Protéines à motif tripartite (TRIM) chez le porc (Sus scrofa) et réplication du rétrovirus endogène porcin

Les études des interactions entre cellules hôtes et rétrovirus ont conduit à définir le concept de restriction virale dont les facteurs constituent une part de l'immunité innée des cellules hôtes. Ces facteurs contribuent au contrôle des rétrovirus endogènes (ERV) dont l'émergence peut être associée à certaines pathologies telles que des leucémies ou des immunodéficiences. Chez le porc, certains ERV (PERV) sont réplicatifs, pourtant aucune pathologie ne leur a, à ce jour, été associée. Les mécanismes de restriction virale impliqués dans ce phénomène ont fait l'objet de nombreuses études. Elles n'ont cependant concerné que certains facteurs. Les protéines porcines à motif tripartite (poTRIM) n'ont ainsi fait l'objet que de peu d'études. Pourtant, de nombreux membres de cette famille participent à la restriction virale chez d'autres organismes que le porc. La présente étude s'intéresse par conséquent aux orthologues porcins de ces protéines et à leur relation avec les PERV. L'élaboration d'une stratégie d'expression de ces protéines dans un modèle humain, sensible à l'infection par le PERV nous a permis d'évaluer et de caractériser les effets des TRIM sur le cycle infectieux du PERV. Cette stratégie a mis en évidence une activité de restriction par TRIM8 tandis que TRIM44 semble au contraire agir en faveur de la réplication virale. En ce qui concerne poTRIM11, elle favorise l'entrée du PERV tout en inhibant son expression. L'étude a également confirmé l'insensibilité du PERV vis-à-vis de poTRIM5a. L'ensemble de ces résultats contribuent à la compréhension de la relation entre la réplication des PERV et le contrôle mené par son hôte.From studies of pathogens and their host interaction has emerged the concept of viral restriction considered to be part of an innate immune system. These factors contribute to the control of endogenous retroviruses (ERV) whose emergence may be associated with several diseases such as leukemia or immunodeficiency. Three subgroups of the porcine ERV-g-1 group (PERV) are replicative. Nevertheless, these PERVs are not associated with any pathology in the pig. Several studies have been performed on viral restriction mechanism capabilities of the pig but these covered a very limited number of restriction factors. Regarding the porcine tripartite motif-containing (poTRIM) proteins, knowledge is weak although several members of this family have proved to be implicated in the viral restriction of other species. The purpose of this study is to investigate the relationship between these orthologous poTRIMs proteins and replicating PERVs. In order to explore this potential interaction, a TRIM protein expressing model in human cells, known to be sensitive to the PERV infection, has been developed. It has enabled us to assess and characterize potential TRIMs effects on the PERV infection cycle. We equally identified poTRIM8 as a restriction factor. Conversely, poTRIM44 seems to act as an enhancer of the PERV infection, while, TRIM11 displayed ambiguous effects including an enhancer effect of the early infectious stages and an inhibitor activity of the late infectious stages. In this study, we also confirmed the PERV insensitivity to the porcine TRIM5a protein. Finally, this work aims at contributing to the understanding of the relationship between PERV replication and their control leading by the host cells.RENNES1-Bibl. électronique (352382106) / SudocSudocFranceF

Ivy : un bus logiciel au service du développement de prototypes de systèmes interactifs

Ce document présente l'expérience acquise au cours du développement et de l'utilisation du bus logiciel Ivy, dans un cadre de prototypage de systèmes interactifs pour le contrôle du trafic aérien. Après une description du principe de fonctionnement de ce système, nous verrons comment cet outil a pu influer sur notre approche de problématiques IHM spécifiques comme la multimodalité, l'interaction répartie ou la mobilité. L'accent est porté sur les services rendus par ce bus pour le développement rapide de systèmes interactifs " légers ", facilement intégrables dans un banc de démonstration et basés sur la logique des langages de script. En présentant cet outil que nous utilisons depuis maintenant cinq ans, nous espérons partager ici une expérience utile pour la conception de futures architectures de systèmes interactifs à des fins de recherche prospective

Acute induction of cell death-related IFN stimulated genes (ISG) differentiates highly from moderately virulent CSFV strains

Classical swine fever (CSF) severity is dependent on the virulence of the CSF virus (CSFV) strain. The earliest event detected following CSFV infection is a decrease in lymphocytes number. With some CSFV strains this leads to lymphopenia, the severity varying according to strain virulence. This lymphocyte depletion is attributed to an induction of apoptosis in non-infected bystander cells. We collected peripheral blood mononuclear cells (PBMC) before and during 3 days post-infection with either a highly or moderately virulent CSFV strain and subjected them to comparative microarray analysis to decipher the transcriptomic modulations induced in these cells in relation to strain virulence. The results revealed that the main difference between strains resided in the kinetics of host response to the infection: strong and immediate with the highly virulent strain, progressive and delayed with the moderately virulent one. Also although cell death/apoptosis-related IFN stimulated genes (ISG) were strongly up-regulated by both strains, significant differences in their regulation were apparent from the observed differences in onset and extent of lymphopenia induced by the two strains. Furthermore, the death receptors apoptotic pathways (TRAIL-DR4, FASL-FAS and TNFa-TNFR1) were also differently regulated. Our results suggest that CSFV strains might exacerbate the interferon alpha response, leading to bystander killing of lymphocytes and lymphopenia, the severity of which might be due to the host’s loss of control of IFN production and downstream effectors regulation

Shipborne vertical profiles of dust aerosols obtained with Unmanned Aerial Vehicles in the Mediterranean and the Middle East: First results ofthe AQABA campaign

International audienceAtmospheric aerosols have a large role in the earth climate through direct or indirect effects on the radiative energy budget. As the aerosol characteristics are highly variable spatially and in time, observations of these characteristics are needed in regions, where the climate change effects are the most severe. One of these types of hotspots is the East Mediterranean and Middle East (EMME region) (Lelieveld et al., 2012), however, high quality in-situ observations in the Middle East and Arabian Peninsula region are still missing. To gain such a high quality observations in this region, the "Air Quality and climate change in the Arabian Basin" (AQABA) oceanographic campaign was organized during summer 2017, shipping from France, through the Suez Canal and around the Arabian Peninsula to Kuwait and back to France. The total length of the campaign was more than 2 months. A wide spectrum of environmental conditions was encountered during the campaign, ranging from pristine conditions over the Indian Ocean, to dusty (low polluted) atmosphere in the Red Sea affected by the Saharan dust and the highly dusty and polluted Gulf. To add on the remote sensing data of aerosol characteristics above the sea surface collected on the ship, the Cyprus Institute's Unmanned Systems Research Laboratory (USRL) team deployed Unmanned Aerial Vehicles (UAVs) to gain in-situ observations of aerosol properties inside and above the marine boundary layer. A small, fixed wing UAV was hand launched from the ship, which then climbed up to 2000 m (a.s.l.) and then returned to the ship and landed on a net. A modified AlphaSense N-2 Optical Particle Counter (OPC) was used on board the UAV to observe the number size distribution of aerosol particles (range: 0.38-17.5 µm, with 16 channels). Meteorological parameters (T, RH and P), as well as a video was recorded also. A total of 16 Successful flights were made, mostly in the Mediterranean and in the Persian Gulf, with few flights in the Red Sea and the Arabian Sea. The presentation will show data acquired on board the UAVs and comparison with ceilometer data obtained on the ship to identify possible dust layers and other interesting events. The differences in aerosol size distributions inside and above the boundary layer will be discussed, as well as any interesting case studies or events during the measurements

Key issues in the design of interaction with Electronic Operational Documentation for Air Traffic controllers

Enhancing air traffic control safety requires to improve the access to operational documentation. Shifting from paper to electronic documentation raises important issues we are trying to address in the IGLOO project. We describe the kind and format of the documentation available on the working position. Then we explain the user centered design process we have adopted. This has led us to build prototypes and gather key issues that we describe. They cover various domains, stretching from media to the interaction style and to graphical design

An Introduction to ACAS Xu and the Challenges Ahead

ording to a 2013 AUVSI report, delays in integrating Unmanned Aerial Systems (UAS) into the National Airspace System (NAS) could cost more than $10 billions a year for the United States alone. Worldwide regulatory bodies are under pressure by the UAS industry to accelerate the regulation process, but safety remains their main objective. One condition for the safe introduction of UAS in the NAS is for them to be equipped with a collision avoidance system. Though the existing Airborne Collision Avoidance System II (ACAS II) could have been an option, the transformations of air traffic management engaged through NextGen (US) and SESAR (Europe) led to the definition of a new ACAS based on new logics, namely ACAS X. Its definition contains in particular two variations : ACAS Xa, for large aircraft, and ACAS Xu, for unmanned aircraft. As noted in a 2014 RTCA annual report, divide in technological knowledge between those experienced in ACAS II and those involved in the development of ACAS X is a concern. To help preventing this divide we believe it is essential to keep the community updated with the latest evolutions of the ACAS X standards. As work on Minimum Operational Performance Standards (MOPS) for ACAS Xu just started, it is of interest to know which parts of the MOPS are already decided, which remain flexible for the industries to make the difference and which are open research problems. Being a member of the ACAS X family, ACAS Xu lays on the same foundations as the well defined ACAS Xa standard. This work proposes an introduction to the ACAS Xa/Xu common basis, as it is unlikely to change, including the general architecture and Collision Avoidance (CA) logics. It is followed by a presentation of concepts specific to ACAS Xu such as the tailored threat logic, horizontal CA logic, CA coordination and automatic responses. For the flexible part, we believe it mainly concerns the surveillance sources. Instead of a precise standard, the regulation is likely to ask for requirements on the sensors capabilities. A state of the art of recent works allows proposing minimum sensor performances and focusing on an essential set of sensors. This work is concluded by presenting future challenges that need to be addressed to build a safe ACAS Xu baseline and to extend it to smaller and lower altitude UAS

Are You Clear About " Well Clear " ?

International audienceRegulations from the ICAO use the term Well Clear without defining it. Now, this definition is needed to design air traffic Detect And Avoid systems. A definition is currently discussed at the ICAO level, with work on the associated Remain Well Clear (RWC) function underway at standardisation bodies level (RTCA, EUROCAE). But many members of the communities impacted by these works are not well aware of their state. To adress this lack of awareness, this paper provides three contributions. First, it derives from ICAO texts the components of a RWC function: boundaries, alerts and guidances. These are linked to essential elements required to define the Well Clear term: a start and end, the actors involved, and the expected actions. Second, it summarizes the current regulatory efforts in RTCA, EUROCAE and ICAO regarding the Well Clear and Remain Well Clear notions. Third, it proposes discussion topics to move forward. From a DAA perspective, the notion of Well Clear is key to unlock RPAS full integration, i.e. operation in all classes of airspaces. Though existing works make good progress, the ressources engaged on this topic seem insufficient when compared with the complexity and importance of the task at hand

An Introduction to Fast Time Simulations for RPAS Collision Avoidance System Evaluation

International audienceCollision voidance systems are crucial for RPAS integration, yet comparing their performances remain difficult. We believe that using fast time simulations and standard evaluation metrics would facilitate their comparison while providing insight into their benefits. However, fast time simulations are often viewed as hard to set up and limited to large scale demonstrations. We believe even small experiments can take advantage of them with huge benefits. The aim of this work is to ease access to fast time simulations by providing explanations, examples and references to previous works and to free software. We also list commonly used evaluation metrics for collision avoidance system performance ranking. By easing the setup of fast time simulation experiments, we believe future works will be able to provide their results in a more detailed and comparable form

Centre d’Études de la Navigation Aérienne

In this paper we describe our exploration of some distributedinteraction prototypes designed for Air Traffic Control purposes. We think that this new form of interaction can play an important role in bringing closer together the user and the systems he is using. We believe that mobile devices, combined with new interaction styles, can be used as a lever to change the way user interfaces are designed. The Air Traffic Control application domain raises interesting issues in its transformation, which we have tried to address using personnal digital assistants. Our work focused particularly in an interaction shared between a fixed working position and a mobile one such as PDA. In this document, we want to show how we used previous studies on collaborative work and how we applied very simple but efficient design techniques to elaborate an experimental platform which explore different aspects and issues related to distributed interaction