Conception, expérimentation et évaluation d’une plate-forme en ligne intégrée dans un dispositif hybride :: analyse de pratique en classe de français du secondaire I et recherche de plus-values sur la motivation et l’apprentissage des élèves

Ce travail s’insère dans le champ de recherche des technologies dans le domaine de l’enseignement. Il propose de décrire et d’évaluer l’utilisation pratique d’un dispositif technologique (une plate-forme en ligne Wordpress) dans une classe de français. Plusieurs méthodes sont utilisées: une ingénierie didactique d’une séquence spécifique et des enquêtes par questionnaire auprès des élèves. Les résultats s’articulent autour de l’identification de plus-values, sur la motivation et l’apprentissage de certains élèves. Les propos de ces derniers illustrent leur usage de la plate-forme et permettent d’évaluer cette dernière selon son utilité, son utilisabilité et son acceptabilité pour une classe du secondaire I

Le choix d’un support papier ou numérique influence-t-il les capacités des apprenants pour l’observation d’une image ?

Les supports de lecture de textes ou d’image ont toujours évolué parallèlement aux progrès technologiques. Cependant, dans le cadre scolaire, l’évolution des supports s’est limitée à l’abandon des instruments de type ardoise à écrire au profit du papier. Les tablettes numériques y trouveraient-elles leur place ? Si elles présentent des atouts financiers et écologiques, leurs performances pédagogiques ne sont pas clairement établies. Des études se sont attardées sur les performances de lecture et de compréhension de texte sur support écran et papier avec des résultats comparables pour les études les plus récentes. Aucune étude ne s’est préoccupée des performances d’observation d’images. Des expériences comparatives d’observation d’images fixes ont donc été réalisées dans le cadre de l’école obligatoire avec une centaine d’élèves. Des expériences basées sur l’observation d’illustrations en couleur et de photographies en noir et blanc sont réalisées, avec la moitié des participants travaillant sur papier et l’autre moitié sur tablette. L’analyse des résultats démontre que la performance moyenne des participants est meilleure sur tablette, à hauteur de 10% de réponses correctes supplémentaires, malgré un environnement non adapté. En outre, si on laisse le choix du support à l’élève en fonction de son estimation de performance, le taux de réponses correctes supplémentaires sur tablette atteint 15% comparée aux résultats obtenus sur papier. Les performances des tablettes numériques équipées d’un écran haute-résolution ne doivent pas être considérées comme inférieures en ce qui concerne la lecture d’images

Reisen in den indischen Meeren bei Gelegenheit des Durchgangs der Venus durch die Sonnenscheibe 1761 bis 1771 auf könglichen Befehl unternommen ; dritter Theil [und] Reise nach der Insel Malta in dem Jahre 1776

Enthält: Reise nach der Insel Malta in dem Jahre 1776 + Le Gentils Reisen in den indischen Meeren in den Jahren 1761 bis 177

Proyecto La Cadena-Quevedo-La Maná. Primera síntesis modal y cronológica así como breves referencias a la cerámica del Formativo Temprano final

Este proyecto de invesetigación, iniciado en 1992, consiste en un aporte a la historia material y cultural poco estudiada de los piedemontes andinos occidentales del Ecuador. La zona tropical donde se han hecho las investigaciones es muy rica en nichos ecológicos y en recursos naturales. La topografía del terreno ha estimulado un poblamiento muy antiguo (al menos 6000 a. C.) y ha dado lugar a una adaptación al medio muy húmedo. El hombre edificó estructuras elevadas, tolas, que permiten desarrollarse en tales condiciones. Paso inevitable entre la Costa, la Sierra y el Oriente, el piedemonte andino se halla en el centro de las vías de comunicación que favorecen los intercambios e inducen una mezcla cultural aún difícil de evaluar. El estudio de la cerámica valora este concepto ya que revela numerosos estilos que cubren todo el periodo prehispánico. En este artículo, se presenta únicamente la cerámica del Formativo temprano.Ce projet de recherche, entamé en 1992, souhaite contribuer à l’histoire matérielle et culturelle fort peu étudiée des piémonts andins occidentaux de l’Équateur. Cette zone tropicale est riche en niches écologiques et en ressources naturelles. Sa topographie a stimulé le peuplement ancien (depuis au moins 6000 av. J.-C.), et a donné lieu à une adaptation de l’homme dans un milieu humide, l’obligeant à élaborer des structures d’habitat, tolas, permettant de vivre dans de telles conditions. Passage obligé de la Costa à la Sierra et à l’Amazonie, le piémont andin se trouve ainsi au centre des voies de communication qui favorisent les échanges et induisent un brassage culturel encore difficile à évaluer aujourd’hui. L’étude de la céramique met en valeur ce concept, car elle révèle de nombreux faciès qui couvrent l’ensemble de l’ère préhispanique. Dans cet article, seule la céramique du Formatif ancien est traitée.This research project started in 1992 consists in a contribution to the material and cultural history of the Andean western piedmonts of Ecuador, which has been little studied. This tropical area is rich in ecological niches and natural resources. Its topography has stimulated settlement since at least 6000 BC, and has led to a human adaptation in wet surroundings, obliging human beings to build living structures, called tolas, which made life possible under such conditions. The movement from the coast to the highlands and Amazonia inevitably crosses the Andean piedmont which is situated in the center of the communication routes which promote exchanges and lead to a cultural intermixing that is still difficult to estimate today. The study of ceramics highlights this concept, because it reveals a great number of styles which cover the whole Prehispanic era. In this article, only the ceramics dating to the Early Formative are treated

Electrochemically switchable platform for the micro-patterning and release of heterotypic cell sheets

This article describes a dynamic platform in which the biointerfacial properties of micro-patterned domains can be switched electrochemically through the spatio-temporally controlled dissolution and adsorption of polyelectrolyte coatings. Insulating SU-8 micro-patterns created on a transparent indium tin oxide electrode by photolithography allowed for the local control over the electrochemical dissolution of polyelectrolyte mono- and multilayers, with polyelectrolytes shielded from the electrochemical treatment by the underlying photoresist stencil. The platform allowed for the creation of micro-patterned cell co-cultures through the electrochemical removal of a non-fouling polyelectrolyte coating and the localized adsorption of a cell adhesive one after attachment of the first cell population. In addition, the use of weak adhesive polyelectrolyte coatings on the photoresist domains allowed for the detachment of a contiguous heterotypic cell sheet upon electrochemical trigger. Cells grown on the ITO domains peeled off upon electrochemical dissolution of the sacrificial polyelectrolyte substrate, whereas adjacent cell areas on the insulated weakly adhesive substrate easily detached through the contractile force generated by neighboring cells. This electrochemical strategy for the micro-patterning and detachment of heterotypic cell sheets combines simplicity, precision and versatility, and presents great prospects for the creation of cellular constructs which mimic the cellular complexity of native tissue

Photoactivatable Caged Cyclic RGD Peptide for Triggering Integrin Binding and Cell Adhesion to Surfaces

We report the synthesis and properties of a photoactivatable caged RGD peptide and its application for phototriggering integrin- and cell-binding to surfaces. We analysed in detail 1) the differences in the integrin-binding affinity of the caged and uncaged forms by quartz crystal microbalance (QCM) studies, 2) the efficiency and yield of the photolytic uncaging reaction, 3) the biocompatibility of the photolysis by-products and irradiation conditions, 4) the possibility of site, temporal and density control of integrin-binding and therefore human cell attachment, and 5) the possibility of in situ generation of cell patterns and cell gradients by controlling the UV exposure. These studies provide a clear picture of the potential and limitations of caged RGD for integrin-mediated cell adhesion and demonstrate the application of this approach to the control and study of cell interactions and responses.The authors thank Martina Knecht for help in the synthetic part and Alexander Specht and Maurice Goeldner (University Strasbourg) for previous work in the caged RGD and discussion of the photolysis experiments. AdC and VSM thank the DFG for financial support (DFG-ANR project, CA880-3). AdC and MW thank the Materials World Network (DFG AOBJ 569628) for financial support

Uncoupling bacterial attachment on and detachment from polydimethylsiloxane surfaces through empirical and simulation studies

Bacterial infections related to medical devices can cause severe problems, whose solution requires in-depth understanding of the interactions between bacteria and surfaces. This work investigates the influence of surface physicochemistry on bacterial attachment and detachment under flow through both empirical and simulation studies. We employed polydimethylsiloxane (PDMS) substrates having different degrees of crosslinking as the model material and the extended Derjaguin - Landau - Verwey - Overbeek model as the simulation method. Experimentally, the different PDMS materials led to similar numbers of attached bacteria, which can be rationalized by the identical energy barriers simulated between bacteria and the different materials. However, different numbers of residual bacteria after detachment were observed, which was suggested by simulation that the detachment process is determined by the interfacial physicochemistry rather than the mechanical property of a material. This finding is further supported by analyzing the bacteria detachment from PDMS substrates from which non-crosslinked polymer chains had been removed: similar numbers of residual bacteria were found on the extracted PDMS substrates. The knowledge gained in this work can facilitate the projection of bacterial colonization on a given surface

ASIC for High-Speed-Gating and Free Running Operation of SPADs

Single photon detection at telecom wavelengths is of importance in many industrial applications ranging from quantum cryptography, quantum optics, optical time domain reflectometry, non-invasive testing of VLSI circuits, eye-safe LIDAR to laser ranging. In practical applications, the combination of an InGaAs/InP APD with an appropriate electronic circuit still stands as the best solution in comparison with emerging technologies such as superconducting single photon detectors, MCP-PMTs for the near IR or up-conversion technique. An ASIC dedicated to the operation of InGaAs/InP APDs in both gated mode and free-running mode is presented. The 1.6mm2 chip is fabricated in a CMOS technology. It combines a gate generator, a voltage limiter, a fast comparator, a precise timing circuit for the gate signal processing and an output stage. A pulse amplitude of up to +7V can be achieved, which allows the operation of commercially available APDs at a single photon detection probability larger than 25% at 1.55μm. The avalanche quenching process is extremely fast, thus reducing the afterpulsing effects. The packaging of the diode in close proximity with the quenching circuit enables high speed gating at frequencies larger than 10MHz. The reduced connection lengths combined with impedance adaptation technique provide excellent gate quality, free of oscillations or bumps. The excess bias voltage is thus constant over the gate width leading to a stable single photon detection probability and timing resolution. The CMOS integration guarantees long-term stability, reliability and compactness

Bioinspired, nanoscale approaches in contemporary bioanalytics (Review)

The genesis for this topical review stems from the interdisciplinary Biointerfaces International conference 2016 (BI 2016) in Zurich, Switzerland, wherein the need for advances in analytical tools was both expressed and addressed. Pushing the limits of detection for characterizing individual components, such as single proteins, single drug-delivery vehicles, or probing single living cells in a more natural environment, will contribute to the understanding of the complex biomolecular systems central to a number of applications including medical diagnostics, tissue engineering, and drug screening and delivery. Accordingly, the authors begin with an overview of single nanoparticle analytics highlighting two emerging techniques and how they compare with existing techniques. The first is based on single particle tracking of nanoparticles tethered to a mobile supported lipid bilayer, enabling the simultaneous characterization of both size and composition of individual nanoparticles. The second technique is based on probing variations in the ionic conduction across nanoscale apertures for detection of not only nanoparticles but also membrane-tethered proteins, thereby allowing a multiparameter characterization of individual nanoscopic objects, addressing their size, shape, charge, and dipole moment. Subsequently, the authors lead into an example of an area of application that stands to benefit from such advances in bioanalytics, namely, the development of biomimetic lipid- and polymer-based assemblies as stimuli-responsive artificial organelles and nanocarriers designed to optimize delivery of next generation high-molecular-weight biological drugs. This in turn motivates the need for additional advanced techniques for investigating the cellular response to drug delivery, and so the review returns again to bioanalytics, in this case single-cell analysis, while highlighting a technique capable of probing and manipulating the content of individual living cells via fluidic force microscopy. In presenting a concerted movement in the field of bioinspired bioanalytics, positioned in the context of drug delivery, while also noting the critical role of surface modifications, it is the authors’ aim to evaluate progress in the field of single component bioanalytics and to emphasize the impact of initiating and maintaining a fruitful dialogue among scientists, together with clinicians and industry, to guide future directions in this area and to steer innovation to successful translation