Aprendizaje en una tarea de navegación: el papel de la saliencia de pares de puntos de referencia y diferencias de sexo

In two experiments rats were trained to find an invisible platform in the presence of four objects or landmarks which were centred at equal intervals round the edge of the pool. One pair of landmarks had more intrinsic salience than the other pair: The relative proximal from the platform landmarks were those with more intrinsic salience in Experiment 1 and those with less intrinsic salience in Experiment 2. In Experiment 1, the two proximal from the platform and with more intrinsic salience landmarks prevented learning about the two relatively distal from the platform and with less intrinsic salience landmarks. No sex differences were found. In Experiment 2, the two relatively distal and with more intrinsic salience landmarks did not prevent learning about the two proximal but with less intrinsic salience landmarks. No sex differences were found after extended training. These results have implications to understand spatial overshadowing among landmarks.En dos experimentos se entrenó a unas ratas a encontrar una plataforma oculta en presencia de cuatro objetos o puntos de referencia, centrados a inter-valos regulares alrededor del borde de la piscina. Una pareja de puntos de referencia tenía mayor saliencia intrínseca que el otro par: los objetos más próximos de la plataforma eran los que tenían más saliencia intrínseca en el Experimento 1 y los que tenían menos en el Experimento 2. En el Experimento 1, los dos objetos más próximos de la plataforma y con más saliencia intrínseca impidieron el aprendizaje de los dos objetos más alejados de la plataforma y con menos saliencia intrínseca. No se encontraron diferencias de sexo. En el Experimento 2 los dos objetos más alejados de la plataforma y con más saliencia intrínseca no impidieron el aprendizaje de los dos objetos más próximos de la plataforma aunque con menos saliencia intrínseca. No se encontraron diferencias de sexo con un entrenamiento prolongado. Estos resultados tienen implicaciones para entender el ensombrecimiento espacial entre puntos de referencia

Acrometástasis por cáncer de pulmón, diagnóstico simultáneo: a propósito de un caso

Las acrometástasis son hallazgos patológicos malignos muy poco frecuentes. La importancia de estas lesiones reside en que en ocasiones puede ser la primera manifestación de una neoplasia oculta y avanzada y que además por sus características puede confundirse con otras patologías esqueléticas y tratarse de manera inadecuada. Presentamos el caso de una acrometástasis localizada en la falange distal del dedo de una mano en un paciente que previamente no había sido diagnosticado de cáncer de pulmón.Acrometastasis are rare malignant pathological findings. They can sometimes be the first mani - festation of an occult and advanced neoplasia and also they can be confused with other skeletal pathologies and treated inappropriately. We report a case of acrometastasis to the distal phalanx of the finger of the hand in a patient who previously hadn't been diagnosed with lung cancer

Estudio de los parámetros endoscópicos en 48 perros con colitis linfoplasmocitaria

En el presente trabajo se realiza un estudio en cuarenta y ocho perros, sobre los hallazgos endoscópicos que caracterizan a la colitislinfoplasmocitaria. La colitis linfoplasmocitaria es una enfermedad difusa que afecta en mayor o menor grado a todas las porciones del colon. Sin embargo, los resultados del estudio demuestran que el colon descendente y el colon transverso tienen mayor predisposición a presentar úlceras y erosiones, y por tanto, también a la posterior presentación de zonas de fibrosis.In this paper the gross endoscopic appearance of lymphocytic-plasmocytic colitis was studied in forty-eight dogs. Lymphocytic-plasmocytic colitis is a díffuse disease involving all the colonic portions. Nevertheless, the results of our study showed that descending and transverse colon were particularly prone to develop ulcerative and consequent fibrotic lesions

Visible light emitting waveguide on Si chip

This is the author accepted manuscript. The final version is available from SPIE via the DOI in this record.Photonic lab-on-a-chip portable platforms have proved to be very sensitive, rapid in analysis and easy-to-use. However, they still rely on a bulk light source to operate, thus hindering the actual portability and potential for commercial realization. In the present paper we have proposed a design for a light emitting structure that could be easily implemented on chip. The design consists of a Si3N4 strip waveguide on SiO2 substrate, with an active material that emits light as top and lateral cladding. The cross-section of the waveguide was optimised to support both excitation and emission as guided modes, with a high mutual overlap and high confinement to the cladding. This ensures an efficient light emission activation from the cladding and a stable propagation along the waveguide. The proposed structure shows to be operative along the visible range; demonstrated from 400nm to 633nm. The procedure we have followed along this report can be virtually used for designing the cross-section geometry of any strip waveguide system so that the performance is optimised for a given cladding refractive index and emission and excitation wavelengths. In addition we have proposed the use of polymeric quantum dots as the gain material to be used as active cladding. The ease of on-chip integration of this gain material via spin-coating, together with the simplicity of our light emitting waveguide, makes our light source design suitable for large-scale integration on Si chip. Specially, for lab-on-chip applications where multiplexed operation is essential.This research was possible thanks to the Engineering and Physical Sciences Research Council (EPSRC) Centre for Doctoral Training in Electromagnetic Metamateriales at University of Exeter (Grant No. EP/L015331/1) and also via the EPSRC Grant EP/N035569/1

Chiral transition-metal complexes as Brønsted-acid catalysts for the asymmetric Friedel-Crafts hydroxyalkylation of indoles.

The Friedel-Crafts reaction between 3,3,3-trifluoropyruvates and indoles is efficiently catalysed by the iridium complex [(η5-C 5Me5)Ir{(R)-Prophos}(H2O)][SbF 6]2 (1) with up to 84% ee. Experimental data and theoretical calculations support a mechanism involving the Brønsted-acid activation of the pyruvate carbonyl by the protons of the coordinated water molecule in 1. Water is not dissociated during the process and, therefore, the catalytic reaction occurs with no direct interaction between the substrates and the metal. This journal is © the Partner Organisations 2014.The authors acknowledge the Ministerio de Economía y Competitividad (MINECO, Grants CTQ2006-03030/BQU, CTQ2009-10303/BQU, CTQ2011-27033 and Consolider Ingenio 2010 CSD2006-003), Gobierno de Aragón (Grupo Consolidado: Catálisis Homogénea Enantioselectiva), Generalitat de Catalunya (2009SGR0259) and the ICIQ foundation for financial support. A. S. and R. R. acknowledge MINECO for predoctoral fellowships. S. D.-G. acknowledges MINECO for a “Torres Quevedo” contract.Peer Reviewe

Tumor desmoide extraabdominal en rodilla: a propósito de un caso

Los tumores desmoides o fibromatosis agresiva son neoplasias de partes blandas muy poco frecuentes. Son localmente agresivos y recurrentes, aunque carecen de potencial metastásico. La forma extraabdominal es la más infrecuente y asienta habitualmente sobre la cintura pélvica o escapular. Presentamos el caso de una paciente a la que se le diagnosticó un tumor desmoide extraabdominal en la rodilla izquierda que se manifestó inicialmente como una tumoración dolorosa.Desmoid tumours or aggressive fibromatosis are rare neoplasm of soft tissues. They are locally aggressive and recurrent, although they have no metastatic potential. The extra-abdominal appearance is the less common and tumors are frequently located around pelvic or scapular vicinity. We report a case of a patient who suffered an extra-abdominal desmoid tumor in her left knee that arose as a painful bump

Halocyclization of o-(Alkynyl)styrenes. Synthesis of 3-Halo-1H-indenes

Junta de Castilla y Leon (BU021A09 and GR-172), Ministerio de Educacion y Ciencia (MEC), FEDER (CTQ2007-61436/BQU and CTQ2009-09949/BQU), MEC (FPU grant), Juan de la Cierva, Ramon y Cajal and "Young Foreign Researchers" (SB2009-0186) contract

Dynamic necking in materials with strain induced martensitic transformation

This work investigates the interplay between inertia and strain induced martensitic transformation (SIMT) on necking inception and energy absorption in dynamically stretched cylindrical rods. For that task a linear stability technique, derived within a quasi-1D framework and specifically accounting for SIMT, has been developed. Likewise, finite element simulations have been performed, using a specific constitutive equation to consider SIMT. Stability analysis and numerical simulations demonstrate that, at high strain rates, inertia may take the dominant role in stabilizing the material, on top of the transformation hardening effects. Furthermore, under certain loading conditions the martensitic transformation may penalize either ductility or energy absorption capacity.Ministerio de Ciencia e Innovación de España (Projects DPI/2011-24068 and DPI/2011-23191)Publicad