179 research outputs found

    The diet of great cormorants Phalacrocorax carbo wintering in southwestern France

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    L'Ă©tude du rĂ©gime alimentaire du Grand Cormoran Phalacrocorax carbo dans le sud-ouest de la France a Ă©tĂ© rĂ©alisĂ©e grĂące Ă  l'analyse de 385 contenus stomacaux issus d'oiseaux prĂ©levĂ©s dans le cadre du plan de rĂ©gulation national de cette espĂšce. Suite Ă  l'augmentation des effectifs nicheurs dans le nord-ouest de l'Europe au dĂ©but des annĂ©es 80, le nombre d'oiseaux hivernants dans le sud-ouest de la France a fortement augmentĂ©. Cette hausse a provoquĂ© de vives rĂ©actions notamment chez les pĂȘcheurs qui ont obtenu des tirs de contrĂŽle du Grand Cormoran. Dans cette Ă©tude nous analysons les contenus stomacaux d'oiseaux provenant de diffĂ©rentes riviĂšres de Midi-PyrĂ©nĂ©es et d'Aquitaine. 22 espĂšces de poissons dont la taille varie de 2 Ă  50 cm ont Ă©tĂ© rĂ©pertoriĂ©es. Les proies principales sont constituĂ©es par la famille des cyprinidĂ©s. Le gardon Rutilus rutilus est l'espĂšce ayant la plus forte occurrence, mais en terme de biomasse, le barbeau Barbus barbus est la proie la plus importante. Le poisson-chat Ictalurus melas joue aussi un rĂŽle important dans le rĂ©gime alimentaire du Grand Cormoran. Ces premiers rĂ©sultats dans des riviĂšres françaises et l'impact du Grand Cormoran sur ces milieux sont discutĂ©s

    Socioeconomic determinants of organic cotton adoption in Benin, West Africa

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    Organic cotton relies on ecological processes and the use of natural resources to sustain the production system, unlike conventional cotton, mainly characterized by massive utilization of synthesis chemicals. In West Africa, where rural livelihoods are particularly vulnerable, organic cotton is expected to contribute not only to poverty reduction but also to strengthen households’ resilience. The objective of this study was to assess institutional and socioeconomic factors determining farmers’ decisions to adopt organic cotton. For this purpose, we applied a probit model on empirical data collected from producers of the Centre and the Northern parts of Benin. Overall, we found that organic cotton adoption is mainly determined by farmers’ socioeconomic characteristics, the physical distance between farm and house, and contact with extension and advisory services. Organic farming is more attractive to women compared to conventional farming. This because such type of cotton farming enables women to hold a separate cotton farm and thus increase their economic independence, whereas with the conventional system they depend mainly on the farm of the (male) head of the household. Older, less educated and low-income farmers who express environmental concern are more likely to adopt organic cotton. Subsequently, organic cotton should be considered as a prospective policy option to reach the poor and strengthen their livelihoods conditions while contributing to preserve the environment and natural resources. Furthermore, farmers who have their farm near home are more likely to adopt organic farming than those who have the farm far from their home. It also came out that organic farmers have more contacts with advisory and extension services. Finally, the study noted that there is still a need to enhance the extension system by: (1) exploring, designing, and upgrading innovative pedagogic tools such as videos and mobile phone technology to foster learning; and (2) strengthening organic farmer’s organizations and the linkage with agricultural research organizations for technology development

    Update on Dendritic Cell-Induced Immunological and Clinical Tolerance.

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    Dendritic cells (DCs) as highly efficient antigen-presenting cells are at the interface of innate and adaptive immunity. As such, they are key mediators of immunity and antigen-specific immune tolerance. Due to their functional specialization, research efforts have focused on the characterization of DCs subsets involved in the initiation of immunogenic responses and in the maintenance of tissue homeostasis. Tolerogenic DCs (tolDCs)-based therapies have been designed as promising strategies to prevent and control autoimmune diseases as well as allograft rejection after solid organ transplantation (SOT). Despite successful experimental studies and ongoing phase I/II clinical trials using autologous tolDCs in patients with type 1 diabetes, rheumatoid arthritis, multiple sclerosis, and in SOT recipients, additional basic research will be required to determine the optimal DC subset(s) and conditioning regimens for tolDCs-based treatments in vivo. In this review, we discuss the characteristics of human DCs and recent advances in their classification, as well as the role of DCs in immune regulation and their susceptibility to in vitro or in vivo manipulation for the development of tolerogenic therapies, with a focus on the potential of tolDCs for the treatment of autoimmune diseases and the prevention of allograft rejection after SOT

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