Impact de l'usage des TICE sur la diversification des rôles et compétences de l'enseignant de langue : typologie d'usages et modifications du profil de l'enseignant à Grenoble Universités

Dans un contexte universitaire o\uf9 les technologies sont de plus en plus pl\ue9biscit\ue9es aussi bien par l\u2019institution que les apprenants, et o\uf9 leur usage ne rel\ue8ve pas toujours d\u2019un souhait d\u2019innovation p\ue9dagogique (Galisson, 2004), il devient difficile en tant qu\u2019enseignant de feindre l\u2019indiff\ue9rence devant l\u2019injonction\ua0: \uab\ua0il faut utiliser les technologies\ua0\ubb.\ua0Le triangle didactique se transforme alors en triangle des Bermudes, dans lequel de nombreux enseignants de langue voient leur r\uf4le s\u2019inverser, parce qu'ils se retrouvent alors dans la position de devoir apprendre \ue0 utiliser des supports, des outils, des ressources qu\u2019ils ne ma\ueetrisent pas. Les r\ue9serves \ue9mises par le praticien, dans certains cas \ue0 juste titre, ne lui sont h\ue9las d\u2019aucun secours. Nous verrons en premier lieu que les usages des technologies d\ue9terminent la nature et l\u2019int\ue9r\ueat des nouveaux r\uf4les que les enseignants de langues sont susceptibles d\u2019assumer \ue0 diff\ue9rents degr\ue9s d\u2019usage des technologies. Nous nous attacherons ensuite \ue0 d\ue9crire, en fonction des usages, les nouveaux r\uf4les que les enseignants de langue peuvent \ueatre amen\ue9s \ue0 endosser dans le cadre d\u2019un recours aux technologies raisonnable et raisonn\ue9. Il s\u2019agira dans un troisi\ue8me temps, de mettre en \ue9vidence les comp\ue9tences \ue0 acqu\ue9rir et les moyens mis \ue0 la disposition des praticiens pour leur permettre d\u2019assumer leurs nouveaux r\uf4les

Médiatisation de l'événement scientifique sur internet : les concepts d'affordance et de technologie intellectuelle

Cet article entend apporter des éléments de définition du colloque en sciences humaines en tant qu’événement scientifique. Pour ce faire, nous nous appuyons sur un corpus constitué de supports Internet utilisés pour médiatiser le présent colloque « Langages, Discours, Evénements » et le colloque « Epal : Echanger et Apprendre en Ligne ». Nous essaierons de décrire la plurimodalité des supports de diffusion en réseau, qui permet aux acteurs de la communauté scientifique d'optimiser le rayonnement et l'audience du colloque en tant qu'événement. Nous partons de l'hypothèse selon laquelle la médiatisation de l'événement scientifique peut contribuer à son succès et à sa pérennité. Sur le plan théorique, nous recourons à deux concepts, le concept d’affordance (Gibson, 1977 ; Norman, 1999) et le concept de technologie intellectuelle (Robert, 2000). En premier lieu, nous nous attacherons à définir le colloque en tant qu'événement scientifique. Nous mettrons ensuite en évidence, par le biais de notre corpus, les affordances des différents supports de communication utilisés pour, d'une part annoncer le colloque, inciter la communauté à y participer et d'autre part, dans le cas du colloque EPAL, pour archiver les savoirs échangés. Enfin, après avoir dégagé les limites du concept d’affordance, nous examinerons l’apport complémentaire du concept de technologie intellectuelle

Dynamic of a lacustrine sedimentary system during late rifting at the Cretaceous‐Palaeocene transition: Example of the Yacoraite Formation, Salta Basin, Argentina

The architecture of lacustrine systems is the result of the complex interaction between tectonics, climate and environmental parameters, and constitute the main forcing parameters on the lake dynamics. Field analogue studies have been performed to better assess such interactions, and their impact on the facies distribution and the stratigraphic architecture of lacustrine systems. The Yacoraite Formation (Late Cretaceous/Early Palaeocene), deposited during the sag phase of the Salta rift basin in Argentina, is exposed in world-class outcrops that allowed the dynamics of this lacustrine system to be studied through facies analysis and stratigraphic evolution. On the scale of the Alemania-Met\ue1n-El Rey Basin, the Yacoraite Formation is organized with a siliciclastic-dominated margin to the west, and a carbonate-dominated margin to the east. The Yacoraite can be subdivided into four main \u2018mid-term\u2019 sequences and further subdivided into \u2018short-term\u2019 sequences recording high frequency climate fluctuations. Furthermore, the depositional profiles and identified system tracts have been grouped into two end-members at basin scale: (a) a balanced \u2018perennial\u2019 depositional system for the lower part of the Yacoraite Formation and (b) a highly alternating \u2018ephemeral\u2019 depositional system for the upper part of the Yacoraite Formation. The transition from a perennial system to an ephemeral system indicates a change in the sedimentary dynamics of the basin, which was probably linked with the Cretaceous/Tertiary boundary that induced a temporary shutdown of carbonate production and an increase in siliciclastic supply

Role of PTX3 in Cystic Fibrosis-associated infections

PTX3, a soluble innate immunity receptor, binds to selected microbes and facilitates their clearance by phagocytes. PTX3 selectively binds to Pseudomonas aeruginosa and Aspergillus fumigatus, two microorganisms frequently colonizing the airways of patients with cystic fibrosis (CF), and sometimes causing true respiratory infections. PTX3 -/- mice are sensitive to A. fumigatus infection, highlighting the role of this protein in the protection against this pathogen. We thus hypothesized that PTX3 could be altered in CF patients and that this could be responsible, at least in part, to their susceptibility to some opportunistic pathogens. Serum and sputum samples from 30 CF patients (20 adults and 15 children) and 7 patients with chronic obstructive pulmonary disease (COPD) as the control group were analyzed for PTX3 expression and integrity by ELISA and Western-blotting, respectively. The role of endogenous or microbial proteases on recombinant human PTX3 was also analyzed. Results showed that PTX3 level was increased in CF and COPD serum, highlighting their infectious/inflammatory status, while, in contrast, PTX3 concentration was lower or undetectable in CF sputum than in COPD. Western-blotting showed that PTX3 is degraded in sputum samples from most of CF patients, but not in clinical specimens from COPD patients. The degradation of PTX3 was shown to be mediated by serine proteases. More precisely, both the neutrophil elastase and the alkaline proteinase from A. fumigatus have the ability to degrade in vitro PTX3. This study which shows that PTX3 is degraded in respiratory secretions from CF patients, provide new insights into the pathogenesis of microbial colonization of the airways and respiratory infections in CF patients, since degradation of PTX3 could be responsible, at least in part, for the sensitivity of CF patients to some opportunistic infections

Functional Principles of Posterior Septal Inputs to the Medial Habenula.

The medial habenula (MHb) is an epithalamic hub contributing to expression and extinction of aversive states by bridging forebrain areas and midbrain monoaminergic centers. Although contradictory information exists regarding their synaptic properties, the physiology of the excitatory inputs to the MHb from the posterior septum remains elusive. Here, combining optogenetics-based mapping with ex vivo and in vivo physiology, we examine the synaptic properties of posterior septal afferents to the MHb and how they influence behavior. We demonstrate that MHb cells receive sparse inputs producing purely glutamatergic responses via calcium-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), heterotrimeric GluN2A-GluN2B-GluN1 N-methyl-D-aspartate (NMDA) receptors, and inhibitory group II metabotropic glutamate receptors. We describe the complex integration dynamics of these components by MHb cells. Finally, we combine ex vivo data with realistic afferent firing patterns recorded in vivo to demonstrate that efficient optogenetic septal stimulation in the MHb induces anxiolysis and promotes locomotion, contributing long-awaited evidence in favor of the importance of this septo-habenular pathway

Comparative Study of Different Memetic Algorithm Configurations for the Cyclic Bandwidth Sum Problem

The Cyclic Bandwidth Sum Problem (CBSP) is an NP-Hard Graph Embedding Problem which aims to embed a simple, finite graph (the guest) into a cycle graph of the same order (the host) while minimizing the sum of cyclic distances in the host between guest’s adjacent nodes. This paper presents preliminary results of our research on the design of a Memetic Algorithm (MA) able to solve the CBSP. A total of 24 MA versions, induced by all possible combinations of four selection schemes, two operators for recombination and three for mutation, were tested over a set of 25 representative graphs. Results compared with respect to the state-of-the-art top algorithm showed that all the tested MA versions were able to consistently improve its results and give us some insights on the suitability of the tested operators

Epigenetic Silencing of Host Cell Defense Genes Enhances Intracellular Survival of the Rickettsial Pathogen Anaplasma phagocytophilum

Intracellular bacteria have evolved mechanisms that promote survival within hostile host environments, often resulting in functional dysregulation and disease. Using the Anaplasma phagocytophilum–infected granulocyte model, we establish a link between host chromatin modifications, defense gene transcription and intracellular bacterial infection. Infection of THP-1 cells with A. phagocytophilum led to silencing of host defense gene expression. Histone deacetylase 1 (HDAC1) expression, activity and binding to the defense gene promoters significantly increased during infection, which resulted in decreased histone H3 acetylation in infected cells. HDAC1 overexpression enhanced infection, whereas pharmacologic and siRNA HDAC1 inhibition significantly decreased bacterial load. HDAC2 does not seem to be involved, since HDAC2 silencing by siRNA had no effect on A. phagocytophilum intracellular propagation. These data indicate that HDAC up-regulation and epigenetic silencing of host cell defense genes is required for A. phagocytophilum infection. Bacterial epigenetic regulation of host cell gene transcription could be a general mechanism that enhances intracellular pathogen survival while altering cell function and promoting disease

Cooperation between Engulfment Receptors: The Case of ABCA1 and MEGF10

The engulfment of dying cells is a specialized form of phagocytosis that is extremely conserved across evolution. In the worm, it is genetically controlled by two parallel pathways, which are only partially reconstituted in mammals. We focused on the recapitulation of the CED-1 defined pathway in mammalian systems. We first explored and validated MEGF10, a novel receptor bearing striking structural similarities to CED-1, as a bona fide functional ortholog in mammals and hence progressed toward the analysis of molecular interactions along the corresponding pathway. We ascertained that, in a system of forced expression by transfection, MEGF10 function can be modulated by the ATP binding cassette transporter ABCA1, ortholog to CED-7. Indeed, the coexpression of either a functional or a mutant ABCA1 exerted a transdominant positive or negative modulation on the MEGF10-dependent engulfment. The combined use of biochemical and biophysical approaches indicated that this functional cooperation relies on the alternate association of these receptors with a common partner, endogenously expressed in our cell system. We provide the first working model structuring in mammals the CED-1 dependent pathway

Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea

Observing, modelling and understanding the climate-scale variability of the deep water formation (DWF) in the North-Western Mediterranean Sea remains today very challenging. In this study, we first characterize the interannual variability of this phenomenon by a thorough reanalysis of observations in order to establish reference time series. These quantitative indicators include 31 observed years for the yearly maximum mixed layer depth over the period 1980–2013 and a detailed multi-indicator description of the period 2007–2013. Then a 1980–2013 hindcast simulation is performed with a fully-coupled regional climate system model including the high-resolution representation of the regional atmosphere, ocean, land-surface and rivers. The simulation reproduces quantitatively well the mean behaviour and the large interannual variability of the DWF phenomenon. The model shows convection deeper than 1000 m in 2/3 of the modelled winters, a mean DWF rate equal to 0.35 Sv with maximum values of 1.7 (resp. 1.6) Sv in 2013 (resp. 2005). Using the model results, the winter-integrated buoyancy loss over the Gulf of Lions is identified as the primary driving factor of the DWF interannual variability and explains, alone, around 50 % of its variance. It is itself explained by the occurrence of few stormy days during winter. At daily scale, the Atlantic ridge weather regime is identified as favourable to strong buoyancy losses and therefore DWF, whereas the positive phase of the North Atlantic oscillation is unfavourable. The driving role of the vertical stratification in autumn, a measure of the water column inhibition to mixing, has also been analyzed. Combining both driving factors allows to explain more than 70 % of the interannual variance of the phenomenon and in particular the occurrence of the five strongest convective years of the model (1981, 1999, 2005, 2009, 2013). The model simulates qualitatively well the trends in the deep waters (warming, saltening, increase in the dense water volume, increase in the bottom water density) despite an underestimation of the salinity and density trends. These deep trends come from a heat and salt accumulation during the 1980s and the 1990s in the surface and intermediate layers of the Gulf of Lions before being transferred stepwise towards the deep layers when very convective years occur in 1999 and later. The salinity increase in the near Atlantic Ocean surface layers seems to be the external forcing that finally leads to these deep trends. In the future, our results may allow to better understand the behaviour of the DWF phenomenon in Mediterranean Sea simulations in hindcast, forecast, reanalysis or future climate change scenario modes. The robustness of the obtained results must be however confirmed in multi-model studies