Implicit Euler Time-Discretization of a Class of Lagrangian Systems with Set-Valued Robust Controller

International audienceA class of Lagrangian continuous dynamical systems with set-valued controller and subjected to a perturbation force has been thoroughly studied in [S. Adly, B. Brogliato, B. K. Le, Well-posedness, robustness and stability analysis of a set-valued controller for Lagrangian systems, SIAM J. Control Optim., 51(2), 1592--1614, 2013]. In this paper, we study the time discretization of these set-valued systems with an implicit Euler scheme. Under some mild conditions, the well-posedness (existence and uniqueness of solutions) of the discrete-time scheme, as well as the convergence of the sequences of discrete positions and velocities in finite steps are assured. Furthermore, the approximate piecewise linear function generated by these discrete sequences is shown to converge to the solution of the continuous time differential inclusion with order $\frac{1}{2}$. Some numerical simulations on a two-degree of freedom example illustrate the theoretical developments

On the well-posedness and solvability of Lur'e quasi-variational inequalities

In the paper, a new class of quasi-variational inequalities is introduced which can be applied in the study of Lur'e set-valued dynamical systems and game theory. An efficient method to solve the problem and the convergence analysis are provided

Prevalence and Scanning Electron Microscopic Identification of Anoplocephalid Cestodes among Small Ruminants in Senegal

This study was undertaken to determine the prevalence of anoplocephalid cestodes in sheep and goats in Senegal. Intestines of 462 sheep and 48 goats were examined; 47.4% of sheep and 6.2% of goats were infected. The species identified and their prevalence were, among sheep, Avitellina centripunctata 38.7%, Moniezia expansa 15.4%, Stilesia globipunctata 16.7%, and Thysaniezia ovilla 0.4%. Among goats, they were M. expansa 6.2% and T. ovilla 2.1%. The prevalence of all species was not statistically different between dry and rainy seasons. The infections were single or multiple. Indeed, 56.2% of sheep were infected by a single species, 37.4% by two species, and 6.4% by three species. For goats, 66.7% were infected by M. expansa and 33.3% by both M. expansa and T. ovilla. Scanning electron microscopic (SEM) observations of tapeworms show the general diagnosis characters of these species

Fluorescent labeling in semi-solid medium for selection of mammalian cells secreting high-levels of recombinant proteins

<p>Abstract</p> <p>Background</p> <p>Despite the powerful impact in recent years of gene expression markers like the green fluorescent protein (GFP) to link the expression of recombinant protein for selection of high producers, there is a strong incentive to develop rapid and efficient methods for isolating mammalian cell clones secreting high levels of marker-free recombinant proteins. Recently, a method combining cell colony growth in methylcellulose-based medium with detection by a fluorescently labeled secondary antibody or antigen has shown promise for the selection of Chinese Hamster Ovary (CHO) cell lines secreting recombinant antibodies. Here we report an extension of this method referred to as fluorescent labeling in semi-solid medium (FLSSM) to detect recombinant proteins significantly smaller than antibodies, such as IGF-E5, a 25 kDa insulin-like growth factor derivative.</p> <p>Results</p> <p>CHO cell clones, expressing 300 μg/ml IGF-E5 in batch culture, were isolated more easily and quickly compared to the classic limiting dilution method. The intensity of the detected fluorescent signal was found to be proportional to the amount of IGF-E5 secreted, thus allowing the highest producers in the population to be identified and picked. CHO clones producing up to 9.5 μg/ml of Tissue-Plasminogen Activator (tPA, 67 kDa) were also generated using FLSSM. In addition, IGF-E5 high-producers were isolated from 293SF transfectants, showing that cell selection in semi-solid medium is not limited to CHO and lymphoid cells. The best positive clones were collected with a micromanipulator as well as with an automated colony picker, thus demonstrating the method's high throughput potential.</p> <p>Conclusion</p> <p>FLSSM allows rapid visualization of the high secretors from transfected pools prior to picking, thus eliminating the tedious task of screening a high number of cell isolates. Because of its rapidity and its simplicity, FLSSM is a versatile method for the screening of high producers for research and industry.</p

Transoral rotational esophagogastric fundoplication: technical, anatomical, and safety considerations

Background: Gastroesophageal reflux disease (GERD) results primarily from the loss of an effective antireflux barrier, which forms a mechanical barrier against the retrograde movement of gastric content. Restoration of the incompetent antireflux barrier is possible by longitudinal and rotational advancement of the gastric fundus about the lower esophagus, creating an esophagogastric fundoplication. This article describes the technique of performing a rotational and longitudinal esophagogastric fundoplication, performed transorally using EsophyX. Methods: The transoral incisionless fundoplication (TIF) technique enables the creation of a full-thickness esophagogastric fundoplication with fixation extending longitudinally up to 3.5 cm above the Z-line and rotationally more than 270 degrees around the esophagus. A key element of the technique involves rotating the fundus around the esophagus with a tissue mold during gastric desufflation. Anatomic considerations and use of the device's tissue invaginator to push the esophagus caudally are important to ensure safe positioning of the plications below the diaphragm. The steps of the technique are described in detail, and suggestions are given about patient selection and care, as well as prevention and management of complications. © 2010 The Author(s).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

L'acacia au Sénégal

L'intérêt agronomique et écologique des rhizobiums repose essentiellement sur leurs propriétés symbiotiques. Il est donc capital de pouvoir apprécier la diversité des souches sur la base de leur pouvoir de nodulation. L'objectif de ce travail est de proposer une nouvelle approche, alternative aux tests de nodulation, permettant de classer les souches en fonction de leur spécificité symbiotique. Au cours des premières étapes de l'interaction rhizobium-légumineuses, les rhizobiums excrètent des molécules signal, appelées facteurs Nod, qui jouent un rôle déterminant dans l'infection et la nodulation des plantes-hôtes. Leur utilisation potentielle comme marqueur de la spécificité de nodulation a été évaluée à partir de l'étude d'une collection de souches isolées d'#Acacia et de #Sesbania au Sénégal. L'analyse chromatographique des facteurs Nod de ces souches a montré que les profils chromatographiques sont parfaitement corrélés à la fois à la structure chimique des facteurs Nod et à la spécificité d'hôte des souches, et plus particulièrement à la plante d'isolement. Une telle méthode de caractérisation globale des facteurs Nod pourrait donc être utilisée pour la caractérisation symbiotique des rhizobiums, en particulier pour l'étude taxonomique, l'étude de la biodiversité des souches ou pour le contrôle des inoculums. (Résumé d'auteur

Supporting the advancement of science: Open access publishing and the role of mandates

In December 2011 the United States House of Representatives introduced a new bill, the Research Works Act (H.R.3699), which if passed could threaten the public's access to US government funded research. In a digital age when professional and lay parties alike look more and more to the online environment to keep up to date with developments in their fields, does this bill serve the best interests of the community? Those in support of the Research Works Act argue that government open access mandates undermine peer-review and take intellectual property from publishers without compensation, however journals like Journal of Translational Medicine show that this is not the case. Journal of Translational Medicine in affiliation with the Society for Immunotherapy of Cancer demonstrates how private and public organisations can work together for the advancement of science

Ascite fébrile chez la femme, ne pas méconnaitre une tumeur de Krukenberg

Les tumeurs de Krukenberg (TK) se définissent comme des métastases ovariennes d'un cancer, le plus souvent digestif. Elles représentent 5 à 15% des tumeurs malignes ovariennes. Notre objectif était de décrire les caractéristiques épidémiologiques, diagnostiques, thérapeutiques et évolutives.Nous  rapportons deux observations de tumeur de Krukenberg découvertes à l'occasion de l'exploration d'une ascite fébrile.Il s'agit de deux patientes multipares âgées respectivement de 32 ans et 50 ans. Les signes d'appel étaient essentiellement digestifs. La découverte de ces métastases ovariennes était survenue à distance des foyers primitifs. L'atteinte des ovaires était bilatérale dans le premier cas et unilatérale  droite dans le second cas. Le diagnostic est apporté par la tomodensitométrie abdominopelvienne dans les deux cas. La fibroscopie oesogastroduodénale avait permis de retrouver le foyer primitif  respectivement sous forme d'un processus bourgeonnant et d'un ulcère en position antrale avec des stigmates d'hémorragies. L'examen anatomopathologique des biopsies réalisées mettait en évidence un adénocarcinome tubuleux moyennement différencié de l'estomac avec composante mucineuse dans la première observation et un adénocarcinome de type intestinal moyennement différencié dans la seconde. Le traitement chirurgical confirme le diagnostic histologique. Dans notre série, le traitement n'a pu être que symptomatique en raison de l'existence constante d'une carcinose péritonéale et de l'altération profonde de l'état général. Les deux patientes ont été confiées à l'institut de cancérologie pour une chimiothérapie palliative. La première est décédée 1 mois après. La tumeur de Krukenberg est une  maladie rare. Le diagnostic est facilité par la radiologie et confirmé par l'histologie. Son pronostic  demeure encore très sombre. Le seul espoir réside dans les mesures préventives.Key words: Métastases ovariennes, tumeur de Krukenberg, pronostic sombre

Three-dimensional localization of ultracold atoms in an optical disordered potential

We report a study of three-dimensional (3D) localization of ultracold atoms suspended against gravity, and released in a 3D optical disordered potential with short correlation lengths in all directions. We observe density profiles composed of a steady localized part and a diffusive part. Our observations are compatible with the self-consistent theory of Anderson localization, taking into account the specific features of the experiment, and in particular the broad energy distribution of the atoms placed in the disordered potential. The localization we observe cannot be interpreted as trapping of particles with energy below the classical percolation threshold.Comment: published in Nature Physics; The present version is the initial manuscript (unchanged compared to version 1); The published version is available online at http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2256.htm