1,281 research outputs found

    La Mezquita-Catedral de Córdoba en la Literatura de Viajes del siglo XIX

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    Con el título La Mezquita-Catedral de Córdoba en la literatura de viajes del siglo XIX, nuestra Tesis Doctoral pretende estudiar una etapa histórica de la que apenas hay nada escrito. La ciudad de Córdoba siempre ha estado muy eclipsada por su esplendor cuando esta fue capital del Califato de Al Ándalus y muchas de las investigaciones se han centrado en esa etapa que, sin duda, marcó un punto de inflexión en la historia de la capital cordobesa. Sin embargo, pocos historiadores se han preocupado de estudiar otras etapas históricas tan interesantes y cruciales como es el caso del siglo XIX. Así, hemos querido contextualizar nuestra investigación con un amplio capítulo titulado Córdoba en los libros de viajes del siglo XIX, donde realizamos un pormenorizado estudio sobre las numerosas visitas que, tanto viajeros extranjeros como españoles, realizaron a la capital cordobesa a lo largo de la centuria decimonónica, ya que la ciudad de Córdoba se convirtió en un mito de Al Ándalus en pleno siglo XIX. De esta forma, hemos analizado los diarios de viajes de los más importantes viajeros españoles, británicos, franceses e incluso americanos que visitaron la capital cordobesa y hemos reflejado cuáles fueron sus impresiones, algunas más idealizadas y otras más realistas. Córdoba era una ciudad decadente en pleno siglo XIX, con un casco histórico en situación de semiabandono, debido a las desamortizaciones, a la invasión francesa, así como a algunas catástrofes naturales que se sucedieron en esa época como los continuos desbordamientos del río Guadalquivir y a otros eventos históricos. No obstante, esta situación de abandono y ruina hizo que Córdoba se convirtiera en un prototipo de ciudad romántica, donde por sus calles cobraban protagonismo la melancolía y la nostalgia y de ahí, su fuerte atractivo para viajeros románticos decimonónicos

    Impact of stress, fear and anxiety on the nociceptive responses of larval zebrafish

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    Both adult and larval zebrafish have been demonstrated to show behavioural responses to noxious stimulation but also to potentially stress- and fear or anxiety- eliciting situations. The pain or nociceptive response can be altered and modulated by these situations in adult fish through a mechanism called stress-induced analgesia. However, this phenomenon has not been described in larval fish yet. Therefore, this study explores the behavioural changes in larval zebrafish after noxious stimulation and exposure to challenges that can trigger a stress, fear or anxiety reaction. Five-day post fertilization zebrafish were exposed to either a stressor (air emersion), a predatory fear cue (alarm substance) or an anxiogenic (caffeine) alone or prior to immersion in acetic acid 0.1%. Pre- and post-stimulation behaviour (swimming velocity and time spent active) was recorded using a novel tracking software in 25 fish at once. Results show that larvae reduced both velocity and activity after exposure to the air emersion and alarm substance challenges and that these changes were attenuated using etomidate and diazepam, respectively. Exposure to acetic acid decreased velocity and activity as well, whereas air emersion and alarm substance inhibited these responses, showing no differences between pre- and post-stimulation. Therefore, we hypothesize that an antinociceptive mechanism, activated by stress and/or fear, occur in 5dpf zebrafish, which could have prevented the larvae to display the characteristic responses to pain

    Tasa de asimilación neta y rendimiento de girasol en función de urea y urea de liberación lenta

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    El nitrógeno es un nutrimento que incrementa el crecimien - to, la duración del área foliar y la fotosíntesis del cultivo, ca - racterísticas que permiten al girasol ( Helianthus annuus L.) aumentar el rendimiento de semilla por unidad de superficie. El objetivo del presente estudio fue evaluar la tasa de asimi - lación neta, el rendimiento y sus principales componentes en dos cultivares de girasol (Periquero y Victoria) en función de dos tipos de urea (urea común y urea de liberación lenta) y tres dosis de N (40, 80 y 120 kg N ha - 1 ), en tres localidades del Estado de México (Toluca, Balderas y Chalco). El diseño experimental fue bloques completos al azar con arreglo fac - torial. Los 36 tratamientos resultaron de las combinaciones de las tres localidades, los dos cultivares, los dos tipos de urea y los tres niveles de nitrógeno. Los datos se analizaron con ANDEVA y las medias de los tratamientos se compararon con la prueba DSH (p £ 0.05). Para conocer la relación entre el rendimiento de semilla y la tasa de asimilación neta se cal - culó la regresión lineal simple. El análisis de los resultados indicó que en Chalco el girasol rindió (732.0 g m - 2 ) más que Toluca (285.9 g m - 2 ) y Balderas (467.0 g m - 2 ), debido a la mayor tasa de asimilación neta (0.89 g dm - 2 d - 1 ); Victoria, con rendimiento promedio de 508.2 g m - 2 e índice de co - secha de 0.33, fue superior a Periquero en 5.1 % y 11.76 %, respectivamente. Con urea común se alcanzó una producción promedio de grano de 508 g m - 2 , superior en 5.2 % al obte - nido con urea de liberación lenta. La mejor dosis en este es - tudio fue 120 kg N ha - 1 ya que su rendimiento promedio fue 541.5 g m - 2 . Se concluye que la tasa de asimilación neta afectó positivamente el rendimiento de semilla, porque la ecuación de regresión y = 217.8 + 308.2 (x) (r 2 = 0.69**) significa que por cada unidad de incremento en la tasa de asimilación neta, el rendimiento aumenta 308.2 g m - 2

    Reduction in activity by noxious chemical stimulation is ameliorated by immersion in analgesic drugs in zebrafish

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    Research has recently demonstrated that larval zebrafish show similar molecular responses to nociception to those of adults. Our study explored whether unprotected larval zebrafish exhibited altered behaviour after exposure to noxious chemicals and screened a range of analgesic drugs to determine their efficacy to reduce these responses. This approach aimed to validate larval zebrafish as a reliable replacement for adults as well as providing a high-throughput means of analysing behavioural responses. Zebrafish at 5 days postfertilization were exposed to known noxious stimuli: acetic acid (0.01%, 0.1% and 0.25%) and citric acid (0.1%, 1% and 5%). The behavioural response of each was recorded and analysed using novel tracking software that measures time spent active in 25 larvae at one time. Subsequently, the efficacy of aspirin, lidocaine, morphine and flunixin as analgesics after exposure to 0.1% acetic acid was tested. Larvae exposed to 0.1% and 0.25% acetic acid spent less time active, whereas those exposed to 0.01% acetic acid and 0.1–5% citric acid showed an increase in swimming activity. Administration of 2.5 mg l−1 aspirin, 5 mg l−1 lidocaine and 48 mg l−1 morphine prevented the behavioural changes induced by acetic acid. These results suggest that larvae respond to a noxious challenge in a similar way to adult zebrafish and other vertebrates and that the effect of nociception on activity can be ameliorated by using analgesics. Therefore, adopting larval zebrafish could represent a direct replacement of a protected adult fish with a non-protected form in pain- and nociception-related research

    DPDnet: A Robust People Detector using Deep Learning with an Overhead Depth Camera

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    In this paper we propose a method based on deep learning that detects multiple people from a single overhead depth image with high reliability. Our neural network, called DPDnet, is based on two fully-convolutional encoder-decoder neural blocks based on residual layers. The Main Block takes a depth image as input and generates a pixel-wise confidence map, where each detected person in the image is represented by a Gaussian-like distribution. The refinement block combines the depth image and the output from the main block, to refine the confidence map. Both blocks are simultaneously trained end-to-end using depth images and head position labels. The experimental work shows that DPDNet outperforms state-of-the-art methods, with accuracies greater than 99% in three different publicly available datasets, without retraining not fine-tuning. In addition, the computational complexity of our proposal is independent of the number of people in the scene and runs in real time using conventional GPUs

    Fish sentience denial: Muddying the waters

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    Recent empirical studies have reported evidence that many aquatic species, including fish, cephalopods and crustaceans, have the capacity for nociception and pain, and that their welfare should be taken into consideration. Some sceptics, rejecting the precautionary principle, have denied that any study demonstrates pain or other aspects of sentience in fish. This target article discusses some of the scientific shortcomings of these critiques through a detailed analysis of a study exploring nociception and analgesia in larval zebrafish

    Disturbed, diffuse, or just missing? A global study of the H I content of Hickson compact groups

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    Context. Hickson compact groups (HCGs) are dense configurations of four to ten galaxies, whose H I morphology appears to follow an evolutionary sequence of three phases, with gas initially confined to galaxies, then significant amounts spread throughout the intra-group medium, and finally with almost no gas remaining in the galaxies themselves. It has also been suggested that several groups may harbour a diffuse H I component that is resolved out by interferometric observations. Aims. The H I deficiency of HCGs is expected to increase as the H I morphological phase progresses along the evolutionary sequence. If this is the case, H I deficiency would be a rough proxy for the age and evolutionary state of a HCG. We aim to test this hypothesis for the first time using a large sample of HCGs and to investigate the evidence for diffuse H I in HCGs. Methods. We performed a uniform reduction of all publicly available VLA H I observations (38 HCGs) with a purpose-built pipeline that also maximises the reproducibility of this study. The resulting H I data cubes were then analysed with the latest software tools to perform a manual separation of emission features into those belonging to galaxies and those extending into the intra-group medium. We thereby classified the H I morphological phase of each group as well as quantified their H I deficiency compared to galaxies in isolation. Results. We find little evidence that H I deficiency can be used as a proxy for the evolutionary phase of a compact group in either of the first two phases, with the distribution of H I deficiency being consistent in both. However, for the final phase, the distribution clearly shifts to high H I deficiencies, with more than 90% of the expected H I content typically missing. Across all HCGs studied, we identify a few cases where there is strong evidence for a diffuse gas component in the intra-group medium, which might be detectable with improved observations. We also classify a new sub-phase where groups contain a lone H I-bearing galaxy, but are otherwise devoid of gas. Conclusions. The new morphological phase we have identified is likely the result of an evolved, gas-poor group acquiring a new, gas-rich member. The large spread of H I deficiencies in the first two morphological phases suggests that there is a broad range of initial H I content in HCGs, which is perhaps influenced by large-scale environment, and that the timescale for morphological changes is, in general, considerably shorter than the timescale for the destruction or consumption of neutral gas in these systems

    Evolution of compact groups from intermediate to final stages: A case study of the HI content of HCG 16

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    Hickson Compact Group (HCG) 16 is a prototypical compact group of galaxies, apparently in an intermediate stage of evolution, where its galaxies are losing gas to the intra-group medium (IGrM). The wide variety of ongoing process in HCG 16 make it an ideal case study for exploring which processes are likely to dominate the late stages of evolution in compact groups. In order to build a coherent picture of the evolution of this group we make use of the multi-wavelength data available, but focus particularly on HI as a tracer of interactions and evolutionary phase. We reprocess archival VLA L-band data of HCG 16 using the multi-scale CLEAN algorithm to accurately recover diffuse features. Despite the clear disruption of the HI component of HCG 16 we find that it is not globally HI deficient, even though HCG 16a and b have lost the majority of their HI and almost 50% of the group's HI is in the IGrM, including a 160 kpc long tail extending towards the SE. This study indicates that in the recent past (~1 Gyr) galaxies HCG 16a and b likely underwent major interactions that unbound gas without triggering significant star formation. This gas was then swept away by a high speed, close encounter with NGC 848. The starburst events HCG 16c and d have triggered galactic winds which, in the case of HCG 16d, appears to have disrupted its HI reservoir. The tidal features still connected to these galaxies indicate that more HI will soon be lost to the IGrM, while that which remains in the discs will likely be consumed by star formation episodes. This is expected to result in a collection of gas-poor galaxies embedded in a diffuse HI structure, which will gradually be evaporated by the UV background, resembling the final stage of the evolutionary model of compact groups. This work is accompanied by a complete workflow to reproduce the final data products, intended to improve reproducibility. (Abridged)Comment: Accepted for publication in A&A, 35 pages, 18 figure

    Overview of recent TJ-II stellarator results

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    The main results obtained in the TJ-II stellarator in the last two years are reported. The most important topics investigated have been modelling and validation of impurity transport, validation of gyrokinetic simulations, turbulence characterisation, effect of magnetic configuration on transport, fuelling with pellet injection, fast particles and liquid metal plasma facing components. As regards impurity transport research, a number of working lines exploring several recently discovered effects have been developed: the effect of tangential drifts on stellarator neoclassical transport, the impurity flux driven by electric fields tangent to magnetic surfaces and attempts of experimental validation with Doppler reflectometry of the variation of the radial electric field on the flux surface. Concerning gyrokinetic simulations, two validation activities have been performed, the comparison with measurements of zonal flow relaxation in pellet-induced fast transients and the comparison with experimental poloidal variation of fluctuations amplitude. The impact of radial electric fields on turbulence spreading in the edge and scrape-off layer has been also experimentally characterized using a 2D Langmuir probe array. Another remarkable piece of work has been the investigation of the radial propagation of small temperature perturbations using transfer entropy. Research on the physics and modelling of plasma core fuelling with pellet and tracer-encapsulated solid-pellet injection has produced also relevant results. Neutral beam injection driven Alfvénic activity and its possible control by electron cyclotron current drive has been examined as well in TJ-II. Finally, recent results on alternative plasma facing components based on liquid metals are also presentedThis work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under Grant Agreement No. 633053. It has been partially funded by the Ministerio de Ciencia, Inovación y Universidades of Spain under projects ENE2013-48109-P, ENE2015-70142-P and FIS2017-88892-P. It has also received funds from the Spanish Government via mobility grant PRX17/00425. The authors thankfully acknowledge the computer resources at MareNostrum and the technical support provided by the Barcelona S.C. It has been supported as well by The Science and Technology Center in Ukraine (STCU), Project P-507F
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