2,944 research outputs found
La contaminación atmosférica del transporte urbano en Arequipa : un enfoque sectorial
En Arequipa, el crecimiento de la motorización y la urbanización durante las últimas décadas se ha desarrollado con poca preocupación por los efectos en la salud y los problemas ambientales. En los últimos años, la contaminación ambiental se ha convertido en un problema de los medios de comunicación y del interés público en general, debido al aumento de las molestias causadas por la contaminación atmosférica del sector transporte, en el que el transporte público urbano tiene un gran impacto.This study has analysed the atmospheric pollution from urban transport and the different aspects that influence it. Automotive emissions are the major source of air pollution in the city. The increase in particular paratransit system and car ownership and usage has resulted in high traffic volumes and road congestion in the city centre, main corridors and avenues with environmental and health effects. This is aggravated by lack of clear legislation and regulations, inadequate public transportation planning and management, and overlapping institutions.Programa de Educación en Gestión Urbana para el Perú (PEGUP) / NUFFIC - (The Dutch organisation for internationalisation in education - The Netherlands.Tesi
Un Método de Perturbaciones Especiales en la Dinámica de Tethers
En la simulación dinámica de tethers se usan "bead models" que discretizan el cable mediante "cuentas" distribuidas en toda su longitud y cuya evolución temporal se aborda numéricamente. Dependiendo de la precisión deseada, el número de partículas oscila, típicamente, entre 5 y 50. En ocasiones la simulación se extiende sobre tiempos largos (varios años). La complejidad de las interacciones del cable con el medio espacial exige optimizar, en tiempo y precisión, los propagadores que constituyen el núcleo central del proceso. El "método de perturbaciones especiales" objeto de este artículo conjuga sencillez de programación, rapidez y precisión, y permite propagar la órbita de cualquier partícula material. Describe la evolución de ciertos "elementos orbitales", constantes del problema "no perturbado}"que, en el "perturbado", evolucionan en la escala de tiempos impuesta por la perturbación. Puede usarse con cualquier tipo de órbita, está libre de singularidades asociadas a inclinación y/o excentricidad pequeñas, y el uso de parámetros de Euler le confiere robustez
Event-based Vision for Early Prediction of Manipulation Actions
Neuromorphic visual sensors are artificial retinas that output sequences of
asynchronous events when brightness changes occur in the scene. These sensors
offer many advantages including very high temporal resolution, no motion blur
and smart data compression ideal for real-time processing. In this study, we
introduce an event-based dataset on fine-grained manipulation actions and
perform an experimental study on the use of transformers for action prediction
with events. There is enormous interest in the fields of cognitive robotics and
human-robot interaction on understanding and predicting human actions as early
as possible. Early prediction allows anticipating complex stages for planning,
enabling effective and real-time interaction. Our Transformer network uses
events to predict manipulation actions as they occur, using online inference.
The model succeeds at predicting actions early on, building up confidence over
time and achieving state-of-the-art classification. Moreover, the
attention-based transformer architecture allows us to study the role of the
spatio-temporal patterns selected by the model. Our experiments show that the
Transformer network captures action dynamic features outperforming video-based
approaches and succeeding with scenarios where the differences between actions
lie in very subtle cues. Finally, we release the new event dataset, which is
the first in the literature for manipulation action recognition. Code will be
available at https://github.com/DaniDeniz/EventVisionTransformer.Comment: 15 pages, 9 figure
Mania as Debut of Cushing's Syndrome
This is a case of a patient affected by Cushing syndrome that was admitted at the hospital due to hormonal problems. He had presented psychiatric symptoms that were mistakenly considered not directly connected to the pathology causing the clinical condition, but a mere psychological reaction to it
Formulación del problema de la optimización multiobjetivo del confort en edificación sostenible
3D reconstruction of magnetization from dichroic soft X-ray transmission tomography
The development of magnetic nanostructures for applications in spintronics requires methods capable of visualizing their magnetization. Soft X‐ray magnetic imaging combined with circular magnetic dichroism allows nanostructures up to 100–300 nm in thickness to be probed with resolutions of 20–40 nm. Here a new iterative tomographic reconstruction method to extract the three‐dimensional magnetization configuration from tomographic projections is presented. The vector field is reconstructed by using a modified algebraic reconstruction approach based on solving a set of linear equations in an iterative manner. The application of this method is illustrated with two examples (magnetic nano‐disc and micro‐square heterostructure) along with comparison of error in reconstructions, and convergence of the algorithm
The atf2 gene is involved in triacylglycerol biosynthesis and accumulation in the oleaginous Rhodococcus opacus PD630
Rhodococcus opacus PD630 is an oleaginous bacterium able to accumulate large amounts of triacylglycerols (TAG) in different carbon sources. The last reaction for TAG biosynthesis is catalyzed by the bifunctional wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) enzymes encoded by atf genes. R. opacus PD630 possesses at least 17 putative atf homologous genes in its genome, but only atf1 and atf2 exhibited a significant DGAT activity when expressed in E. coli, as revealed in a previous study. The contribution of atf1 gene to TAG accumulation by strain PD630 has been demonstrated previously, although additional Atfs may also contribute to lipid accumulation, since the atf1-disrupted mutant is still able to produce significant amounts of TAG (Alvarez et al. 2008). In this study, we investigated the in vivo role of atf2 gene in TAG accumulation by R.opacus PD630 by using different genetic strategies. The atf2-disrupted mutant exhibited a decrease in TAG accumulation (up to 25-30 %, w/w) and an approximately tenfold increase in glycogen formation in comparison with the wild type strain. Surprisingly, in contrast to the single mutants, a double mutant generated by the disruption of atf1 and atf2 genes, only showed a very low effect in TAG and in glycogen accumulation under lipid storage conditions. Over-expression of atf1 and atf2 genes in strain PD630 promoted an increase of approximately 10 % (w/w) in TAG accumulation; while heterologous expression of atf2 gene in Mycobacterium smegmatis caused an increase in TAG accumulation during cultivation in nitrogen-rich media. This study demonstrated that, in addition to atf1 gene, atf2 is actively involved in TAG accumulation by the oleaginous R. opacus PD630.Fil: Hernández, Martín Alejandro. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arabolaza, Ana Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Rodriguez, Eduardo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gramajo, Hugo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Dismorfia muscular y uso de sustancias ergogénicas. Una revisión sistemática.
El uso de sustancias ergogénicas (USE) no se restringe a la consecución de un mayor desempeño atlético, actualmente también es una conducta de cambio corporal, vía el desarrollo muscular; no obstante, poco se sabe de la relación entre dismorfia muscular (DM) y USE. Por tanto se realizó una revisión sistemática de los estudios empíricos que, durante la última década (2004-2014), la han examinado. De entrada, destaca el hecho de que, de los 22 artículos analizados, solo en 13 se explicita este interés. Además, aunque los datos documentados delinean algunas vertientes relevantes, como la existencia de una alta concomitancia (60-90%) de DM y USE, en general las evidencias son aún incipientes e inciertas, principalmente debido a la gran disparidad metodológica entre estudios y, particularmente, en cuanto a los indicadores, los parámetros y las medidas que, en el contexto de la DM, se han venido empleando para evaluar USE
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