3 research outputs found

    Forage resources and animals’ feeding in southern groudnut bassin and eastern regions of Senegal

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    Rainfall disturbances, a consequence of the effects of climate change, aggravated by anthropogenic pressure on vegetation, are leading to the progressive disappearance of several adapted local plant species in the so-called "groundnut basin" and eastern Senegal. Also, the clearing of land for agriculture potentiates and amplifies this degradation. At this rate, the loss of most of the local plant, forage and forest resources will follow. As part of a multi-species census and collection of plant genetic resources for food and agriculture, an inventory of available forage resources in the groundnut basin and eastern Senegal was made. This inventory was made by field observations triangulated with interview data. The results show that the methods and level of exploitation of natural forage resources and crop residues differ from one area to another. The natural rangeland, which still constitutes the essential part of domestic ruminants feed in these regions, is in continuous degradation. In fact, this rangeland in groundnut basin is not very diversified like southern area, with a low index of quality and volume of pastures. Crop residues are abundant but not very varied. They represent an interest for the breeders of this zone and their sale prices can sometimes exceed those of the harvested products. This is a snapshot of the situation, valid for a given time. This situation is dynamic and can change significantly from one moment to the next. Nevertheless, the results obtained will make it possible to conceive methods of conservation and production of the identified species; in order to identify the best methods of management and sustainable use

    Recherche des partenaires de l'amyloĂŻde-bĂȘta 1-42 par spectromĂ©trie de masse

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    L utilisation de la protĂ©omique et de la spectromĂ©trie de masse est devenue indispensable pour la comprĂ©hension au niveau molĂ©culaire de nombreuses pathologies. Le peptide amyloĂŻde bĂȘta (Ab) 1-42 tient un rĂŽle central dans le dĂ©veloppement de la maladie d Alzheimer (MA). Cependant, les mĂ©canismes de la toxicitĂ© induite par ce peptide sont toujours mal connus. Ce travail vise Ă  identifier les partenaires protĂ©iques de la forme fibrillaire du peptide Ab, afin d'avoir une meilleure comprehĂ©nsion des mĂ©canismes molĂ©culaires induits par ce peptide et d'identifier d'Ă©ventuels candidats comme cibles thĂ©rapeutiques de traitement contre la MA. Pour cela, nous avons mis en place une stratĂ©gie de co-prĂ©cipitation des protĂ©ines en interaction avec le peptide Ab 1-42 sous forme fibrillaire, en utilisant des protĂ©ines extraites de synaptosomes de rat. L identification des protĂ©ines co-prĂ©cipitĂ©es avec les fibrilles est rĂ©alisĂ©e en LC-MS/MS (Hesse et al. 2011) (ESI-LIT-FTICR). Les rĂ©sultats obtenus sur six expĂ©riences indĂ©pendantes nous ont permis d identifier 172 protĂ©ines spĂ©cifiquement co-prĂ©cipitĂ©es Ă  l Ab. Parmi ces protĂ©ines, 11 sont identifiĂ©es dans l ensemble des rĂ©plicats biologiques Ras-related protein Ral-A, Cytochrome b-c1, amine oxidase B, 3-hydroxyacyl-CoA dehydrogenase type 2, mitochondrial import TOM70, Dynamin-like 120 kDA protein, Succinate dehydrogenase, LETM1, EF-hand domain containing protein, Up-regulated during skeletal muscle growth protein et Dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex.. Certaines de ces protĂ©ines sont associĂ©es dans la littĂ©rature au contrĂŽle de l homĂ©ostasie du calcium, ou l organisation des microtubules, qui sont perturbĂ©es dans la MA. Afin de pouvoir complĂ©ter cette liste nous avons mis au point au laboratoire le couplage entre la chromatographie liquide et les spectromĂštres de masse Ă©quipĂ©s d une source MALDI. Ce couplage nous offre des possibilitĂ©s d anlyses supplĂ©mentaires (Chiappetta et al. 2010) ainsi qu une complĂ©mentaritĂ© d analyse comparĂ© au montage classique (LC-ESI). Pour comprendre la complĂ©mentaritĂ© protĂ©ique et peptidique de ces deux approches(LC-MALDI et LC-ESI) nous avons Ă©tudiĂ© diffĂ©rents facteurs phyisco-chimiques pouvant induire une discrimination et une ionisation prĂ©fĂ©rentiellePARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF
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