Determination of 105 antibiotic,anti-inflammatory,antiparasitic agents and tranquilizers by LC-MS/MS based on an acidic QuEChERS-like extraction

A procedure for screening 105 veterinary drugs in foods by liquid chromatography tandem mass-spectrometry (LC-MS/MS) is presented. Its scope encompasses raw materials of animal origin (milk, meat, fish, egg and fat) but also related processed ingredients and finished products commonly used and manufactured by food business operators. Due to the complexity of the matrices considered and to efficiently deal with losses during extraction and matrix effects during MS source ionisation, each sample was analysed twice, that is ‘unspiked’ and ‘spiked at the screening target concentration’ using a QuEChERS-like extraction. The entire procedure was validated according to the European Community Reference Laboratories Residues Guidelines. False-negative and false-positive rates were below 5% for all veterinary drugs whatever the food matrix. Effectiveness of the procedure was further demonstrated through participation to five proficiency tests and its ruggedness demonstrated in quality control operations by a second laboratory.     

Démarches méthodologiques pour approcher les points de vue d'enseignants et enseignantes sur des QSV en lien avec le vivant

Les avancées dans le domaine des biotechnologies ainsi que des questions relatives à la santé publique soulèvent des enjeux sociaux, éthiques et culturels se répercutant dans la recherche et l'enseignement des sciences. L'intégration scolaire de contenus liés à ces enjeux fait appel à des approches d'enseignement dont la visée intègre l'objectif de formation de citoyennes et citoyens réfléchis et critiques. La nécessité d'adopter des méthodes de recherche favorisant l’émergence de la pluralité des points de vue d'enseignantes et enseignants de sciences se pose alors devant la diversité de ces enjeux. Le recours à des méthodes issues de l'interactionnisme symbolique (récits de vie, groupes de discussion) peut répondre à cette nécessité. C'est ce que montre cet article qui illustre le caractère heuristique de ces démarches ainsi que la multidimensionnalité, la pluralité et l'hétérogénéité des points de vue pouvant être recueillis.     

Différences entre adolescents et adolescentes à quatre taches de visualisation spatiale.

Compared the performance of 64 adolescent boys and 42 adolescent girls (aged 15–17 yrs) on 4 visual-spatial skills tasks. The administrative conditions of these computerized tasks are highly standardized. Three of these tasks, Spatial Visualization, Perception and Spatial Relations, are taken from the Computerized Aptitude Test for adolescents and adults, whereas the 4th task is an adaptation for adolescents of the Puzzle subtest of the Computerized Aptitude Test for infants. The dependent variables are the average success scores and the speed of execution scores derived from latency times in a group of the best scores for each of the 4 tasks. The results show that the adolescent boys are more successful at the Spatial Visualization and Spatial Relations tasks. On the whole, the boys and the girls showed a comparable speed of success, except in the Spatial Relations subtest, where the girls were much faster. The observed differences are interpreted as reflecting the better strategies adopted by the boys to solve mental rotation tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Component Management in a Dynamic Architecture

Modern distributed programming environments commonly restrict programmers to a single form of inter-component configuration of an application. However, these distributed applications are prone to evolve drastically during their lifetime, to take into account the new users requirements, the technological evolution, or to improve the performance of the application. Evolution involves changes related to the application architecture, the software implementation, or the physical location of software components in a distributed environment during the application execution. In this paper, we describe an original approach for the dynamic application management which fulfills the above requirements with minimal perturbation. In order to prove the advantage of our approach, we have implemented a prototype of this service by extending a CORBA environment.     

Optimizing the Aspect Ratio of Nanopatterned Mesoporous TiO2 Thin-Film Layer to Improve Energy Conversion Efficiency of Perovskite Solar Cells

The energy conversion efficiency (ECE) (η), current density (J_sc), open-circuit voltage (V_oc), and fill factor (ff) of perovskite solar cells were studied by using the transmittance of a nanopatterned mesoporous TiO₂ (mp-TiO₂) thin-film layer. To improve the ECE of perovskite solar cells, a mp-TiO₂ thin-film layer was prepared to be used as an electron transport layer (ETL) via the nanoimprinting method for nanopatterning, which was controlled by the aspect ratio. The nanopatterned mp-TiO₂ thin-film layer had a uniform and well-designed structure, and the diameter of nanopatterning was 280 nm. The aspect ratio was controlled at the depths of 75, 97, 127, and 167 nm, and the perovskite solar cell was fabricated with different depths. The ECE of the perovskite solar cells with the nanopatterned mp-TiO₂ thin-film layer was 14.50%, 15.30%, 15.83%, or 14.24%, which is higher than that of a non-nanopatterned mp-TiO₂ thin-film layer (14.07%). The enhancement of ECE was attributed to the transmittance of the nanopatterned mp-TiO₂ thin-film layer that is due to the improvement of the electron generation. As a result, better electron generation affected the electron density, and J_sc increased the V_oc, and ff of perovskite solar cells.     

Determination of Electron Collision Cross Sections Set for Tetramethysilane

A swarm analysis technique based on the solution of the Boltzmann equation is used to derive low energy electron collision cross sections for tetramethylsilane （TMS）. The calculated swarm parameters with this first available cross sections set is consistent with measured values of the swarm parameters. Calculations of transport parameters in mixtures of TMS with argon are also presented.     

Nanoporous networks derived from functional semi-Interpenetrating Polymer Networks: Preparation and use as ion-exchange chromatographic supports

The utilization of poly(ε-caprolactone) (PCL)/poly(methyl methacrylate-co-methacrylic acid)-based semi-Interpenetrating Polymer Networks as nanostructured precursors provides a straightforward and effective route for engineering COOH-functionalized nanoporous networks. Such functional frameworks can be used as cation-exchange supports in Ion-Exchange Chromatography for the separation of proteins, provided the structures contain a significant initial content of carboxylic acid functions. This investigation illustrates the major role played by the presence of the interconnected pores generated by the oligoester template in the protein retention. The resolution turns out to be better than that obtained with a classically prepared porous support using an organic solvent as a porogen.     

Green projects: An information drives analysis of four cases

An analysis of four transportation systems (Vélib, Zipcar, ERP Singapore, and Transantiago) shows the strategic value of creating a symbiotic relationship between physical and informational systems in order to increase the convenience and patronage of these systems. The four information drives (ubiquity, uniqueness, unison, and universality) are extended to a physical setting and used to report the key characteristics of each system from both a physical and informational perspective. The article argues that the traditional customer orientation to determining systems requirements may fail to create the breakthrough systems designs that are required to reduce society’s climate harming emissions. Rather, we need an innovation orientation based on understanding consumers’ fundamental physical and informational needs.     

Intercalated carbon nanotubes as a template for the preparation of supported heteroatomic nanoparticles

Chemistry in confined conditions is explored at the level of the interlayer space of multiwall carbon nanotubes. Starting from preliminary intercalated tubes, a ligand exchange reaction has been successfully conducted within the former Van der Waals gap, resulting in a final dispersion of heteroatomic particles, around 2 nm large and nearly homogeneous in size, on the outer surface of the tubes. Intercalated tubular carbon architectures thus prove to be interesting templates for a bottom-up preparation of chemically complex supported nanoparticles, with potential activities for versatile applications.     

Aggregation of random parameters Ornstein-Uhlenbeck or AR processes: some convergence results

Abstract.  It is shown that by aggregating simple random parameters, processes such as autoregressive micro-relationships or Ornstein-Uhlenbeck processes, one can obtain various seasonal long memory Gaussian models. The investigation concerns the discrete as well as the continuous time setting. In both situations the precise asymptotic behaviour of the covariance is studied. The regularity of sample paths is evaluated when possible.