Estudio sobre los efectos de un tratamiento multimodal (audio-vídeo-texto) sobre la competencia de la comprensión oral de los alumnos de ESO y Bachillerato.

Estudiar y analizar los resultados obtenidos con dos grupos de trabajo utilizando metodologías diferentes para la comprensión oral de la lengua inglesa en alumnos de enseñanza secundaria y Bachillerato. La investigación se ha realizado con dos grupos de tercero de enseñanza secundaria obligatoria del Instituto Infanta Elena de Jumilla (Murcia). Estudio semi experimental de análisis tomando un grupo de control y otro experimental que incluye la aplicación de un tratamiento continuado de exposición al componente oral de la lengua inglesa utilizando materiales audiovisuales. Las variables utilizadas han sido la comprensión oral antes y después del tratamiento y la nota global de inglés del curso anterior. El grupo de control está formado por los alumnos que realizan las pruebas de compresión oral tradicionales y el grupo experimental el sometido a pruebas utilizando medios audiovisuales. El estudio duró un trimestre. Se realizaron cuestionarios KET (Key English Test) a ambos grupos para determinar su nivel inicial en cuanto a aprendizaje en comprensión oral. Se realizó tambien un segundo tipo de cuestionario para conocer la homogeneidad en cuanto a sus conocimientos previos, variables de carácter afectivo y socioeconómico. Estos datos, así como sus calificaciones y expediente académico fueron tratadas con el programa SPSS. También se empleó SACODEYL como interfaz para profesores y alumnos en cuanto al acceso de recursos digitales. Los alumnos que forman parte del grupo experimental obtienen mejores resultados que los del grupo de control. La utilización de material audiovisual mejora la compresión oral de la lengua inglesa .

A formaçao metacognitiva de futuros professores de matemática através da utilizaçao do vídeo. 'La formación metacognitiva de futuros profesores de matemáticas a través de la utilización del vídeo'.

Se sitúa en el contexto del paradigma de investigación sobre el pensamiento del profesor. Se analiza el proceso de autoscopia, si permite desarrollar la capacidad metacognitiva de futuros profesores de matemáticas. Se centra en el estudio de las concepciones manifestadas relativas a cuatro grandes temas relacionados con la futura profesión: matemáticas, enseñanza y aprendizaje, resolución de problemas y perfil resolutor. Esta información incide directamente en el papel del profesor durante el proceso de enseñanza-aprendizaje, en el papel del alumno durante el mismo proceso, en la resolución de problemas en el aula y en el papel del profesor en las actividades de resolución de problemas. Se recurre a un diseño experimental con dos grupos equivalentes para verificar si existe una relación casual entre el uso o no de la autoscopia por medio de la observación de registros de vídeo y transcripciones, y por otro lado la capacidad metacognitiva de los futuros profesores de matemáticas. El estudio se lleva a cabo con 22 futuros profesores de Matemáticas y de Ciencias de la Naturaleza del Segundo Ciclo de Enseñanza Básica de una escuela superior de educación portuguesa durante sus dos últimos años de carrera. Durante el proceso de autoscopia la intervención incidió en la sensibilización de los sujetos acerca de la importancia de varias etapas de resolución de problemas del modelo de Polya y en las categorías metacognitivas del modelo de Lester. Cada subgrupo resolvió un primer problema que servió de pre-test para poder comparar inicialmente a los dos grupos en términos metacognitivos y su resolución grabada en vídeo. De los problemas solucionados se realizó un proceso de autoscopia en base a las cintas de vídeo y sus transcripciones. Por último se compararon las resoluciones escritas con los modelos de resolución elaborados. La relación entre concepciones manifestadas y concepciones activas de los sujetos del estudio no siempre fue convergente. La autoscopia aumento la capacidad metacognitiva de los futuros profesores de Matemáticas. Los sujetos del grupo experimental evidenciaron ser en las resoluciones escritas de los problemas, mejores resolutores que los del grupo de control. El proceso de autoscopia puede estar en la base de las diferencias metacognitivas y de las capacidades manifestadas como resolutores de problemas entre los sujetos del grupo experimental y los del grupo de control.

El uso del vídeo como herramienta de análisis para la formación y mejora de la práctica docente.

Resumen basado en el de la publicación

Reflexiones sobre la utilización del vídeo en estudio de casos.

Resumen tomado de la publicación

El trabajo por proyectos en el aula de ELE : "Vídeo presentación de una ciudad para futuros alumnos Erasmus españoles"

Resumen basado en el de la publicación.

Aprender a enseñar ciencias a través del uso del vídeo en formación inicial

Resumen tomado de la publicación

Classificació i reconeixement de vídeo

El principal objectiu d’aquest projecte és aconseguir classificar diferents vídeos d’esports segons la seva categoria. Els cercadors de text creen un vocabulari segons el significat de les diferents paraules per tal de poder identificar un document. En aquest projecte es va fer el mateix però mitjançant paraules visuals. Per exemple, es van intentar englobar com a una única paraula les diferents rodes que apareixien en els cotxes de rally. A partir de la freqüència amb què apareixien les paraules dels diferents grups dins d’una imatge vàrem crear histogrames de vocabulari que ens permetien tenir una descripció de la imatge. Per classificar un vídeo es van utilitzar els histogrames que descrivien els seus fotogrames. Com que cada histograma es podia considerar un vector de valors enters vàrem optar per utilitzar una màquina classificadora de vectors: una Support vector machine o SVM

Agonist-dependent internalization of D2 receptors: imaging quantification by confocal microscopy

In positron emission tomography and single photon emission computed tomography studies using D2 dopamine (DA) receptor radiotracers, a decrease in radiotracer binding potential (BP) is usually interpreted in terms of increased competition with synaptic DA. However, some data suggest that this signal may also reflect agonist (DA)-induced increases in D2 receptor (D2R) internalization, a process which would presumably also decrease the population of receptors available for binding to hydrophilic radioligands. To advance interpretation of alterations in D2 radiotracer BP, direct methods of assessment of D2R internalization are required. Here, we describe a confocal microscopy-based approach for the quantification of agonist-dependent receptor internalization. The method relies upon double-labeling of the receptors with antibodies directed against intracellular as well as extracellular epitopes. Following agonist stimulation, DA D2R internalization was quantified by differentiating, in optical cell sections, the signal due to the staining of the extracellular from intracellular epitopes of D2Rs. Receptor internalization was increased in the presence of the D2 agonists DA and bromocriptine, but not the D1 agonist SKF38393. Pretreatment with either the D2 antagonist sulpiride, or inhibitors of internalization (phenylarsine oxide and high molarity sucrose), blocked D2-agonist induced receptor internalization, thus validating this method in vitro. This approach therefore provides a direct and streamlined methodology for investigating the pharmacological and mechanistic aspects of D2R internalization, and should inform the interpretation of results from in vivo receptor imaging studies.

Platelet PECAM-1 inhibits thrombus formation in vivo

Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell surface glycoprotein receptor expressed on a range of blood cells, including platelets, and on vascular endothelial cells. PECAM-1 possesses adhesive and signaling properties, the latter being mediated by immunoreceptor tyrosine-based inhibitory motifs present on the cytoplasmic tail of the protein. Recent studies in vitro have demonstrated that PECAM-1 signaling inhibits the aggregation of platelets. In the present study we have used PECAM-1-deficient mice and radiation chimeras to investigate the function of this receptor in the regulation of thrombus formation. Using intravital microscopy and laser-induced injury to cremaster muscle arterioles, we show that thrombi formed in PECAM-1-deficient mice were larger, formed more rapidly than in control mice, and were more stable. Larger thrombi were also formed in control mice that received transplants of PECAM-1-deficient bone marrow, in comparison to mice that received control transplants. A ferric chloride model of thrombosis was used to investigate thrombus formation in carotid arteries. In PECAM-1-deficient mice the time to 75% vessel occlusion was significantly shorter than in control mice. These data provide evidence for the involvement of platelet PECAM-1 in the negative regulation of thrombus formation.

Time course of gag protein assembly in HIV-1-infected cells: a study by immunoelectron microscopy

Recent biochemical studies have identified high molecular complexes of the HIV Gag precursor in the cytosol of infected cells. Using immunoelectron microscopy we studied the time course of the synthesis and assembly of a HIV Gag precursor protein (pr55gag) in Sf9 cells infected with recombinant baculovirus expressing the HIV gag gene. We also immunolabeled for pr55gag human T4 cells acutely or chronically infected with HIV-1. In Sf9 cells, the time course study showed that the first Gag protein appeared in the cytoplasm at 28-30 h p.i. and that budding started 6-8 h later. Colloidal gold particles, used to visualize the Gag protein, were first scattered randomly throughout the cytoplasm, but soon clusters representing 100 to 1000 copies of pr55gag were also observed. By contrast, in cells with budding or released virus-like particles the cytoplasm was virtually free of gold particles while the released virus-like particles were heavily labeled. Statistical analysis showed that between 80 and 90% of the gold particles in the cytoplasm were seen as singles, as doublets, or in small groups of up to five particles probably representing small oligomers. Clusters of gold particles were also observed in acutely infected lymphocytes as well as in multinuclear cells of chronically infected cultures of T4 cells. In a few cases small aggregates of gold particles were found in the nuclei of T4 lymphocytes. These observations suggest that the Gag polyprotein forms small oligomers in the cytoplasm of expressing cells but that assembly into multimeric complexes takes place predominantly at the plasma membrane. Large accumulations of Gag protein in the cytoplasm may represent misfolded molecules destined for degradation.

Crystallization in poly(L-lactide)-b-poly(epsilon-caprolactone) double crystalline diblock copolymers: a study using X-ray scattering, differential scanning calorimetry, and polarized optical microscopy

The crystallization of well-defined poly(L-lactide)-b-poly(epsilon-caprolactone) diblock copolymers, PLLA-b-PCL, was investigated by time-resolved X-ray techniques, polarized optical microscopy (POM), and differential scanning calorimetry (DSC). Two compositions were studied that contained 44 and 60 wt % poly(L-lactide), PLLA (they are referred to as (L44C5614)-C-11 and (L60C409)-C-12, respectively, with the molecular weight of each block in kg/mol as superscript). The copolymers were found to be initially miscible in the melt according to small-angle X-ray scattering measurements (SAXS). Their thermal behavior was also indicative of samples whose crystallization proceeds from a mixed melt. Sequential isothermal crystallization from the melt at 100 degreesC (for 30 min) and then at 30 degreesC (for 15 min) was measured. At 100 degreesC only the PLLA block is capable of crystallization, and its crystallization kinetics was followed by both WAXS and DSC; comparable results were obtained that indicated an instantaneous nucleation with three-dimensional superstructures (Avrami index of approximately 3). The spherulitic nature of the superstructure was confirmed by POM. When the temperature was decreased to 30 degreesC, the PCL block was able to crystallize within the PLLA negative spherulites (with an Avrami index of 2, as opposed to 3 in homo-PCL), and its crystallization rate was much slower than an equivalent homo-PCL. Time-resolved SAXS experiments in (L60C409)-C-12 revealed an initial melt mixed morphology at 165 degreesC that upon cooling transformed into a transient microphase-separated lamellar structure prior to crystallization at 100 degreesC.

Comparative characterisation by atomic force microscopy and ellipsometry of soft and solid thin films

Ellipsometry and atomic force microscopy (AFM) were used to study the film thickness and the surface roughness of both 'soft' and solid thin films. 'Soft' polymer thin films of polystyrene and poly(styrene-ethylene/butylene-styrene) block copolymer were prepared by spin-coating onto planar silicon wafers. Ellipsometric parameters were fitted by the Cauchy approach using a two-layer model with planar boundaries between the layers. The smooth surfaces of the prepared polymer films were confirmed by AFM. There is good agreement between AFM and ellipsometry in the 80-130 nm thickness range. Semiconductor surfaces (Si) obtained by anisotropic chemical etching were investigated as an example of a randomly rough surface. To define roughness parameters by ellipsometry, the top rough layers were treated as thin films according to the Bruggeman effective medium approximation (BEMA). Surface roughness values measured by AFM and ellipsometry show the same tendency of increasing roughness with increased etching time, although AFM results depend on the used window size. The combined use of both methods appears to offer the most comprehensive route to quantitative surface roughness characterisation of solid films. Copyright (c) 2007 John Wiley & Sons, Ltd.

Use of thermography and fibre optics microscopy for the evaluation of railway structures in the Athens Metro in Greece (Invited Paper)

Rolling Contact Fatigue (RCF) is one of the main issues that concern, at least initially, the head of the railway; progressively they can be of very high importance as they can propagate inside the material with the risk of damaging the railway. In this work, two different non-destructive techniques, infrared thermography (IRT) and fibre optics microscopy (FOM), were used in the inspection of railways for the tracing of defects and deterioration signs. In the first instance, two different approaches (dynamic and pulsed thermography) were used, whilst in the case of FOM, microscopic characterisation of the railway heads and classification of the deterioration -- damage on the railways according to the UIC (International Union of Railways) code, took place. Results from both techniques are presented and discussed.