Les animations interactives multimédias sont-elles efficaces pour l’apprentissage ?

Avec l’augmentation croissante de l’usage des technologies de l’information et de la communication, l’utilisation d’animations multimédias interactives pour apprendre est de plus en plus fréquente dans différentes disciplines. Motivantes, les animations semblent particulièrement adaptées pour optimiser et concrétiser de façon réaliste la compréhension et l’apprentissage de concepts portant sur des processus dynamiques, des phénomènes complexes et invisibles en sciences et en technologie. Mais ces animations interactives sont-elles vraiment efficaces pour l’apprentissage ? Dans cet article, nous proposons un bilan des recherches réalisées dans le domaine et nous proposons des perspectives pour l’utilisation pédagogique des ces nouveaux formats dynamiques et interactifs de construction des connaissances.Interactive animations become more and more used in learning at school. Attractive, interactive animations seem very suitable to optimize in a realistic way understanding of knowledge about dynamic processes, particularly in science and technology. But can it facilitate learning? This paper proposes a review of the recent research realised in the domain of animation in learning and provides some recommendations for the pedagogical use of these new interactive learning medias.Con el aumento creciente del uso de las TIC, la utilización de animaciones multimedias interactivas para aprender es cada vez más frecuente en diferentes asignaturas. Motivadoras, las animaciones parecen particularmente adaptadas para optimizar y concretizar de manera realista la comprensión y el aprendizaje de conceptos que tratan de procesos dinámicos, fenómenos complejos e invisibles en ciencias y en tecnología. Pero estas animaciones interactivas ¿son verdaderamente eficaces para el aprendizaje? En este artículo, proponemos un balance de las investigaciones realizadas en este tema, después proporcionamos perspectivas para la utilización pedagógica de estos nuevos formatos dinámicos e interactivos de construcción de los conocimientos.Mit der zunehmenden Anwendung des Computers im Unterricht ist die Anwendung interaktiver Multimedia-Vorstellungen zum Lernen in verschiedenen Fächern immer häufiger. Diese Vorstellungen scheinen motivierend und besonders dafür geeignet zu sein, auf realistische Weise das Verständnis und das Lernen von Begriffen zu verbessern und zu konkretisieren, die in Wissenschaft und Technologie dynamische Prozesse, komplexe und unsichtbare Phänomene betreffen. Aber sind diese interaktiven Vorstellungen tatsächlich wirksam zum Lernen? In diesem Awrtikel legen wir einen Überblick über die in diesem Gebiet durchgeführten Forschungsarbeiten vor. Dann bieten wir Perspektiven an zur pädagogischen Benutzung dieser neuen dynamischen und interaktiven Formen der Wissensbildung

Recalage élastique 3-D de surfaces numériques par optimisation génétique

Ce papier présente une méthode de mise en correspondance par transformation géométrique élastique de deux surfaces numériques. La recherche de la transformation géométrique se fait à l'aide d'un algorithme génétique originalement modifié suivi d'une optimisation locale par analyse de la population génétique finale

Blood Signature of Pre-Heart Failure: A Microarrays Study

International audienceBACKGROUND: The preclinical stage of systolic heart failure (HF), known as asymptomatic left ventricular dysfunction (ALVD), is diagnosed only by echocardiography, frequent in the general population and leads to a high risk of developing severe HF. Large scale screening for ALVD is a difficult task and represents a major unmet clinical challenge that requires the determination of ALVD biomarkers. METHODOLOGY/PRINCIPAL FINDINGS: 294 individuals were screened by echocardiography. We identified 9 ALVD cases out of 128 subjects with cardiovascular risk factors. White blood cell gene expression profiling was performed using pangenomic microarrays. Data were analyzed using principal component analysis (PCA) and Significant Analysis of Microarrays (SAM). To build an ALVD classifier model, we used the nearest centroid classification method (NCCM) with the ClaNC software package. Classification performance was determined using the leave-one-out cross-validation method. Blood transcriptome analysis provided a specific molecular signature for ALVD which defined a model based on 7 genes capable of discriminating ALVD cases. Analysis of an ALVD patients validation group demonstrated that these genes are accurate diagnostic predictors for ALVD with 87% accuracy and 100% precision. Furthermore, Receiver Operating Characteristic curves of expression levels confirmed that 6 out of 7 genes discriminate for left ventricular dysfunction classification. CONCLUSIONS/SIGNIFICANCE: These targets could serve to enhance the ability to efficiently detect ALVD by general care practitioners to facilitate preemptive initiation of medical treatment preventing the development of HF

I-SceI-Mediated Double-Strand Break Does Not Increase the Frequency of Homologous Recombination at the Dct Locus in Mouse Embryonic Stem Cells

Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Robust 3-D Elastic Multimodality Image Registration though Genetic Algorithms

This article introduce an original approach to overcome difficulties of multimodality global elastic registration. A structural description of the volumes and in addition a combinatorial optimization process allows us to solve, in a reasonable time, a non-linear problem presenting numerous degrees of freedom. In an other way, our algorithm could be seen as a generalized stochastic Hough transform using the principles of natural selection. Thus, the great originality of our algorithm resides from the particular use of a genetic algorithm (from encoding to the examination of the genetic space of the solutions). After a non-exhaustive state of the art of medical image registration, we will introduce in section III the geometrical consideration of registration we used for our algorithm, then we will focus (section IV) on genetic algorithms and global optimization problems. In section V we will detail our registration procedure and illustrate it with an example in section VI. Eventually we will conclude and give some open issues and future directions. II Medical image registration, a state of the art

Boxe : Médaille sans assurance

Contrairement à Christophe Tiozzo, beaucoup de stars de la boxe mondiale n'ont jamais disputé les jeux Olympiques. Les français engagés à Barcelone : Djamel Lifa, Julien Lorcy, Bruno Wartelle et Patrice Aouissi

Les animations graphiques sont-elles vraiment bénéfiques à la compréhension ?

International audienc

Dopamine beta-hydroxylase deficiency.

Dopamine beta-hydroxylase (DbetaH) deficiency is a very rare form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. The prevalence of DbetaH deficiency is unknown. Only a limited number of cases with this disease have been reported. DbetaH deficiency is mainly characterized by cardiovascular disorders and severe orthostatic hypotension. First symptoms often start during a complicated perinatal period with hypotension, muscle hypotonia, hypothermia and hypoglycemia. Children with DbetaH deficiency exhibit reduced ability to exercise because of blood pressure inadaptation with exertion and syncope. Symptoms usually worsen progressively during late adolescence and early adulthood with severe orthostatic hypotension, eyelid ptosis, nasal stuffiness and sexual disorders. Limitation in standing tolerance, limited ability to exercise and traumatic morbidity related to falls and syncope may represent later evolution. The syndrome is caused by heterogeneous molecular alterations of the DBH gene and is inherited in an autosomal recessive manner. Restoration of plasma noradrenaline to the normal range can be achieved by therapy with the synthetic precursor of noradrenaline, L-threo-dihydroxyphenylserine (DOPS). Oral administration of 100 to 500 mg DOPS, twice or three times daily, increases blood pressure and reverses the orthostatic intolerance

De la polycondensation des oxydes de titane à la génération d'une photobatterie

Depuis plusieurs décennies, la chimie du titane et plus particulièrement celle du dioxyde (TiO2) fait l objet d une grande activité de recherche tant sur le plan fondamental qu appliqué. Elle concerne des domaines allant du pigment blanc des peintures à la photocatalyse (purification de l air et traitement des eaux) et aux activités photoélectrochimiques (cellules solaires à colorant). Parmi toutes les technologies impliquant TiO2, la photoactivité constitue, sans aucun doute, la propriété la plus attractive. Afin d améliorer les propriétés photoactives, il importe de contrôler la polycondensation des oxydes de titane, qui est à l heure actuelle, mal connue. Nous avons, ainsi, montré que l hydrolyse de [Ti8O12(H2O)24]Cl8.HCl.7H2O en milieu aqueux permet d obtenir différentes variétés d oxydes de titane aux morphologies particulières. L hydrolyse de TiOCl2 a, quant à elle, permis la synthèse de sols et gels de titane photosensibles prometteurs pour la réalisation d une photobatterie.Since several decades, the chemistry of titanium and more particularly that of the dioxide (TiO2) is the subject of a great activity of research as well on the fundamental level as applied. It relates to fields going of the white pigment of paintings to the photocatalysis (air cleaning and water treatment) and to the photoelectrochemical activities (solar cells with dye). Among all technologies implying TiO2, the photoactivity constitutes, without any doubt, the most attractive property. In order to improve the photoactives properties, it is important to control the polycondensation of titanium oxides, which remains, at the present time, partially known. We, thus, showed that the hydrolysis of [Ti8O12(H2O)24]Cl8.HCl.7H2O in aqueous medium allows to obtain various varieties of titanium oxides with particular morphologies. The hydrolysis of TiOCl2 has, as for it, allowed the synthesis of titanium sols and gels photosensitive promising for the realization of a photobattery.NANTES-BU Sciences (441092104) / SudocSudocFranceF