465 research outputs found

    Characterization, passive and active treatment in strabismic amblyopia: a narrative review

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    Strabismic amblyopia is characterized by a distorted spatial perception. In this condition, the neurofunctional disorder occurring during first years of life provoke several monocular and binocular anomalies such as crowding, deficits in the accommodative response, contrast sensitivity, and ocular motility abilities. The inhibition of the binocular function of the brain by the misaligned amblyopic eye induces a binocular imbalance leading to interocular suppression and the reduction or lack of stereoacuity. Passive treatments such as occlusion, optical and/or pharmacological penalization, and Bangerter foils has been demonstrated to be potentially useful treatments for strabismic amblyopia. Recent researches have proved new pharmacological options to improve and maintain visual acuity after occlusion treatment in strabismic amblyopia. Likewise, the active vision therapy, in the last years, is becoming a very relevant therapeutic option in combination with passive treatments, especially during and after monocular therapy, in the attempt of recovering the imbalanced binocular vision.Supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal (RYC-2016-20471)

    A stochastic frontier analysis approach for estimating energy demand and efficiency in the transport sector of Latin America and the Caribbean

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    In this paper, a stochastic frontier analysis approach is applied to estimate energy demand functions in the transport sector. This approach allows us to obtain energy efficiency measures at country level that are a robust alternative to the energy intensity indicators commonly used for international comparisons. A transitive multilateral price index is constructed for aggregating the diverse energy components employed in the sector. Due to the likely unobserved heterogeneity among countries, the use of a random parameters model is proposed to accommodate these differences and to obtain different income and price elasticities per country. The estimated model is compared with alternative approaches of addressing this issue such as latent class, true fixed effects or true random effects models. This study is the first to use a random parameters stochastic frontier approach in the estimation of energy demand functions. The proposed procedure is applied to Latin America and the Caribbean, where the transport sector represents a large share of total energy consumption

    Long-Term Efficacy of the Combination of Active Vision Therapy and Occlusion in Children Strabismic and Anisometropic Amblyopia

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    This retrospective study was conducted to evaluate the efficacy of the combined treatment of occlusion and active vision therapy in a total of 27 amblyopic children, including 14 strabismic and 13 anisometropic cases. For such purpose, changes in distance and near visual acuity as well as in the binocular function was evaluated during a two-year follow-up. In both amblyopia groups, significant improvements were found in distance and near visual acuity in the non-dominant eye (p 3.3 decreased significantly from a baseline value of 64.3% to a two-year follow-up value of 7.1% (p < 0.001). In the anisometropic amblyopia group, this percentage also decreased significantly from a baseline value of 15.4% to a two-year follow-up value of 0.0% (p < 0.001). No recurrences were observed in the anisometropic amblyopia group, whereas recurrence occurred in two cases of the strabismic amblyopia group after finishing the vision rehabilitation process. In conclusion, the combined approach of the treatment evaluated is efficacious for providing an improvement in visual acuity and binocular function in both anisometropic and strabismic amblyopia, which was maintained over time.The author David P Piñero has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC‐2016‐20471

    Análisis de las propuestas de los actores sociales en la recuperación ambiental de la Bahía de Portmán (Región de Murcia). Nuevas perspectivas para un desarrollo sostenible

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    La bahía de Portmán representa uno de los casos de contaminación más importantes en el Mediterráneo. En este trabajo se analizan las posiciones de los diferentes actores sociales, así como las principales fortalezas-debilidades y oportunidades-amenazas que existen en las posibilidades de un planteamiento estratégico de regeneración de la bahía y de la Sierra Minera. Desde una perspectiva socio-ecológica, los análisis realizados ponen de manifiesto las potencialidades para el desarrollo de un turismo ambiental y cultural de este entorno. Sin embargo, las propias debilidades y amenazas podrían superar esas potencialidades si no se lleva a cabo una gestión cuidadosa y una apuesta clara por un modelo de desarrollo sensible en extremo con el patrimonio natural, paisajístico y cultural. Un modelo de turismo ligado a la restauración ambiental y al consenso con los agentes sociales locales debe constituir un elemento básico para la adaptación del territorio como producto turístico, y así debe reflejarse en las futuras decisiones

    The correspondence between long-range and short-range spin glasses

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    We compare the critical behavior of the short-range Ising spin glass with a spin glass with long-range interactions which fall off as a power sigma of the distance. We show that there is a value of sigma of the long-range model for which the critical behavior is very similar to that of the short-range model in four dimensions. We also study a value of sigma for which we find the critical behavior to be compatible with that of the three dimensional model, though we have much less precision than in the four-dimensional case.Comment: 15 pages, 10 figure

    Low-loss inverted taper edge coupler in silicon nitride

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    "This paper is a postprint of a paper submitted to and accepted for publication in IET Optoelectronics and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library"[EN] An inverted lateral taper with one vertical discrete step was designed for a medium confinement silicon nitride waveguide platform in the C-band, as a chip edge coupler, with a predicted insertion loss of 0.58¿dB. The design is supported by an extensive study to evaluate the impact of fabrication process variations on the performance of such a coupler. The device was manufactured and measured, showing an insertion loss of 1.47 dB, which was traced back to fabrication process variations as cross-checked with simulations. To the authors¿ knowledge, the reported edge coupler is the shortest and among the best performing found for silicon nitride platforms.The authors acknowledge financial support through projects TEC2015-69787-REDT PIC4TB, TEC2016-80385-P SINXPECT, TEC2014-54449-C3-1-R, GVA PROMETEO 2017/103, EC H2020-ICT-27-2015 PICs4all CSA 68777.Fernández-Vicente, J.; Baños Lopez, R.; Doménech Gómez, JD.; Domínguez-Horna, C.; Muñoz Muñoz, P. (2019). Low-loss inverted taper edge coupler in silicon nitride. IET Optoelectronics. 13(2):62-66. https://doi.org/10.1049/iet-opt.2018.5065S6266132Marcatili, E. A. J. (1969). Dielectric Rectangular Waveguide and Directional Coupler for Integrated Optics. Bell System Technical Journal, 48(7), 2071-2102. doi:10.1002/j.1538-7305.1969.tb01166.xMiller, S. E. (1969). Integrated Optics: An Introduction. Bell System Technical Journal, 48(7), 2059-2069. doi:10.1002/j.1538-7305.1969.tb01165.xTomlinson, W. J., & Brackett, C. A. (1987). Telecommunications applications of integrated optics and optoelectronics. Proceedings of the IEEE, 75(11), 1512-1523. doi:10.1109/proc.1987.13912Lim, A. E.-J., Junfeng Song, Qing Fang, Chao Li, Xiaoguang Tu, Ning Duan, … Tsung-Yang Liow. (2014). Review of Silicon Photonics Foundry Efforts. IEEE Journal of Selected Topics in Quantum Electronics, 20(4), 405-416. doi:10.1109/jstqe.2013.2293274Smit, M., Leijtens, X., Ambrosius, H., Bente, E., van der Tol, J., Smalbrugge, B., … van Veldhoven, R. (2014). An introduction to InP-based generic integration technology. Semiconductor Science and Technology, 29(8), 083001. doi:10.1088/0268-1242/29/8/083001Taillaert, D., Bogaerts, W., Bienstman, P., Krauss, T. F., Van Daele, P., Moerman, I., … Baets, R. (2002). An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers. IEEE Journal of Quantum Electronics, 38(7), 949-955. doi:10.1109/jqe.2002.1017613Dillon, T., Murakowski, J., Shi, S., & Prather, D. (2008). Fiber-to-waveguide coupler based on the parabolic reflector. Optics Letters, 33(9), 896. doi:10.1364/ol.33.000896Li, H., Cao, Z., Lu, H., & Shen, Q. (2003). Free-space coupling of a light beam into a symmetrical metal-cladding optical waveguide. Applied Physics Letters, 83(14), 2757-2759. doi:10.1063/1.1616205Cardenas, J., Poitras, C. B., Luke, K., Luo, L.-W., Morton, P. A., & Lipson, M. (2014). High Coupling Efficiency Etched Facet Tapers in Silicon Waveguides. IEEE Photonics Technology Letters, 26(23), 2380-2382. doi:10.1109/lpt.2014.2357177Shiraishi, K., Yoda, H., Ohshima, A., Ikedo, H., & Tsai, C. S. (2007). A silicon-based spot-size converter between single-mode fibers and Si-wire waveguides using cascaded tapers. Applied Physics Letters, 91(14), 141120. doi:10.1063/1.2795337Tao, H., Song, J., Fang, Q., Yu, M., Lo, G., & Kwong, D. (2008). Improving coupling efficiency of fiber-waveguide coupling with a double-tip coupler. Optics Express, 16(25), 20803. doi:10.1364/oe.16.020803Muñoz, P., Micó, G., Bru, L., Pastor, D., Pérez, D., Doménech, J., … Domínguez, C. (2017). Silicon Nitride Photonic Integration Platforms for Visible, Near-Infrared and Mid-Infrared Applications. Sensors, 17(9), 2088. doi:10.3390/s17092088Papes, M., Cheben, P., Benedikovic, D., Schmid, J. H., Pond, J., Halir, R., … Vašinek, V. (2016). Fiber-chip edge coupler with large mode size for silicon photonic wire waveguides. Optics Express, 24(5), 5026. doi:10.1364/oe.24.005026Cheben, P., Schmid, J. H., Wang, S., Xu, D.-X., Vachon, M., Janz, S., … Picard, M.-J. (2015). Broadband polarization independent nanophotonic coupler for silicon waveguides with ultra-high efficiency. Optics Express, 23(17), 22553. doi:10.1364/oe.23.022553Shani, Y., Henry, C. H., Kistler, R. C., Orlowsky, K. J., & Ackerman, D. A. (1989). Efficient coupling of a semiconductor laser to an optical fiber by means of a tapered waveguide on silicon. Applied Physics Letters, 55(23), 2389-2391. doi:10.1063/1.102290Zhuang, L., Marpaung, D., Burla, M., Beeker, W., Leinse, A., & Roeloffzen, C. (2011). Low-loss, high-index-contrast Si_3N_4/SiO_2 optical waveguides for optical delay lines in microwave photonics signal processing. Optics Express, 19(23), 23162. doi:10.1364/oe.19.02316

    Multivariable PID Control of a Boiler

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    [EN] This document presents the proposal of the authors to the Control Engineering Benchmark 2016, organized by the Control Engineering Group of the Spanish Committee of Automatica. This is the winner design in the postgraduate category. The benchmark proposes the design of a control system for a boiler, that is modelled by a nonlinear multivariable model with three input, three output, and a measurable disturbance. The control system presented in this report is based on the design of a multivariable proportional-integral-derivative (PID) controller by using convex optimization techniques. In addition, prefilters for the references and for the measurable disturbance have also been proposed. Finally, the performance of the designed control system is shown under the same scenarios to the ones considered in the benchmark.[ES] Este documento presenta la propuesta de los autores para el Concurso en Ingeniería de Control 2016 (CIC2016) organizado por el Grupo Temático de Ingeniería de Control del Comité Español de Automática (CEA). Esta propuesta resultó ganadora en la categoría de estudiantes de máster y postgrado. El concurso consiste en el diseño de un sistema de control para una caldera de vapor, que es modelada por un modelo no lineal multivariable con tres entradas, tres salidas y una perturbación medible. El sistema de control propuesto en este documento se basa en el diseño de un controlador tipo proporcional integrador derivativo (PID) multivariable, mediante técnicas de optimización convexa. Además, se contempla el uso de más grados de libertad mediante el diseño de precompensadores para referencias y para la perturbación medible. Finalmente, se analiza el desempeño del sistema de control diseñado, bajo los escenarios propuestos en el concurso.Este trabajo está financiado por el Ministerio de Economía e Innovación de España (incluyendo cofinanciación FEDER-UE) bajo los proyectos DPI2013-47100-C2-1-P y DPI2016-79278-C2-1-R.Mercader, P.; Cánovas, CD.; Baños, A. (2018). Control PID multivariable de una caldera de vapor. Revista Iberoamericana de Automática e Informática. 16(1):15-25. https://doi.org/10.4995/riai.2018.9034SWORD152516

    Relationship of indicators of ability and experience of military sports skydiving with the psychological state and performance in competition of elite jumpers

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    © 2018: Servicio de Publicaciones de la Universidad de Murcia. This document is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the Accepted version of a Published Work that appeared in final form in Cuadernos de Psicología del Deporte.Se deben considerar múltiples variables cuando se habla de rendimiento deportivo. Entre ellas, la literatura establece la importancia de la psicología y las técnicas indicadoras de la experiencia adquirida en la disciplina. Este estudio pretende establecer la relación entre determinados constructos que definen el perfil psicológico del deportista con indicadores de habilidad en paracaidismo militar. Para ello, se encuestó a 42 saltadores de 40,86 años (±7,35) pertenecientes al ejército español y a la guardia civil durante la celebración del Campeonato Nacional Militar de paracaidismo que se celebra anualmente, para conocer su nivel de optimismo, resiliencia, bienestar psicológico y burnout. Se concluye que los años de experiencia en paracaidismo y el número de saltos, como indicadores de habilidad, deben ser tomados en cuenta con un mayor nivel de concreción y especificidad, ya que ciertas variables psicológicas pueden aumentar o disminuir dependiendo de ellas. Conviene estudiar cada caso en particular para comprender qué puede ocurrir en el estado del paracaidista y desarrollar estrategias para optimizar el rendimiento deportivo.Multiple variables must be considered when talking about sports performance. Among them, the literature estblishes the importance of psychology and indicator techniques of experience acquired in the discipline. This study aims to establish the relationship between certain constructs that define the psychological profile of the athlete with skill indicators in military parachuting. For this, 42 jumpers aged 40.86 years old (±7.35) belonging to the Spanish army and the civil guard during the celebration of the National Military Championship of Skydiving which is held annually surveyed to know their level of optimism, resilience, psychological well-being, and burnout. It is concluded that the years of skydiving experience and the number of jumps, as indicators of skill, must be taken into account with a higher level of concreteness and specificity since certain psychological variables can increase or decrease depending on them. It is convenient to study each case, in particular, to understand what can happen in the state of the parachutist and develop strategies for optimizing sports performance.Múltiplas variáveis devem ser consideradas quando se fala em desempenho desportivo. Eentre eles, a literatura estabelece a importância da psicologia e das técnicas indicadoras da experiência adquirida na disciplina. Este estudo visa estabelecer a relação entre determinados constructos que definem o perfil psicológico do atleta com indicadores de habilidade no paraquedismo militar. Para tal, foram inquiridos 42 saltadores com 40,86 anos (±7,35) pertencentes ao exército espanhol e à guarda civil durante a celebração do Campeonato Nacional Militar de paraquedismo que se realiza anualmente para conhecer o seu nível de optimismo, resiliência, bem-estar psicológico e esgotamento. Conclui-se que os anos de experiência em paraquedismo e o número de saltos, como indicadores de habilidade, devem ser levados em consideração com maior grau de especificidade, pois certas variáveis psicológicas podem aumentar ou diminuir. É conveniente estudar cada caso em articular para entender o que pode acontecer no estado do paraquedista e desenvolver estratégias para otimizar o desempenho esportivo
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