208 research outputs found

    Goulphar: rapid access and expertise for standard two-color microarray normalization methods

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    BACKGROUND: Raw data normalization is a critical step in microarray data analysis because it directly affects data interpretation. Most of the normalization methods currently used are included in the R/BioConductor packages but it is often difficult to identify the most appropriate method. Furthermore, the use of R commands for functions and graphics can introduce mistakes that are difficult to trace. We present here a script written in R that provides a flexible means of access to and monitoring of data normalization for two-color microarrays. This script combines the power of BioConductor and R analysis functions and reduces the amount of R programming required. RESULTS: Goulphar was developed in and runs using the R language and environment. It combines and extends functions found in BioConductor packages (limma and marray) to correct for dye biases and spatial artifacts. Goulphar provides a wide range of optional and customizable filters for excluding incorrect signals during the pre-processing step. It displays informative output plots, enabling the user to monitor the normalization process, and helps adapt the normalization method appropriately to the data. All these analyses and graphical outputs are presented in a single PDF report. CONCLUSION: Goulphar provides simple, rapid access to the power of the R/BioConductor statistical analysis packages, with precise control and visualization of the results obtained. Complete documentation, examples and online forms for setting script parameters are available from

    Speech Events in the Middle West

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    International audienc

    MODÉLISATION SIMPLIFIEE DE L'IMPACT DE LA PRESENCE D'UN ECRAN NON PARFAITEMENT CYLINDRIQUE SUR LA CONVERSION EN MODE COMMUN D'UNE LIGNE BIFILAIRE TORSADÉE

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    International audienceCet article est consacré à la modélisation de la conversion du mode différentiel en courant du mode commun pour des lignes torsadées écrantées dans la bande de fréquence [1MHz-2GHz], dans l'hypothèse d'un écran non parfaitement cylindrique. La méthode consiste tout d'abord à extraire le profil des capacités linéiques sur une période (code électrostatique). Ensuite, la simulation de la conversion de mode commun est effectuée au moyen de la modulation fictive de la permittivité diélectrique de la gaine des conducteurs, non torsadés, et dans un écran cylindrique

    Décomposition de Hodge-Helmholtz Discrète

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    La décomposition de Hodge-Helmholtz permet de séparer un champ de vecteurs quelconque en la somme d'un champ irrotationnel et d'un champ solénoïdal. Le but de notre étude consiste à appliquer cette décomposition à des champs issus de la mécanique des fluides. D'une part, pour l'analyse des champs turbulents en vue de leurs modélisation. D'autre part, pour la décomposition des termes sources dans les équations de Navier-Stokes, par exemple, séparer la pression capillaire des effets de mouvement contenus dans le terme capillaire. Cette décomposition s'effectue au niveau discret. La première étape de ce travail consiste à établir un ensemble d'algorithmes efficaces permettant la décomposition discrète. Les études bibliographiques ont montré l'importance de la méthode de discrétisation, notamment le respect des identités vectorielles div(rot) = 0 et rot(grad) = 0 au niveau discret. Une famille de méthodes numériques, dénommée communément 'mimetic', permet de vérifier ces identités. Associés à cette méthodologie, plusieurs algorithmes permettant la décomposition ont été mis en œuvre et leurs performances ont été comparées. Deux types d'analyse de la turbulence ont été envisagés. D'une part, l'analyse de spectre de champs turbulents homogènes isotropes compressibles, d'autre part, l'analyse de champs turbulents au niveau de l'interface entre deux fluides non miscibles. La décomposition de Hodge-Helmholtz fait intervenir deux composantes découlant de potentiels. Un potentiel scalaire associé au champ irrotationnel et un potentiel vectoriel associé au champ solénoïdal. De manière physique, on peut associer le potentiel scalaire à la pression et le potentiel vectoriel au mouvement. La décomposition discrète permettra d'établir des algorithmes de résolution des équations de Navier-Stokes permettant de contrôler ces deux effets

    Comprehensive determination of the solid state stability of bethanechol chloride active pharmaceutical ingredient using combined analytical tools

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    International audienceThe use of an integrative analytical approach allowed us to establish the intrinsic solid state stability of bethanechol chloride (BC), an active pharmaceutical ingredient used in the treatment of urinary retention. First, the crystal structure of the monoclinic form has been described using single crystal X-ray diffraction studies. Second, thermal analyses revealed that the compound degrades upon melting, with an apparent melting temperature estimated to be 231 °C. No transition from the monoclinic to the orthorhombic form has been observed, suggesting that the monoclinic form is the stable one. Third, the two-step melting–decomposition process has been elucidated by liquid chromatography and thermogravimetry coupled to mass spectrometry. The first step corresponds to the sample liquefaction, which consists of the gradual dissolution of bethanechol chloride in its liquid degradant, i.e. betamethylcholine chloride. This step is in agreement with Bawn kinetics and the activation energy of the reaction has been estimated at 35.5 kcal mol−1. The second step occurs with accelerated degradation in the melt. Elucidation of secondary decomposition pathways evidenced autocatalytic properties conferred by the formation of both isocyanic acid and methyl chloride. Finally, dynamic water vapor sorption analysis showed a substantial hygroscopicity of the drug substance. A deliquescent point has been determined at 56% relative humidity at 25 °C

    Supramolecular Anchoring of Octahedral Molybdenum Clusters onto Graphene and Their Synergies in Photocatalytic Water Reduction

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    "This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.inorgchem.9b02529"[EN] Dihydrogen (H-2) production from sunlight should become one of the most important energy production means in the future. To reach this goal, low-cost and efficient photocatalysts still need to be discovered. Here we show that red near-IR luminescent metal cluster anions, once combined with pyrene-containing cations, are able to photocatalytically produce molecular hydrogen from water. The pyrene moieties act simultaneously as energy transmitters and as supramolecular linkers between the cluster anions and graphene. This association results in a hybrid material combining the emission abilities of pyrene and cluster moieties with the electronic conduction efficiency of graphene. Hydrogen evolution reaction (HER) studies show that this association induces a significant increase of H 2 production compared to that produced separately by clusters or graphene. Considering the versatility of the strategy described to design this photocatalytic hybrid material, transition-metal clusters are promising candidates to develop new, environmentally friendly, and low-cost photocatalysts for HER.The Severo Ochoa Program (SEV-2016-0683), Ministerio de Ciencia, Innovation y Universidades (PGC2018-099744), Consejo Superior de Investigaciones Cientificas (I-Link1063), and University of Rennes are thanked for financial support. We thank Dr. Marta Puche for her technical assistance with the preparation of dispersed graphene solutions at the ITQ.Feliz Rodriguez, M.; Atienzar Corvillo, PE.; Amela-Cortes, M.; Dumait, N.; Lemoine, P.; Molard, Y.; Cordier, S. (2019). Supramolecular Anchoring of Octahedral Molybdenum Clusters onto Graphene and Their Synergies in Photocatalytic Water Reduction. Inorganic Chemistry. 58(22):15443-15454. https://doi.org/10.1021/acs.inorgchem.9b02529S1544315454582

    An evaluation of custom microarray applications: the oligonucleotide design challenge

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    The increase in feature resolution and the availability of multipack formats from microarray providers has opened the way to various custom genomic applications. However, oligonucleotide design and selection remains a bottleneck of the microarray workflow. Several tools are available to perform this work, and choosing the best one is not an easy task, nor are the choices obvious. Here we review the oligonucleotide design field to help users make their choice. We have first performed a comparative evaluation of the available solutions based on a set of criteria including: ease of installation, user-friendly access, the number of parameters and settings available. In a second step, we chose to submit two real cases to a selection of programs. Finally, we used a set of tests for the in silico benchmark of the oligo sets obtained from each type of software. We show that the design software must be selected according to the goal of the scientist, depending on factors such as the organism used, the number of probes required and their localization on the target sequence. The present work provides keys to the choice of the most relevant software, according to the various parameters we tested

    The CRE1 carbon catabolite repressor of the fungus Trichoderma reesei: a master regulator of carbon assimilation

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    <p>Abstract</p> <p>Background</p> <p>The identification and characterization of the transcriptional regulatory networks governing the physiology and adaptation of microbial cells is a key step in understanding their behaviour. One such wide-domain regulatory circuit, essential to all cells, is carbon catabolite repression (CCR): it allows the cell to prefer some carbon sources, whose assimilation is of high nutritional value, over less profitable ones. In lower multicellular fungi, the C2H2 zinc finger CreA/CRE1 protein has been shown to act as the transcriptional repressor in this process. However, the complete list of its gene targets is not known.</p> <p>Results</p> <p>Here, we deciphered the CRE1 regulatory range in the model cellulose and hemicellulose-degrading fungus <it>Trichoderma reesei </it>(anamorph of <it>Hypocrea jecorina</it>) by profiling transcription in a wild-type and a delta-<it>cre1 </it>mutant strain on glucose at constant growth rates known to repress and de-repress CCR-affected genes. Analysis of genome-wide microarrays reveals 2.8% of transcripts whose expression was regulated in at least one of the four experimental conditions: 47.3% of which were repressed by CRE1, whereas 29.0% were actually induced by CRE1, and 17.2% only affected by the growth rate but CRE1 independent. Among CRE1 repressed transcripts, genes encoding unknown proteins and transport proteins were overrepresented. In addition, we found CRE1-repression of nitrogenous substances uptake, components of chromatin remodeling and the transcriptional mediator complex, as well as developmental processes.</p> <p>Conclusions</p> <p>Our study provides the first global insight into the molecular physiological response of a multicellular fungus to carbon catabolite regulation and identifies several not yet known targets in a growth-controlled environment.</p

    Ville et campagne de Fréjus romaine

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    En 2006, une fouille d’archéologie préventive, désignée sous le nom de « Villa Romana », a été réalisée dans le quartier de Villeneuve à Fréjus. Durant l’Antiquité il s’agit d’une zone périurbaine située entre la ville de Forum Iulii et le débouché de l’Argens. Connu depuis longtemps en raison de la présence d’un édifice thermal toujours en élévation, le quartier a été fouillé à plusieurs occasions et est interprété comme étant l’emplacement du camp de la flotte, établi après la bataille d’Actium. Celui-ci se transforme progressivement durant le Ier siècle apr. J.-C. en quartier suburbain au fur et à mesure que se développe Forum Iulii. Le secteur fouillé se situe dans la partie sud du camp, bordée par la mer durant les premiers temps de l’Antiquité. La fouille a permis de révéler la présence d’une plage aménagée. Les terrains ont ensuite été rapidement gagnés sur la mer, en raison d’une avancée rapide du littoral, que des études récentes ont permis de bien connaitre à Fréjus. Des jardins y sont alors aménagés. A partir du IIe siècle, cet espace est transformé en zone agricole, et constitue l’illustration de l’exploitation de la campagne aux portes de Fréjus, et cela, jusqu’à la fin de l’Antiquité. S’ensuit une longue période d’abandon de plusieurs siècles, avant que l’espace ne soit à nouveau voué à l’agriculture et ce jusqu’à l’orée des années soixante. Depuis, le développement de la ville actuelle de Fréjus a de nouveau transformé ce quartier en zone urbaine. Cet ouvrage, publié quelques années seulement après la fouille, présente l’ensemble des études archéologiques et paléoenvironnementales, réalisées à l’occasion de cette opération, largement pluridisciplinaire. Elles fournissent un contexte environnemental nouveau pour ce quartier antique et permettent de redéfinir un paysage à partir d’analyses bioarchéologiques et paléoécologiques récentes. L’étude de l’ensemble des mobiliers archéologiques est également présentée, en suivant la chronologie et l’évolution de ce quartier à travers l’Antiquité et l’époque moderne
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