Anion–π Enzymes

In this report, we introduce artificial enzymes that operate with anion-π interactions, an interaction that is essentially new to nature. The possibility to stabilize anionic intermediates and transition states on an π-acidic surface has been recently demonstrated, using the addition of malonate half thioesters to enolate acceptors as a biologically relevant example. The best chiral anion-π catalysts operate with an addition/decarboxylation ratio of 4:1, but without any stereoselectivity. To catalyze this important but intrinsically disfavored reaction stereoselectively, a series of anion-π catalysts was equipped with biotin and screened against a collection of streptavidin mutants. With the best hit, the S112Y mutant, the reaction occurred with 95% ee and complete suppression of the intrinsically favored side product from decarboxylation. This performance of anion-π enzymes rivals, if not exceeds, that of the best conventional organocatalysts. Inhibition of the S112Y mutant by nitrate but not by bulky anions supports that contributions from anion-π interactions exist and matter, also within proteins. In agreement with docking results, K121 is shown to be essential, presumably to lower the p K a of the tertiary amine catalyst to operate at the optimum pH around 3, that is below the p K a of the substrate. Most importantly, increasing enantioselectivity with different mutants always coincides with increasing rates and conversion, i.e., selective transition-state stabilization

Simulation in Contexts Involving an Interactive Table and Tangible Objects

International audienceBy using an interactive table, it is possible to interact with several people (decision-makers) in a simultaneous and collaborative way, around the table, during a simulation session. Thanks to the RFID technology with which the table is fitted, it is possible to give tangible objects a unique identity to include and to consider them in the simulation. The paper describes a context model, which takes into consideration the specificities related to interactive tables. The TangiSense interactive table is presented; it is connected to a multi-agent system making it possible to give the table a certain level of adaptation: each tangible object can be associated to an agent which can bring roles to the object (i.e., the roles are the equivalent of a set of behaviors). The multi-agent system proposed in this paper is modeled according to an architecture adapted to the exploitation of tangible and virtual objects during simulation on an interactive table. A case study is presented; it concerns a simulation of road traffic management. The illustrations give an outline of the potentialities of the simulation system as regards the context-awareness aspect, following both the actions of the decision-makers implied in simulation, and the agents composing the road traffic simulation

In vivo TssA proximity labeling reveals temporal interactions during Type VI secretion 1 biogenesis and TagA, a protein that stops and holds the sheath.

International audienceThe Type VI secretion system (T6SS) is a multiprotein weapon used by bacteria to destroy competitor cells. The T6SS contractile sheath wraps an effector-loaded syringe that is injected into the target cell. This tail structure assembles onto the baseplate that is docked to the membrane complex. In entero-aggregative Escherichia coli TssA plays a central role at each stage of the T6SS assembly pathway by stabilizing the baseplate and coordinating the polymerization of the tail. Here we adapted an assay based on APEX2-dependent biotinylation to identify the proximity partners of TssA in vivo. By using stage-blocking mutations, we define the temporal contacts of TssA during T6SS biogenesis. This proteomic mapping approach also revealed an additional partner of TssA, TagA. We show that TagA is a cytosolic protein tightly associated with the membrane. Analyses of sheath dynamics further demonstrate that TagA captures the distal end of the sheath to stop its polymerization and to maintain it under the extended conformation

A Formal Approach to Distinguish Games, Toys, Serious Games & Toys, Serious Re-purposing & Modding and Simulators

While the concept of serious game has considerably evolved in the last two decades, it still needs to be clearly differentiated from other types of artifacts. Thus, for most outside the domain, there is a degree of confusion about the relationship between serious games and other related applications such as simulators or the re-purposing of entertainment games within educational practices. This article proposes a formal approach towards classifying Games, Toys, Serious Games, Serious Toys, Serious Re-purposing & Modding and Simulators. The aim of this theoretical work is twofold. Firstly, on a practical level, this approach aims at helping actors from different ecosystems, such as health, for instance, to differentiate between these various devices and use them to their best advantage. Secondly, from a research perspective, based on a formal approach, our work aims to contribute to the development of a taxonomy for gamified intervention with serious purposes. This formal approach allows us to demonstrate that unique combinations can be proposed to distinguish each kind of application. In this context, Serious Games can be seen as a specific purpose and not as a synonym for other existing applications

Mutations in TUBG1, DYNC1H1, KIF5C and KIF2A cause malformations of cortical development and microcephaly.

International audienceThe genetic causes of malformations of cortical development (MCD) remain largely unknown. Here we report the discovery of multiple pathogenic missense mutations in TUBG1, DYNC1H1 and KIF2A, as well as a single germline mosaic mutation in KIF5C, in subjects with MCD. We found a frequent recurrence of mutations in DYNC1H1, implying that this gene is a major locus for unexplained MCD. We further show that the mutations in KIF5C, KIF2A and DYNC1H1 affect ATP hydrolysis, productive protein folding and microtubule binding, respectively. In addition, we show that suppression of mouse Tubg1 expression in vivo interferes with proper neuronal migration, whereas expression of altered γ-tubulin proteins in Saccharomyces cerevisiae disrupts normal microtubule behavior. Our data reinforce the importance of centrosomal and microtubule-related proteins in cortical development and strongly suggest that microtubule-dependent mitotic and postmitotic processes are major contributors to the pathogenesis of MCD

Architecture multi-agent pour la gestion d'objets tangibles et virtuels sur Table Interactive

Les recherches menées par le travail de thèse visent à proposer une nouvelle architecture multi-agent pour la conception d’applications sur de nouvelles plateformes de communication telles que les tables interactives. Les systèmes Multi-Agents sont utilisés depuis de nombreuses années et peuvent répondre aux problématiques de telles plateformes. Dans notre contexte, nous avons défini les interactions et les comportements d’agents hétérogènes (virtuels et tangibles), qui évoluent simultanément sur une même surface interactive.Nous avons défini une typologie des agents, utilisés dans le cadre de plateformes interactives, en fonction d’un ensemble de critères permettant d’analyser les caractéristiques logicielles et technologiques (système de capture, affichage, etc.) employées sur ces nouveaux supports. Nous proposons de modéliser les comportements élémentaires nécessaires à la description du problème (interactions éventuelles de plusieurs utilisateurs, utilisation d’objets, visualisation de l’environnement et des agents simulés, traitement des messageséchangés, etc.), lesquels sont représentés par des rôles joués simultanément par un ou plusieurs agents selon un ensemble de prérequis. La réflexion proposée a conduit à la construction d’une architecture multi-agent, laquelle a été appliquée sur la table interactive TangiSense (intégrant une technologie RFID). Nous illustrons et nous validons notre propos à l’aide d’une application, un simulateur de trafic routier.Research done in this thesis aims to propose a new multiagent architecture to design applications for the new communication platforms like the interactive tables. Multiagent systems are used for many years and can respond to the challenges of such platforms. The motivation of our work is to manage the interactions and the behavior of several heterogeneous entities (virtual and tangible) evolving simultaneously on a single interactive surface. We caracterized the agents typology and their interactions for interactive platforms.We consider a set of criteria to analyze software and technological (e.g. capture system, display, etc.) characteristics used on these new platforms. We proposed to modelize basic behaviors needed to describe the problem (potential interactions between multiple users, tangible objects use, visualization of the environment and simulated agents, treatment of exchanged messages, etc.), which are represented by roles played simultaneously by one or several agents according to a set of prerequisites. With these elements, we propose to apply our multiagent architecture on the interactive table TangiSense (equipped with RFID technology). We illustrate and validate our purpose with an application, a traffic simulator

Architecture multi-agent pour la gestion d'objets tangibles et virtuels sur Table Interactive

Les recherches menées par le travail de thèse visent à proposer une nouvelle architecture multi-agent pour la conception d applications sur de nouvelles plateformes de communication telles que les tables interactives. Les systèmes Multi-Agents sont utilisés depuis de nombreuses années et peuvent répondre aux problématiques de telles plateformes. Dans notre contexte, nous avons défini les interactions et les comportements d agents hétérogènes (virtuels et tangibles), qui évoluent simultanément sur une même surface interactive.Nous avons défini une typologie des agents, utilisés dans le cadre de plateformes interactives, en fonction d un ensemble de critères permettant d analyser les caractéristiques logicielles et technologiques (système de capture, affichage, etc.) employées sur ces nouveaux supports. Nous proposons de modéliser les comportements élémentaires nécessaires à la description du problème (interactions éventuelles de plusieurs utilisateurs, utilisation d objets, visualisation de l environnement et des agents simulés, traitement des messageséchangés, etc.), lesquels sont représentés par des rôles joués simultanément par un ou plusieurs agents selon un ensemble de prérequis. La réflexion proposée a conduit à la construction d une architecture multi-agent, laquelle a été appliquée sur la table interactive TangiSense (intégrant une technologie RFID). Nous illustrons et nous validons notre propos à l aide d une application, un simulateur de trafic routier.Research done in this thesis aims to propose a new multiagent architecture to design applications for the new communication platforms like the interactive tables. Multiagent systems are used for many years and can respond to the challenges of such platforms. The motivation of our work is to manage the interactions and the behavior of several heterogeneous entities (virtual and tangible) evolving simultaneously on a single interactive surface. We caracterized the agents typology and their interactions for interactive platforms.We consider a set of criteria to analyze software and technological (e.g. capture system, display, etc.) characteristics used on these new platforms. We proposed to modelize basic behaviors needed to describe the problem (potential interactions between multiple users, tangible objects use, visualization of the environment and simulated agents, treatment of exchanged messages, etc.), which are represented by roles played simultaneously by one or several agents according to a set of prerequisites. With these elements, we propose to apply our multiagent architecture on the interactive table TangiSense (equipped with RFID technology). We illustrate and validate our purpose with an application, a traffic simulator.VALENCIENNES-Bib. électronique (596069901) / SudocSudocFranceF

Combination between Multi-Agent System and Tangigets for DUI Design on several Tabletops

International audienceThe paper concerns the design of DUI composed with interactive tabletops allowing users to manipulate virtual and tangible objects around these several surfaces. We propose a model dedicated to the management of distributed interactive surfaces with Multi-Agent platforms. A case study illustrates the approach used: this case study implies a traffic management simulator distributed on two TangiSense tabletops equipped with RFID technology

Simulation on RFID Interactive Tabletop of Working Conditions in Industry 4.0

International audienceIn a changing world, in permanent international competition, Industry 4.0 must be able to adapt, to transform itself, especially from an organizational point of view. In case of reorganization or major changes, having the means for the design, training and appropriation of future working conditions becomes an asset. For this purpose, a simulator on interactive tabletop with RFID sensors is proposed. This tabletop is associated with tangible objects equipped with RFID tags. This simulator allows Industry 4.0 stakeholders to project themselves into future work situations. These situations can be simulated collectively, around the interactive tabletop, in relation to scenarios that can be replayed. Principles of implementation in Industry 4.0 are described. Different research perspectives are also highlighted

Exploitation de la technologie RFID associée à une table interactive avec objets tangibles et traçables, Application a la gestion de trafic routier

National audienceLe présent article se focalise sur une nouvelle plate-forme d'interaction utilisant la technologie RFID. Après une présentation de la technologie RFID elle-même (principe de fonctionnement et caractéristiques des différentes étiquettes RFID), l'article propose quelques exemples d'applications de cette technologie dans la vie courante ou dans l'industrie. Nous proposons d'utiliser la RFID sur une table interactive permettant d'interagir avec des objets tangibles et traçables et de la mettre en application afin de pouvoir gérer le trafic routier dans le but de le réguler en réduisant, par exemple, l'attente aux feux, de simuler les situations d'accidents ou d'anticiper sur les actions des véhicules afin d'émettre des hypothèses pour fluidifier le trafic