Résumé : Le laboratoire IFREMER "Génétique Aquaculture et Pathologie" (GAP) (La Tremblade et Bouin) a entrepris des actions de recherche sur ces différents points. L'Unité de Recherche en Génétique, en collaboration avec tous les membres du Réseau Génétique Mollusques (REGEMO), a axé une partie de ses travaux sur l'acclimatation et l'hybridation de différentes espèces du genre Crassostrea. Ces recherches ont débuté avec le soutien du Conseil Général de Charente-Maritime depuis 1992 sur des essais d'acclimatation de C. virginica, l'huître creuse américaine. En prolongement de cette étude, l'URGE a proposé à la région Poitou-Charentes un programme de recherche plus vaste sur l'ensemble des espèces d'huîtres creuses.

Droits : 1995 Ifremer
http://archimer.ifremer.fr/doc/00044/15515/12902.pdf
http://archimer.ifremer.fr/doc/00044/15515/

Éditeur(s) : Inter-Research
Résumé : The marine environment is of special interest for studying hybridization between closely related taxa because of the high dispersal potential of planktonic larvae, such as those of most bivalve species. The oysters Crassostrea angulata and C. gigas are known to be very close genetically and entirely inter-fertile under controlled conditions. However, hybridization in the wild had not been investigated, mainly due to the lack of nuclear diagnostic markers. In the present paper, we first estimated genetic differentiation between these 2 closely related taxa using 8 microsatellite markers. Interestingly, 5 markers displayed significant differences of allele size between taxa. The subsequent sequencing of alleles of one of these microsatellites showed several mutational events, which suggested null alleles and homoplasy. The presence of 1 insertion/deletion event in its 5' flanking sequence enabled us to design a new bi-allelic ('C' and 'NC') nuclear PCR-restriction fragment length polymorphism (-RFLP) marker (CG44R). This, together with a mitochondrial DNA marker, was used to analyze populations of C. angulata and C. gigas. The CG44R allele frequencies were very different between C. angulata (f[C] = 0.91) and C. gigas (f[NC] = 0.92) populations. This analysis also provided evidence for hybridization between C. angulata and C. gigas in a wild Portuguese population where the 2 taxa are in contact due to recent transportation of C. gigas stocks for aquacultural production. Our results represent the first indication of hybridization between these 2 taxa in the natural environment, and contribute to knowledge of the evolutionary history of the Crassostrea genus.
Marine Ecology Progress Series (0171-8630) (Inter-Research), 2004 , Vol. 272 , P. 141-152

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2004/publication-3355.pdf
http://archimer.ifremer.fr/doc/00000/3355/

Éditeur(s) : HAL CCSD Kluwer
Résumé : This paper presents some considerations about hybrid optimization algorithms useful to optimize real complex system. The given indication could be used by readers to conceive hybrid algorithms. These considerations have been deducted from a concrete application case: the satellites constellations design problem. But each of the advanced techniques proposed in this paper are considered in a more general way to solve other problems. This problem is used to illustrate the techniques along the paper because it is grouping many characteristics (di culties) of contemporary real complex systems: the size and the characteristics of the search space engendered by a combinatorial problem; The irregularity of the criterions; The mathematical and physical heterogeneity of parameters forbids the use of classical algorithms; The evaluation of a solution, which uses a time consuming simulation; A need of accurate values. More details are available in previous papers ([?], [?], [?], [?]). For these reasons, we could learn a lot from this experiment in order to detach hybrid techniques usable for problems having close characteristics. This paper presents the historic leading to the current algorithm, the modeling of the complex system and the sophisticated algorithm proposed to optimize it. Application cases and ways to built signi cant tests of hybrid algorithm are also given.
International Federation for Information Processing

hal-00602279
https://hal.archives-ouvertes.fr/hal-00602279

Éditeur(s) : HAL CCSD NRC Research Press
Résumé : Molecular, cytological, and morphological data support the existence of a hybrid population between Schoenus nigricans and Schoenus ferrugineus. This population was found in northeastern Italy, where S. nigricans is central with respect to its natural range and S. ferrugineus is marginal, being most common in the Alps and in central and northern Europe. Molecular marker data show that the putative hybrid population is genetically intermediate between nearby populations of the parent species. Cytological evidence confirmed the hybrid nature of this population, as does the almost complete sterility of plants within the population. Although no seeds were produced by the hybrid population, some possibly fertile pollen grains were produced; this suggests that the possibility of introgression between the two species through the hybrids cannot completely be excluded.
ISSN: 0831-2796

hal-01032047
https://hal.archives-ouvertes.fr/hal-01032047
DOI : 10.1139/G01-138

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : International audience
Meiotic recombination is required for the segregation of homologous chromosomes and is essential for fertility. In most mammals, the DNA double-strand breaks (DSBs) that initiate meiotic recombination are directed to a subset of genomic loci (hot spots) by sequence-specific binding of the PRDM9 protein. Rapid evolution of the DNA-binding specificity of PRDM9 and gradual erosion of PRDM9-binding sites by gene conversion will alter the recombination landscape over time. To better understand the evolutionary turnover of recombination hot spots and its consequences, we mapped DSB hot spots in four major subspecies of Mus musculus with different Prdm9 alleles and in their F1 hybrids. We found that hot spot erosion governs the preferential usage of some Prdm9 alleles over others in hybrid mice and increases sequence diversity specifically at hot spots that become active in the hybrids. As crossovers are disfavored at such hot spots, we propose that sequence divergence generated by hot spot turnover may create an impediment for recombination in hybrids, potentially leading to reduced fertility and, eventually, speciation
ISSN: 0890-9369

hal-01281480
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01281480
DOI : 10.1101/gad.270009.115
PUBMED : 26833728

Éditeur(s) : Copernicus Gesellschaft Mbh
Résumé : The Mediterranean Sea is one of the most oligotrophic marine areas on earth where nitrogen fixation has formally believed to play an important role in carbon and nitrogen fluxes. Although this view is under debate, the diazotrophs responsible for this activity have still not been investigated in the open sea. In this study, we characterised the surface distribution and species richness of unicellular and filamentous diazotrophs across the Mediterranean Sea by combining microscopic counts with size fractionated in situ hybridization (TSA-FISH), and 16S rDNA and nifH genes phylogenies. These genetic analyses were possible owing to the development of a new PCR protocol adapted to scarce microorganisms that can detect as few as 1 cell ml(-1) in cultures. Low concentrations of diazotrophic cyanobacteria were detected and this community was dominated at 99.9% by picoplankton hybridized to the Nitro821 probe, specific for unicellular diazotrophic cyanobacteria (UCYN). Among filamentous cyanobacteria only 0.02 filament ml(-1) of Richelia were detected in the eastern basin, while small (0.7-1.5 mu m) and large (2.5-3.2 mu m) Nitro821-targeted cells were recovered at all stations with a mean concentration of 3.5 cell ml(-1). The affiliation of the small Nitro821-targeted cells to UCYN-A was confirmed by 16S and nifH phylogenies in the western Mediterranean Sea. In the central and the eastern Mediterranean Sea no 16S rDNA and nifH sequence from UCYN was obtained as cells concentration were close to, or below PCR detection limit. Bradyrhizobium sequences dominated nifH clone libraries from picoplanktonic size fractions. A few sequences of gamma-proteobacteria were also detected in the central Mediterranean Sea. While low phosphate and iron concentrations could explain the absence of Trichodesmium sp., the factors that prevent the development of UCYN-B and C remain unknown. We also propose that the dominating picoplankters probably developed specific strategies, such as associations with protists or particles, and/or photosynthetic activity, to acquire carbon for sustaining diazotrophy.
Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2011 , Vol. 8 , N. 3 , P. 827-840

Droits : Author(s) 2011. CC Attribution 3.0 License.
http://archimer.ifremer.fr/doc/00133/24392/22416.pdf
DOI:10.5194/bg-8-827-2011
http://archimer.ifremer.fr/doc/00133/24392/

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper presents some considerations about hybrid optimization algorithms useful to optimize real complex system. The given indication could be used by readers to conceive hybrid algorithms. These considerations have been deducted from a concrete application case: the satellites constellations design problem. But each of the advanced techniques proposed in this paper are considered in a more general way to solve other problems. This problem is used to illustrate the techniques along the paper because it is grouping many characteristics (di culties) of contemporary real complex systems: the size and the characteristics of the search space engendered by a combinatorial problem; The irregularity of the criterions; The mathematical and physical heterogeneity of parameters forbids the use of classical algorithms; The evaluation of a solution, which uses a time consuming simulation; A need of accurate values. More details are available in previous papers ([?], [?], [?], [?]). For these reasons, we could learn a lot from this experiment in order to detach hybrid techniques usable for problems having close characteristics. This paper presents the historic leading to the current algorithm, the modeling of the complex system and the sophisticated algorithm proposed to optimize it. Application cases and ways to built signi cant tests of hybrid algorithm are also given.
HPCSE Proceedings
Toulouse, France

hal-00602264
https://hal.archives-ouvertes.fr/hal-00602264

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Sur fond de crise du tourisme au Nord, de la globalisation de l’économie et de l’accélération des mobilités, une évolution des formes de développement touristiques semble à l’œuvre dans les confins géographiques. Dans certains territoires touristiques du fait de conflits dans l’usage des ressources naturelles, des pratiques récréatives alternatives émergent qui combinent une logique économique avec des préoccupations socio-environnementales.Notre article analyse l’apparition du tourisme scientifique dans la région « non-touristique » de Aysén, en Patagonie chilienne. Des acteurs d’un territoire se mobilisent selon des pôles culturels et des axes thématiques autour de projets pilotes, de recherche expérientielle et de médiations scientifiques innovantes. Sur ce front pionnier, un réseau informel d’acteurs coordonne ses actions pour aborder les problématiques sociales et environnementales de leur territoire. Opérateurs et prestataires pour le tourisme scientifique créent de manière participative une offre originale. Un système touristique alternatif, axé sur la protection de l’environnement, de la culture et des dynamiques sociales de la communauté d’accueil, favorise l’acquisition et le partage de savoirs entre scientifiques, acteurs locaux et visiteurs.Le tourisme scientifique s’inscrit-il dans une évolution globale des pratiques touristiques ? En proposant de dépasser les frontières, entre activités récréatives et le travail, de lieux de vie et de loisir, il apparaît comme l’expression d’un « après-tourisme ». L’hybridation des pratiques, une approche scientifique associée à l’esprit de la découverte inhérent au voyage, semble pouvoir relever des défis sociétaux liés à l’essor d’un tourisme globalisé. Alors que le tourisme est pensé depuis longtemps en termes de transfert de compétences, de modèles et d’ingénierie du Nord vers le Sud, une périphérie propose de nouveaux cadres de pensée, d’action et de participation qui renouvellent le sens du voyage.
In the context of a tourism crisis in the north, a globalized economy and an increase of mobility, a change in the forms of tourism development seems to occur in peripheral areas. In some tourism areas and due to conflicts over the use of natural resources, alternative recreational practices arise that combine economic needs and socio-environmental concerns.Our article analyzes the appearance of scientific tourism in the "non-tourist" region of Aysén, in Chilean Patagonia. Actors of a territory unite according to specific cultural poles and thematic axes through experiential research and innovative scientific mediation pilot projects. On this pioneer front, an informal network of stakeholders coordinates its actions to address the social and environmental issues of their territory. Operators and service providers for scientific tourism create an innovative offer in a participatory process. An alternative tourism system, focused on protecting the environment, the culture and social dynamics of the host community, promotes the acquisition and sharing of knowledge between scientists, local actors and visitors.Is scientific tourism part of a global evolution of tourism practices? By proposing to go beyond established boundaries, of recreational activities and work, everyday places and leisure areas, it appears as the expression of an “After-Tourism”. The hybridization of practices, a scientific approach associated with the spirit of the discovery inherent of the travel experience, seems to respond to the challenges of the community confronted to the rise of a globalized tourism. While tourism has always been thought of in terms of transfer of skills, models and engineering from the North to the South, a periphery offers new frameworks of thought, action and participation that renew the meaning of travel.
En un escenario de crisis del turismo en los países desarrollados, de la globalización de la economía y del incremento de las movilidades, una evolución de las formas de desarrollo del turismo parece estar en marcha en los confines geográficos. En ciertos territorios turísticos, debido a los conflictos de uso de los recursos naturales, prácticas recreativas alternativas surgen que combinan una lógica económica con preocupaciones socio-ambientales.El presente artículo analiza el surgimiento del turismo científico en la región “no-turística” de Aysén en la Patagonia chilena. Actores del territorio se unen según polos y temáticas científicas, a través de proyectos pilotos, de investigación experiencial y mediaciones científicas innovadoras. En este frente pionero, una red informal se organiza para abordar las problemáticas sociales y ambientales de su territorio. Operadores y proveedores de servicios para el turismo científico crean de manera participativa una oferta novedosa. Un sistema turístico alternativo, basado en el cuidado del medio ambiente, de la cultura y de las dinámicas sociales del comunidad de acogida, favorece la adquisición y el intercambio de conocimientos entre científicos, actores locales y visitantes. ¿Será la aparición del turismo científico la expresión de una evolución global de las practicas turísticas? Al invitar a que sean sobrepasadas las fronteras, entre actividades recreativas y el trabajo, lugares de vida y sitios de esparcimiento, este se presenta como un “Pos-Turismo”. La hibridación de las prácticas, una aproximación científica asociada al espíritu de descubrimiento inherente del viaje, parece poder resolver los desafíos de nuestras sociedades vinculados al auge de un turismo globalizado. Cuando el turismo suele ser pensado desde hace mucho, como un proceso de transferencia de capacidades, de modelos y de ingenierías, del Norte hacia el Sur, una periferia propone nuevos marcos conceptuales, de acción y de participación, que renuevan el sentido del viaje.
Patagonie

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.11169
http://journals.openedition.org/etudescaribeennes/11169

Éditeur(s) : HAL CCSD Elsevier
Résumé : Primary arc melts may form through fluxed or adiabatic decompression melting in the mantle wedge, or via a combination of both processes. Major limitations to our understanding of the formation of primary arc melts stem from the fact that most arc lavas are aggregated blends of individual magma batches, further modified by differentiation processes in the sub-arc mantle lithosphere and overlying crust. Primary melt generation is thus masked by these types of second-stage processes. Magma-hosted peridotites sampled as xenoliths in subduction zone magmas are possible remnants of sub-arc mantle and magma generation processes, but are rarely sampled in active arcs. Published studies have emphasised the predominantly harzburgitic lithologies with particularly high modal orthopyroxene in these xenoliths; the former characteristic reflects the refractory nature of these materials consequent to extensive melt depletion of a lherzolitic protolith whereas the latter feature requires additional explanation.Here we present major and minor element data for pristine, mantle-derived, lava-hosted spinel-bearing harzburgite and dunite xenoliths and associated primitive melts from the active Kamchatka and Bismarck arcs. We show that these peridotite suites, and other mantle xenoliths sampled in circum-Pacific arcs, are a distinctive peridotite type not found in other tectonic settings, and are melting residues from hydrous melting of silica-enriched mantle sources. We explore the ability of experimental studies allied with mantle melting parameterisations (pMELTS, Petrolog3) to reproduce the compositions of these arc peridotites, and present a protolith (‘hybrid mantle wedge’) composition that satisfies the available constraints. The composition of peridotite xenoliths recovered from erupted arc magmas plausibly requires their formation initially via interaction of slab-derived components with refractory mantle prior to or during the formation of primary arc melts. The liquid compositions extracted from these hybrid sources are higher in normative quartz and hypersthene (i.e., they have a more silica-saturated character) in comparison with basalts derived from prior melt-depleted asthenospheric mantle beneath ridges. These primary arc melts range from silica-rich picrite to boninite and high-Mg basaltic andesite along a residual spinel harzburgite cotectic. Silica enrichment in the mantle sources of arc-related, subalkaline picrite-boninite-andesite suites coupled with the amount of water and depth of melting, are important for the formation of medium-Fe (‘calc-alkaline’) andesite-dacite-rhyolite suites, key lithologies forming the continental crust.
ISSN: 0016-7037

hal-01553520
https://hal.archives-ouvertes.fr/hal-01553520
DOI : 10.1016/j.gca.2016.09.030

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
In contrast to mammals that have limited proliferation and neurogenesis capacities, the Xenopus frog exhibit a great potential regarding proliferation and production of new cells in the adult brain. This ability makes Xenopus a useful model for understanding the molecular programs required for adult neurogenesis. Transcriptional factors that control adult neurogenesis in vertebrate species undergoing widespread neurogenesis are unknown. NeuroD1 is a member of the family of proneural genes, which function during embryonic neurogenesis as a potent neuronal differentiation factor. Here, we study in detail the expression of NeuroD1 gene in the juvenile and adult Xenopus brains by in situ hybridization combined with immunodetections for proliferation markers (PCNA, BrdU) or in situ hybridizations for cell type markers (Vimentin, Sox2). We found NeuroD1 gene activity in many brain regions, including olfactory bulbs, pallial regions of cerebral hemispheres, preoptic area, habenula, hypothalamus, cerebellum and medulla oblongata. We also demonstrated by double staining NeuroD1/BrdU experiments, after long post-BrdU administration survival times, that NeuroD1 gene activity was turned on in new born neurons during post-metamorphic neurogenesis. Importantly, we provided evidence that NeuroD1-expressing cells at this brain developmental stage were post-mitotic (PCNA-) cells and not radial glial (Vimentin+) or progenitors (Sox2+) cells.
ISSN: 1932-6203

hal-00877023
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00877023/file/The_Neurogenic_Factor-accepted.pdf
DOI : 10.1371/journal.pone.0066487

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : L’eau joue un rôle incontournable dans l’Histoire de la Caraïbe. Ainsi que le remarque Aimé Césaire, les premiers colons furent des aventuriers, des pirates qui traversèrent les eaux avec pour mission de violer la terre et ses hommes. L’océan fut ainsi le vecteur qui aboutit au premier génocide de l’histoire. L’eau abonde dans les écrits de Roland Brival qui sont marqués par la mémoire ancestrale liée au « passage du milieu ». Il présente aussi des personnages métis dont la subjectivité est imbibée des composantes de l’eau. Leur corps et leur identité deviennent un prolongement archétypique de l’élément liquide. Ils sont attirés par la mer qui appelle leurs multiples « moi ». L’eau les invite à conjuguer toutes les identités possibles contrairement à la vie terrestre qui leur impose un ancrage identitaire. L’article présente aussi l’eau comme élément complice dans les rencontres Les couples se retrouvent souvent au bord d’une rivière, d’une source, de la mer. L’océanique est ainsi un élément de prédilection pour les héros brivaliens et représente l’espace métis par excellence. L’eau, l’identité et le corps métis partagent la violence de l’histoire, l’entre-deux, le flou, la mouvance et l’impossibilité d’une fin. La métaphore filée de l’eau marque son empreinte dans des textes qui inscrivent la complexité de l’être métis
The water plays an inescapable role in the History of the Caribbean. As Aimé Césaire remarks, the first colons were adventurers, buccaneers who crossed the sea with a mission to rape the earth and its men and women. The ocean was a vector, which lead to the first genocide in history. The imagery of water is abundant in the works of Roland Brival: his novels are infused with the ancestral memory linked to the “middle passage.” He also introduces metis characters whose identity is infused by the components of the liquid element. Their body and identity become an archetypical extension of the water. They are attracted by the sea, which invites the multiplicity of self. The water enables them to “conjugate” all the potential identities unlike the life on earth, which imposes an identitarian anchoring. This article also presents the water as an accomplice in sexual encounters. Characters often meet by the river, the spring water, the sea, and the ocean. The water represents the ideal space par excellence for the metis protagonists. The hybrid body, identity, and the waters share the violence of history, the “third space,” the ever-changing and the unfeasibility of closure. The metaphors of water brand the texts of Roland Brival and reveal the complexity of the hybrid body and identity.
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6348
http://journals.openedition.org/etudescaribeennes/6348

Éditeur(s) : HAL CCSD
Résumé : International audience
This paper deals with hybrid optimization take different methods to solve a complex problem. As if the choice of concerning methods is important, the way to combine them is determinant for an ef cient search. The article deals with cooperation strategy between the different layers of an hybrid optimization algorithm. We describ the way it is articulated for an Satellite Constellation Optimization problem. This cooperation allows a dynamical adaptation of the optimization algorithm parameters according to the mutual advance of each search
Journal Européen des Systèmes Avancés

hal-00602267
https://hal.archives-ouvertes.fr/hal-00602267

Éditeur(s) : HAL CCSD Yokohama
Résumé : International audience
We make use of the viscosity technique to develop a convergent method for approximating a common element of the set of fixed points of a demicontractive operator and the set of solutions of a monotone equilibrium problem. The proposed algorithm is obtained by coupling a modified hybrid steepest descent method with the extragradient algorithm. Under mild conditions, the strong convergence of the sequences generated by the algorithm is obtained. Using this result we obtain two corollaries which improve or develop several corresponding results in this field.
Journal of Nonlinear and Convex Analysis

hal-00779988
https://hal.univ-antilles.fr/hal-00779988

Éditeur(s) : HAL CCSD Université des Antilles
Résumé : International audience
Loin d’apparaître comme de simples interfaces, les littoraux de la Caraïbe sont constituésd’enclaves fonctionnelles qui se juxtaposent donnant une mosaïque créole polyéthnique(mosaïque raciale), aux fractures sociales et spatiales marquées (mosaïque sociale et spatiale).Dans ces îles paysannes qui traditionnellement tournent le dos à la mer, la plage a longtempsété perçue par les populations littorales et les pêcheurs comme une continuité de l’île de laplantation pour y habiter et y pêcher. Une marge ouverte à tous dont la population rurale seméfiait pour ne l’aborder que quelques heures dans l’année à Pâques ou à la Pentecôte.2 Tout au long du XX siècle, une véritable subversion du regard s’opère par les classesdominantes, bourgeoises et touristes qui investissent les plages, souvent celles qui n’étaientguère fréquentées. Quitter la plage peu à peu investie par les touristes pour les fonds blancsou la Baignoire de Joséphine constitue une nouvelle marque, une volonté de maintenir unehiérarchie sociale par la distance.3 Depuis quelques années, les plages deviennent des lieux d’hybridation entre les populationslocales et les touristes. Avec la tertiairisation des sociétés, les populations antillaises desclasses moyennes et défavorisées découvrent les plages qui occupent une place importantedans la culture (publicité, télé…) des jeunes générations. Les plages sont investies etdeviennent peu à peu des espaces conviviaux.4 La ségrégation sociospatiale demeure cependant dans les pratiques, les temps et même lesespaces occupés. Si certains îlets et fonds blancs, comme les plages s’ouvrent au plus grandnombre, la piscine privée, le yacht, l’îlet privé, l’enclave protégée permettent toujours deconserver distance et discrétion. De même la capacité financière nécessaire à la pratique decertains sports nautiques permet cette démarcation. Ainsi, touristes, Métropolitains et Antillaisdes classes moyennes ou appartenant à la bourgeoisie, se côtoient et se croisent mais nepratiquent pas forcément la même plage.
ISSN: 1779-0980

hal-01202979
https://hal.archives-ouvertes.fr/hal-01202979
https://hal.archives-ouvertes.fr/hal-01202979/document
https://hal.archives-ouvertes.fr/hal-01202979/file/etudescaribeennes-693-4-la-plage-reflet-des-fractures-sociales-et-ethniques-aux-antilles.pdf
DOI : 10.4000/etudescaribeennes.693

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cette étude démontre que l’écriture du roman The Swinging Bridge constitue une action de récupération de la mémoire féminine indienne qui réactive les liens entre Indo-Trinidadiens du Canada et Indo-Trinidadiens vivant à Trinidad tout en rétablissant une relation avec l’Inde des origines. Elle montre que, dans l’espace du roman, des relations s’établissent entre le centre historique réel ou mythique des établissements dispersés, et des sociétés d’installation par le biais d’une intrigue qui amène personnages et lecteurs à la conscience de former un peuple en diaspora.Elle analyse les procédés littéraires d’une récupération de la mémoire qui révèle, rectifie et réorganise dans une nouvelle cohérence des fragments épars réintroduisant dans la mémoire collective les qualités ancestrales d’indépendance de la femme indienne. Elle révèle le caractère hybride de l’identité culturelle diasporique qui se construit tout au long du roman puis analyse les enjeux pour l’écrivain féminin postcolonial diasporique de cet acte de représentation.Elle conclut que cette représentation constitue une réécriture contre discursive de l’Histoire trinidadienne et qu’elle introduit la définition d’un continuum identitaire indo-américain qui contribue à résorber la dislocation et la fragmentation qui caractérisent cet espace essentiellement diasporique.
This work proposes to read The Swinging Bridge as a process by which a hybrid Indo-Trinidadian Diaspora is created. It argues that the novel’s recovery of memory constitutes a process by which individual memories turn into a collective diasporic memory which re-establishes links between Indo-Trinidadians dispersed in Canada and Trinidad. We demonstrate that rebinding to the Trinidadian space and recovering part of the memory of the Indian historical centre set the three spaces in a diasporic relation.This study also demonstrates that the novel’s narrative semantics rejects cultural conflict, as well as essentialism and creates a hybrid cultural identity. It establishes that the construction of diaspora at work in The Swinging Bridge advocates for the appreciation routes rather than roots and is compatible with the idea of a multi-locational diasporic consciousness.
Caraïbes
Trinité

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5757
http://journals.openedition.org/etudescaribeennes/5757

Éditeur(s) : Elsevier
Résumé : Polyploids can be defined as organisms with one or more additional chromosome sets with respect to the number most frequently found in nature for a given species. Triploids, organisms with three sets of homologous chromosomes, are found spontaneously in both wild and cultured populations and can be easily induced in many commercially relevant species of fish and shellfish. The major consequence of triploidy is gonadal sterility, which is of advantage in the aquaculture of molluscs since it can result in superior growth. In fish, the induction of triploidy is mainly used to avoid problems associated with sexual maturation such as lower growth rates, increased incidence of diseases and deterioration of the organoleptic properties. Triploidy can also be used to increase the viability of some hybrids, and is regarded as a potential method for the genetic containment of farmed shellfish and fish. This review focuses on some current issues related to the application of induced polyploidy in aquaculture, namely: 1) the artificial induction of polyploidy and the effectiveness of current triploidisation techniques, including the applicability of tetraploidy to generate auto- and allotriploids; 2) the performance capacity of triploids with respect to diploids; 3) the degree and permanence of gonadal sterility in triploids; and 4) the prospects for the potential future generalised use of triploids to avoid the genetic impact of escapees of farmed fish and shellfish on wild populations. Finally, directions for future research on triploids and their implementation are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Aquaculture (0044-8486) (Elsevier), 2009-08 , Vol. 293 , N. 3-4 , P. 125-156

Droits : 2009 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6648.pdf
DOI:10.1016/j.aquaculture.2009.04.036
http://archimer.ifremer.fr/doc/00000/6648/

Éditeur(s) : Université de Paris 6 – Pierre et Marie Curie
Résumé : Since 1997, a new pathology seasonally occurs in new caledonian shrimp farms during the warm season and was named Summer Syndrome. Diseased Litopenaeus stylirostris shrimp suffer from a septicemic vibriosis which was attributed to V. nigripulchritudo. Preliminary studies based on a collection of V. nigripulchritudo strains have brought to light different virulence levels according to experimental infections results; three virulence statuses were defined: highly (HP), moderately (MP) and non pathogenic (NP). The aim of this work was to genetically characterize virulent V. nigripulchritudo strains. In a first step the genetic diversity of 58 V. nigripulchritudo strains was analyzed by MLST and AP-PCR, revealing a cluster of HP and MP strains, characterized by a low genetic variability and that includes all Summer Syndrome-associated isolates. This confirms the emergence of one cluster of pathogenic V. nigripulchritudo simultaneously with the emergence of the Summer Syndrome ; in a second step, 368 genetic markers of virulence were identified by a Suppressive Subtractive Hybridization performed between the genomes of a HP strain and a genetically close, NP isolate; the distribution of the screened SSH fragments was studied in 58 V. nigripulchritudo isolates by macro-array: 78 DNA fragments were selected, allowing to characterize clusters identified and pathogenic statuses; 13 are specific of the HP strains involved in Summer Syndrome. Interestingly, 10 of these markers are carried by a plasmid pSFn1 that contains sequences highly similar to those of a plasmid pAK1, detected in Vibrio shilonii, a coral pathogen. The origin and consequences of this plasmid acquisition are discussed.
Depuis 1997, les élevages de crevettes en Nouvelle-Calédonie sont confrontés à une nouvelle maladie, le Syndrome d'été, une vibriose septicémique dont l'agent étiologique est Vibrio nigripulchritudo. Les résultats d'infection expérimentale sur une collection de souches, ont montré l'existence de trois pathotypes distincts : hautement (HP), moyennement (MP) et non pathogène (NP). L'étude du polymorphisme génétique de 58 souches par typage moléculaire en MLST et AP-PCR, a mis en évidence un groupe phylogénétique particulier caractérisé par un très faible degré de variabilité génétique (confirmant l'émergence de ce groupe en parallèle à l'émergence du Syndrome d'été) et constitué uniquement de souches HP (dont toutes celles associées au Syndromed'été) et de souches MP. Afin d'identifier des marqueurs génétiques de la virulence des souches responsables du Syndrome d'été, et parmi ces marqueurs des gènes codant potentiellement pour des effecteurs de la virulence, une approche soustractive par SSH a été développée entre une souche HP de type Syndrome d'été et une souche NP : 368 marqueurs génétiques ont ainsi été mis en évidence ; la distribution de ces marqueurs a été étudiée chez les 58 souches de la collection par une approche en macroarray : 78 marqueurs ont été sélectionnés, qui permettent de caractériser les différents groupes phylogénétiques et les différents pathotypes, dont 13 fragments spécifiques des souches HP type Syndrome d'été. Parmi ces 13 fragments, 10 ont été localisés sur le plasmide pSFn1 qui a été entièrement séquencé. Ce même plasmide a été purifié uniquement des souches HP de type Syndrome d'été. Par ailleurs, une très forte homologie a été mise en évidence entre pSFn1 et pAK1, un autre plasmide également séquencé et retrouvé chez la souche V. shilonii AK1, responsable du blanchiment du corail Oculina patagonica en Méditerranée. Ces résultats ont ouvert la discussion sur le rôle de pSFn1 dans la virulence de V. nigripulchritudo.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-3906.pdf
http://archimer.ifremer.fr/doc/00000/3906/

Résumé : Les objectifs pour l'année 1997 étaient les suivants : • Poursuivre les premières reproductions des espèces pour lesquelles nous disposons de géniteurs GO. L'objectif est toujours de limiter le stockage d'animaux importés en produisant une descendance simultanément à des témoins C. gigas qui serviront de comparaison. • Tenter des hybridations inter-spécifiques des différents taxons présents au sein du conservatoire en fonction des connaissances disponibles dans la littérature sur ce sujet (voir pour revue Gaffney et Allen, 1993). • Importer de nouvelles souches ou espèces. Élargir la gamme des espèces présentes au sein du conservatoire de souches (les capacités d'accueil de la salle de quarantaine étant limitée).

Droits : 1997 Ifremer
http://archimer.ifremer.fr/doc/00044/15519/12906.pdf
http://archimer.ifremer.fr/doc/00044/15519/

Éditeur(s) : HAL CCSD
Résumé : Enamel formation requires the involvement of secretory calcium-binding phosphoproteins. Three of them, amelogenin (AMEL), ameloblastin (AMBN) and enamelin (ENAM), have been extensively studied in mammals. More recently, a fourth protein belonging to the same family has been identified: amelotin (AMTN). AMTN has only been studied in rodents and its role during amelogenesis remains unclear.The aim of this thesis is to extend the knowledge on AMTN by studying its evolution in amniotes and its expression in the lizard Anolis carolinensis.AMTN sequences from many amniote species have been extracted from databases or obtained by PCR, and analyzed. Those analyses allowed us to reveal differences in the gene structure and to highlight residues that were conserved during mammalian or amniote evolution. These conserved amino acids are essential to the structure and/or function of the protein.The expression of AMTN and of AMEL, AMBN and ENAM has been studied by in situ hybridization on lizard jaw sections. Comparison of the expression pattern of these genes during amelogenesis in the lizard with that described in rodents points to similarities (AMEL, AMBN and ENAM) but also to important differences, especially in the spatio-temporal expression of AMTN. In order to better understand AMTN evolution in tetrapods, I studied its expression in an amphibian (Pleurodeles waltl) and a marsupial (Monodelphis domestica).Taken together, these results suggest a link between the evolution of AMTN gene structure (loss of exons and of functional domains in mammals) and its expression (early in non-mammals versus late in mammals) with the emergence of prismatic structure of enamel in early mammals.
La formation de l'émail dentaire met en jeu des phosphoprotéines sécrétées liant le calcium. Parmi celles-ci figurent amélogénine (AMEL), améloblastine (AMBN) et énaméline (ENAM), qui ont fait l'objet de nombreuses études chez les mammifères. Plus récemment, une quatrième protéine de la même famille a été découverte, l'amélotine (AMTN). Elle n'a été étudiée que chez les rongeurs et son rôle au cours de l'amélogenèse reste mal défini. L'objectif de cette thèse est d'élargir les connaissances sur AMTN en étudiant son évolution chez les amniotes et son expression au cours de l'amélogenèse chez le lézard Anolis carolinensis. Les séquences d'AMTN d'un grand nombre d'amniotes ont été extraites des bases de données ou obtenues par PCR, et analysées. Ces analyses ont mis en évidence différentes structures géniques et des acides aminés très conservés au cours de l'évolution. Cette conservation indique qu'ils sont essentiels à la structure ou à la fonction de la protéine. L'expression d'AMTN ainsi que celle d'AMEL, AMBN et ENAM ont été étudiées par hybridation in situ sur des coupes de mâchoires de lézard. La comparaison des patrons d'expression chez le lézard avec ceux décrits chez la souris a révélé des différences dans l'expression spatio-temporelle d'AMTN. De ce fait, afin de mieux comprendre l'évolution de ce gène, son expression a été étudiée chez un amphibien (Pleurodeles waltl) et un marsupial (Monodelphis domestica).Ces travaux suggère un lien entre l'évolution de la structure génique d'AMTN (perte d'exons et de domaines fonctionnels) et de son expression (précoce versus tardive) avec l'émergence de la structure prismatique de l'émail chez les mammifères.
https://tel.archives-ouvertes.fr/tel-01154518

NNT : 2015PA066066
tel-01154518
https://tel.archives-ouvertes.fr/tel-01154518
https://tel.archives-ouvertes.fr/tel-01154518/document
https://tel.archives-ouvertes.fr/tel-01154518/file/2015PA066066.pdf

Éditeur(s) : HAL CCSD Impact journals
Résumé : International audience
Targeted therapies have substantially changed the management of non-small cell lung cancer (NSCLC) patients with driver oncogenes. Given the high frequency, EGFR and ALK aberrations were the first to be detected and paved the way for tyrosine kinase inhibitor (TKI) treatments. Other kinases such as ROS1 and more recently RET have emerged as promising targets, and ROS1 and RET TKIs are already available for precision medicine. We screened a large cohort of 713 Caucasian non-squamous NSCLC patients lacking EGFR/KRAS/BRAF/HER2/PI3KCA/ALK aberrations for ROS1 and RET rearrangements using fluorescence in situ hybridization to determine the frequency and clinicopathological characteristics of ROS1- and RET-positive patients. Frequencies of ROS1 and RET rearrangements were 2.1% and 2.52%, respectively. Contrary to common belief, both ROS1 and RET rearrangements were detected in patients with a history of smoking, and the RET-positive patients were not younger than the negative patients. Moreover, RET but not ROS1 rearrangement was associated with the female gender. Nearly half of the ROS1-rearranged patients were successfully treated with ROS1 TKIs. In contrast, only 5/18 RET-positive patients received off-label RET TKIs. Two patients had stable disease, and three experienced disease progression. In addition to the 18 RET-positive cases, 10 showed isolated 5' signals. The clinical relevance is unknown but if the frequency is confirmed by other groups, the question whether these patients are eligible to TKIs will arise. More potent RET TKIs are under development and may improve the response rate in RET-positive patients. Therefore, we recommend the routine implementation of RET testing in non-squamous NSCLC patients, including those with a history of smoking.
ISSN: 1949-2553

hal-01578586
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01578586
DOI : 10.18632/oncotarget.18408
PUBMED : 28881815