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Search Results: 1 - 10 of 1091 matches for " Lesage Pascale "
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Two large-scale analyses of Ty1 LTR-retrotransposon de novo insertion events indicate that Ty1 targets nucleosomal DNA near the H2A/H2B interface
Bridier-Nahmias Antoine,Lesage Pascale
Mobile DNA , 2012, DOI: 10.1186/1759-8753-3-22
Abstract: Background Over the years, a number of reports have revealed that Ty1 integration occurs in a 1-kb window upstream of Pol III-transcribed genes with an approximate 80-bp periodicity between each integration hotspot and that this targeting requires active Pol III transcription at the site of integration. However, the molecular bases of Ty1 targeting are still not understood. Findings The publications by Baller et al. and Mularoni et al. in the April issue of Genome Res. report the first high-throughput sequencing analysis of Ty1 de novo insertion events. Their observations converge to the same conclusion, that Ty1 targets a specific surface of the nucleosome at he H2A/H2B interface. Conclusion This discovery is important, and should help identifying factor(s) involved in Ty1 targeting. Recent data on transposable elements and retroviruses integration site choice obtained by large-scale analyses indicate that transcription and chromatin structure play an important role in this process. The studies reported in this commentary add a new evidence of the importance of chromatin in integration selectivity that should be of interest for everyone interested in transposable elements integration.
Dynamic Behavior of Polycyclic Aromatic Hydrocarbons and Their Derivatives after Oils Spill in Water  [PDF]
Pranudda Pimsee, Caroline Sablayrolles, Mireille Montréjaud-Vignoles, Julien Guyomarch, Nicolas Lesage, Pascale de Caro
Journal of Environmental Protection (JEP) , 2014, DOI: 10.4236/jep.2014.58069

Within the framework of Migr’Hycar research project, the fate of oil spill was studied with the aim to characterize their physical-chemical behaviour. For this purpose, seven petroleum oils commercially available were tested and the distributions of the water soluble components were determined according to two experimental devices; laboratory conditions and pilot conditions in Polludrome. In the dissolved fraction, 41 polycyclic aromatic hydrocarbons and their derivates were quantified, among them are 16 EPA priority pollutants. A coupling of the stir bar sorptive extraction method and high performance gas chromatography mass spectrometry were used. Analyses showed that naphthalenes series constitute the major part of the water soluble fraction from fresh oils. In fact, light and heavy molecules have different contributions to solubilization kinetics. From the results, a linear correlation was established between the density of oils and the times of maximum solubilization. Moreover, the effect of 10% ethanol in gasoline was observed on the profile of solubilized PAHs in water. Kinetic patterns obtained with Polludrome showed the influence of surface water/oil ratio (WOR) on the volatilization process. Compared to laboratory conditions, the dynamic conditions of Polludrome led to an enhanced evaporation process, thus shifting the solubility peak.

Hierarchical Aggregate Assessment (HAA): An Assessment Process of Teams with Several Levels of Hierarchy in Education  [PDF]
Martin Lesage
Creative Education (CE) , 2016, DOI: 10.4236/ce.2016.714200
Abstract: Usually, the assessment of teams with several levels of hierarchy is done in the Management field with Management Information Systems (MIS). The problematics studied in the present paper is to consider the assessment of teams with several levels of hierarchy in the field of Education. Regarding this issue, very few authors and scientists have done work on these teams that have an inverted treelike structure similar as large organizations. Both teams studied in the Management and Education fields are evaluated by the processing of the information contained in each node of the three or by the work, production and performance of each individual with three traversal algorithms. In that particular case, links and similarities are established between Management and Education fields because both assess treelike structure organizations with several levels of hierarchy. The concept of Hierarchical Aggregate Assessment (HAA) is based on the assessment of teams with several levels of hierarchy in education. This assessment process is done on a treelike organization similar as the ones in management information systems. The process is done in three phases: the first phase consists in the team formation and the attribution of hierarchical levels to team members that is the aggregation process; the second phase is the presentation of a test or an assessment task done in team to the student; and the third phase is the team dislocation and the return to the initial phase until the course is done. This iterative process consists of the course curriculum management. While the process iterates, assessment data are collected through the process as summative and formative assessment data that can be used to determine the course success or to guide student for improvement. The aim of this paper is to define the HAA process in education that is similar to Management Information Systems (MIS). There is a lot of research and literature produced on Management Information Systems and also on teamwork assessment. In education, most of the research concerning teamwork assessment has been done on teams with a unique level of hierarchy. The main measurement tools to assess team in education according to previous research are team leaders and team member’s assessment grids. To explore this field of research, an E-Learning Internet application named “Cluster” has been developed with a research and development (R & D) methodology and tested with high school students and Army Cadets. Resistance to change has been a major obstacle to the implementation of the “Cluster” application in
Automatic estimation of optimal autoregressive filters for the analysis of volcanic seismic activity
P. Lesage
Natural Hazards and Earth System Sciences (NHESS) & Discussions (NHESSD) , 2008,
Abstract: Long-period (LP) events observed on volcanoes provide important information for volcano monitoring and for studying the physical processes in magmatic and hydrothermal systems. Of all the methods used to analyse this kind of seismicity, autoregressive (AR) modelling is particularly valuable, as it produces precise estimations of the frequencies and quality factors of the spectral peaks that are generated by resonance effects at seismic sources and, via deconvolution of the observed record, it allows the excitation function of the resonator to be determined. However, with AR modelling methods it is difficult to determine the order of the AR filter that will yield the best model of the signal. This note presents an algorithm to overcome this problem, together with some examples of applications. The approach described uses the kurtosis (fourth order cumulant) of the deconvolved signal to provide an objective criterion for selecting the filter order. This approach allows the partial automation of the AR analysis and thus provides interesting possibilities for improving volcano monitoring methods.
Les élastomères dans les industries pétrolière et parapétrolière Elastomers in the Oil and Automotive Industries
Lesage J.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1993025
Abstract: L'accroissement des contraintes subies par les matériaux utilisés dans les techniques pétrolières et parapétrolières et liées aux températures et pressions élevées ainsi qu'aux agressions chimiques, fait que l'on exige de ces matériaux qu'ils soient de plus en plus performants. Ceci implique, pour les concepteurs et utilisateurs de matériel comportant des élastomères en contact avec les hydrocarbures, une connaissance actualisée des produits existants, lesquels sont en constante évolution. On commence donc par décrire les principales familles d'élastomères résistant en milieu pétrolier actuellement disponibles sur le marché. Puis, après avoir évoqué les problèmes que rencontrent les industries pétrolière et automobile dans l'utilisation des élastomères et présenté sommairement les résultats de travaux réalisés à l'Institut Fran ais du Pétrole (IFP), on définira quelques axes de recherches dont la finalité est de participer à l'amélioration des techniques pétrolières dans le sens d'une meilleure fiabilité et d'une réduction des co ts. The materials used in the oil and automotive industries are being subjected to higher and higher mechanical, thermal and chemical stresses, so these materials, and especially elastomers, have to be more and more resistant. For designers and users of equipment containing elastomers in contact with hydrocarbons, this requires an updated understanding of existing products. The aim of this article is thus to describe, first of all, the leading families of resistant elastomers now available for use in a petroleum environment, with particular emphasis on chlorinated, fluorinated, acrylic and nitrile rubbers and their derivatives, which have evolved greatly in recent years with the appearance of new varieties and new types of elastomers, such as Atlas, Vamac, Eypel, etc. For each family of elastomer, the structure is described along with the vulcanization method, its properties and its uses. Then the problems with which elastomers are confronted in the petroleum industry are described. They are mainly linked to the high pressures and temperatures encoutered in boreholes and to chemical attacks due to acid gases, corrosion inhibitors and completion and treatment fluids. Elastomers must also be resistant to blistering, extrusion and abrasion. The proper choice of a material can lead to a reduction in operating costs and to increased safety. Concerted action among elastomer producers and users seems indispensable. Problems in the automotive industry are linked to the increase in thermal stresses due to the raising of the temperature u
Amélioration des propriétés des bétons pour les structures pétrolières en mer Improving Properties of Concrete for Offshore Petroleum Structures
Lesage J.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1981021
Abstract: L'intérêt de l'Institut Fran ais du Pétrole (IFP) pour le béton trouve sa source dans le développement relativement récent de structures en béton devant être mises en contact avec des produits pétroliers, telles que les réservoirs en mer, enterrés ou semi-enterrés. Bien que les ouvrages en mer aient généralement une bonne durabilité, il apparait intéressant de rechercher à améliorer les performances des bétons en vue de leurs applications dans les structures pétrolières marines. Les voies de recherche ont porté essentiellement, d'une part sur la réduction du rapport eau/ciment (E/C) auquel sont liées beaucoup de propriétés des bétons, en particulier l'étanchéité, et d'autre part sur l'allègement. La recherche de la réduction du rapport E/C a conduit à la mise au point des bétons étanches IFP. Il s'agit de bétons hydrauliques caractérisés par une fluidité exceptionnelle, une grande facilité de mise en place, une bonne imperméabilité aux hydrocarbures, à l'eau et aux gaz, une bonne résistance à l'abrasion et une excellente résistance aux agents agressifs. Bien que les premières applications industrielles soient terrestres, il s'agit d'un matériau bien adapté à la réalisation de structures pétrolières en mer. La deuxième voie de recherche concerne l'étude de bétons légers améliorés. L'allègement des structures pouvant être l'un des critères les plus recherchés pour l'utilisation de béton en mer, il était tout naturel d'essayer d'adapter au béton léger les formulations mises au point pour les bétons de densité normale. Les premiers résultats sont prometteurs et laissent entrevoir la possibilité de formuler des bétons légers de structure, étanches et résistants mécaniquement. Institut Fran ais du Pétrole (IFP) is interested in concrete because of the relatively recent development of concrete structures for use in contact with petroleum products, e. g. storage tanks, offshore tanks and buried or semiburied tanks. Although offshore structures are generally quite durable, it appeared interesting to try to improve the performances of concrete for use in offshore petroleum structures. Research has mainly been done (i) on reducing the water/cement (W/C) ratio which is of great importance in the properties of concrete, especially its leakproofness, and (ii) on making concrete lighter. Research on reducing the W/C ratio has resulted in the development of IFP leakproof concrete . This hydraulic concrete is characterized by exceptional fluidity, great ease of installation, good impermeability to hydrocarbons and to water and gas, good resistance to abrasion and excell
L’impossible seconde vie ? Le poids des standards éditoriaux et la résistance de la bande dessinée franco-belge au format de poche
Sylvain Lesage
Comicalités : études de Culture Graphique , 2011, DOI: 10.4000/comicalites.221
Abstract: Si le livre de poche a joué un r le central dans la diffusion du patrimoine littéraire, la bande dessinée ne dispose pas de cet outil permettant la constitution d’un corpus de classiques aisément accessibles au plus grand nombre. En ceci, la bande dessinée constitue bien une véritable exception dans le champ éditorial fran ais, par la quasi-absence de collections permettant de republier des classiques en format de poche. L’importance de l’image et l’impératif de lisibilité compliquent en effet le problème de l’adaptation du grand format vers le poche, mais demeurent insuffisants pour comprendre la réticence de la bande dessinée au poche. Le présent article propose un retour en arrière sur les expériences des années 1980-1990, afin de mieux cerner cette singularité éditoriale.
Human Face Recognition, Information Processing and Social Behavior in Children with Autism  [PDF]
Pascale Planche
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.511147

The aim of this study was to investigate whether children with high-functioning autism (HFA) and Asperger’s syndrome (AS) can be differentiated from each other and from typically developing children in ability to recognize a human face. The present study included 69 participants: children with autism (high-functioning autism or Asperger’s syndrome, n = 15 per group) and a control group of 39 typically developing children. It involved a face recognition task included in the NEPSY scale. Results showed that the autism groups performed poorer than the typically developing group, but no difference was found between high-functioning and Asperger groups. Both the information processing peculiarities of children with autism and their (interactional and communicative) social impairments could explain their difficulty to recognize human faces.

Fully On-Chip Integrated Photodetector Front-End Dedicated to Real-Time Portable Optical Brain Imaging  [PDF]
Ehsan Kamrani, Frederic Lesage, Mohamad Sawan
Optics and Photonics Journal (OPJ) , 2012, DOI: 10.4236/opj.2012.24037

Optical brain imaging using functional near infra-red spectroscopy (fNIRS) offers a portable and noninvasive tool for monitoring of blood oxygenation. In this paper we have introduced a new miniaturized photodetector front-end on achip to be applied in a portable fNIRS system. It includes silicon avalanche photodiodes (SiAPD), Transimpedance amplifier (TIA) front-end and Quench-Reset circuitry to operate in both linear and Geiger modes. So it can be applied for both continuous-wave fNIRS (CW-fNIRS) and also single-photon counting. Proposed SiAPD exhibits high-avalanche gain (>100), low-breakdown voltage (<12 V) and high photon detection efficiency accompanying with low dark count rates. The proposed TIA front-end offer a low power consumption (<1 mW), high-transimpedance gain (up to 250 MV/A), tunable bandwidth (1 kHz - 1 GHz) and very low input and output noise (~few fA/√Hz and few μV/√Hz). The Geiger-mode photon counting front-end also exhibits a controllable hold-off and rest time with an ultra fast quench-reset time (few ns). This integrated system has been implemented using submicron (0.35 μm) standard CMOS technology.

First Record of the European Rusted Flea Beetle, Neocrepidodera ferruginea (Scopoli, 1763), in North America (Coleoptera: Chrysomelidae: Galerucinae: Alticini)
Laurent LeSage,Karine Savard
Psyche , 2012, DOI: 10.1155/2012/387564
Abstract: The European rusted flea beetle Neocrepidodera ferruginea (Scopoli, 1763) is reported for the first time from Québec and Ontario, Canada. It was likely introduced into southern Ontario at an international port on the Great Lakes in early 1970s, or possibly earlier in the 1960s. However, the exact location and date of introduction could not be precisely determined. The flea beetle has since dispersed northeastwards and reached Aylmer, north of Ottawa River, in Québec, by 2003. This is about 375 km from Niagara Falls, where the oldest known specimens were collected in 1977. In 2009, various wild habitats and cultivated areas of Aylmer were surveyed. The host plants of the larvae could not be determined, but adults were swept from many plant species including various weeds and cultivated grasses: Alopecurus pratense (meadow foxtail), Dactylis glomerata (orchard-grass), Festuca rubra (red fescue-grass), and Poa pratensis (Kentucky blue-grass). Adults were also collected from flowers of several weeds: Aster sp. (undetermined species), Aster novae-angliae (New England aster), Ambrosia artemisiifolia (small ragweed), Echium vulgare (viper’s bugloss), Nasturtium officinale (water cress), Melilotus alba (white sweet-clover), Hypericum perforatum (common St. John’s-wort), Lythrum salicaria (purple loosestrife), Ranunculus acris (buttercup), and Solidago spp. (goldenrods). Since larvae are known to develop inside the roots and central stems of cereals, this new alien species represents a threat to Canadian agriculture, particularly if it reaches the Prairies in western Canada, where cereals represent a considerable part of their economy. European rusted flea beetle and Altise ferrugineuse européenne are suggested for the English and French common names of this flea beetle, respectively.
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