979 resultados para Représentations externes et concept-mapping


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Traceability is a concept that arose from the need for monitoring of production processes, this concept is usually used in sectors related to food production or activities involving some kind of direct risk to people. Agribusiness in the cotton industry does not have a comprehensive infrastructure for all stages of the processes involved in production. Map and define the data to enable traceability of products is synonymous to delegate responsibilities for all involved in the production, the collection of aggregate data on cotton production is done in stages and specific pre-defined since the choice of the variety through the processing, the scope of this article specifically addresses the production of lint cotton. The paper presents a proposal based on service oriented architecture (SOA) for data integration processes in the cotton industry, this proposal provide support for the implementation of platform independent solutions.

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Background The genetic mechanisms underlying interindividual blood pressure variation reflect the complex interplay of both genetic and environmental variables. The current standard statistical methods for detecting genes involved in the regulation mechanisms of complex traits are based on univariate analysis. Few studies have focused on the search for and understanding of quantitative trait loci responsible for gene × environmental interactions or multiple trait analysis. Composite interval mapping has been extended to multiple traits and may be an interesting approach to such a problem. Methods We used multiple-trait analysis for quantitative trait locus mapping of loci having different effects on systolic blood pressure with NaCl exposure. Animals studied were 188 rats, the progenies of an F2 rat intercross between the hypertensive and normotensive strain, genotyped in 179 polymorphic markers across the rat genome. To accommodate the correlational structure from measurements taken in the same animals, we applied univariate and multivariate strategies for analyzing the data. Results We detected a new quantitative train locus on a region close to marker R589 in chromosome 5 of the rat genome, not previously identified through serial analysis of individual traits. In addition, we were able to justify analytically the parametric restrictions in terms of regression coefficients responsible for the gain in precision with the adopted analytical approach. Conclusion Future work should focus on fine mapping and the identification of the causative variant responsible for this quantitative trait locus signal. The multivariable strategy might be valuable in the study of genetic determinants of interindividual variation of antihypertensive drug effectiveness.

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Abstract Background Tachycardia is commonly observed in hypertensive patients, predominantly mediated by regulatory mechanisms integrated within the autonomic nervous system. The genetic loci and genes associated with increased heart rate in hypertension, however, have not yet been identified. Methods An F2 intercross of Spontaneously Hypertensive Rats (SHR) × Brown Norway (BN) linkage analysis of quantitative trait loci mapping was utilized to identify candidate genes associated with an increased heart rate in arterial hypertension. Results Basal heart rate in SHR was higher compared to that of normotensive BN rats (365 ± 3 vs. 314 ± 6 bpm, p < 0.05 for SHR and BN, respectively). A total genome scan identified one quantitative trait locus in a 6.78 cM interval on rat chromosome 8 (8q22–q24) that was responsible for elevated heart rate. This interval contained 241 genes, of which 65 are known genes. Conclusion Our data suggest that an influential genetic region located on the rat chromosome 8 contributes to the regulation of heart rate. Candidate genes that have previously been associated with tachycardia and/or hypertension were found within this QTL, strengthening our hypothesis that these genes are, potentially, associated with the increase in heart rate in a hypertension rat model.

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Abstract Background RNAs transcribed from intronic regions of genes are involved in a number of processes related to post-transcriptional control of gene expression. However, the complement of human genes in which introns are transcribed, and the number of intronic transcriptional units and their tissue expression patterns are not known. Results A survey of mRNA and EST public databases revealed more than 55,000 totally intronic noncoding (TIN) RNAs transcribed from the introns of 74% of all unique RefSeq genes. Guided by this information, we designed an oligoarray platform containing sense and antisense probes for each of 7,135 randomly selected TIN transcripts plus the corresponding protein-coding genes. We identified exonic and intronic tissue-specific expression signatures for human liver, prostate and kidney. The most highly expressed antisense TIN RNAs were transcribed from introns of protein-coding genes significantly enriched (p = 0.002 to 0.022) in the 'Regulation of transcription' Gene Ontology category. RNA polymerase II inhibition resulted in increased expression of a fraction of intronic RNAs in cell cultures, suggesting that other RNA polymerases may be involved in their biosynthesis. Members of a subset of intronic and protein-coding signatures transcribed from the same genomic loci have correlated expression patterns, suggesting that intronic RNAs regulate the abundance or the pattern of exon usage in protein-coding messages. Conclusion We have identified diverse intronic RNA expression patterns, pointing to distinct regulatory roles. This gene-oriented approach, using a combined intron-exon oligoarray, should permit further comparative analysis of intronic transcription under various physiological and pathological conditions, thus advancing current knowledge about the biological functions of these noncoding RNAs.

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Financial support. Brazilian Ministry of Science and Technology (CNPq Grant 577047-2008-6), FAP-DF NEXTREE Grant 193.000.570/2009 and EMBRAPA Macroprogram 2 project grant 02.07.01.004.

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Background Diminishing supplies of fossil fuels and oil spills are rousing to explore the alternative sources of energy that can be produced from non-food/feed-based substrates. Due to its abundance, sugarcane bagasse (SB) could be a model substrate for the second-generation biofuel cellulosic ethanol. However, the efficient bioconversion of SB remains a challenge for the commercial production of cellulosic ethanol. We hypothesized that oxalic-acid-mediated thermochemical pretreatment (OAFEX) would overcome the native recalcitrance of SB by enhancing the cellulase amenability toward the embedded cellulosic microfibrils. Results OAFEX treatment revealed the solubilization of hemicellulose releasing sugars (12.56 g/l xylose and 1.85 g/l glucose), leaving cellulignin in an accessible form for enzymatic hydrolysis. The highest hydrolytic efficiency (66.51%) of cellulignin was achieved by enzymatic hydrolysis (Celluclast 1.5 L and Novozym 188). The ultrastructure characterization of SB using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Fourier transform–near infrared spectroscopy (FT-NIR), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed structural differences before and after OAFEX treatment with enzymatic hydrolysis. Furthermore, fermentation mediated by C. shehatae UFMG HM52.2 and S. cerevisiae 174 showed fuel ethanol production from detoxified acid (3.2 g/l, yield 0.353 g/g; 0.52 g/l, yield, 0.246 g/g) and enzymatic hydrolysates (4.83 g/l, yield, 0.28 g/g; 6.6 g/l, yield 0.46 g/g). Conclusions OAFEX treatment revealed marked hemicellulose degradation, improving the cellulases’ ability to access the cellulignin and release fermentable sugars from the pretreated substrate. The ultrastructure of SB after OAFEX and enzymatic hydrolysis of cellulignin established thorough insights at the molecular level.

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Abstract Background Delignification pretreatments of biomass and methods to assess their efficacy are crucial for biomass-to-biofuels research and technology. Here, we applied confocal and fluorescence lifetime imaging microscopy (FLIM) using one- and two-photon excitation to map the lignin distribution within bagasse fibers pretreated with acid and alkali. The evaluated spectra and decay times are correlated with previously calculated lignin fractions. We have also investigated the influence of the pretreatment on the lignin distribution in the cell wall by analyzing the changes in the fluorescence characteristics using two-photon excitation. Eucalyptus fibers were also analyzed for comparison. Results Fluorescence spectra and variations of the decay time correlate well with the delignification yield and the lignin distribution. The decay dependences are considered two-exponential, one with a rapid (τ1) and the other with a slow (τ2) decay time. The fastest decay is associated to concentrated lignin in the bagasse and has a low sensitivity to the treatment. The fluorescence decay time became longer with the increase of the alkali concentration used in the treatment, which corresponds to lignin emission in a less concentrated environment. In addition, the two-photon fluorescence spectrum is very sensitive to lignin content and accumulation in the cell wall, broadening with the acid pretreatment and narrowing with the alkali one. Heterogeneity of the pretreated cell wall was observed. Conclusions Our results reveal lignin domains with different concentration levels. The acid pretreatment caused a disorder in the arrangement of lignin and its accumulation in the external border of the cell wall. The alkali pretreatment efficiently removed lignin from the middle of the bagasse fibers, but was less effective in its removal from their surfaces. Our results evidenced a strong correlation between the decay times of the lignin fluorescence and its distribution within the cell wall. A new variety of lignin fluorescence states were accessed by two-photon excitation, which allowed an even broader, but complementary, optical characterization of lignocellulosic materials. These results suggest that the lignin arrangement in untreated bagasse fiber is based on a well-organized nanoenvironment that favors a very low level of interaction between the molecules.

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Abstract Background The database of sugarcane expressed sequence tags (EST) offers a great opportunity for developing molecular markers that are directly associated with important agronomic traits. The development of new EST-SSR markers represents an important tool for genetic analysis. In sugarcane breeding programs, functional markers can be used to accelerate the process and select important agronomic traits, especially in the mapping of quantitative traits loci (QTL) and plant resistant pathogens or qualitative resistance loci (QRL). The aim of this work was to develop new simple sequence repeat (SSR) markers in sugarcane using the sugarcane expressed sequence tag (SUCEST database). Findings A total of 365 EST-SSR molecular markers with trinucleotide motifs were developed and evaluated in a collection of 18 genotypes of sugarcane (15 varieties and 3 species). In total, 287 of the EST-SSRs markers amplified fragments of the expected size and were polymorphic in the analyzed sugarcane varieties. The number of alleles ranged from 2-18, with an average of 6 alleles per locus, while polymorphism information content values ranged from 0.21-0.92, with an average of 0.69. The discrimination power was high for the majority of the EST-SSRs, with an average value of 0.80. Among the markers characterized in this study some have particular interest, those that are related to bacterial defense responses, generation of precursor metabolites and energy and those involved in carbohydrate metabolic process. Conclusions These EST-SSR markers presented in this work can be efficiently used for genetic mapping studies of segregating sugarcane populations. The high Polymorphism Information Content (PIC) and Discriminant Power (DP) presented facilitate the QTL identification and marker-assisted selection due the association with functional regions of the genome became an important tool for the sugarcane breeding program.

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Network virtualization is a promising technique for building the Internet of the future since it enables the low cost introduction of new features into network elements. An open issue in such virtualization is how to effect an efficient mapping of virtual network elements onto those of the existing physical network, also called the substrate network. Mapping is an NP-hard problem and existing solutions ignore various real network characteristics in order to solve the problem in a reasonable time frame. This paper introduces new algorithms to solve this problem based on 0–1 integer linear programming, algorithms based on a whole new set of network parameters not taken into account by previous proposals. Approximative algorithms proposed here allow the mapping of virtual networks on large network substrates. Simulation experiments give evidence of the efficiency of the proposed algorithms.

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The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project.

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[EN] The purpose of this paper is to present a fixed point theorem for generalized contractions in partially ordered complete metric spaces. We also present an application to first-order ordinary differential equations.

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[FR]Dans cet article, la notion de réalisme magique est appliquée à la littérature québécoise. D’abord l’auteure présente le concept afin de bien préciser ses traits caractéristiques. Ensuite, elle analyse le roman historique La tribu de l’écrivain québécois François Barceloen essayant de mettre en lumière son appartenance à cette tendance latino-américaine. Cet examen permet d’enrichir de nouveaux aspectsl’analyse des lettres du Québec.

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Entre les années 1950 et 1980, émerge une nouvelle forme de labyrinthe chez des romanciers européens comme Michel Butor, Alain Robbe-Grillet, Italo Calvino, Patrick Modiano et Alasdair Gray : un labyrinthe insaisissable et non cartographiable. Pour en rendre compte nous avons recours au modèle du rhizome, issu de la philosophie de Gilles Deleuze et de Félix Guattari, aussi bien qu'au concept d'hétérotopie de Michel Foucault. La spatialité de nos romans nous pousse à prendre en compte également les réécritures ironiques du mythe de Thésée, Ariane, le Minotaure, Dédale. Les citations et les allusions au mythe nous font remarquer la distance d'avec le modèle traditionnel et les effets de ce qu'on peut considérer comme un « bricolage mythique », dans le cadre d'un regard ironique, parodique ou satirique. La représentation romanesque du labyrinthe accentue d'un côté l'absence d'un centre, et de l'autre côté l'ouverture extrême de cet espace qu'est la ville contemporaine. En même temps, la présence de nombreux « espaces autres », les hétérotopies de Foucault, définit l'égarement des protagonistes des romans. Au fur et à mesure que les écrivains acquièrent conscience des caractéristiques « labyrinthiques » de ces espaces, celles-ci commencent à informer l'œuvre romanesque, créant ainsi un espace métafictionnel. Entre les années Cinquante et le début des années Soixante-dix, les Nouveaux romanciers français accentuent ainsi l'idée de pouvoir jouer avec les instruments de la fiction, pour exaspérer l'absence d'un sens dans la ville comme dans la pratique de l'écriture. Calvino reformule cette conception du roman, remarquant l'importance d'un sens, même s'il est caché et difficile à saisir. Pour cette raison, à la fin de l'époque que nous analysons, des auteurs comme Modiano et Gray absorbent les techniques d'écriture de ces prédécesseurs, en les faisant jouer avec la responsabilité éthique de l'auteur.

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La tesi di ricerca si propone di esaminare due tipologie della canzone sociale nel XIX secolo, ed in particolare attorno al 1848. Lo studio del canto nei contesti presi in esame (l’Italia e la Francia) viene analizzato attraverso due piste di ricerca parallele tra loro. Da una parte si è utilizzato il concetto di sociabilité per conoscere i luoghi di produzione e di diffusione del canto (l’importanza della strada, dell’osteria, delle goguette parigine, degli chansonniers des rues e dei cantastorie) e le circostanze di utilizzazione della canzone (la canzone in quanto forma d’espressione orale ma anche come scrittura murale, foglio volante e volantino). Dall’altra l’analisi si è focalizzata sui contenuti dei testi musicali per mette in luce le differenti tematiche, le immagini linguistiche e le figure retoriche cantate dall’artigiano-operaio per far emergere le differenze dell’idea di nazione tra i due contesti presi in esame. L’attenzione posta alla comparazione condurrà all’evidenziazione di punti di contatto tra le due nazioni. Il canto, infatti, costituisce un terreno privilegiato per comprendere l’immagine dell’“altro”: quale immagine possedevano i lavoratori francesi dell’Italia risorgimentale? E gli artigiani italiani come percepivano la nazione francese? Il canto viene analizzato non solamente come un “testo” ma anche come una “pratica sociale”. Queste operazioni permetteranno di sondare più in profondità la funzione sociale svolta dalla canzone all’interno della cultura popolare e la sua importanza in quanto forma d’espressione e vettore di politicizzazione. La duplice utilizzazione del canto, in quanto “testo” e “pratica”, consente di inserire la ricerca all’interno di un filone storiografico che dalla storia sociale si muove a quella culturale. La canzone sociale rappresenta un fertile terreno di ricerca, non solamente all’interno di un singolo territorio nazionale, ma possiede un prezioso valore euristico in funzione comparativa.

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Les recherches relatives à l'utilisation des TICE se concentrent fréquemment soit sur la dimension cognitive, sur la dimension linguistique ou sur la dimension culturelle. Le plus souvent, les recherches empiriques se proposent d'évaluer les effets directs des TICE sur les performances langagières des apprenants. En outre, les recherches, surtout en psychologie cognitive, sont le plus souvent effectuées en laboratoire. C'est pourquoi le travail présenté dans cette thèse se propose d'inscrire l'utilisation des TICE dans une perspective écologique, et de proposer une approche intégrée pour l'analyse des pratiques effectives aussi bien en didactique des langues qu'en didactique de la traduction. En ce qui concerne les aspects cognitifs, nous recourons à un concept apprécié des praticiens, celui de stratégies d'apprentissage. Les quatre premiers chapitres de la présente thèse sont consacrés à l'élaboration du cadre théorique dans lequel nous inscrivons notre recherche. Nous aborderons en premier lieu les aspects disciplinaires, et notamment l’interdisciplinarité de nos deux champs de référence. Ensuite nous traiterons les stratégies d'apprentissage et les stratégies de traduction. Dans un troisième mouvement, nous nous efforcerons de définir les deux compétences visées par notre recherche : la production écrite et la traduction. Dans un quatrième temps, nous nous intéresserons aux modifications introduites par les TICE dans les pratiques d'enseignement et d'apprentissage de ces deux compétences. Le cinquième chapitre a pour objet la présentation, l'analyse des données recueillies auprès de groupes d'enseignants et d'étudiants de la section de français de la SSLMIT. Il s’agira dans un premier temps, de présenter notre corpus. Ensuite nous procéderons à l’analyse des données. Enfin, nous présenterons, après une synthèse globale, des pistes didactiques et scientifiques à même de prolonger notre travail.