Assistance visuelle des malvoyants par traitement d’images adaptatif

This thesis was done in the context of visual impaired needs analysis with the goal of new augmented reality visual assistance device development. The main goal of this work was the development of assistive device for mobility of visual impaired people by the use real-time image processing algorithm which take into account user needs and the context. The first postulate is the use of residual visual acuity of visual impaired people to allow them to see more information. The second postulate is the use only most useful information for visual impaired people for the understanding of the situation where are they. The first research axis was an analysis of needs of visual impaired to identify visual cues, which one we need to enhance to help them. To do this, I have done an immersive stage into a re-adaptation clinic for visually impaired. I have also done a questionnaire to identify and understand how current products answers partially to their needs. The second research axis was the development of a new image processing to answer identified needs. I have developed an interactive tools that allow the user to select the amount of edges for each situation, context. This detector optimizes its result to provide better results than others state of the art evaluated methods. This tool was evaluated and validated during visual test by visual impaired people. We have demonstrated that edges are one of the most important visual cues for visual impaired people to analyze a scene. The third research axis was the development of the augmented reality system to use my tool in a context of mobility. To do this, I have analyzed the needs of visual impaired people for this type of devices. I have also defined main requirements of the desired device for the processing unit, the camera and the display module. For display module, I have analyzed physiologic needs of visually impaired, in terms of profile, colors, and thickness to answer their needs. I have also developed an image generation model which takes into account many physiologic parameters of each observer to create visually comfortable imagesCette thèse s’inscrit dans le cadre de l’analyse des besoins de personnes malvoyantes dans le but de développer de nouvelles solutions d’assistance visuelle en utilisant le principe de réalité augmentée. Le principal objectif de ces travaux était le développement d’un dispositif d’assistance visuelle pour faciliter la mobilité de personnes malvoyantes grâce à un algorithme qui en temps réel adapte sa réponse en fonction des besoins de l’utilisateur et de la situation dans laquelle il évolue. Le premier postulat de cette thèse est d’utiliser l’acuité résiduelle fonctionnelle des malvoyants afin de leur permettre de percevoir un certain nombre d’informations. Le second postulat est d’utiliser les seules informations pertinentes, utiles à un malvoyant, afin d’améliorer sa perception du monde dans lequel il évolue. Le premier axe de recherche a consisté à analyser les besoins des malvoyants afin de recenser, les indices visuels utiles à rehausser afin d’améliorer la perception des malvoyants. Cette étude a été réalisée en immersion et une enquête précise a été menée auprès de malvoyants. Cette étude permet de mieux comprendre les besoins des malvoyants, les méthodes qu’ils utilisent ainsi que leurs usages des dispositifs actuels. Le deuxième axe de recherche a consisté à concevoir et à mettre en oeuvre un algorithme de traitement d’images répondant aux besoins identifiés. Un outil interactif a été développé qui permet de sélectionner la quantité de contours en fonction de la situation. Ce détecteur de contour optimise sa détection afin d’obtenir des contours plus exploitables pour les malvoyants, comparés aux résultats des autres méthodes de l’état de l’art. Cet outil a été testé et validé auprès d’une population donnée de personnes malvoyantes. Ces tests réalisés sur écran ont démontré que les contours constituent des indices visuels très importants qui peuvent être d’une grande aide dans l’analyse d’une scène. Le troisième axe de travail a consisté au développement d’un système de réalité augmentée permettant d’utiliser ce détecteur de contours dans un contexte de mobilité. L’analyse des besoins des malvoyants vis-à-vis d’un tel dispositif nous a permis de définir les caractéristiques indispensables pour le système de calcul, la caméra et le dispositif d’affichage. Concernant le système d’affichage, l’analyse des besoins des malvoyants en termes de profil, de couleur, de largeur des contours, nous a permis de définir les paramètres nécessaires pour un affichage qui répond à ces besoins. Il a également été pris en compte dans les développements les paramètres physiologiques de chaque observateur afin que les images affichées soient visuellement confortable

An enhanced learning analytics plugin for Moodle: Student engagement and personalised intervention

© ASCILITE 2015 - Australasian Society for Computers in Learning and Tertiary Education, Conference Proceedings.All right reserved. Moodle, an open source Learning Management System (LMS), collects a large amount of data on student interactions within it, including content, assessments, and communication. Some of these data can be used as proxy indicators of student engagement, as well as predictors for performance. However, these data are difficult to interrogate and even more difficult to action from within Moodle. We therefore describe a design-based research narrative to develop an enhanced version of an open source Moodle Engagement Analytics Plugin (MEAP). Working with the needs of unit convenors and student support staff, we sought to improve the available information, the way it is represented, and create affordances for action based on this. The enhanced MEAP (MEAP+) allows analyses of gradebook data, assessment submissions, login metrics, and forum interactions, as well as direct action through personalised emails to students based on these analyses

A learning analytics pilot in Moodle and its impact on developing organisational capacity in a university

© ASCILITE 2017 - Conference Proceedings - 34th International Conference of Innovation, Practice and Research in the Use of Educational Technologies in Tertiary Education.All right reserved. Moodle is used as a learning management system around the world. However, integrated learning analytics solutions for Moodle that provide actionable information and allow teachers to efficiently use it to connect with their students are lacking. The enhanced Moodle Engagement Analytics Plugin (MEAP), presented at ASCILITE2015, enabled teachers to identify and contact students at-risk of not completing their units. Here, we discuss a pilot using MEAP in 36 units at Macquarie University, a metropolitan Australian university. We use existing models for developing organisational capacity in learning analytics and to embed learning analytics into the practice of teaching and learning to discuss a range of issues arising from the pilot. We outline the interaction and interdependency of five stages during the pilot: technology infrastructure, analytics tools and applications; policies, processes, practices and workflows; values and skills; culture and behaviour; and leadership. We conclude that one of the most significant stages is to develop a culture and behaviour around learning analytics

The Ubiquitin Ligase Rsp5p is Required for the Modification and Sorting of Biosynthetic Membrane Proteins into Multivesicular Bodies in S. cerevisiae.

Precursor forms of vacuolar proteins with transmembrane domains, such as the carboxypeptidase S Cps1p and the polyphosphatase Phm5p, are selectively sorted in endosomal compartments to vesicles that invaginate, budding into the lumen of the late endosomes, resulting in the formation of multivesicular bodies (MVBs). These proteins are then delivered to the vacuolar lumen following fusion of the MVBs with the vacuole. The sorting of Cps1p and Phm5p to these structures is mediated by ubiquitylation, and in a doa4 mutant, which has reduced level of free ubiquitin, these proteins are missorted to the vacuolar membrane. A RING-finger ubiquitin ligase Tul1p has been shown to participate to the ubiquitylation of Cps1p and Phm5p. We show here that the HECT-ubiquitin ligase Rsp5p is also required for the ubiquitylation of these proteins, and therefore for their sorting to MVBs. Rsp5p is an essential ubiquitin ligase containing an N-terminal C2 domain followed by three WW domains, and a C-terminal catalytic HECT domain. In cells with low levels of Rsp5p (npi1 mutant cells), vacuolar hydrolases do not reach the vacuolar lumen and are instead missorted to the vacuolar membrane. The C2 domain and the second WW domain of Rsp5p are important determinants for sorting to MVBs. Removal of the Bul proteins, two components of the Rsp5p ubiquitin ligase complex, also impairs the sorting of these proteins, but to a lesser extent. Ubiquitylation of Cps1p was strongly reduced in the npi1 mutant strain and ubiquitylation was completely abolished in the npi1 tul1 double mutant. These data demonstrate that Rsp5p plays a novel and key role in intracellular trafficking, and extend the currently very short list of substrates ubiquitylated in vivo by several different ubiquitin ligases acting cooperatively

Analogies of painting and the "pecio" as a literary genre

[EN] We can find interesting analogies between the ¿pecios¿ or short texts of Rafael Sánchez Ferlosio and a certain figurative painting, both in the concept and in the gestation and plastic production of an idea. In both cases this genre explores the provisional and fragmentary, the emotion before the demonstration, the doubt before the answer.[ES] Podemos encontrar interesantes analogías entre los ¿pecios¿ o textos breves de Rafael Sánchez Ferlosio y cierta pintura de actitud figurativa, tanto en el concepto como en la gestación y producción plástica de una idea. En ambos casos este género explora lo provisional y fragmentario, la emoción antes que la demostración, la duda antes que la respuesta.Mestre-Froissard, J. (2018). Analogías de la pintura y el "pecio" como género literario. Revista Sonda: investigación y docencia en artes y letras. 7(7):339-360. http://hdl.handle.net/10251/123284S3393607

The vacuolar proton-ATPase plays a major role in several membrane-bounded organelles in Paramecium

The vacuolar proton-ATPase (V-ATPase) is a multisubunit enzyme complex that is able to transfer protons over membranes against an electrochemical potential under ATP hydrolysis. The enzyme consists of two subcomplexes: V0, which is membrane embedded; and V1, which is cytosolic. V0 was also reported to be involved in fusion of vacuoles in yeast. We identified six genes encoding c-subunits (proteolipids) of V0 and two genes encoding F-subunits of V1 and studied the role of the V-ATPase in trafficking in Paramecium. Green fluorescent protein (GFP) fusion proteins allowed a clear subcellular localization of c- and F-subunits in the contractile vacuole complex of the osmoregulatory system and in food vacuoles. Several other organelles were also detected, in particular dense core secretory granules (trichocysts). The functional significance of the V-ATPase in Paramecium was investigated by RNA interference (RNAi), using a recently developed feeding method. A novel strategy was used to block the expression of all six c- or both F-subunits simultaneously. The V-ATPase was found to be crucial for osmoregulation, the phagocytotic pathway and the biogenesis of dense core secretory granules. No evidence was found supporting participation of V0 in membrane fusion

Heterologous expression of a plant uracil transporter in yeast: improvement of plasma membrane targeting in mutants of the Rsp5p ubiquitin protein ligase.

Plasma membrane proteins involved in transport processes play a crucial role in cell physiology. On account of these properties, these molecules are ideal targets for development of new therapeutic and agronomic agents. However, these proteins are of low abundance, which limits their study. Although yeast seems ideal for expressing heterologous transporters, plasma membrane proteins are often retained in intracellular compartments. We tried to find yeast mutants potentially able to improve functional expression of a whole set of heterologous transporters. We focused on Arabidopsis thaliana ureide transporter 1 (AtUPS1), previously cloned by functional complementation in yeast. Tagged versions of AtUPS1 remain mostly trapped in the endoplasmic reticulum and were able to reach slowly the plasma membrane. In contrast, untagged AtUPS1 is rapidly delivered to plasma membrane, where it remains in stable form. Tagged and untagged versions of AtUPS1 were expressed in cells deficient in the ubiquitin ligase Rsp5p, involved in various stages of the intracellular trafficking of membrane-bound proteins. rsp5 mutants displayed further plasma membrane stabilization of untagged AtUPS1, and improved steady state amounts of tagged versions of AtUPS1. rsp5 cells are thus powerful tools to solve the many problems inherent in heterologous expression of membrane proteins in yeast, including ER retention

Intervención pictórica a partir de una imagen audiovisual en movimiento

La pintura es una actividad intelectual que emplea en muchos casos acciones automáticas y decisiones muy intuitivas. El azar, el accidente plástico, la sensibilidad y las destrezas técnicas o el propio bagaje de cada autor será determinante en la eficaz ejecución de una pintura. La compleja observación del entorno y la influencia del contexto nos obligan a ser selectivos, a combinar y asociar referentes de muy distinta naturaleza. En este artículo vamos a desviar nuestra atención hacia ese momento más irreflexivo, y ver de qué modo influye como estrategia de renovación formal. Comprobaremos como pueden llegan a conciliarse dos medios de representación distintos; uno técnico y digital en movimiento: el documento audiovisual; con otro estático más tradicional y plástico: la pintura. Mientras que la mirada, nuestra actitud más reflexiva, escoge el documento más adecuado a nuestras inquietudes; la visión se muestra selectiva y funciona por estímulos. El color, la forma, el ritmo, etc, pueden determinar la acción que vamos a llevar a cabo. Basándonos en la experiencia y obra reciente del artista español Ángel Vergara (Mieres, 1953) realizaremos mediante la pintura, capturas y apropiación de fragmentos de color e imagen directamente durante la observación de una reproducción audiovisual. Esta práctica nos permite trabajar un modelo de apropiacionismo no icónico, estableciendo vínculos entre la pintura tradicional y el medio técnico audiovisual.Mestre Froissard, JR.; Aldás Ruiz, J. (2016). Intervención pictórica a partir de una imagen audiovisual en movimiento. http://hdl.handle.net/10251/68309DE

Apropiación y transferencia de una imagen al soporte pictórico

A traves de este artículo podemos realizar y poner en práctica el modo en que una imagen de naturaleza mediática, publicada en: revistas, catalogos, interenet, etc., puede pasar a formar parte de una composición pictórica mediante un proceso de apropiación y transferencia.Mestre Froissard, JR.; Aldás Ruiz, J. (2013). Apropiación y transferencia de una imagen al soporte pictórico. http://hdl.handle.net/10251/2941