687 research outputs found
Estado actual y perspectivas de las bibliotecas digitales latinas
En este trabajo, se hace una revisión de las bibliotecas electrónicas disponibles para profesionales de la Filología latina. Se parte de la base de que el uso de las Tecno- logías de la Información y las Comunicaciones (TIC) no puede ser considerado ajeno a nuestro normal desempeño, pero tampoco una moda más. Las herramientas deben servir para algo concreto, de donde que la evaluación de su utilidad sea un elemento básico del trabajo de cualquier campo científico. Tras una reflexión inicial acerca del concepto y lí- mites de las bibliotecas electrónicas, se hace un repaso por las principales, atendiendo so- bre todo a su facilidad de uso y a la utilidad de los materiales que proporciona
Technology Assessment in Software Development Projects Using a System Dynamics Approach: A Case of Application Frameworks
Photodynamic Inactivation of Pseudomonas aeruginosa by PHEMA Films Loaded with Rose Bengal: Potentiation Effect of Potassium Iodide
Four formulations have been used to produce different poly(2-hydroxyethyl methacrylate) (PHEMA) thin films, containing singlet oxygen photosensitizer Rose Bengal (RB). The polymers have been characterized employing Thermogravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and UV-vis Absorption Spectroscopy. When irradiated with white light (400–700 nm) films generated singlet oxygen (1O2), as demonstrated by the reactivity with 1O2 trap 9,10-dimethylanthracene (DMA). Material with the highest RB loading (polymer A4, 835 nmol RB/g polymer) was able to perform up to ten cycles of DMA oxygenation reactions at high conversion rates (ca. 90%). Polymer A4 was also able to produce the complete eradication of a Pseudomonas aeruginosa planktonic suspension of 8 log10 CFU/mL, when irradiated with white light (total dose 72 J/cm2). The antimicrobial photodynamic effect was remarkably enhanced by adding potassium iodide (100 mM). In such conditions the complete bacterial reduction occurred with a total light dose of 24 J/cm2. Triiodide anion (I3−) generation was confirmed by UV-vis absorption spectroscopy. This species was detected inside the PHEMA films after irradiation and at concentrations ca. 1 M. The generation of this species and its retention in the matrix imparts long-lasting bactericidal effects to the RB@PHEMA polymeric hydrogels. The polymers here described could find potential applications in the medical context, when optimized for their use in everyday objects, helping to prevent bacterial contagion by contact with surfaces
Non-cooperative identification of civil aircraft using a generalised mutual subspace method
The subspace-based methods are effectively applied to classify sets of feature vectors by modelling them as
subspaces. However, their application to the field of non-cooperative target identification of flying aircraft is barely seen in the literature. In these methods, setting the subspace dimensionality is always an issue. Here, it is demonstrated that a modified mutual subspace method, which uses softweights to set the importance of each subspace basis, is a promising classifier for identifying sets of range profiles coming from real in-flight targets with no need to set the subspace dimensionality in advance. The assembly of a recognition database is also a challenging task.
In this study, this database comprises predicted range profiles coming from electromagnetic simulations. Even though the predicted and actual profiles differ, the high recognition rates achieved reveal that the algorithm might be a good candidate for its application in an operational target recognition system
Chronic Vitamin D Intoxication in Captive Iberian Lynx (Lynx pardinus)
To document the biochemical and pathologic features of vitamin D intoxication in lynx and
to characterize mineral metabolism in healthy lynx, blood samples were obtained from 40
captive lynx that had been receiving excessive (approximately 30 times the recommended
dose) vitamin D3 in the diet, and from 29 healthy free ranging lynx. Tissue samples (kidney,
stomach, lung, heart and aorta) were collected from 13 captive lynx that died as a result of
renal disease and from 3 controls. Vitamin D intoxication resulted in renal failure in most
lynx (n = 28), and widespread extraskeletal calcification was most severe in the kidneys and
less prominent in cardiovascular tissues. Blood minerals and calciotropic hormones in
healthy lynx were similar to values reported in domestic cats except for calcitriol which was
higher in healthy lynx. Changes in mineral metabolism after vitamin D intoxication included
hypercalcemia (12.0 ± 0.3 mg/dL), hyperphosphatemia (6.3 ± 0.4 mg/dL), increased plasma
calcidiol (381.5 ± 28.2 ng/mL) and decreased plasma parathyroid hormone (1.2 ± 0.7 pg/
mL). Hypercalcemia and, particularly, hyperphosphatemia were of lower magnitude that
what has been previously reported in the course of vitamin D intoxication in other species.
However, extraskeletal calcifications were severe. The data suggest that lynx are sensitive
to excessive vitamin D and extreme care should be taken when supplementing this vitamin
in captive lynx diets
Sustainability improvement in complex systems composed of products and services
Purpose: A wide number of research efforts have been carried out over the last decades to assess and improve system sustainability. Different methods and tools are increasingly implemented in product systems; nevertheless its application to services and other systems, in which products and services are combined, is rather limited. In this work, an approach to improve the sustainability of systems composed of products and services (P + S systems) is proposed and implemented in two case studies. Methods: The sustainability improvement of P + S systems is addressed integrating different methods and approaches. The flows between system approach is used to identify links between all systems involved. The life cycle sustainability assessment (LCSA) method is applied to simultaneously evaluate environmental, economic and social aspects of sustainability with a life cycle perspective. In addition, sustainable design principles are taken into account to propose effective improvement strategies. The systematic development of four phases is required to carry out the integration of these approaches: (i) identification of links between involved systems; (ii) sustainability assessment of the P + S system; (iii) application of sustainability strategies; and (iv) sustainability results comparison. Results and discussion: Two different P + S systems are analysed. First, sustainability improvements in the service provided by a clothing boutique are proposed, taking into account that the store where the service is developed and the clothes acquired by the service provider are product systems involved in the service operation. Next, the sustainability of an itinerary exhibition is investigated. Products required for the exhibition space layout as well as the service used to transport all materials between different locations are taken into account. In each case, sustainability indicators obtained in both initial and alternative systems are compared, and variations detected due to strategies applied are analysed. Conclusions: Sustainability of P + S systems is evaluated using a set of quantitative indicators, the relative incidence of each system is determined and more sustainable alternatives are projected. Thus, this research supposes an advance towards the sustainable design of complex systems composed of products and services, since effects due to the interconnection between systems are studied and criteria to carry out sustainability-oriented decision making are provided. © 2021, The Author(s)
Non-cooperative target identification based on singular value decomposition
Non-Cooperative Target Identification based on High Resolution Range Profiles is a key research domain in the Defense industry. In this paper a method based on the application of Singular Value Decomposition to a matrix of range profiles is defined. The decomposition is applied to reduce dimensionality and to accomplish recognition in the transformed domain. So as to confirm the feasibility of the methodology, identification experiments of profiles coming from electromagnetic
simulations are conducted, revealing promising results
Study of Uncertainty in Noise Mapping
Noise mapping is a complex process requiring a large amount of data from different sources, which are not always available. In the process, there are many factors involving simplifications, approaches and deviations that contribute to the final uncertainty of the result. An error in the final result of the noise map causes an incorrect amount of exposed population, as well as the design and implementation of inadequate or wrong noise action plans. The uncertainty analysis in the creation of noise maps is therefore a key tool to design noise action plans. However, up to now, there are only guides giving an approximate range of possible contribution to the uncertainty depending on the quality of input data. The present paper analyses the contributions to the total uncertainty of a noise map, proposing a methodology to quantify it. After analyzing the sources that contribute to the overall system uncertainty, a method to quantify the expanded uncertainty properly is proposed, through an analytical calculation and experimental determination. Thus, a specific value of the uncertainty of a map can be calculated avoiding approximations and range values
La plataforma siette una herramienta para el aprendizaje de la botánica forestal
El avance tecnológico está incorporando nuevas herramientas de aprendizaje para complementar el estudio y realizar prácticas de autoevaluación de valor formativo, ya que mediante el ejercicio de evaluación el estudiante puede reflexionar sobre su progreso y dirigir mejor su esfuerzo en el estudio. En este marco la plataforma SIETTE es un sistema web que permite la creación y mantenimiento de bancos de preguntas, y realización de tests, que implementa la Teoría Clásica de Test (CTT), Teoría de Respuesta al Ítem (TRI), permite realizar Tests Adaptativos Informatizados (TAI), y puede usarse como herramienta para el aprendizaje colaborativo. Siette puede usarse como módulo de evaluación de un Sistema Tutor Inteligente (STI) o conectado a una Plataforma de Teleeducación (LMS) como Moodle. Siette implementa muchas otras opciones para la realización de prácticas de reconocimiento, repaso, y evaluación. Esta comunicación presenta los resultados de varios años de trabajo con esta herramienta, las diversas experiencias de formación y evaluación de conocimientos sobre Botánica Forestal. Se han definido más de 2500 preguntas, la mayoría basadas en imágenes y realizado mas de 4300 sesiones de evaluación en la Escuela Universitaria de Ingeniería Técnica Forestal de la Universidad Politécnica de Madrid en colaboración con la Universidad de Málaga
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