59 research outputs found

    Diversity of indigeneous bradyrhizobia associated with three cowpea cultivars (Vigna unguiculata (L.) Walp.) grown under limited and favorable water conditions in Senegal (West Africa)

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    The diversity of Bradyrhizobium strains nodulating three cowpea (Vigna unguiculata L. Walp.) cultivars in favorable and water-limited conditions occuring at flowering was analysed. PCR- Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of 16S-23S rDNA intergenic spacer region (IGS) directly applied on 85 crushed nodules distinguished four genetic profiles, IGS types I, II, III and IV. The distribution of these IGS types according to water conditions and cowpea cultivars (B-21, TN 88-63 and Mouride) showed that nodulating strains appeared more diverse in water-limited condition. More than three quarters of prospected nodules presented the IGS type I. They were formed on all three cultivars and in both water conditions. Only a small part of nodules was distributed between the IGS type II, III and IV. Nodules showing the IGS types II and III were found mainly in limited conditions on TN 88-63 and Mouride cultivars, whereas nodules presenting the IGS type IV were collected only from cultivars B-21 and Mouride, in both water conditions. Strains corresponding to the different profiles were isolated. The phylogenetic analysis of 16S rRNA gene sequences showed that they belong to the genus, Bradyrhizobium. The sequence analysis of 16S-23S rDNA IGS revealed that the strains exhibiting IGS types II, III and IV were closely related to some Faidherbia albida isolates from Senegal. IGS type II can be assigned with at least 98% similarity to Bradyrhizobium genospecies IV. IGS types III and IV showed more than 96% similarity with genospecies VII and could belong to the same genospecies. IGS type I, the most frequent, exhibits low IGS similarity with reported sequences in the databases, and could represent a new genospecies. (African Journal of Biotechnology: 2003 2(1): 13-23

    Mesures radiatives dans le cas de cultures associées arborées et sous arborées. Méthode de caractérisation du climat radiatif sous cocoteraies. Rapport final

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    La lumière est généralement le facteur le plus limitant pour les cultures sous couvert dans la mesure où une fumure adaptée permet de limiter les compétitions trophiques pour les éléments minéraux. Les résultats expérimentaux en matière de potentialités des cultures sous cocoteraie doivent pouvoir être interprétés en fonction du climat radiatif. Le programme MRT 90 concerne la compétition pour la lumière au sein des associations à base de cocotiers. Ce rapport comporte les parties suivantes : Caractérisation du climat radiatif sous cocoteraies par des mesures in situ. Modélisation architecturale du cocotier. Modélisation de l'architecture du cacaoyer. Simulation radiative sur maquettes informatiques. Sont présentés en annexe : le rapport de DEA de M.L. Girard, le rapport CP 165 de J. Dauzat, le rapport de stage de V. Garrouste (juillet-aout 1993

    L’importance de la diminution de la pression artérielle nocturne

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    La pression artérielle nocturne est un facteur de risque cardiovasculaire indépendant et un meilleur indicateur d'atteinte d'organes cibles que la pression arterielle moyenne sur 24 heures ou la pression arterielle diurne. La perte du rythme tensionnel circadien avec une baisse physiologique de la pression la nuit a aussi un impact négatif sur la morbi-mortalité cardio-vasculaire. A l’heure actuelle, il y a encore peu d’évidence qu'une baisse thérapeutique de la pression artérielle nocturne réduise les événements cardiovasculaires. Il faudra attendre les résultats d'études sur la chronothérapie visant à restaurer un rythme circadien avec «dipping» nocturne normal qui sont en cours

    Forecasting and managing multi-risks in Mediterranean, temperate and boreal forests: comparison between North-American and European approaches: conference proceedings

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    This conference (July 2022, Bordeaux, France) was organized by the FORWARD network, which is an International research network dedicated to "FORest, Wood, mARket anD Society » for the ecological transition through and for forest-wood systems.It focussed on present and emergent risks and their interactions in order to help to produce survey tools for multi-risks management and to elaborate different strategies for risks mitigation in North-American and European forests. One of the major challenges for forest sciences (including ecology, pathology, forest modelling, forest management, wood science, social sciences) are to analyse present and emergent risks and their interactions, to produce survey tools for multi-risks management and to analyse the different strategies for risks mitigation. The first objective of this conference was to give a prospective analysis of knowledge gaps, needs for tools (model, platforms, etc.), the limits of the available multi-risks management tools in regards to the demand of stakeholders (public, foresters, policymakers). The second objective was to compare North-American and European approaches to highlight possible solutions for common difficulties to mitigate multi-risks. This workshop focused on North-American and European forests that represent more than 20% of the world forest area.
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