serie de suposiciones teóricas sobreestos procesos y a partir de datos obtenidos de forma experimental, proceder a la creación deherramientas que sean capaces de calcular los tiempos de carga de las aeronaves.Estas herramientas de cálculo han permitido visualizar como afecta a los tiempos de carga enlos canales logísticos citados con anterioridad, la distinta repartición de operarios en las tareasa realizar, también se han cuantificado las reducciones de tiempos que pueden conseguirse sise aplican una serie de mejoras, seleccionando aquellas más interesantes. Se ha estudiado elimpacto de las distintas mejoras tanto a nivel puramente operativo, como a nivel económico.Para finalizar, se ha realizado una reflexión sobre la conveniencia de implementar unasmejoras concretas en función de su rentabilidad tanto a corto como a largo plazo teniendo encuenta las previsiones de desarrollo que existen para el Aeropuerto de Zaragoza.<br /

    Decomposition and biological colonization of native and exotic leaf litter in a Central Spain stream

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    Riparian invasion by exotic trees may lead to changes in the quality of leaf-litter inputs to freshwater ecosystems. Leaflitter inputs are especially important in headwater streams, where aquatic food webs largely depend on the organic matter provided by the terrestrial vegetation. In a headwater stream of Central Spain, North of Guadalajara Province (Tagus basin) we compared the decomposition and biological colonization of leaf litter among two exotic (Ailanthus altissima Mill. Swingle and Robinia pseudoacacia L.) and two native trees (Fraxinus angustifolia Vahl. and Populus alba L.) co-existing in riparian zones. We hypothesized a lower biological colonization of exotic leaves due to organisms have not co-evolved with the exotic trees according to the Novel Weapons Hypothesis (NWH) and, consequently, lower decomposition rates of exotic leaves. To test our hypothesis, litter bags with different mesh sizes (coarse (C) and fine (F)), were used to distinguish between the total and microbial decomposition. The litter bags were placed in the stream and recovered after 2, 20, 39, 62 and 82 days of incubation. After each collection, we assessed the amount of remaining litter, analysed the nitrogen (N) and phosphorous (P) in the litter, identified the macroinvertebrates and quantified the fungal biomass. Consistent with our hypothesis, we found greater fungal biomass buildup on native leaves than on exotic leaves. However, decomposition rates (k) were species-specific, being the ranking in C-bags (A. altissima = F. angustifolia > P. alba > R. pseudoacacia) slightly different than in F-bags (A. altissima > F. angustifolia > P. alba > R. pseudoacacia). The k in both the C-bags and F-bags were correlated with leaf traits, such as lignin, acid detergent fibre (ADF) and lignin:P. There was not a clear effect of the exotic species on macroinvertebrate variables, but the contribution of macroinvertebrates to litter decomposition was lower in exotic litter than in native litter, as shown by a lower ratio between k in C-bags and k in F-bags (kC : kF). Our results supported that invasive species might impact both biological colonization and decomposition rates in stream ecosystems by the addition of different quality leaf litter when compared to native vegetation. The differences in the biological colonization may be explained by the NWH, but differences in the decomposition rates were better explained by litter quality

    Study of scenarios and technical requirements of a social assistive robot for Alzheimer's disease patients and their caregivers

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    Robots have begun to assist elders and patients suffering dementia. In particular, recent studies have shown how robots can benefit Alzheimer's disease (AD) patients. This is a novel area with a promising future but lot of researching needs to be done. The RobAlz project is aimed to assist AD patients and their caregivers by social robots. This project is divided in three phases: the definition of the requirements and scenarios, the development of a new robotic platform, and the evaluation. This work presents the results obtained in the first phase, in which several meetings were conducted with a set of subject-matter experts in the areas of Alzheimer's Disease and social robotics. The meetings were classified according to the application areas they covered: general aspects, safety, entertainment, personal assistance, and stimulation. The meetings ended up with a repertory of scenarios where robots can be applied to Alzheimer's patients and their caregivers at their home or in longterm care facilities. These scenarios present different psychological, social and technical concerns that must be addressed for the design of the robot. In this work we perform an analysis on the scenarios and present the technical requirements for the development of a first robotic prototype. This prototype will be constructed and tested in real environments in the subsequent phases of the RobAlz project.The authors gratefully acknowledge the collaboration of the Spanish Alzheimer Foundation (FAE) and the funds provided by the Spanish Government through the project Aplicaciones de los robots sociales DPI2011-26980, from the Spanish Ministry of Economy and Competitiveness

    Decomposition and biological colonization of native and exotic leaf litter in a stream

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    Riparian invasion by exotic trees may lead to changes in the quality of leaf-litter inputs to freshwater ecosystems. Leaflitterinputs are especially important in headwater streams, where aquatic food webs largely depend on the organic matterprovided by the terrestrial vegetation. In a headwater stream of Central Spain, North of Guadalajara Province (Tagus basin)we compared the decomposition and biological colonization of leaf litter among two exotic (Ailanthus altissima Mill. Swingleand Robinia pseudoacacia L.) and two native trees (Fraxinus angustifolia Vahl. and Populus alba L.) co-existing in riparianzones.We hypothesized a lower biological colonization of exotic leaves due to organisms have not co-evolved with the exotictrees according to the Novel Weapons Hypothesis (NWH) and, consequently, lower decomposition rates of exotic leaves. Totest our hypothesis, litter bags with different mesh sizes (coarse (C) and fine (F)), were used to distinguish between the totaland microbial decomposition. The litter bags were placed in the stream and recovered after 2, 20, 39, 62 and 82 days ofincubation. After each collection, we assessed the amount of remaining litter, analysed the nitrogen (N) and phosphorous(P) in the litter, identified the macroinvertebrates and quantified the fungal biomass. Consistent with our hypothesis, we foundgreater fungal biomass buildup on native leaves than on exotic leaves. However, decomposition rates (k) were species-specific,being the ranking in C-bags (A. altissima = F. angustifolia > P. alba > R. pseudoacacia) slightly different than in F-bags (A.altissima > F. angustifolia > P. alba > R. pseudoacacia).La invasión de las riberas por árboles exóticos puede provocar cambios en la calidad de las entradas de hojarasca a los ecosistemas de agua dulce, especialmente importantes en arroyos de cabecera, donde las redes tróficas dependen en gran medida de los aportes de materia orgánica proporcionada por la vegetación terrestre. En un arroyo de cabecera del Centro de España, Norte de la provincia de Guadalajara (Cuenca del Tajo), comparamos entre la descomposición y colonización biológica de la hojarasca de dos árboles exóticos (Ailanthus altissima Mill. Swingle y Robinia pseudoacacia L.) y dos nativos (Fraxinus angustifolia Vahl. y Populus alba L.), que coexisten en zonas de ribera. Hipotetizamos que habrá una menor colonización biológica de las hojas exóticas debido a que los organismos del arroyo no han co-evolucionado con los árboles exóticos de acuerdo con la Hipótesis de las Nuevas Armas (NWH) y, por tanto, menores tasas de descomposición de éstas. Para testar nuestra hipótesis, se sumergieron en el arroyo bolsas de descomposición con distinta de luz de malla, gruesa (C) y fina (F) –usadas para distinguir entre descomposición total y microbiana– y se recuperaron después de 2, 20, 39, 62 y 82 días de incubación. Después de la recolección pesamos la cantidad de hojarasca remanente, analizamos el nitrógeno (N) y fósforo (P) de la hojarasca, identificamos los macroinvertebrados y cuantificamos la biomasa fúngica. De acuerdo con nuestra hipótesis, encontramos mayor biomasa fúngica acumulada en hojas nativas que en exóticas. Sin embargo, la tasa de descomposición (k) fue específica de la especie, siendo el ranking en las bolsas C (A. altissima = F. angustifolia > P. alba > R. pseudoacacia) ligeramente diferente al de las bolsas F (A. altissima > F. angustifolia > P. alba > R. pseudoacacia). Ambas k (en bolsas C y F) se correlacionaron con lignina, fibra ácido detergente (ADF) y lignina:P. No hubo un efecto claro de las especies exóticas sobre las variables de macroinvertebrados, pero la contribución de los macroinvertebrados a la descomposición fue menor en la hojarasca exótica que en la nativa, como muestra el menor ratio entre k en bolsas C y F (kC : kF). Nuestros resultados apoyan que las especies invasoras pueden impactar tanto la colonización biológica como las tasas de descomposición de la hojarasca en los ecosistemas de arroyos mediante el aporte de hojarasca de distinta calidad respecto de la vegetación nativa. Las diferencias en colonización biológica pueden ser explicadas por la NHW pero las diferencias en descomposición son mejor explicadas por la calidad de la hojarasca.Ministerio de Economía y CompetitividadJunta de Comunidades de Castilla-La ManchaComunidad de Madri

    Retinoprotective Effect of Wild Olive (Acebuche) Oil-Enriched Diet against Ocular Oxidative Stress Induced by Arterial Hypertension

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    Oxidative stress plays an important role in the pathogenesis of ocular diseases, including hypertensive eye diseases. The beneficial effects of olive oil on cardiovascular diseases might rely on minor constituents. Currently, very little is known about the chemical composition and/or therapeutic effects of the cultivated olive tree’s counterpart, wild olive (also known in Spain as acebuche—ACE). Here, we aimed to analyze the antioxidant and retinoprotective effects of ACE oil on the eye of hypertensive mice made hypertensive via administration of NG-nitro-L-arginine-methyl-ester (L-NAME), which were subjected to a dietary supplementation with either ACE oil or extra virgin olive oil (EVOO) for comparison purposes. Deep analyses of major and minor compounds present in both oils was accompanied by blood pressure monitoring, morphometric analyses, as well as different determinations of oxidative stress-related parameters in retinal layers. Aside from its antihypertensive effect, an ACE oil-enriched diet reduced NADPH (nicotinamide adenine dinucleotide phosphate) oxidase activity/gene/protein expression (with a major implication of NADPH oxidase (NOX)2 isoform) in the retinas of hypertensive mice. Supplementation with ACE oil in hypertensive animals also improved alterations in nitric oxide bioavailability and in antioxidant enzyme profile. Interestingly, our findings show that the use of ACE oil resulted in better outcomes, compared with reference EVOO, against hypertension-related oxidative retinal damage.Consejería de Economía, Conocimiento, Empresas y Universidad, Junta de Andalucía (2017/440; 2020/275; CTS-584)Ministerio de Ciencia e Innovación, Gobierno de España (Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020Programa Estatal de I+D+I PID2019-109002RB-I0

    A local user mapping architecture for social robots

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    User detection, recognition, and tracking is at the heart of human-robot interaction, and yet, to date, no universal robust method exists for being aware of the people in a robot's surroundings. The present article imports into existing social robotic platforms different techniques, some of them classical, and other novel, for detecting, recognizing, and tracking human users. The outputs from the parallel execution of these algorithms are then merged, creating a modular, expandable, and fast architecture. This results in a local user mapping through fusion of multiple user recognition techniques. The different people detectors comply with a common interface called PeoplePoseList Publisher, while the people recognition algorithms meet an interface called PeoplePoseList Matcher. The fusion of all these different modules is based on the Unscented Kalman Filtering technique. Extensive benchmarks of the subcomponents and of the whole architecture demonstrate the validity and interest of all levels of the architecture. In addition, all the software and data sets generated in this work are freely available.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The research leading to these results has received funding from several projects: from the project called: Development of social robots to help seniors with cognitive impairment-ROBSEN, funded by the Ministerio de Economía y Competitividad (DPI2014-57684-R); and from the RoboCity2030-III-CM project (S2013/MIT-2748), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU

    Feature-preserving downsampling for medical images

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    In the medical imaging field, interactive direct volume rendering of large volume datasets is a challenging task. Multi-resolution techniques deal with this problem by downsampling the original dataset to produce coarser representations. We present an evaluation of different downsampling filters with respect to their effectiveness at preserving details of the original dataset. Moreover, we propose a new Gaussian-based filter that produces quality lower-resolution representations and preserves small features that are prone to disappear.Peer ReviewedPostprint (author's final draft

    Géneros de lectura preferidos por los alumnos extremeños. Datos y análisis

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    The abundant research work on reading habits in Spain shows a disaggregation of municipalities and cities with little geographical sample of their results. In this way, taking as a starting point the previous studies of 2007 for Extremadura carried out by the Germán Sánchez Ruipérez Foundation, our work intends to update and extend the data of reading habits by applying them to the contemporary geographical reality and the degree of rurality of the region. Thus, in the context of a survey focused on reading habits in Extremadura responded by 9.212 students of all educational levels (Primary, Secondary, University) during the year 2017, this study exposes and specifically analyzes the data obtained on the preferred genres according to the educational level and sex of participants. The study is completed with the data to the CDU of the public and school libraries of Extremadura. As a relevant result, the literary genres of mystery and adventure are, in general, the most demanded at all levels of education. In the Senior College, history is preferred. More women than men prefer romantic novels. The lyric genre is not very popular in terms of reading preferences among any of the educational levels analyzed.Los abundantes trabajos de investigación acerca de los hábitos de lectura en España muestran una desagregación de municipios y ciudades con escasa muestra geográfica de sus resultados. Tomando como punto de partida los estudios previos de 2007 realizados por la Fundación Germán Sánchez Ruipérez para Extremadura, nuestro trabajo pretende actualizar y ampliar los datos de hábitos de lectura aplicándolos a la realidad geográfica contemporánea y el grado de ruralidad de la región. Así, en el contexto de una encuesta propia sobre hábitos lectores en Extremadura realizada a 9.212 estudiantes de todos los niveles educativos (Primaria, Secundaria, Universidad) durante el año 2017, este estudio expone y analiza específicamente los datos obtenidos sobre los géneros preferidos atendiendo al nivel educativo y sexo de los encuestados. El estudio se completa con los datos referidos al CDU de las bibliotecas públicas y escolares de Extremadura. Como resultados más relevantes, los géneros literarios de misterio y aventuras son, en general, los más demandados en todos los niveles educativos. En la Universidad de Mayores se prefieren los de historia. La novela romántica gusta más a las mujeres que a los hombres. El género lírico no atraviesa un buen momento en cuanto a las preferencias de lectura en ninguno de los niveles educativos analizados

    Model of monthly electricity consumption of healthcare buildings based on climatological variables using PCA and linear regression

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    [EN] At this time, due to the global pandemic that has occurred, public administrations want to optimize resources and reduce greenhouse gases with more interest than before. It is the case of the Energy Regional Entity of the Junta de Castilla y León (Spain) that pursues the optimization of the energy consumption in particular of healthcare sector buildings. For this purpose, this work focuses on estimating electricity consumption for each month, for which different scenarios will be generated and the corresponding model is obtained for each scenario. This model has been developed considering the historical monthly data of consumption and climatic variables for the last 3 years. Electricity consumption in public sanitary buildings is related to their climatology, due to the use of air conditioning to adjust the indoor temperature. Subsequently, from the models obtained, the results will be analyzed. Significant differences have been observed in the estimation of electricity consumption with respect to the real data provided by the Junta de Castilla y León. The results obtained show how the availability of climatic variables increases the accuracy of the model obtained by about 30%.S
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