1,280 research outputs found

    Evaluation of radiography as a screening method for detection and characterisation of congenital vertebral malformations in dogs

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    Congenital vertebral malformations (CVM) are common in brachycephalic ‘screw-tailed’ dogs; they can be associated with neurological deficits and a genetic predisposition has been suggested. The purpose of this study was to evaluate radiography as a screening method for congenital thoracic vertebral malformations in brachycephalic ‘screw-tailed’ dogs by comparing it with CT. Forty-nine dogs that had both radiographic and CT evaluations of the thoracic vertebral column were included. Three observers retrospectively reviewed the images independently to detect CVMs. When identified, they were classified according to a previously published radiographic classification scheme. A CT consensus was then reached. All observers identified significantly more affected vertebrae when evaluating orthogonal radiographic views compared with lateral views alone; and more affected vertebrae with the CT consensus compared with orthogonal radiographic views. Given the high number of CVMs per dog, the number of dogs classified as being CVM free was not significantly different between CT and radiography. Significantly more midline closure defects were also identified with CT compared with radiography. Malformations classified as symmetrical or ventral hypoplasias on radiography were frequently classified as ventral and medial aplasias on CT images. Our results support that CT is better than radiography for the classification of CVMs and this will be important when further evidence of which are the most clinically relevant CVMs is identified. These findings are of particular importance for designing screening schemes of CVMs that could help selective breeding programmes based on phenotype and future studies

    On the quasinormal modes of the de Sitter spacetime

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    Modifying a method by Horowitz and Hubeny for asymptotically anti-de Sitter black holes, we establish the classical stability of the quasinormal modes of the de Sitter spacetime. Furthermore using a straightforward method we calculate the de Sitter quasinormal frequencies of the gravitational perturbations and discuss some properties of the radial functions of these quasinormal modes.Comment: 11 pages, 4 figure

    Applications of exchange coupled bi-magnetic hard/soft and soft/hard magnetic core/shell nanoparticles

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    The applications of exchange coupled bi-magnetic hard/soft and soft/hard ferromagnetic core/shell nanoparticles are reviewed. After a brief description of the main synthesis approaches and the core/shell structural-morphological characterization, the basic static and dynamic magnetic properties are presented. Five different types of prospective applications, based on diverse patents and research articles, are described: permanent magnets, recording media, microwave absorption, biomedical applications and other applications. Both the advantages of the core/shell morphology and some of the remaining challenges are discussed

    Método de construcción de dígrafos a partir de redes viales reales en mapas digitales con aplicaciones en la búsqueda de rutas óptimas

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    In urban areas, street networks are exposed to road obstructions since some traffic obstacles such as street protest, and traffic congestion are frequent. According to this, drivers are forced to choose alternative routes. Building alternative routes on digital maps represents a solution to these road problems. We determine alternative routes associating graphs to characteristics of real road networks using a API and incorporating optimization algorithms. In this work we propose a method to construct a graph from a zone with traffic blockages considering the network features. With an optimization algorithm (Dijkstra) the alternative routes are defined using digital maps. In addition, a computer program was developed (using Google Maps API) as a tool to create the graph, which is composed of: vertices (intersections) and directional edges (driving direction). This graph is used to establish alternative routes represented as polylines in digital maps.Actualmente las redes viales en zonas urbanas sufren obstrucciones, ya sea por manifestaciones, embotellamientos, u otro tipo de bloqueo, causando el cierre momentáneo o permanente de vías o zonas de tránsito que obligan a conductores a establecer nuevas rutas. Una solución es la creación de rutas alternativas en mapas digitales a partir de dígrafos relacionados con las características de una red vial real, y la aplicación de algoritmos de optimización de rutas. En este trabajo se propone un método para construir dígrafos con una aplicación en la API de Google Maps en la extracción visual de elementos como vértices (intersecciones), aristas (calles) y flechas de sentido (dirección vial), lo que permite la aplicación del algoritmo de Dijkstra en busca de rutas alternativas

    Análisis de los factores formadores y distribución de los suelos en la Sierra del Rayo (Granada)

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    Se realiza un análisis del medio físico: Relieve, Material original y Clima de los suelos que existen en la Sierra del Rayo, así como una cartografía detallada de los mismos, expresando las unidades de suelo que se contemplan en la zona.It has been made an analysis of the Physical medium (relief, parent material and climate) on the soils of Sierra del Rayo (Granada), which its detailed cartography, expressing also the soil units which appear in the zone

    Constant probe orientation for fast contact-based inspection of 3D free-form surfaces using (3+2)-axis inspection machines

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    A new probe optimization method for contact based (3+2)-axis inspection machines is proposed. Given an inspection path of a stylus on a free-form surface, an optimal orientation of the stylus is computed such that (i) the inclination angle of the stylus is within a given angular range with respect to the surface normal, (ii) the motion of the stylus is globally collision free, and (iii) the stylus remains constant in the coordinate system of the measuring machine. The last condition guarantees that the inspection motion requires only the involvement of the three translational axes of the measuring machine. The numerical simulations were validated through physical experiments on a testcase of a tooth of a bevel gear due to the surface complexity and probe accessibility. This optimized method was compared to 3-axis and 5-axis inspection strategies, showing that the fixed (3+2)-axis stylus returns more accurate inspection results compared to the traditional 3-axis approach and similar to 5-axis approach

    Software público, libre, abierto, gratuito, privativo y comercial para la innovación y mejora de la calidad en la docencia, investigación, gestión y asistencia

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    The public free software (now renamed as open software) is the basis of the open source software (OSS) project. This initiative promotes the use of open standards and platform-independent accessibility. Many OSS products are free or low cost, which allows their deployment even in the absence of large economic resources (developing countries, schools, etc.). Besides, their source code can be modified, adapted and optimized by anyone, since it is public. Nevertheless, the OSS may also have drawbacks. Thus, its development may not be as orderly and hierarchical as the privative software is, and may not have an appropriate funding. This may jeopardize the ease of use and coherence of the final product, increasing the transition, training and technical support costs. Besides, it must be taken into account that there is also commercial open software, as well as free privative software. In any case, the excellence of the software may be independent of such variables. Thus, the best strategy is the coexistence and free competition of all kinds of software. This will allow a quality improvement and an innovation enhancement, which will benefit the education, research, management and assistance at the university in particular and at the whole society in general.El software público libre es el fundamento del movimiento de software de fuente abierta (OSS). Éste puede facilitar el uso de estándares abiertos, con accesibilidad independiente de plataforma informática. El bajo coste o gratuidad de muchos productos OSS permite su implantación cuando los recursos económicos son escasos (países en desarrollo, escuelas, etc.). Además, su código se puede modificar, adaptar y mejorar por cualquiera, ya que es público. No obstante, el OSS también puede presentar inconvenientes. Así, su desarrollo puede no ser tan ordenado y jerárquico como el del software privativo y puede no tener una financiación apropiada. De este modo, puede verse comprometida la facilidad de uso y coherencia del producto final. Ello puede incrementar los costes de transición, entrenamiento y soporte técnico. Por otra parte, conviene recordar que existe software libre comercial y software privativo gratuito. En cualquier caso, la excelencia del software puede ser independiente de dichas variables. Por tanto, la mejor estrategia es la coexistencia y libre competencia de todo tipo de software. Así se puede conseguir una mejora de calidad y una potenciación de la innovación, que beneficie a la docencia, investigación, gestión y asistencia universitarias en particular, así como a la sociedad en general

    Photoelectric Properties of MOS-like Structures with Twofold SRO Films

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    AbstractThe optical properties of silicon rich oxide (SRO) have been deeply studied because, between other reasons, they emit an intense photoluminescence (PL) from visible to the near infrared range when excited with UV light. MOS-like structures with SRO film as the active layer have shown an enhanced conductivity under different illumination conditions. In this paper, MOS-like structures with double SRO layer were fabricated in order to have a barrier to isolate the silicon substrate from the active SRO layer. Results show that all structures have a higher current when light shines on them than that obtained under dark conditions. A possible application of this photo-effect can be used to increase the response of photodetectors and silicon solar cells
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