664 research outputs found

    La desaparición de la barrera del análisis estructural en el desarrollo de los proyectos arquitectónicos

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    A lo largo de la historia en numerosas ocasiones la imaginación de los creadores ha ido por delante de las posibilidades técnicas de cada momento. Muchas de estas nuevas ideas han requerido largos periodos de tiempo para materializarse como realidad construida, hasta que el desarrollo tecnológico e industrial ha alcanzado un desarrollo suficiente. Estas limitaciones técnicas se han acotado paulatinamente desembocando en la situación actual en la que cualquier planteamiento formal puede ser representado y analizado desde un punto de vista estructural, concluyéndose por tanto que ha desaparecido la barrera del análisis y de la representación gráfica en lo que al desarrollo de los proyectos arquitectónicos se refiere. A lo largo del artículo se analiza cómo la formulación del método de los elementos finitos en la década de los 50 y la posterior generalización de los ordenadores personales y de los paquetes de software de dibujo (C.A.D.) y análisis estructural (F.E.M.) en los estudios de arquitectura e ingeniería en la década de los 80 del siglo pasado, posibilitó el desarrollo de cualquier propuesta arquitectónica por compleja que ésta sea. Esto ha provocado una verdadera revolución a nivel formal en el mundo de la arquitectura, especialmente en el campo de la edificación singular o icónica. Se estudia este proceso a través de ocho casos de estudio

    Modulating effects of emotional valence on recognition memory for high-arousal pictures

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    The main aim of this paper was to provide new evidence on the effects of valence on recognition memory of emotional pictures, on the basis of rigorous experimental control of stimulus material. Valence was manipulated using pleasant and unpleasant pictures, keeping arousal constant at a high level. A reference condition with a neutral value in both dimensions was also included. We found greater discrimination and a more conservative response bias, as well as slower recognition decisions, for pleasant pictures. Also worthy of mention is the high positive correlation between response times and discrimination measures just for such pictures. These results would be consistent with an adaptive interpretation based on motivation and personal relevance of emotional informationEl principal objetivo del presente trabajo fue aportar nueva evidencia sobre los efectos de la valencia en el reconocimiento de imágenes de contenido emocional, a partir de un riguroso control experimental del material estimular. Se manipuló la valencia a niveles agradable y desagradable, manteniendo constante el arousal a un nivel alto. Se incluyó también una condición de referencia con un valor neutro en ambas dimensiones. Se encontró una mejor discriminación, un sesgo de respuesta más conservador y un reconocimiento más lento para las imágenes agradables. Además, solo para estas imágenes existió alta correlación positiva entre tiempos de respuesta y discriminación. Estos resultados serían consistentes con una interpretación de carácter adaptativo basada en la motivación y relevancia personal de la información emocionalS

    Memoria de reconocimiento para estímulos pictóricos: sesgos inducidos por la emocionalidad del estímulo

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    The possibility that stimulus emotionality might influence recognition bias in a long-term memory task was studied with respect to both the valence and arousal dimensions of emotion. For this purpose, we used 108 International Affective Picture System pictures that were representative of all regions of this two-dimensional space. Signal detection theory analysis was applied using A'and B''D as discrimination and bias measures, respectively. In general, the results showed that greater discrimination was accompanied by a response bias that was more conservative for pleasant and for unarousing pictures than for unpleasant and for arousing ones. These results provide new evidence in connection with the emotion-induced recognition bias in long-term memory performanceEn la presente investigación se estudió la posibilidad de que la emocionalidad del estímulo, tanto en la dimensión de valencia como en la de arousal, pudiera afectar al sesgo de reconocimiento en una tarea de memoria a largo plazo. Para ello se emplearon 108 imágenes del IAPS (International Affective Picture System) representativas de todas las regiones del espacio afectivo bidimensional. Los análisis basados en la teoría de detección de señales, utilizando A' y BD como medidas de discriminación y sesgo, respectivamente, mostraron una mayor discriminación y un sesgo de respuesta más conservador para las imágenes agradables y las desactivadoras en comparación con las desagradables y las activadoras. Estos resultados proporcionan nueva evidencia con respecto al sesgo de reconocimiento inducido por la emoción en el rendimiento de memoria a largo plazoS

    Clipping herbaceous vegetation improves early performance of planted seedlings of the Mediterranean shrub Quercus coccifera

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    We tested how the conditions resulting from alternative management strategies addressed to mitigate abiotic and biotic limitations to plant establishment affect the performance of planted Quercus coccifera seedlings. This species is a xerophytic and heliophillous Mediterranean shrub, of interest for the restoration of abandoned farmland. We hypothesised that release from herb competition by clipping would allow Q. coccifera seedlings to cope more efficiently with water shortage by adjusting their mass allocation pattern. We established three environments of herb competition: absence of competition (AC), reduced competition by clipping (RC), and total competition (TC); and applied two irrigation treatments: low and high irrigation. We measured soil moisture at different depths, above- and below-ground herb biomass, and evaluated seedling responses, such as mortality, growth, biomass allocation, and morphological and physiological features. The TC treatment reduced water availability more than the RC treatment, in agreement with the highest water stress of seedlings under TC conditions. Irrigation increased above- and below-ground herb biomass, whereas clipping reduced herb production. Release of herb competition by clipping increased seedling survivorship by one order of magnitude and resulted in a growth rate comparable to the absence of competition. This growth was mostly related to carbon gain allocated to roots. The competition intensity imposed by treatments was related to a parallel reduction in total plant leaf area, biomass allocated to leaves and shoot:root ratio, and an increase in biomass allocated to roots and leaf mass area. The negative effects of herbs on Q. coccifera seedlings seem the result of competition for both water and light, in contrast with previous research with more mesic Quercus species, for which competition is primarily for water. Clipping of herbs is a feasible technique that greatly improved seedling performance, and thus a valuable alternative to herbicide application, common in native plantations aimed at restoring Mediterranean farmland

    EEG activity represents the correctness of perceptual decisions trial-by-trial

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    Performance monitoring is an executive function, which we depend on for detecting and evaluating the consequences of our behavior. Although event related potentials (ERPs) have revealed the existence of differences after correct and incorrect decisions, it is not known whether there is a trial-by-trial representation of the accuracy of the decision. We recorded the electroencephalographic activity (EEG) while participants performed a perceptual discrimination task, with two levels of difficulty, in which they received immediate feedback. Receiver Operating Characteristic (ROC) analyses were used to reveal two components that convey trial-by-trial representations of the correctness of the decisions. Firstly, the performance monitoring-related negativity (PM-N), a negative deflection whose amplitude is higher (more negative) after incorrect trials. Secondly, the performance monitoring-related positivity (PM-P), a positive deflection whose amplitude is higher after incorrect trials. During the time periods corresponding to these components, trials can be accurately categorized as correct or incorrect by looking at the EEG activity; this categorization is more accurate when based on the PM-P. We further show that the difficulty of the discrimination task has a different effect on each component: after easy trials the latency of the PM-N is shorter and the amplitude of the PM-P is higher than after difficult trials. Consistent with previous interpretations of performance-related ERPs, these results suggest a functional differentiation between these components. The PM-N could be related to an automatic error detection system, responsible for fast behavioral corrections of ongoing actions, while the PM-P could reflect the difference between expected and actual outcomes and be related to long-term changes in the decision process

    Batteries and Hydrogen Storage: Technical Analysis and Commercial Revision to Select the Best Option

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    : This paper aims to analyse two energy storage methods—batteries and hydrogen storage technologies—that in some cases are treated as complementary technologies, but in other ones they are considered opposed technologies. A detailed technical description of each technology will allow to understand the evolution of batteries and hydrogen storage technologies: batteries looking for higher energy capacity and lower maintenance, while hydrogen storage technologies pursuing better volumetric and gravimetric densities. Additionally, as energy storage systems, a mathematical model is required to know the state of charge of the system. For this purpose, a mathematical model is proposed for conventional batteries, for compressed hydrogen tanks, for liquid hydrogen storage and for metal hydride tanks, which makes it possible to integrate energy storage systems into management strategies that aim to solve the energy balance in plants based on hybrid energy storage systems. From the technical point of view, most batteries are easier to operate and do not require special operating conditions, while hydrogen storage methods are currently functioning at the two extremes (high temperatures for metal and complex hydrides and low temperatures for liquid hydrogen or physisorption). Additionally, the technical comparison made in this paper also includes research trends and future possibilities in an attempt to help plan future policiesThis research was funded by 1) Spanish Government, grant Ref: PID2020-116616RB-C31, 2) Andalusian Regional Program of R+D+i, grant Ref: P20-00730, and 3) FEDER-University of Huelva 2018, grant Ref: UHU-125931

    The geography of high-value biodiversity areas for terrestrial vertebrates in Western Europe and their coverage by protected area networks

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    We identified high-value biodiversity areas (HVBAs) of terrestrial vertebrates according to a combined index of biodiversity (CBI) for each major taxon and a standardized biodiversity index (SBI) for all taxa in 2195 cells of 50 × 50 km in Western Europe to evaluate whether these areas are included in the current protected area networks. The World Database on Protected Areas (WDPA) and NATURA 2000 protected area network were used to assess the protected area cover in HVBAs. WDPA and NATURA 2000 were geographically quite complementary as WDPA is more densely represented in Central and Northern Europe and NATURA 2000 in the Mediterranean basin. A total of 729 cells were identified as HVBAs. From the total of these HVBA areas, NATURA 2000 network was present in more cells (660) than the WDPA network (584 cells). The sum of protected land percentages across all the HVBA cells was 28.8%. The identified HVBA cells according to the SBI included 603 or 78.2% of all vertebrate species in the study region, whereas the identified HVBA cells according to the SBI for individual taxa included 47 (90.4%) species of amphibians, 79 (74.5%) of reptiles, 417 (88.5%) of birds, and 130 (91.5%) of mammals. However, neither network was present in 7 or 3% of the identified HVBA cells. Thus, we recommend expanding protected areas in Europe to fill this gap and improve coverage of vertebrate species to strengthen biodiversity conservation.This research was supported by the\ud Spanish Ministry of Science and Innovation (grants CGL2010-\ud 18312 to JMRB, and CGL2010-22119 to MAR), and the\ud Madrid Government REMEDINAL project (S2009AMB-1783).\ud M. J. T. Assunc¸ao-Albuquerque was supported by the Brazil- ˜\ud ian Ministry of Education, through CAPES (Coordenac¸ao de ˜\ud Aperfeic¸oamento de Pessoal de N´ıvel Superior) Doctorate\ud scholarship and FSA was supported by BIOTREE-net-project\ud funded by BBVA Foundation. We are indebted to two anonymous\ud reviewers that greatly improved a former version of this manuscrip

    Estallido de la cabeza de cerámica en 1 prótesis total de cadera cementada

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    Se describen las características clínicas y quirúrgicas de 1 caso de estallido de la cabeza de cerámica en 1 artroplastia total de cadera cementada tipo Weller. A los 6 años y 2 meses de su implante requirió nueva intervención quirúrgica para sustituir el componente dañado. Describimos las posibles causas de esta complicación en base a la literatura revisada. El interés del caso estriba en la rareza de su presentación y en la conservación de la prótesis sustituyendo solamente el núcleo cefálico dañado.The clinical and surgical characteristics of one case of breakage of the ceramic head in a Weller cemented hip arthroplasty is described. The patient needed revision surgery six years and two months after the primary arthroplasty in order to replace the demaged component of the implant. The possible reasons of this complication, according to a literature review, are discussed. The interest of this clinical case is the rare of its presentation, its cause and the surgical solution that allow preservation of the prosthesis, doing exclusively the replacement of the damaged part of the implant

    Unexpected homology between inducible cell wall protein QID74 of filamentous fungi and BR3 salivary protein of the insect Chironomus

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    A gene, qid74, of mycoparasitic filamentous fungus Trichoderma harzianum and its allies encodes a cell wall protein that is induced by replacing glucose in the culture medium with chitin (simulated mycoparasitism conditions). Because no trace of this gene can be detected in related species such as Gibberella fujikuroi and Saccharomyces cerevisiae, the qid74 gene appears to have arisen de novo within the genus Trichoderma. Qid74 protein, 687 residues long, is now seen as highly conserved tandem repeats of the 59- residue-long unit. This unit itself, however, may have arisen as tandem repeats of the shorter 13-residue-long basic unit. Within the genus Trichoderma, the amino acid sequence of Qid74 proteins has been conserved in toto. The most striking is the fact that Qid74 shares 25.3% sequence identity with the carboxyl-terminal half of the 1,572-residue-long BR3 protein of the dipteran insect Chironomus tentans. BR3 protein is secreted by the salivary gland of each aquatic larva of Chironomus to form a tube to house itself. Furthermore, the consensus sequence derived from these 59-residue-long repeating units resembles those of epidermal growth factor-like domains found in divergent invertebrate and vertebrate proteins as to the positions of critical cysteine residues and homology of residues surrounding these cysteines.Comisión Interministerial de la Ciencia y la Tecnología BIO 94-0289European Commission TS3-CT92-014
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