223 research outputs found

    ÉpidĂ©miologie molĂ©culaire des avipoxvirus chez l’Outarde houbara

    Get PDF
    L’Outarde houbara (Chlamydotis undulata et Chlamydotis macqueenii), dont les populations sont en dĂ©clin, fait l’objet d’élevages conservatoires en Afrique du Nord, Asie centrale et Moyen Orient. Des Ă©pisodes de variole aviaire y sont rĂ©guliĂšrement rapportĂ©s malgrĂ© une vaccination systĂ©matique. En nous appuyant sur une approche Ă©pidĂ©miologique et molĂ©culaire, nous avons montrĂ© que cette maladie, frĂ©quemment observĂ©e dans ces Ă©levages, prĂ©sente des fluctuations saisonniĂšres et est causĂ©e par une grande diversitĂ© d’avipoxvirus. L’évaluation de ses impacts sur les performances de reproduction des oiseaux a rĂ©vĂ©lĂ© qu’ils sont minimes. Cependant, l’étude de la phylogĂ©nie et de l’évolution de ces virus, en montrant des introductions rĂ©pĂ©tĂ©es de virus dans les Ă©levages, a prouvĂ© que les avipoxvirus sont un risque pour les projets de conservation. Enfin, un modĂšle d’infection expĂ©rimentale, dĂ©veloppĂ© chez l’Outarde houbara, permet d’envisager de futurs travaux de recherche sur les avipoxvirus. ABSTRACT : The Houbara Bustard (Chlamydotis undulata and Chlamydotis macqueenii), whose populations are declining, is captive-bred for conservation purposes in North Africa, Central Asia and the Middle East. Avian pox is regularly reported in captive-bred birds despite systematic vaccination. By using epidemiological and molecular approaches, we showed that the disease, caused by a wide diversity of avipoxviruses in captive-bred houbara bustards, is frequently reported in captive-flocks, and seasonal variations of incidence are observed. Impacts assessment of the disease on breeding performances has shown they are very limited. However, the study of avipoxviruses phylogeny and evolution has demonstrated repeated virus introductions in captive-flock and thus, prove that avipoxviruses are a risk for conservation projects. Finally, an experimental model developed in the Houbara Bustard offers further opportunities of research on avipoxviruses

    "Too Big To Ignore": A feasibility analysis of detecting fishing events in Gabonese small-scale fisheries.

    Get PDF
    This is the final version. Available from Public Library of Science via the DOI in this record. All shapefiles are available from the Dryad database (datadryad.org/stash/share/BN9V6JHrdep3pMWH7zGuUiOfK9IEaeeodQ9LzVOY1Cw).In many developing countries, small-scale fisheries provide employment and important food security for local populations. To support resource management, the description of the spatiotemporal extent of fisheries is necessary, but often poorly understood due to the diffuse nature of effort, operated from numerous small wooden vessels. Here, in Gabon, Central Africa, we applied Hidden Markov Models to detect fishing patterns in seven different fisheries (with different gears) from GPS data. Models were compared to information collected by on-board observers (7 trips) and, at a larger scale, to a visual interpretation method (99 trips). Models utilizing different sampling resolutions of GPS acquisition were also tested. Model prediction accuracy was high with GPS data sampling rates up to three minutes apart. The minor loss of accuracy linked to model classification is largely compensated by the savings in time required for analysis, especially in a context of nations or organizations with limited resources. This method could be applied to larger datasets at a national or international scale to identify and more adequately manage fishing effort.US Fish and Wildlife ServiceDepartment for Environment, Food and Rural Affairs UKLMI TAPIOCAEuropean UnionArc Emeraude Projec

    PET imaging of brain inflammation during early epileptogenesis in a rat model of temporal lobe epilepsy.

    Get PDF
    Background Recently, inflammatory cascades have been suggested as a target for epilepsy therapy. Positron emission tomography (PET) imaging offers the unique possibility to evaluate brain inflammation longitudinally in a non-invasive translational manner. This study investigated brain inflammation during early epileptogenesis in the post-kainic acid-induced status epilepticus (KASE) model with post-mortem histology and in vivo with [18F]-PBR111 PET. Methods Status epilepticus (SE) was induced (N = 13) by low-dose injections of KA, while controls (N = 9) received saline. Translocator protein (TSPO) expression and microglia activation were assessed with [125I]-CLINDE autoradiography and OX-42 immunohistochemistry, respectively, 7 days post-SE. In a subgroup of rats, [18F]-PBR111 PET imaging with metabolite-corrected input function was performed before post-mortem evaluation. [18F]-PBR111 volume of distribution (V t) in volume of interests (VOIs) was quantified by means of kinetic modelling and a VOI/metabolite-corrected plasma activity ratio. Results Animals with substantial SE showed huge overexpression of TSPO in vitro in relevant brain regions such as the hippocampus and amygdala (P < 0.001), while animals with mild symptoms displayed a smaller increase in TSPO in amygdala only (P < 0.001). TSPO expression was associated with OX-42 signal but without obvious cell loss. Similar in vivo [18F]-PBR111 increases in V t and the simplified ratio were found in key regions such as the hippocampus (P < 0.05) and amygdala (P < 0.01). Conclusion Both post-mortem and in vivo methods substantiate that the brain regions important in seizure generation display significant brain inflammation during epileptogenesis in the KASE model. This work enables future longitudinal investigation of the role of brain inflammation during epileptogenesis and evaluation of anti-inflammatory treatments. © 2012, Springer

    Aspergillus fumigatus in Poultry

    Get PDF
    Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood

    Episode H5N8 d'influenza aviaire en France en 2016-2017 : quel rĂŽle pour la faune sauvage ?

    Full text link
    L'influenza aviaire (IA) est une menace permanente, qui arrive parfois en Europe par le biais des oiseaux migrateurs. Un dispositif de surveillance est en place en permanence pour surveiller les mortalitĂ©s dans l'avifaune, et particuliĂšrement celles des oiseaux d'eau migrateurs. En octobre 2016, un Ă©pisode d'IA H5N8 qui Ă©tait surveillĂ© depuis sa survenue en RĂ©publique de Touva (FĂ©dĂ©ration de Russie, avril 2016) s'est dĂ©clarĂ© en Europe. Il a entraĂźnĂ© des pertes consĂ©quentes dans certaines populations d'oiseaux sauvages en Europe, ainsi que dans des filiĂšres avicoles. La situation en France s'est rĂ©vĂ©lĂ©e paradoxale : l'atteinte a Ă©tĂ© majeure dans la filiĂšre avicole de canards gras du Sud- Ouest, mais les cas dans la faune sauvage sont restĂ©s peu nombreux et circonscrits. Ce n'est pas faute d'avoir renforcĂ© la surveillance, soit Ă©vĂ©nementielle (analyse des oiseaux trouvĂ©s morts) soit active autour des foyers domestiques. Plus de 800 cadavres d'oiseaux sauvages ont Ă©tĂ© analysĂ©s, dont beaucoup d'anatidĂ©s, 90 ont Ă©tĂ© dĂ©tectĂ©s infectĂ©s regroupĂ©s en 55 cas dans l'avifaune libre et captive, et dix sites stratĂ©giques ont fait l'objet d'une recherche intensifiĂ©e des cadavres et n'ont permis de trouver aucun cas positif supplĂ©mentaire. Plus de 300 oiseaux commensaux des Ă©levages domestiques foyers ont Ă©tĂ© analysĂ©s et se sont tous rĂ©vĂ©lĂ©s nĂ©gatifs. Les performances du systĂšme de surveillance ne semblent pas pouvoir ĂȘtre mises en cause, et il apparaĂźt donc qu'il y a bien eu des diffĂ©rences de circulation du virus par rapport Ă  nos voisins d'outre-Rhin, mal expliquĂ©es Ă  ce stade mais la situation en France est similaire Ă  celle observĂ©e en Italie et en Espagne cet hiver, et correspond assez bien Ă  l'Ă©pisode H5N8 qui avait circulĂ© en Europe fin 2014/dĂ©but 2015, sans toucher la France. (RĂ©sumĂ© d'auteur

    Binding of Pramipexole to Extrastriatal Dopamine D2/D3 Receptors in the Human Brain: A Positron Emission Tomography Study Using 11C-FLB 457

    Get PDF
    The purpose of this study was to determine the binding sites of pramipexole in extrastriatal dopaminergic regions because its antidepressive effects have been speculated to occur by activating the dopamine D2 receptor subfamily in extrastriatal areas. Dynamic positron emission tomography (PET) scanning using 11C-FLB 457 for quantification of D2/D3 receptor subtype was performed on 15 healthy volunteers. Each subject underwent two PET scans before and after receiving a single dose of pramipexole (0, 0.125, or 0.25 mg). The study demonstrated that pramipexole significantly binds to D2/D3 receptors in the prefrontal cortex, amygdala, and medial and lateral thalamus at a dose of 0.25 mg. These regions have been indicated to have some relation to depression and may be part of the target sites where pramipexole exerts its antidepressive effects

    Assessing the state of marine biodiversity in the Northeast Atlantic

    Get PDF
    The Northeast Atlantic, a highly productive maritime area, has been exposed to a wide range of direct human pressures, such as fishing, shipping, coastal development, pollution, and non-indigenous species (NIS) introductions, in addition to anthropogenically-driven global climate change. Nonetheless, this regional sea supports a high diversity of species and habitats, whose functioning provides a variety of ecosystem services, essential for human welfare. In 2017, OSPAR, the Northeast Atlantic Regional Seas Commission, delivered an assessment of marine biodiversity for the Northeast Atlantic. This assessment examined biodiversity indicators separately to identify changes in Northeast Atlantic biodiversity, but stopped short of determining the status of biodiversity for many species and habitats. Here, we expand on this work and for the first time, a semi-quantitative approach is applied to evaluate holistically the state of Northeast Atlantic marine biodiversity across marine food webs, from plankton to top predators, via fish, pelagic and benthic habitats, including xeno-biodiversity (i.e. NIS). Our analysis reveals widespread degradation in marine ecosystems and biodiversity, particularly for marine birds and coastal bottlenose dolphins, as well as for benthic habitats and fish in some regions. The poor biodiversity status of these ecosystem components is likely the result of cumulative effects of human activities, such as habitat destruction or disturbance, overexploitation, eutrophication, the introduction of NIS, and climate change. Bright spots are also revealed, such as recent signs of recovery in some fish and marine bird communities and recovery in harbour and grey seal populations and the condition of coastal benthic communities in some regions. The status of many indicators across all ecosystem components, but particularly for the novel pelagic habitats, food webs and NIS indicators, however, remains uncertain due to gaps in data, unclear pressure-state relationships, and the non-linear influence of some pressures on biodiversity indicators. Improving monitoring and data access and increasing understanding of pressure-state relationships, including those that are non-linear, is therefore a priority for enabling future assessments, as is consistent and stable resourcing for expert involvement

    L'aire marine protégée communautaire de Bamboung (Sine Saloum) : synthÚse 2003-2011

    No full text
    • 

    corecore