9 research outputs found

    Premier signalement en France du Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) (Actinopterygii, Cypriniformes)

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    [EN] First record in France of the Ebro barbel Luciobarbus graellsii (Steindachner, 1866) (Actinopterygii, Cypriniformes). One Ebro Barbel Luciobarbus graellsii (Steindachner, 1866) was caught for the first time on the Egurguy stream, an affluent of the Irati River (Ebro drainage), at the place-called Nekez Egina (Lecumberry town) in the PyrĂ©nĂ©es-Atlantiques department. It is the first record of this species in France known until now only in Spain, and the third barbel species in the French taxonomical frame of reference.[FR] Un Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) a Ă©tĂ© capturĂ© pour la premiĂšre fois sur l’Egurguy, un affluent de l’Irati (bassin de l’Ebre), au lieu-dit de Nekez Egina (commune de Lecumberry) dans les PyrĂ©nĂ©es-Atlantiques. Il s’agit du premier signalement de cette espĂšce en France jusque-lĂ  connue uniquement en Espagne, et donc de la troisiĂšme espĂšce de Barbeau dans le rĂ©fĂ©rentiel taxonomique français

    Premier signalement en France du Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) (Actinopterygii, Cypriniformes)

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    International audienceOne Ebro Barbel Luciobarbus graellsii (Steindachner, 1866) was caught for the first time on the Egurguy stream, an affluent of the Irati River (Ebro drainage), at the place-called Nekez Egina (Lecumberry town) in the PyrĂ©nĂ©es-Atlantiques department. It is the first record of this species in France known until now only in Spain, and the third barbel species in the French taxonomical frame of reference.Un Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) a Ă©tĂ© capturĂ© pour la premiĂšre fois sur l’Egurguy, un affluent de l’Irati (bassin de l’Ebre), au lieu-dit de Nekez Egina (commune de Lecumberry) dans les PyrĂ©nĂ©es-Atlantiques. Il s’agit du premier signalement de cette espĂšce enFrance jusque-lĂ  connue uniquement en Espagne, et donc de la troisiĂšme espĂšce de Barbeau dans le rĂ©fĂ©rentiel taxonomique français

    Premier signalement en France du Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) (Actinopterygii, Cypriniformes)

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    International audienceOne Ebro Barbel Luciobarbus graellsii (Steindachner, 1866) was caught for the first time on the Egurguy stream, an affluent of the Irati River (Ebro drainage), at the place-called Nekez Egina (Lecumberry town) in the PyrĂ©nĂ©es-Atlantiques department. It is the first record of this species in France known until now only in Spain, and the third barbel species in the French taxonomical frame of reference.Un Barbeau de Graells Luciobarbus graellsii (Steindachner, 1866) a Ă©tĂ© capturĂ© pour la premiĂšre fois sur l’Egurguy, un affluent de l’Irati (bassin de l’Ebre), au lieu-dit de Nekez Egina (commune de Lecumberry) dans les PyrĂ©nĂ©es-Atlantiques. Il s’agit du premier signalement de cette espĂšce enFrance jusque-lĂ  connue uniquement en Espagne, et donc de la troisiĂšme espĂšce de Barbeau dans le rĂ©fĂ©rentiel taxonomique français

    New probes based on carbon nano-cones for scanning probe microscopies

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    International audienceAll-graphenic carbon morphologies grown on individual carbon nanotubes (CNTs) consisting of short-fiber segments bearing sharp micro-/nano-cones at both ends were mounted as new probes for scanning probe microscopies (SPM). Three mounting procedures were tested, two based on focused ion and/or electron beam processes operated in scanning electron microscopes, and another based on an irradiation-free procedure under an optical microscope. The benefits and drawbacks of all the methods are described in details. The extent to which the structural integrity of the carbon material of the cones was affected by each of the mounting processes was also investigated using Raman spectroscopy and high-resolution transmission electron microscopy. The carbon cones were found to be sensitive to both ion and electron irradiation to an unusual extent with respect to structurally-close nano-objects such as multi-wall CNTs. This was assumed to be due to the occurrence of a large number of free graphene-edges at the cone surface. The suitability of such carbon cones as SPM probes is demonstrated, the characteristics of which make them potentially superior to Si-, diamond-, or CNT-probes

    Texture, nanotexture, and structure of carbon nanotube-supported carbon cones

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    International audienceGraphene-based carbon micro-/nano-cones were prepared by depositing pyrolytic carbon onto individual carbon nanotubes as supports using a specific chemical vapor deposition process. They were investigated by means of high-resolution scanning electron microscopy, lowvoltage aberration-corrected transmission electron microscopy, Raman spectroscopy, and molecular dynamics modelling. While the graphenes were confirmed to be perfect, the cone texture was determined to be preferably scroll-like, with the scroll turns being parallel to the cone axis. Correspondingly, many of the concentrically-displayed graphenes (actually scroll turns) exhibit the same helicity vector. When radii of curvature are large enough, this could allow for coherent stacking to locally take place in spite of the lattice shift induced by the curvature when radii of curvature are large enough. The graphene nanotexture was found to be perfect. A particular care was taken on investigating the cone apices, in which a specific type of graphene termination was observed, here designated as "zip" defect. Calculations determined a plausible stable structure that such a defect type may correspond to. This defect was found to generate the lowest Raman ID/ID' band ratio (1.5) ever found reported in the literature, for which physical reasons are proposed. Combining our results and that of the literature allowed proposing an identification chart for a variety of defects able to affect the graphene lattice or edges

    Journées Techniques nationales, 5 e édition Détection de l'agent rosette Sphareothecum destruens dans les communautés piscicoles de France (Projet Rosetta)

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    International audienceEn 2005, un risque d’émergence d’une maladie impactant la biodiversitĂ© des poissons d’eau douce a Ă©tĂ© identifiĂ© en Europe et associĂ© Ă  l’introduction du goujon asiatique Pseudorasbora parva (temminck & schlegel, 1846), qui est porteur sain d’un agent pathogĂšne proche des champignons, l’agent rosette Sphaerothecum destruens (arkush, Mendoza, adkison & hedrick, 2003). Ce pathogĂšne, qualifiĂ© de gĂ©nĂ©raliste, est capable d’infecter de nombreuses espĂšces de poissons (hĂŽtes) et d’entraĂźner des mortalitĂ©s plus ou moins sĂ©vĂšres. il semblerait que la premiĂšre introduction de goujon asiatique en France ait eu lieu entre 1978 et 1979 dans la rĂ©gion de Beaumont-sur-Sarthe depuis des populations en provenance d’Albanie. Le projet Rosetta a eu pour objectif de cartographier la distribution de l’agent rosette sur diffĂ©rents cours d’eau français. Dix sites comprenant des populations de goujon asiatique et rĂ©partis sur l’ensemble du territoire mĂ©tropolitain ont Ă©tĂ© Ă©chantillonnĂ©s entre 2017 et 2019. De l’ADN a Ă©tĂ© extrait des organes (foie, rate et reins) de goujons asiatiques, mais Ă©galement de plusieurs espĂšces autochtones et allochtones (anguille europĂ©enne, barbeau fluviatile, bouviĂšre, brĂšme, carassin, chevaine, gardon, hotu, perche, perche soleil, poisson-chat, rotengle, truite commune, vairon) afin de dĂ©terminer par PCR quantitative la prĂ©sence et l’abondance du pathogĂšne. Alors que l’introduction de l’agent rosette en France est passĂ©e inaperçue pendant plus de 40 ans, notre Ă©tude montre que l’agent infectieux est bien prĂ©sent dans plusieurs cours d’eau. Des espĂšces natives sont infectĂ©es avec des prĂ©valences allant de 2 Ă  20%. De nouvelles espĂšces, comme la bouviĂšre Rhodeus amarus (Bloch, 1782), le vairon Phoxinus phoxinus (linnaeus, 1758) ou encore le goujon Gobio gobio (Linnaeus, 1758), ont Ă©tĂ© identifiĂ©es pour la premiĂšre fois comme hĂŽtes potentiels du pathogĂšne. La premiĂšre recommandation est l’isolement des populations de goujon asiatique et le contrĂŽle des transferts de poissons entre les zones dĂ©jĂ  infectĂ©es et les zones non-infectĂ©es. La seconde recommandation est une communication publique des risques, afin d’inclure un maximum d’acteurs (dont les professionnels pisciculteurs, propriĂ©taires d’étangs et pĂȘcheurs amateurs) dans la lutte contre la propagation de cette maladie

    Towards unravelling the Rosette agent enigma: Spread and emergence of the co-invasive host-pathogen complex, Pseudorasbora parva-Sphaerothecum destruens

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    International audienceThe emergence of non-native fungal pathogens is a growing threat to global health, biodiversity, conservation biology, food security and the global economy. Moreover, a thorough understanding of the spread and emergence of pathogens among invasive and native host populations, as well as genetic analysis of the structure of co-invasive host populations, is crucial in terms of conservation biology and management strategies. Here we com-bined extensive catchment sampling, molecular detection tools and genomic signatures to i) assess the prevalence of the rosette agent Sphaerothecum destruens in invasive and native fish populations in contrasting french regions, and ii) characterize the genetic diversity and population structure of its co-invasive and asymptomatic carrier Pseudorasbora parva. Although S. destruens was not detected in all the fish collected its presence in contrasting freshwater ecosystems suggests that the disease may already be widespread in France. Furthermore, our results show that the detection of S. destruens DNA in its asymptomatic carrier P. parva is still limited. Finally, we found that P. parva populations show a homogeneous genetic and geographical structuring, which raises the possibility of the occurrence of successive introduction events in France from their native and invasive range
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