Estudio del efecto solvatocrómico en derivados fenólicos naturales

Se describen las características espectrofluorimétricas de dos derivados de quercetina aislados de las hojas deFlaveria bidentis, un derivado de 6-prenilpinocembrina, aislado de las raíces de Dalea elegans y un compuesto deestructura antraquinónica aislado de las hojas de Heterophyllaea pustulata. Todos ellos presentan espectros deabsorción con máximos en la región UV-visible acordes con los grupos cromóforos presentes en su estructura. Loscuatro compuestos estudiados presentan fluorescencia nativa. La posición de los máximos de emisión de fluorescenciase modifica en función del disolvente. Los desplazamientos producidos están relacionados con el diferente gradode solvatación de las moléculas en estado excitado según la polaridad del disolvente. La adición de ácidos mineralesprovoca desplazamientos en los máximos de fluorescencia concordantes con los ya descritos para compuestos deestructura similar. Estas modificaciones espectrales tienen un gran interés analítico desde el punto de vista de laidentificación y caracterización de productos naturales de estructura fenólica

Implementación del simulador Labsag en el programa de Administración de Empresas de la Facultad de Ciencias Administrativas y Contables de la Universidad de la Salle, resultados académicos y beneficios para el desarrollo de competencias cognitivas

En este artículo se resumen el proceso y los resultados de una investigación adelantada con el fin de medir y analizar los resultados académicos y los beneficios para el desarrollo de las competencias cognitivas, mediante la comparación entre la metodología tradicional de enseñanza y una metodología que incluía el uso de un simulador empresarial, en el marco de una asignatura específica escogida para tal fin y que hace parte del programa académico de Administración de Empresas de la Universidad de La Salle, en Bogotá. A lo largo de este artículo se resumen cada una de las etapas adelantadas durante la investigación, apoyando esta metodología con la discusión y la referenciación bibliográfica adecuadas para dar a este producto la robustez necesaria que permita ponerla en discusión ante la comunidad académica. Es así como, luego de hacer una Introducción a la temática y a la situación objeto de estudio, apoyándola con citas sobre la importancia del uso de simuladores en las diferentes actividades académicas para potenciar los alcances de la didáctica tradicional, se hace una descripción detallada del proceso, iniciando con el planteamiento del problema que se aborda, planteando los objetivos, alcance y diseño de la investigación, continuando con la descripción de las herramientas e instrumentos utilizados en el experimento, el sustento estadístico que soportará la validez de las conclusiones que de este proceso se desprendan, el procedimiento, hipótesis. Este artículo finaliza con la discusión de las hipótesis planteadas a la luz de los resultados obtenidos y con las conclusiones que los autores elaboran a partir de los hallazgos

Implementación del simulador Labsag en el programa de Administración de Empresas de la Facultad de Ciencias Administrativas y Contables de la Universidad de la Salle, resultados académicos y beneficios para el desarrollo de competencias cognitivas

En este artículo se resumen el proceso y los resultados de una investigación adelantada con el fin de medir y analizar los resultados académicos y los beneficios para el desarrollo de las competencias cognitivas, mediante la comparación entre la metodología tradicional de enseñanza y una metodología que incluía el uso de un simulador empresarial, en el marco de una asignatura específica escogida para tal fin y que hace parte del programa académico de Administración de Empresas de la Universidad de La Salle, en Bogotá. A lo largo de este artículo se resumen cada una de las etapas adelantadas durante la investigación, apoyando esta metodología con la discusión y la referenciación bibliográfica adecuadas para dar a este producto la robustez necesaria que permita ponerla en discusión ante la comunidad académica. Es así como, luego de hacer una Introducción a la temática y a la situación objeto de estudio, apoyándola con citas sobre la importancia del uso de simuladores en las diferentes actividades académicas para potenciar los alcances de la didáctica tradicional, se hace una descripción detallada del proceso, iniciando con el planteamiento del problema que se aborda, planteando los objetivos, alcance y diseño de la investigación, continuando con la descripción de las herramientas e instrumentos utilizados en el experimento, el sustento estadístico que soportará la validez de las conclusiones que de este proceso se desprendan, el procedimiento, hipótesis. Este artículo finaliza con la discusión de las hipótesis planteadas a la luz de los resultados obtenidos y con las conclusiones que los autores elaboran a partir de los hallazgos

O lúdico no desenvolvimento das potencialidades criativas musicais na primeira infância

This paper presents a vision of the creative musical development in the early childhood (from two to five years old ) departing from the sound exploration to the construction of a children's own musical making, having the playful activity as a structural basis for learning. We understand that the development of creative potential using the sound and the noise as a material of exploration allows the expansion of ideas and musical concepts, providing the formation of active, perceptive, sensitive and insightful subjects for a differentiated and open relationship with the world around the children. Based on the proposals of François Delalande and their interfaces with theorists such as Gilles Deleuze and Johan Huizinga, we propose an approach aimed at an age group which, although foreseen in Delalande's theoretical proposals, this particular age group is not sufficiently addressed in teaching. At the end, we present an experience report conducted in regular school with kindergarten students.Este artigo apresenta uma visão do desenvolvimento criativo musical na primeira infância (de dois a cinco anos) que parte da exploração sonora para a construção de um fazer musical próprio das crianças, tendo o jogo e a atividade lúdica como base estrutural para o aprendizado. Compreendemos que o desenvolvimento das potencialidades criativas utilizando sons e ruídos como matéria de exploração permite a ampliação de ideias e conceitos musicais proporcionando a formação de sujeitos ativos, perceptivos, sensíveis e perspicazes para uma relação diferenciada e aberta com o mundo que lhes cerca. A partir das propostas de François Delalande e suas interfaces com teóricos como Gilles Deleuze e Johan Huizinga, propomos uma abordagem destinada a uma faixa etária que, embora prevista nas propostas teóricas de Delalande, não foi suficientemente abordada no ensino para essa determinada faixa etária. Ao final, apresentamos um relato de uma experiência realizada em escola regular com alunos de Educação Infantil

A black hole detected in the young massive LMC cluster NGC 1850

We report the detection of a black hole (NGC 1850 BH1) in the $\sim$100 Myr-old massive cluster NGC~1850 in the Large Magellanic Cloud. It is in a binary system with a main-sequence turn-off star (4.9 $\pm$ 0.4 M${_\odot}$), which is starting to fill its Roche Lobe and becoming distorted. Using 17 epochs of VLT/MUSE observations we detected radial velocity variations exceeding 300 km/s associated to the target star, linked to the ellipsoidal variations measured by OGLE-IV in the optical bands. Under the assumption of a semi-detached system, the simultaneous modelling of radial velocity and light curves constraints the orbital inclination of the binary to ($38 \pm 2$)$^{\circ}$, resulting in a true mass of the unseen companion of $11.1_{-2.4}^{+2.1}$ $M_{\odot}$. This represents the first direct dynamical detection of a black hole in a young massive cluster, opening up the possibility of studying the initial mass function and the early dynamical evolution of such compact objects in high-density environments

The Milky Way Bulge: Observed properties and a comparison to external galaxies

The Milky Way bulge offers a unique opportunity to investigate in detail the role that different processes such as dynamical instabilities, hierarchical merging, and dissipational collapse may have played in the history of the Galaxy formation and evolution based on its resolved stellar population properties. Large observation programmes and surveys of the bulge are providing for the first time a look into the global view of the Milky Way bulge that can be compared with the bulges of other galaxies, and be used as a template for detailed comparison with models. The Milky Way has been shown to have a box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an additional spheroidal component. In this review we summarise the global chemical abundances, kinematics and structural properties that allow us to disentangle these multiple components and provide constraints to understand their origin. The investigation of both detailed and global properties of the bulge now provide us with the opportunity to characterise the bulge as observed in models, and to place the mixed component bulge scenario in the general context of external galaxies. When writing this review, we considered the perspectives of researchers working with the Milky Way and researchers working with external galaxies. It is an attempt to approach both communities for a fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure

DISEÑO DE UN SISTEMA ABC, ESTUDIO DE TIEMPOS Y MOVIMIENTOS CON SISTEMA DE INCENTIVOS, CELDAS DE MANUFACTURA, MANUAL DE PROCEDIMIENTOS Y KARDEX PARA LA REDUCCIÓN DE COSTOS EN UNA EMPRESA DE DERIVADOS LÁCTEOS

El presente trabajo fue elaborado con el objetivo principal de determinar el impacto del diseño de herramientas en una empresa de derivados lácteos. Para ello, se diseñaron herramientas como sistema ABC, estudio de tiempos y movimientos con sistema de incentivos, celdas de manufactura, manual de procedimientos y Kardex, las cuales previamente pasaron por un análisis de restricciones realistas, siendo estas las mejores alternativas de solución. Seguidamente, se analizó el impacto de cada herramienta sobre los problemas de la empresa; por lo que se diseñaron indicadores e investigaron valores estándar de ingeniería para después, simular las implementaciones de dichas herramientas. Para la desorganización en el almacén, se simuló un valor de 14.29% para A, 38.1% para B y 47.62% para C frente a los estándares de 15%, 30% y 55% respectivamente; en los altos tiempos de procesamiento, se simuló un valor de 7.31% en reducción de tiempos de operaciones e inspecciones frente a un valor estándar de 25%; para la celda de manufactura, se simuló un valor de 13.04% frente al estándar de 0%; para las mermas, se simuló un valor de 11.26 kg al mes frente al estándar de 0 kg, finalmente, para la ruptura de stock, se simuló un valor de 21.53% frente al estándar de 0%. En los resultados, se aprecia un ahorro del 79.15% frente a las pérdidas. Por último, se calculó el impacto económico, un VAN de S/ 3,622, siendo un valor positivo y rentable, un TIR de 6.79%, mayor que la TMAR de 1.53% y un B/C de 1.2

On environment difficulty and discriminating power

The final publication is available at Springer via http://dx.doi.org/10.1007/s10458-014-9257-1This paper presents a way to estimate the difficulty and discriminating power of any task instance. We focus on a very general setting for tasks: interactive (possibly multiagent) environments where an agent acts upon observations and rewards. Instead of analysing the complexity of the environment, the state space or the actions that are performed by the agent, we analyse the performance of a population of agent policies against the task, leading to a distribution that is examined in terms of policy complexity. This distribution is then sliced by the algorithmic complexity of the policy and analysed through several diagrams and indicators. The notion of environment response curve is also introduced, by inverting the performance results into an ability scale. We apply all these concepts, diagrams and indicators to two illustrative problems: a class of agent-populated elementary cellular automata, showing how the difficulty and discriminating power may vary for several environments, and a multiagent system, where agents can become predators or preys, and may need to coordinate. Finally, we discuss how these tools can be applied to characterise (interactive) tasks and (multi-agent) environments. These characterisations can then be used to get more insight about agent performance and to facilitate the development of adaptive tests for the evaluation of agent abilities.I thank the reviewers for their comments, especially those aiming at a clearer connection with the field of multi-agent systems and the suggestion of better approximations for the calculation of the response curves. The implementation of the elementary cellular automata used in the environments is based on the library 'CellularAutomaton' by John Hughes for R [58]. I am grateful to Fernando Soler-Toscano for letting me know about their work [65] on the complexity of 2D objects generated by elementary cellular automata. I would also like to thank David L. Dowe for his comments on a previous version of this paper. This work was supported by the MEC/MINECO projects CONSOLIDER-INGENIO CSD2007-00022 and TIN 2010-21062-C02-02, GVA project PROMETEO/2008/051, the COST - European Cooperation in the field of Scientific and Technical Research IC0801 AT, and the REFRAME project, granted by the European Coordinated Research on Long-term Challenges in Information and Communication Sciences & Technologies ERA-Net (CHIST-ERA), and funded by the Ministerio de Economia y Competitividad in Spain (PCIN-2013-037).José Hernández-Orallo (2015). On environment difficulty and discriminating power. Autonomous Agents and Multi-Agent Systems. 29(3):402-454. https://doi.org/10.1007/s10458-014-9257-1S402454293Anderson, J., Baltes, J., & Cheng, C. T. (2011). 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The ROSAT International X-ray/Optical Survey (RIXOS): source catalogue

We describe the ROSAT International X-ray/Optical Survey (RIXOS), a medium-sensitivity survey and optical identification of X-ray sources discovered in ROSAT high Galactic latitude fields (|b|>28°) and observed with the Position Sensitive Proportional Counter (PSPC) detector. The survey made use of the central 17 arcmin of each ROSAT field. A flux limit of 3×10−14 erg cm−2 s−1 (0.5–2 keV) was adopted for the survey, and a minimum exposure time of 8000 s was required for qualifying ROSAT observations. X-ray sources in the survey are therefore substantially above the detection threshold of each field used, and many contain enough counts to allow the X-ray spectral slope to be estimated. Spectroscopic observations of potential counterparts were obtained of all sources down to the survey limit in 64 fields, totalling a sky area of 15.77 deg2. Positive optical identifications are made for 94 per cent of the 296 sources thus examined. A further 18 fields (4.44 deg2), containing 105 sources above the 3×10−14 erg cm−2 s−1 survey limit, are completely optically identified to a higher flux of 8×10−14 erg cm−2 s−1 (0.5–2 keV). Optical spectroscopic data are supplemented by deep CCD imaging of many sources to reveal the morphology of the optical counterparts, and objects too faint to register on Sky Survey plates. The faintest optical counterparts have R∼22. This paper describes the survey method, and presents a catalogue of the RIXOS sources and their optical identifications. Finding charts based on Sky Survey data are given for each source, supplemented by CCD imaging where necessary

Search for New Physics in Lepton + Photon + X Events with L=305 pb-1 of ppbar Collisions at roots=1.96 TeV

We present results of a search for anomalous production of events containing a charged lepton (either electron or muon) and a photon, both with high transverse momentum, accompanied by additional signatures, X, including missing transverse energy (MET) and additional leptons and photons. We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb-1, a ppbar collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 Lepton+Photon+MET events versus a standard model expectation of 37.3 +- 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 +- 0.7 events (corresponding to a 2.7 sigma effect), is not supported by the new data. In the signature of Multi-Lepton+Photon+X we observe 31 events versus an expectation of 23.0 +- 2.7 events. In this sample we find no events with an extra photon or MET and so find no events like the one ee+gg+MET event observed in Run I.Comment: 7 pages, 3 figures, 1 table. Accepted to PR