560 research outputs found

    Diferenciación de clases de ocupación del suelo según su multiangularidad

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    Desde los años 70 se conoce que la reflectancia de las distintas ocupaciones del suelo varía según los ángulos de observación e iluminación, es decir, las cubiertas son anisotrópicas. Por tanto, la geometría de captación es un condicionante importante a tener en cuenta a la hora de analizar las imágenes captadas, pero al mismo tiempo se podría aprovechar lo que tal anisotropía nos infiere. A este respecto, existen varios trabajos que hablan de la capacidad de estimar características estructurales de la vegetación y caracterizar distintas ocupaciones del suelo, utilizando variables multiangulares. El objetivo del presente trabajo es evaluar la posibilidad en primera instancia, de poder diferenciar distintas ocupaciones del suelo a partir de la información multiangular que nos proporciona el sensor Multi Angle Spectro Radiometer (MISR) a bordo del satélite TERRA.Para ello se ha trabajado con el producto elaborado MISR L2 Land Surface de 1.1 km de pixel, que proporciona los parámetros ρ, Θ y k para cuatro bandas, azul, verde, rojo e infrarrojo cercano, del modelo RPV, un modelo semiempírico de factor de reflectancia bidireccional (BRF). Los datos utilizados son de fecha 21/7/2005, para píxeles puros de CORINE Land Cover 2006 de la España peninsular. Los resultados muestran que las clases agrícolas tienen medias significativamente más bajas para el parámetro ρ y más altas para los parámetros Θ y k que las clases forestales para todas las bandas. Tales resultados invitan a pensar que la multiangularidad puede ayudar a la hora de mejorar las clasificaciones de imágenes y determinar estructuras en las ocupaciones del suelo

    Mixed Early and Late-Type Properties in the Bar of NGC 6221: Evidence for Evolution along the Hubble Sequence?

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    Rotation curves and velocity dispersion profiles are presented for both the stellar and gaseous components along five different position angles (P.A.=5, 50, 95, 125 and 155 degrees) of the nearby barred spiral NGC 6221. The observed kinematics extends out to about 80" from the nucleus. Narrow and broad-band imaging is also presented. The radial profiles of the fluxes ratio [NII]/Halpha reveal the presence of a ring-like structure of ionized gas, with a radius of about 9" and a deprojected circular velocity of about 280 km/s. The analysis of the dynamics of the bar indicates this ring is related to the presence of an inner Lindblad resonance (ILR) at 1.3 kpc. NGC6221 is found to exhibit intermediate properties between those of the early-type barred galaxies: the presence of a gaseous ring at an ILR, the bar edge located between the ILR's and the corotation radius beyond the steep rising portion of the rotation curve, the dust-lane pattern, and those of the late-type galaxies: an almost exponential surface brightness profile, the presence of Halpha regions along all the bar, the spiral-arm pattern. It is consistent with scenarios of bar-induced evolution from later to earlier-type galaxies.Comment: 1 File ds7406.tar.gz which contains: one latex file (ds7406.tex), and 10 encsulated postscript figures (ds7406f**.eps). To be compiled with aa-l latex2e macro style. To be published in A&A Sup. Serie

    Modelos de decisión : problemas de aplicación

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    El objetivo de este material es apoyar el estudio de los estudiantes de Modelos de Decisión en el proceso de formulación y solución de problemas de los temas que se dictan en la materia. Para cada una de las unidades se proponen problemas de diferente nivel de dificultad con el propósito de fortalecer habilidades para el planteamiento adecuado del modelo matemático del problema, el uso de software para obtener su solución, el análisis e interpretación de los resulta¬dos y la posterior comunicación escrita de las conclusiones y recomendaciones. Entre los numerosos aplicativos desarrollados para resolver los problemas de la ciencia de la administración, hemos optado por utilizar la planilla de cálculo Excel, dada su facilidad de acceso y el extendido uso en el ámbito profesional. A los efectos de guiar a los estudiantes para su aplicación a la solución de problemas de programación lineal, se incluye un instructivo de su manejo.Fil: Funes, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina.Fil: Guevel, Hernán P.. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina

    A NOVEL FUSION 5'AFF3/3'BCL2 ORIGINATED FROM A t(2;18)(Q11.2-Q21.33) TRANSLOCATION IN FOLLICULAR LYMPHOMA

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    Follicular lymphoma is the second most frequent type of non-Hodgkin's lymphoma in adults. The basic molecular defect consists of the t(14;18)(q32;q21) translocation, juxtaposing the B-cell lymphoma protein 2 gene BCL2 to the immunoglobulin heavy chain locus IGH@, and leading to the antiapoptotic BCL2 protein overproduction. Variations in the t(14;18) are rare and can be classified into two categories: (i) simple variants, involving chromosomes 18 and 2, or 22, in which the fusion partner of BCL2 is the light-chain IGK@ or IGL@; (ii) complex variant translocations occurring among chromosomes 14, 18 and other chromosomes. We report a follicular lymphoma case showing BCL2 overexpression, detected by immunohistochemistry and real-time quantitative PCR, consequently to the formation of a novel fusion gene between the 5' of the lymphoid nuclear transcriptional activator gene AFF3 at 2q11.2, and the 3' of BCL2. This case shows evidence, for the first time, of BCL2 overexpression consequently to the fusion of BCL2 to a non-IG partner locus

    Logistic Constraints on 3D Termite Construction

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    Abstract. The building behaviour of termites has previously been modelled mathematically in two dimensions. However, physical and logistic constraints were not taken into account in these models. Here, we develop and test a three-dimensional agent-based model of this process that places realistic constraints on the diffusion of pheromones, the movement of termites, and the integrity of the architecture that they construct. The following scenarios are modelled: the use of a pheromone template in the construction of a simple royal chamber, the effect of wind on this process, and the construction of covered pathways. We consider the role of the third dimension and the effect of logistic constraints on termite behaviour and, reciprocally, the structures that they create. For instance, when agents find it difficult to reach some elevated or exterior areas of the growing structure, building proceeds at a reduced rate in these areas, ultimately influencing the range of termite-buildable architectures

    Nitrogen-doped carbon nanodots deposited on titania nanoparticles: unconventional near-infrared active photocatalysts for cancer therapy

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    Cancer represents a major public health issue and a primary cause of death for the mankind and the search for alternative cancer treatments that assist or alleviate the drawbacks of current cancer therapies remains imperative. Nanocatalytic medicine represents a new discipline that aims at exploiting the unique response of heterogeneous catalysts exposed to unconventional conditions such as those encountered in the tumor microenvironment (TME). Photo-triggered cancer therapies using light-activable catalytic materiales can stimulate and activate multiple biological processes and represent a very promising field of study. Herein, we evaluate the use of carbon nanodots with different composition (CNDs) retrieved by laser pyrolysis as potential near-infrared (NIR) photosensitizers able to activate P25 semiconductor nanostructured photocatalysts. We describe the enhanced photocatalytic response towards glucose conversion and reactive oxygen species (ROS) generation upon irradiation with NIR-LEDs when CNDs doped with heteroatoms were tested. The most active photocatalysts were evaluated in the presence of cancer cells and revealed a promising photodynamic effect under NIR irradiation. This work represents one of the scarce examples of a conventional inorganic photocatalyst containing TiO2 that is translated into a biomedical application with a successful outcome

    Deciphering the Silent Participant. On the Use of Audio-Visual Cues for the Classification of Listener Categories in Group Discussions

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    Estimating a silent participant’s degree of engagement and his role within a group discussion can be challenging, as there are no speech related cues available at the given time. Having this information available, however, can provide important insights into the dynamics of the group as a whole. In this paper, we study the classification of listeners into several categories (attentive listener, side participant and bystander). We devised a thin-sliced perception test where subjects were asked to assess listener roles and engagement levels in 15-second video-clips taken from a corpus of group interviews. Results show that humans are usually able to assess silent participant roles. Using the annotation to identify from a set of multimodal low-level features, such as past speaking activity, backchannels (both visual and verbal), as well as gaze patterns, we could identify the features which are able to distinguish between different listener categories. Moreover, the results show that many of the audio- visual effects observed on listeners in dyadic interactions, also hold for multi-party interactions. A preliminary classifier achieves an accuracy of 64%

    Estudio celular y molecular de los cambios gonadales y espermáticos en conejos hipercolesterolémicos. Análisis del efecto del aceite de oliva

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    La ingesta elevada de grasas de origen animal (“saturadas”) conlleva a un incremento de colesterol en sangre (hipercolesterolemia, HC), y es un factor de riesgo para el desarrollo de enfermedades cardiovasculares
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