Design of experiments for response diversity

International audienceA design method is proposed that sequentially generates observation sites for the construction of a kriging predictive model. The objective of the construction is to allow a precise inversion of the system in the following sense: with any reachable target point T in the output space one wishes to be able to associate an input vector x_T such that the system response at x_T will be close to T (which requires that the model ensures a precise prediction of the response at x_T ). Intuitively, the observation sites should not be spread over the admissible input space, but should rather concentrate in areas such that, when mapped by the system, they cover the reachable output space. Two approaches are proposed that are shown on examples (one with five input and two outputs, derived from a problem in oil industry) to give satisfactory results. They are based on the maximization of a measure of dispersion of the observations in the output space and can cope with the presence of observation errors, a rather typical situation for experimentation with real physical systems

Maximisation séquentielle de la diversité des sorties d'un système boîte noire à l'aide de krigeage

6 pagesNational audienceNous proposons une méthode séquentielle pour maximiser la diversité des sorties d'un système pour lequel aucun modèle paramétrique n'est connu a priori. L'objectif est de pouvoir en quelque sorte "inverser le système", c'est-à-dire déterminer des valeurs d'entrée conduisant à des sorties proches de valeurs cibles quelconques. A chaque itération les sorties sont prédites par krigeage. Puis un point est ajouté en maximisant un critère quantifiant la diversité des sorties correspondant au plan constitué du plan courant et du point candidat. Ce critère utilise la prédiction des sorties au point candidat et l'incertitude associée fournies par le krigeage

Öffentliche Arbeitsvermittlung und Sprachkompetenzen

Le présent rapport final expose les résultats les plus significatifs d’un projet de recherche mené à l’initiative du Centre scientifique de compétence sur le plurilinguisme (CSP). Affilié à l’Université et à la Haute Ecole pédagogique de Fribourg (Suisse), le CSP conduit des travaux de recherche appliquée concernant des questions sociétales d’actualité qui ont un rapport avec le plurilinguisme, et ce sur mandat de la Confédération (cf. art. 12 de l’Ordonnance sur les langues). Trois domaines sont au coeur de la recherche du CSP : le plurilinguisme individuel (1), l’enseignement et l’apprentissage des langues / l’évaluation des compétences langagières (2) et le plurilinguisme institutionnel et sociétal (3). Dans le cadre de ce troisième domaine, le projet « Placement public et compétences linguistiques » a été mené sur deux années (2013– 2014) et a porté sur la question sociétale pertinente de savoir quel est le rôle de la langue dans l’accès au marché du travail. Le projet de recherche a été conduit conjointement par le CSP, sous la direction du professeur Alexandre Duchêne, et par la « Section des sciences du langage et de l’information » de l’Université de Lausanne (UNIL), sous la direction du professeur Pascal Singy.Der vorliegende Schlussbericht beinhaltet die wichtigsten Resultate eines auf Initiative des Wissenschaftlichen Kompetenzzentrums für Mehrsprachigkeit (KFM) durchgeführten Forschungsprojektes. Das KFM, das der Universität und der Pädagogischen Hochschule Freiburg (Schweiz) angegliedert ist, betreibt im Auftrag des Bundes angewandte Forschung zu aktuellen gesellschaftlichen Fragen rund um die Mehrsprachigkeit (siehe Art. 12 der Sprachenverordnung). Im Zentrum der Forschungsaktivitäten des KFM stehen drei Bereiche: individuelle Mehrsprachigkeit (1), Sprachen lehren und lernen / Sprachkompetenzen beurteilen und evaluieren (2) sowie institutionelle und gesellschaftliche Mehrsprachigkeit (3). Im Rahmen dieses dritten Bereichs ist während zwei Jahren (2013–2014) das Projekt „Öffentliche Arbeitsvermittlung und Sprachkompetenzen“ durchgeführt worden, das sich mit der gesellschaftlich relevanten Frage befasste, welche Rolle Sprache beim Arbeitsmarktzugang spielt. Das Projekt wurde in einer Forschungskooperation zwischen dem KFM, unter der Leitung von Prof. Dr. Alexandre Duchêne, und der „Section des sciences du langage et de l’information“ der Universität Lausanne (UNIL), unter der Leitung von Prof. Dr. Pascal Singy, durchgeführt

Experimental assessment of particle mixing fingerprints in the deposit-feeding bivalve Abra alba (Wood)

Particle mixing induced by the deposit-feeding bivalve Abra alba was assessed using a new experimental approach allowing for the tracking of individual particle displacements. This approach combines the adaptation of existing image acquisition techniques with new image analysis software that tracks the position of individual particles. This led to measurements of particle mixing fingerprints, namely the frequency distributions of particle waiting times, and of the characteristics (i.e. direction and length) of their jumps. The validity of this new approach was assessed by comparing the so-measured frequency distributions of jump characteristics with the current qualitative knowledge regarding particle mixing in the genus Abra. Frequency distributions were complex due to the coexistence of several types of particle displacements and cannot be fitted with the most commonly used procedures when using the Continuous Time Random Walk (CTRW) model. Our approach allowed for the spatial analysis of particle mixing, which showed: 1) longer waiting times; 2) more frequent vertical jumps; and 3) shorter jump lengths deep in the sediment column than close to the sediment-water interface. This resulted in lower DbX and DbY (vertical and horizontal particle mixing bioffusion coefficients) deep in the sediment column. Our results underline the needs for: 1) preliminary checks of the adequacy of selected distributions to the species/communities studied; and 2) an assessment of vertical changes in particle mixing fingerprints when using CTRW

Triplicity and Physical Characteristics of Asteroid (216) Kleopatra

To take full advantage of the September 2008 opposition passage of the M-type asteroid (216) Kleopatra, we have used near-infrared adaptive optics (AO) imaging with the W.M. Keck II telescope to capture unprecedented high resolution images of this unusual asteroid. Our AO observations with the W.M. Keck II telescope, combined with Spitzer/IRS spectroscopic observations and past stellar occultations, confirm the value of its IRAS radiometric radius of 67.5 km as well as its dog-bone shape suggested by earlier radar observations. Our Keck AO observations revealed the presence of two small satellites in orbit about Kleopatra (see Marchis et al., 2008). Accurate measurements of the satellite orbits over a full month enabled us to determine the total mass of the system to be 4.64+/-0.02 10^18 Kg. This translates into a bulk density of 3.6 +/-0.4 g/cm3, which implies a macroscopic porosity for Kleopatra of ~ 30-50%, typical of a rubble-pile asteroid. From these physical characteristics we measured its specific angular momentum, very close to that of a spinning equilibrium dumbbell.Comment: 35 pages, 3 Tables, 9 Figures. In press to Icaru

Distinct and Specific Role of NlpC/P60 Endopeptidases LytA and LytB in Cell Elongation and Division of Lactobacillus plantarum

Peptidoglycan (PG) is an essential lattice of the bacterial cell wall that needs to be continuously remodeled to allow growth. This task is ensured by the concerted action of PG synthases that insert new material in the pre-existing structure and PG hydrolases (PGHs) that cleave the PG meshwork at critical sites for its processing. Contrasting with Bacillus subtilis that contains more than 35 PGHs, Lactobacillus plantarum is a non-sporulating rod-shaped bacterium that is predicted to possess a minimal set of 12 PGHs. Their role in morphogenesis and cell cycle remains mostly unexplored, except for the involvement of the glucosaminidase Acm2 in cell separation and the NlpC/P60 D, L-endopeptidase LytA in cell shape maintenance. Besides LytA, L. plantarum encodes three additional NlpC/P60 endopeptidases (i.e., LytB, LytC and LytD). The in silico analysis of these four endopeptidases suggests that they could have redundant functions based on their modular organization, forming two pairs of paralogous enzymes. In this work, we investigate the role of each Lyt endopeptidase in cell morphogenesis in order to evaluate their distinct or redundant functions, and eventually their synthetic lethality. We show that the paralogous LytC and LytD enzymes are not required for cell shape maintenance, which may indicate an accessory role such as in PG recycling. In contrast, LytA and LytB appear to be key players of the cell cycle. We show here that LytA is required for cell elongation while LytB is involved in the spatio-temporal regulation of cell division. In addition, both PGHs are involved in the proper positioning of the division site. The absence of LytA activity is responsible for the asymmetrical positioning of septa in round cells while the lack of LytB results in a lateral misplacement of division planes in rod-shaped cells. Finally, we show that the co-inactivation of LytA and LytB is synthetically affecting cell growth, which confirms the key roles played by both enzymes in PG remodeling during the cell cycle of L. plantarum. Based on the large distribution of NlpC/P60 endopeptidases in low-GC Gram-positive bacteria, these enzymes are attractive targets for the discovery of novel antimicrobial compounds

Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination

Des vestiges témoignant des dernières positions allemandes de la Grande Guerre (08, Ardennes)

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Characterization of phosphatase and TENsin homolog deleted on chromosome 10 (PTEN) in chicken muscle

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