41 research outputs found
Importance des composés phénoliques dans les interactions entre plantes et microorganismes : exemple des relations Rhizobium/légumineuses
National audienc
First characterization of lipid emulsification in the human stomach
International audienc
First characterization of lipid emulsification in the human stomach
International audienc
Characterization of dietary fat emulsification in the digestive tract of healthy human subjects
International audienc
Characterization of emulsions and lipolysis of dietary lipids in the human stomach
International audienc
Deciphering the evolutionary biology of freshwater fish using multiple approaches â insights for the biological conservation of the Vairone (Leuciscus souffia souffia)
International audienceThe organisation of genetic variability is of primary importance in designing conservation strategies. In this context, the conservation units are often defined using the concept of Evolutionary Significant Units (ESUs) what could appear as a useful guide but are very rarely used. Another difficulty arises when species hybridise as it is the case in cyprinid fishes for which the debate joins discussions on the species definitions. For example, the vairone, Leuciscus souffia (Teleostei: Cyprinidae) is a protected species (IUCN, Bern convention, Habitat directive) but current legislation does not take into account its ambiguous taxonomic status, neither its genetic variability nor its ecological preferences. In this paper, we examine the genetic structure and phylogeography of the subspecies Leuciscus souffia souffia in its range (France) with a combination of morphology, allozymes and mitochondrial DNA sequences using analyses mainly based on AMOVA and nested clade analysis. We then decipher the evolutionary biology of this fish as the combined analysis of morphology, nuclear and mitochondrial markers displays decoupling between morphological homogeneity and moderate genetic differentiation, suggesting that Management Units (following Moritz' definition) should be designed. We conclude by proposing directions both for the protection of endangered populations and for the conservation of evolutionary potential based on the evolutionary dynamics found for the examined populations in the light of the most-often used definitions of ESUs
Meth@+.com - ModĂ©liser le dĂ©veloppement dâun systĂšme innovant de mĂ©thanisation collective et Ă hautes performances environnementales Ă lâĂ©chelle dâun micro-territoires.
En 2013, le plan Energie Méthanisation Autonomie Azote était publié, et un modÚle « français de
mĂ©thanisation agricole collective » Ă©tait appelĂ© Ă devenir lâun des leviers de la transition Ă©nergĂ©tique et
Ă©cologique. Les travaux prĂ©sentĂ©s ici ont Ă©tĂ© rĂ©alisĂ©s entre 2013 et 2016 et se sont appliquĂ©s Ă
explorer plusieurs composantes de ce modĂšle de mĂ©thanisation afin de cerner les stratĂ©gies Ă lâorigine
des schémas de méthanisation, et leurs implications environnementales et agronomiques. Ainsi assortie
dâun Ă©tat des lieux des pratiques agronomiques de 4 mĂ©thaniseurs, la connaissance des digestats a Ă©tĂ©
approfondie afin de permettre une meilleure prise en compte de leurs propriétés dans leur stratégie de
gestion des ressources. Les logiques associĂ©es aux flux de matiĂšres et dâĂ©lĂ©ments fertilisants en amont et en aval des installations de mĂ©thanisation ont ainsi Ă©tĂ© explorĂ©es afin dâĂ©tablir un cadre dâanalyse des stratĂ©gies de
gestion des ressources par les mĂ©thaniseurs. Lâapproche des implications agro-environnementale sâest
faite par lâĂ©tude de la valeur fertilisante et amendante de plusieurs sortes de digestats.
La valeur fertilisante azotée de 5 formes de digestats a donc été définie, mettant en évidence la forte
variabilitĂ© de lâintĂ©rĂȘt des digestats au regard de ce critĂšre, mĂȘme si lâammonium reprĂ©sente toujours la
grande majoritĂ© de lâazote total (>70%). Une biodisponibilitĂ© de 100% du phosphore des digestats a Ă©tĂ©
mise en évidence par traçage isotopique. La variabilité des propriétés amendantes des digestats a été
mise en évidence par application de fractionnement biochimique (ISMO 73±8%, n=19)), et par
minĂ©ralisation potentielle du carbone et de lâazote.
Ces travaux restent limitĂ©s par le nombre dâunitĂ©s de mĂ©thanisation suivies (n=3), et appellent
lâapprofondissement des tendances soulevĂ©es.In 2013, in France, the « Energie MĂ©thanisation Autonomie Azote » plan was published, and the
âFrench agricultural and collective biogas modelâ should become a lever of the energetic and ecological
transition. The results presented in this paper were produced between 2013 and 2016 and planned to
explore several dimensions of this methane production plan. These works aimed at produce knowledges about biogas plant resources management and about digestate. Such knowledges and tools should be used to support biogas plant managers and territory stakeholders in order to analyze their own model from an agronomic and environmental point of view. Based on field experience cases, brakes and levers of such projects development have been gathered in a methodology guide. Upstream and downstream biomass and fertilizers flux have equally been explored in order to establish an analysis frame of resources management per biogas plant.
Additional works have been conducted about digestate. Several digestates features were studied.
Nitrogen fertilizing value of 5 digestate types were determined, and evidenced a great variability of
digestates quality regarding this topic. Ammonia remains the major part of total nitrogen (>70%).
Phosphorus bioavailability is 100%, as revealed by isotopic tracing. Biochemical fractioning and Carbon
and Nitrogen potential mineralization showed variability of amending digestates properties (ISMO
73±8%, n=19). Nevertheless, these works remain limited by the number of biogas plants under study
(n=3) and argue for going further into such analyses