2,913 research outputs found
La motivación del alumnado a través de la satisfacción con la asignatura. Efecto sobre el rendimiento
El alto nivel de absentismo y la falta de motivación de los
alumnos son rasgos característicos de una realidad a la que nos
enfrentamos día a día. Este problema, agudizado por la cada vez
más cercana adaptación al Espacio Europeo de Educación
Superior, provoca la necesidad de que nos replanteemos la
forma de hacer las cosas en nuestra labor como docentes universitarios.
La presente experiencia persigue incrementar el interés
y la implicación del alumnado a través de un aumento de su
grado de satisfacción con la asignatura. Adicionalmente se
pretende comprobar cómo esta circunstancia puede redundar en
una mejora de las calificaciones obtenidas por los alumnos
Algunas soluciones exactas para una ecuación de Klein Gordon
In solving practical problems in science and engineering arises as a direct consequence differential equations that explains the dynamics of the phenomena. Finding exact solutions to this equations provides importan information about the behavior of physical systems. The Lie symmetry method allows tofind invariant solutions under certain groups of transformations for differential equations.This method not very well known and used is of great importance in the scientific community. By this approach it was possible to find several exactinvariant solutions for the Klein Gordon Equation uxx − utt = k(u). A particularcase, The Kolmogorov equation uxx − utt = k1u + k2un was considered.These equations appear in the study of relativistic and quantum physics. The general solutions found, could be used for future explorations on the study for other specific K(u) functions.Al resolver problemas prácticos en ciencia e ingeniería surge como consecuencia directa las ecuaciones diferenciales que explican la dinámica de los fenómenos. Encontrar soluciones exactas a estas ecuaciones proporciona información importante sobre el comportamiento de los sistemas físicos. El método de simetría de Lie permite encontrar soluciones invariantes bajo ciertos grupos de transformaciones para ecuaciones diferenciales. Este método, poco conocido y utilizado, es de gran importancia en la comunidad científica. Mediante este enfoque, fue posible encontrar varias soluciones exactas invariables para la ecuación de Klein Gordon uxx - utt = k (u). Un caso particular, se consideró la ecuación de Kolmogorov uxx - utt = k1u + k2un. Estas ecuaciones aparecen en el estudio de la física relativista y cuántica. Las soluciones generales encontradas podrían utilizarse para futuras exploraciones en el estudio para otras funciones específicas de K (u)
Genética de poblaciones amazónicas: la historia evolutiva del jaguar, ocelote, delfín rosado, mono lanudo y piurí, reconstruida a partir de sus genes
The Amazon has more than the half of the world's biodiversity. Nevertheless, the major fraction of the Amazon species has unknown evolutionary histories. This is also certain for mammals and birds. Population genetics, employing molecular markers and theoretical mathematics models, can reconstruct these evolutionary histories and offer very powerful tools for the application of correct conservation politics. Herein, we show a comparative view of population genetics results obtained for Amazon populations of jaguar, ocelot, pink river dolphin, woolly monkey and wattled curassow and provide recommendation for their biological conservation. Each species showed its own specific evolutionary particularities, characteristics that were not shared by the other species. This finding should be taken into consideration for any effective biological conservation program.
Key words: Amazon, Population genetics, Panthera, Leopardus, Inia, Lagothrix, Crax.El Amazonas contiene más de la mitad de la biodiversidad a escala mundial. Sin embargo, muchas de las especies que alberga, poseen historias evolutivas totalmente desconocidas. Esto incluye el caso de los mamíferos y de las aves. La genética de poblaciones, mediante el uso de marcadores moleculares, modelos y metodologías matemáticas, puede intentar reconstruir esa historia evolutiva y ofrecer herramientas efectivas para la aplicación de políticas correctas de conservación. Se muestra aquí un resumen de los estudios genético realizados en poblaciones amazónicas de jaguar, ocelote, delfín rosado, mono lanudo y piurí y se proponen algunas recomendaciones para su conservación biológica. En cada especie se observaron particularidades evolutivas propias no compartidas por las otras especies. Este hecho debe ser recogido por cualquier programa de conservación que pretenda ser efectivo.
Palabras clave: Amazonas, Genética de poblaciones, Panthera, Leopardus, Inia, Lagothrix, Crax
The Logic behind Feynman's Paths
The classical notions of continuity and mechanical causality are left in
order to refor- mulate the Quantum Theory starting from two principles: I) the
intrinsic randomness of quantum process at microphysical level, II) the
projective representations of sym- metries of the system. The second principle
determines the geometry and then a new logic for describing the history of
events (Feynman's paths) that modifies the rules of classical probabilistic
calculus. The notion of classical trajectory is replaced by a history of
spontaneous, random an discontinuous events. So the theory is reduced to
determin- ing the probability distribution for such histories according with
the symmetries of the system. The representation of the logic in terms of
amplitudes leads to Feynman rules and, alternatively, its representation in
terms of projectors results in the Schwinger trace formula.Comment: 15 pages, contribution to Mario Castagnino Festschrif
Abcg2 transporter affects plasma, milk and tissue levels of meloxicam
https://doi.org/10.1016/j.bcp.2020.113924ATP-binding cassette (ABCG2) is an efflux transporter that extrudes xenotoxins from cells in liver, intestine, mammary gland, brain and other organs, affecting the pharmacokinetics, brain accumulation and
secretion into milk of several compounds, including antitumoral, antimicrobial and anti-inflammatory drugs. The aim of this study was to investigate whether the widely used anti-inflammatory drug meloxicam is
an Abcg2 sustrate, and how this transporter affects its systemic distribution. Using polarized ABCG2-transduced cell lines, we found that meloxicam is efficiently transported by murine Abcg2 and human ABCG2. After oral administration of meloxicam, the area under the plasma concentration-time curve in Abcg2-/- mice was 2-fold higher than in wild type mice (146.06 ± 10.57 μg·h/ml versus 73.80 ± 10.00 μg·h/ml). Differences in meloxicam distribution were reported for several tissues after oral and intravenous administration, with a 20-fold higher concentration in the brain of Abcg2-/- after oral administration.
Meloxicam secretion into milk was also affected by the transporter, with a 2-fold higher milk-to-plasma ratio in wild-type compared with Abcg2-/- lactating female mice after oral and intravenous administration. We conclude that Abcg2 is an important determinant of the plasma and brain distribution of meloxicam and is clearly involved in its secretion into milk.S
Bilevel optimal control of urban traffic-related air pollution by means of Stackelberg strategies
Air contamination and road congestion are two major problems in modern cities. Both are closely related and present the same source: traffic flow. To deal with these problems, governments impose traffic restrictions preventing the entry of vehicles into sensitive areas, with the final goal of decreasing pollution levels. Unfortunately, these restrictions force drivers to look for alternative routes that usually generate traffic congestions, resulting in longer travel times and higher levels of contamination. In this work, blending computational modelling and optimal control of partial differential equations, we formulate and analyse a bilevel optimal control problem with air pollution and drivers’ travel time as objectives and look for optimal solutions in the sense of Stackelberg. In this setting, the leader (local government) implements traffic restrictions meanwhile the follower (drivers set) acts choosing travel preferences against leader constraints. We discretize the problem and propose a numerical algorithm to solve it, combining genetic-elitist algorithms and interior-point methods. Finally, computational results for a realistic case posed in the Guadalajara Metropolitan Area (Mexico) are shown.Sistema Nacional de Investigadores | Ref. SNI-52768Programa para el Desarrollo Profesional Docente | Ref. PRODEP/103.5/16/8066Xunta de Galicia | Ref. ED431C 2018/50
Designing an ecologically optimized road corridor surrounding restricted urban areas: a mathematical methodology
The use of optimization techniques for the optimal design of roads and railways has increased in recent years. The environmental impact of a layout is usually given in terms of the land use where it runs (avoiding some ecologically protected areas), without taking into account air pollution (in these or other sensitive areas) due to vehicular traffic on the road. This work addresses this issue and proposes an automatic method for obtaining a specific corridor (optimal in terms of air pollution), where the economically optimized road must be designed in a later stage. Combining a 1D traffic simulation model with a 2D air pollution model, and using classical techniques for optimal control of partial differential equations, the problem is formulated and solved in the framework of Mixed Integer Nonlinear Programming. The usefulness of this approach is shown in a real case study posed in a region that suffers from serious episodes of environmental pollution, the Guadalajara Metropolitan Area (México)Xunta de Galicia | Ref. ED431C 2018/50Sistema Nacional de Investigadores | Ref. SNI-52768Programa para el Desarrollo Profesional Docente | Ref. PRODEP/103.5/16/806
OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level
Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu
Local Anomalies, Local Equivariant Cohomology and the Variational Bicomplex
The locality conditions for the vanishing of local anomalies in field theory
are shown to admit a geometrical interpretation in terms of local equivariant
cohomology, thus providing a method to deal with the problem of locality in the
geometrical approaches to the study of local anomalies based on the
Atiyah-Singer index theorem. The local cohomology is shown to be related to the
cohomology of jet bundles by means of the variational bicomplex theory. Using
these results and the techniques for the computation of the cohomology of
invariant variational bicomplexes in terms of relative Gel'fand-Fuks cohomology
introduced in [6], we obtain necessary and sufficient conditions for the
cancellation of local gravitational and mixed anomalies.Comment: 36 pages. The paper is divided in two part
- …