Provenance et Qualité dans les Workflows Orientés Données : application à la plateforme WebLab

The WebLab platform is an application used to define and execute media-mining workflows. It is an open source platform, developed by the IPCC1 section of Airbus Defence and Space, for the integration of external components. A designer can create complex media-mining workflows using components, whose operation is not always known (black-boxes services). These complex workflows can lead to a problem of data quality, however, and before this work, no tool existed to analyse and improve the quality of WebLab workflows. To deal with black-box services, we choose to tackle this quality problem with a non-intrusive approach: we enhance the definition of the WebLab workflow with provenance and quality propagation rules. Provenance rules generate fine-grained data dependency links between data and services after the execution of a WebLab workflow. Then the quality propagation rules use these links to reason on the influence that the quality of the data used by a component has on the quality of the output data…La plateforme Weblab est un environnement de définition et d’exécution de chaines de traitements média-mining développé par le service IPCC1 d’Airbus Defence and Space. Il s’agit d’une plateforme ouverte d’intégration de composants externes dont la richesse permet aux concepteurs de construire des chaines média-mining très complexes, mais pose également des problèmes liés à la sensibilité de la qualité des résultats par rapport aux composants utilisés. Avant le début de cette thèse, aucun outil n’existait pour l’analyse et l’amélioration de la qualité de workflows WebLab. La problématique principale de la thèse repose sur le fonctionnement dit boite noire des services WebLab. L’approche choisie est non-intrusive : nous complétons la définition du workflow WebLab par des règles de provenance et de propagation de qualité. Les règles de provenance génèrent des liens de dépendance dit grains-fins entre les données et les services après l’exécution d’une chaine de traitements WebLab. Les règles de propagation de qualité profitent des liens inférés précédemment pour raisonner sur l’influence de la qualité d’une donnée utilisée par un service sur la qualité d’une donnée produite..

Imaginaire et représentations: l'œuvre d'Ousmane Sembène

Ce travail est une étude de l’imaginaire africain et ses représentations à partir de l’analyse de la nouvelle La Noire de…, de l’auteur sénégalais Ousmane Sembène, et de sa postérieure adaptation cinématographique. Nous verrons le message que l’auteur voulait transmettre à son public, à son continent, de même que les changements qu’il effectua lors de l’adaptation de l’oeuvre littéraire au cinéma et les raisons de ces changements.80 página

Schedule Earth Observation satellites with Deep Reinforcement Learning

International audienceOptical Earth observation satellites acquire images worldwide , covering up to several million square kilometers every day. The complexity of scheduling acquisitions for such systems increases exponentially when considering the interoperabil-ity of several satellite constellations together with the uncertainties from weather forecasts. In order to deliver valid images to customers as fast as possible, it is crucial to acquire cloud-free images. Depending on weather forecasts, up to 50% of images acquired by operational satellites can be trashed due to excessive cloud covers, showing there is room for improvement. We propose an acquisition scheduling approach based on Deep Reinforcement Learning and experiment on a simplified environment. We find that it challenges classical methods relying on human-expert heuristic

How a plantar pressure-based, tongue-placed tactile biofeedback modifies postural control mechanisms during quiet standing

The purpose of the present study was to determine the effects of a plantar pressure-based, tongue-placed tactile biofeedback on postural control mechanisms during quiet standing. To this aim, sixteen young healthy adults were asked to stand as immobile as possible with their eyes closed in two conditions of No-biofeedback and Biofeedback. Centre of foot pressure (CoP) displacements, recorded using a force platform, were used to compute the horizontal displacements of the vertical projection the centre of gravity (CoGh) and those of the difference between the CoP and the vertical projection of the CoG (CoP-CoGv). Altogether, the present findings suggest that the main way the plantar pressure-based, tongue-placed tactile biofeedback improves postural control during quiet standing is via both a reduction of the correction thresholds and an increased efficiency of the corrective mechanism involving the CoGh displacements

Meningococcal Meningitis Surveillance in the African Meningitis Belt, 2004-2013.

BACKGROUND: An enhanced meningitis surveillance network was established across the meningitis belt of sub-Saharan Africa in 2003 to rapidly collect, disseminate, and use district weekly data on meningitis incidence. Following 10 years' experience with enhanced surveillance that included the introduction of a group A meningococcal conjugate vaccine, PsA-TT (MenAfriVac), in 2010, we analyzed the data on meningitis incidence and case fatality from countries reporting to the network. METHODS: After de-duplication and reconciliation, data were extracted from the surveillance bulletins and the central database held by the World Health Organization Inter-country Support Team in Burkina Faso for countries reporting consistently from 2004 through 2013 (Benin, Burkina Faso, Chad, Democratic Republic of Congo, Ghana, Côte d'Ivoire, Mali, Niger, Nigeria, Togo). RESULTS: The 10 study countries reported 341 562 suspected and confirmed cases over the 10-year study period, with a marked peak in 2009 due to a large epidemic of group A Neisseria meningitidis (NmA) meningitis. Case fatality was lowest (5.9%) during this year. A mean of 71 and 67 districts annually crossed the alert and epidemic thresholds, respectively. The incidence rate of NmA meningitis fell >10-fold, from 0.27 per 100,000 in 2004-2010 to 0.02 per 100,000 in 2011-2013 (P < .0001). CONCLUSIONS: In addition to supporting timely outbreak response, the enhanced meningitis surveillance system provides a global overview of the epidemiology of meningitis in the region, despite limitations in data quality and completeness. This study confirms a dramatic fall in NmA incidence after the introduction of PsA-TT

Differential retention of transposable element-derived sequences in outcrossing Arabidopsis genomes

International audienceBackground: Transposable elements (TEs) are genomic parasites with major impacts on host genome architecture and host adaptation. A proper evaluation of their evolutionary significance has been hampered by the paucity of short scale phylogenetic comparisons between closely related species. Here, we characterized the dynamics of TE accumulation at the micro-evolutionary scale by comparing two closely related plant species, Arabidopsis lyrata and A. halleri. Results: Joint genome annotation in these two outcrossing species confirmed that both contain two distinct populations of TEs with either 'recent' or 'old' insertion histories. Identification of rare segregating insertions suggests that diverse TE families contribute to the ongoing dynamics of TE accumulation in the two species. Orthologous TE fragments (i.e. those that have been maintained in both species), tend to be located closer to genes than those that are retained in one species only. Compared to non-orthologous TE insertions, those that are orthologous tend to produce fewer short interfering RNAs, are less heavily methylated when found within or adjacent to genes and these tend to have lower expression levels. These findings suggest that long-term retention of TE insertions reflects their frequent acquisition of adaptive roles and/or the deleterious effects of removing nearly neutral TE insertions when they are close to genes. Conclusion: Our results indicate a rapid evolutionary dynamics of the TE landscape in these two outcrossing species, with an important input of a diverse set of new insertions with variable propensity to resist deletion

Soil variation response is mediated by growth trajectories rather than functional traits in a widespread pioneer Neotropical tree

1. Trait-environment relationships have been described at the community level across tree species. However, whether interspecific trait-environment relationships are consistent at the intraspecific level is yet unknown. Moreover, we do not know how consistent is the response between organ vs. whole-tree level. 2. We examined phenotypic variability for 16 functional leaf (dimensions, nutrient, chlorophyll) and wood traits (density) across two soil types, Ferralitic Soil (FS) vs. White Sands (WS), on two sites for 70 adult trees of Cecropia obtusa Trécul (Urticaceae) in French Guiana. Cecropia is a widespread pioneer Neotropical genus that generally dominates early successional forest stages. To understand how soil types impact resource use through the processes of growth and branching, we examined the architectural development with a retrospective analysis of growth trajectories. We expect soil types to affect both, functional traits in relation to resource acquisition strategy as already described at the interspecific level, and growth strategies due to resource limitations with reduced growth on poor soils. 3. Functional traits were not involved in the soil response, as only two traits -leaf residual water content and K content-showed significant differences across soil types. Soil effects were stronger on growth trajectories, with WS trees having the slowest growth trajectories and less numerous branches across their lifespan. 4. The analysis of growth trajectories based on architectural analysis improved our ability to characterise the response of trees with soil types. The intraspecific variability is higher for growth trajectories than functional traits for  C. obtusa, revealing the complementarity of the architectural approach with the functional approach to gain insights on the way trees manage their resources over their lifetime. Soil-related responses of Cecropia functional traits are not the same as those at the interspecific level, suggesting that the effects of the acting ecological processes are different between the two levels. Apart from soil differences, much variation was found across sites, which calls for further investigation of the factors shaping growth trajectories in tropical forests