81 research outputs found

    Seminar as a way to educate engineering students on environmental challenges in the textile industry

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    The Ecole Nationale Supérieure des Arts et Industries Textiles (ENSAIT) is one of the few schools specialising in materials for the textile industry. Each year it graduates around 110 engineers whose role is to meet the challenges of the sector while respecting the values of the companies and environmental standards. The ENSAIT engineer's course takes place over three years. From the first year of the engineering cycle, a seminar on sustainable development is offered. It is held in the second semester and lasts two full days. The first objective is to make them aware of corporate social responsibility (CSR) issues in companies. The second is to build on the knowledge acquired during the last 6 months to develop the life cycle of a garment and understand the associated impacts. Finally, it is to highlight the different possible strategies based on eco-design, fair trade, taking into account the regulatory constraints. This seminar is based on active pedagogy, where students work in teams and compare their results with each other. It also aims to provide the minimum tools to understand ecodesign strategies and to be an informed fashion consumer, and to become a textile engineer capable of participating in and technically supporting companies' CSR initiatives

    Genomes of three tomato pathogens within the Ralstonia solanacearum species complex reveal significant evolutionary divergence

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    <p>Abstract</p> <p>Background</p> <p>The <it>Ralstonia solanacearum </it>species complex includes thousands of strains pathogenic to an unusually wide range of plant species. These globally dispersed and heterogeneous strains cause bacterial wilt diseases, which have major socio-economic impacts. Pathogenicity is an ancestral trait in <it>R. solanacearum </it>and strains with high genetic variation can be subdivided into four phylotypes, correlating to isolates from Asia (phylotype I), the Americas (phylotype IIA and IIB), Africa (phylotype III) and Indonesia (phylotype IV). Comparison of genome sequences strains representative of this phylogenetic diversity can help determine which traits allow this bacterium to be such a pathogen of so many different plant species and how the bacteria survive in many different habitats.</p> <p>Results</p> <p>The genomes of three tomato bacterial wilt pathogens, CFBP2957 (phy. IIA), CMR15 (phy. III) and PSI07 (phy. IV) were sequenced and manually annotated. These genomes were compared with those of three previously sequenced <it>R. solanacearum </it>strains: GMI1000 (tomato, phy. I), IPO1609 (potato, phy. IIB), and Molk2 (banana, phy. IIB). The major genomic features (size, G+C content, number of genes) were conserved across all of the six sequenced strains. Despite relatively high genetic distances (calculated from average nucleotide identity) and many genomic rearrangements, more than 60% of the genes of the megaplasmid and 70% of those on the chromosome are syntenic. The three new genomic sequences revealed the presence of several previously unknown traits, probably acquired by horizontal transfers, within the genomes of <it>R. solanacearum</it>, including a type IV secretion system, a rhi-type anti-mitotic toxin and two small plasmids. Genes involved in virulence appear to be evolving at a faster rate than the genome as a whole.</p> <p>Conclusions</p> <p>Comparative analysis of genome sequences and gene content confirmed the differentiation of <it>R. solanacearum </it>species complex strains into four phylotypes. Genetic distances between strains, in conjunction with CGH analysis of a larger set of strains, revealed differences great enough to consider reclassification of the <it>R. solanacearum </it>species complex into three species. The data are still too fragmentary to link genomic classification and phenotypes, but these new genome sequences identify a pan-genome more representative of the diversity in the <it>R. solanancearum </it>species complex.</p

    Genome sequencing of Xanthomonas axonopodis pv. phaseoli CFBP4834-R reveals that flagellar motility is not a general feature of xanthomonads.

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    Xanthomonads are plant-associated bacteria that establish neutral, commensal or pathogenic relationships with plants. The list of common characteristics shared by all members of the genus Xanthomonas is now well established based on the entire genome sequences that are currently available and that represent various species, numerous pathovars of X. axonopodis (sensu Vauterin et al., 2000), X. oryzae and X. campestris, and many strains within some pathovars. These ?-proteobacteria are motile by a single polar flagellum. Motility is an important feature involved in biofilm formation, plant colonization and hence considered as a pathogenicity factor. X. axonopodis pv. phaseoli var. fuscans (Xapf) is one of the causal agents of common bacterial blight of bean and 4834-R is a highly aggressive strain of this pathogen that was isolated from a seed-borne epidemic in France in 1998. We obtained a high quality assembled sequence of the genome of this strain with 454-Solexa and 2X Sanger sequencing. Housekeeping functions are conserved in this genome that shares core characteristics with genomes of other xanthomonads: the six secretion systems which have been described so far in Gram negative bacteria are all present, as well as their ubiquitous substrates or effectors and a rather usual number of mobile elements. Elements devoted to the adaptation to the environment constitute an important part of the genome with a chemotaxis island and dispersed MCPs, numerous two-component systems, and numerous TonB dependent transporters. Furthermore, numerous multidrug efflux systems and functions dedicated to biofilm formation that confer resistance to stresses are also present. An intriguing feature revealed by genome analysis is a long deletion of 35 genes (33 kbp) involved in flagellar biosynthesis. This deletion is replaced by an insertion sequence called ISXapf2. Genes such as flgB to flgL and fliC to fleQ which are involved in the flagellar structure (rod, P- and L-ring, hook, cap and filament) are absent in the genome of strain 4834-R that is not motile. Primers were designed to detect this deletion by PCR in a collection of more than 300 strains representing different species and pathovars of Xanthomonas, and less than 5% of the tested xanthomonads strains were found nonmotile because of a deletion in the flagellum gene cluster. We observed that half of the Xapf strains isolated from the same epidemic than strain 4834-R was non-motile and that this ratio was conserved in the strains colonizing the next bean seed generation. Isolation of such variants in a natural epidemic reveals that either flagellar motility is not a key function for fitness or that some complementation occurs within the bacterial population. (Résumé d'auteur

    Multilocus variable number of tandem repeat analysis reveals multiple introductions in Spain of Xanthomonas arboricola pv. Pruni, the causal agent of bacterial spot disease of stone fruits and almond

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    Xanthomonas arboricola pv. pruni is the causal agent of the bacterial spot disease of stone fruits, almond and some ornamental Prunus species. In Spain it was first detected in 2002 and since then, several outbreaks have occurred in different regions affecting mainly Japanese plum, peach and almond, both in commercial orchards and nurseries. As the origin of the introduction(s) was unknown, we have assessed the genetic diversity of 239 X. arboricola pv. pruni strains collected from 11 Spanish provinces from 2002 to 2013 and 25 reference strains from international collections. We have developed an optimized multilocus variable number of tandem repeat analysis (MLVA) scheme targeting 18 microsatellites and five minisatellites. A high discriminatory power was achieved since almost 50% of the Spanish strains were distinguishable, confirming the usefulness of this genotyping technique at small spatio-temporal scales. Spanish strains grouped in 18 genetic clusters (conservatively delineated so that each cluster contained haplotype networks linked by up to quadruple-locus variations). Furthermore, pairwise comparisons among populations from different provinces showed a strong genetic differentiation. Our results suggest multiple introductions of this pathogen in Spain and redistribution through contaminated nursery propagative plant material

    Origin and mobility of Iron Age Gaulish groups in present-day France revealed through archaeogenomics

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    The Iron Age period occupies an important place in French history, as the Gauls are regularly presented as the direct ancestors of the extant French population. We documented here the genomic diversity of Iron Age communities originating from six French regions. The 49 acquired genomes permitted us to highlight an absence of discontinuity between Bronze Age and Iron Age groups in France, lending support to a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. Genomic analyses revealed strong genetic homogeneity among the regional groups associated with distinct archaeological cultures. This genomic homogenisation appears to be linked to individuals’ mobility between regions as well as gene flow with neighbouring groups from England and Spain. Thus, the results globally support a common genomic legacy for the Iron Age population of modern-day France that could be linked to recurrent gene flow between culturally differentiated communities

    Genome sequence of Xanthomonas fuscans subsp. fuscans strain 4834-R reveals that flagellar motility is not a general feature of xanthomonads

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    Abstract\ud \ud \ud \ud Background\ud Xanthomonads are plant-associated bacteria responsible for diseases on economically important crops. Xanthomonas fuscans subsp. fuscans (Xff) is one of the causal agents of common bacterial blight of bean. In this study, the complete genome sequence of strain Xff 4834-R was determined and compared to other Xanthomonas genome sequences.\ud \ud \ud \ud Results\ud Comparative genomics analyses revealed core characteristics shared between Xff 4834-R and other xanthomonads including chemotaxis elements, two-component systems, TonB-dependent transporters, secretion systems (from T1SS to T6SS) and multiple effectors. For instance a repertoire of 29 Type 3 Effectors (T3Es) with two Transcription Activator-Like Effectors was predicted. Mobile elements were associated with major modifications in the genome structure and gene content in comparison to other Xanthomonas genomes. Notably, a deletion of 33 kbp affects flagellum biosynthesis in Xff 4834-R. The presence of a complete flagellar cluster was assessed in a collection of more than 300 strains representing different species and pathovars of Xanthomonas. Five percent of the tested strains presented a deletion in the flagellar cluster and were non-motile. Moreover, half of the Xff strains isolated from the same epidemic than 4834-R was non-motile and this ratio was conserved in the strains colonizing the next bean seed generations.\ud \ud \ud \ud Conclusions\ud This work describes the first genome of a Xanthomonas strain pathogenic on bean and reports the existence of non-motile xanthomonads belonging to different species and pathovars. Isolation of such Xff variants from a natural epidemic may suggest that flagellar motility is not a key function for in planta fitness.AI is funded by a PhD grant from INRA-SPE and region Pays de la Loire, France. EG was funded by a PhD grant from the French Ministry of National Education and Research and French Guyana. SC, EG, MA, EL and LDN are funded by the LABEX TULIP (ANR-10-LABX-41), LSG is funded by ANR-2010-GENM-013 Xanthomix

    Lexicographie et dictionnairique d'un dictionnaire de spécialité traitant de sport (un cas d'application, le "Dictionnaire du rugby - L'Ovalie dans tous ses sens".)

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    Dans un premier temps, afin de définir et de créer une typologie des ouvrages dictionnairiques existants concernant le sport, plus de 400 disciplines sportives ont été identifiées et plus de 200 ont été définies (celles qui étaient les moins répandues dans le monde). Elles ont été ensuite classées dans 19 groupes thématiques, classement qui a été par la suite soumis à une analyse critique. L'ensemble de ces disciplines a permis de référencer près de 500 ouvrages dictionnairiques à partir desquels différents critères d'élaboration d'un dictionnaire de spécialité ont pu être établis. Ainsi, les critères les plus pertinents et les plus adaptés ont été choisis pour élaborer le "Dictionnaire du rugby L'Ovalie dans tous ses sens".Dans un second temps, une approche concernant ce dictionnaire de spécialité a été présentée en précisant les choix concernant, d'une part, le sujet, et d'autre part, la philosophie d'un tel ouvrage. Cette réflexion a porté sur l'objectif d'un tel dictionnaire, sur le public visé, sur la façon dont il a été rédigé ainsi que sur sa structure. En outre, il a été pertinent d'analyser le traitement du terme rugby (et de son vocabulaire) dans une quinzaine d'ouvrages. Enfin, une étude a été entreprise pour proposer la méthodologie concernant l'élaboration du "Dictionnaire du rugby L'Ovalie dans tous ses sens" en insistant notamment sur le protocole de rédaction, sur la création de la charte graphique, sur la présentation du paratexte, sur l'élaboration de la nomenclature, sur les différentes étapes de la rédaction et sur celles de la correction.Firstly, in order to define and create a typology of existing dictionaries concerning sport, we identified more than 400 sports and among them we defined more than 200 sports (those which were the less common around the world). We then classified them into 19 thematic groups, which classification has been submitted to a technical review. All these sports have allowed us to reference near to 500 dictionaries from which we have been able to identify the various criteria which enable the writing of specialty dictionaries. We have chosen the most relevant and suitable criteria to write our "Dictionnaire du rugby L'Ovalie dans tous ses sens".Secondly, we described our approach concerning this specialty dictionary by specifying our thought and choices related to, on the one hand, the subject and, on the other hand, the philosophy of a work of this kind. This reflection covered the objective of such a dictionary, the targeted public, the way it has been written and its structure. Furthermore, we considered the treatment of the term rugby (and of its vocabulary) in about fifteen books. Finally, we proposed our methodology for the writing of the "Dictionnaire du rugby L'Ovalie dans tous ses sens" focusing in particular on the protocol of writing, the creation of a graphic chart, the presentation of the paratext, the conception of a nomenclature, and on the different steps of the writing and the rectifications.CERGY PONTOISE-Bib. electronique (951279901) / SudocSudocFranceF
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