Raconter la recherche-intervention, retour sur trois opérations de gestion de la biodiversité

L'article se fonde sur un matériau peu courant : des récits de projets de gestion de la biodiversité associant les mondes de l'agriculture et de l'environnement. Trois situations de recherche-intervention sont ainsi analysées grâce aux concepts de la science en action. Elles mettent en évidence les caractéristiques de ces collectifs, les connaissances qu'ils mobilisent, ainsi que les outils d'intervention qu'ils construisent dans des processus mêlant recherche et action. La biodiversité dont il est question ici n'est ni celle du ministère dont les collectifs constitués autour de questions inédites se donnent la charge. En les suivant, grâce aux récits qu'en font les chercheurs, nous analysons les ressorts de la recherche-intervention, comparativement à une recherche plus classique

Polyclonal IgG4 hypergammaglobulinemia associated with plasmacytic lymphadenopathy, anemia and nephropathy.

International audienceMarked polyclonal immunoglobulin (Ig)G4 hypergammaglobulinemia has exceptionally been reported. Here we report on two Algerian patients who presented a syndrome characterized by anemia, plasmacytic lymphadenopathy, renal manifestations, and a marked polyclonal IgG4 hypergammaglobulinemia leading to a hyperviscosity syndrome in one case. The IgG4-expressing cell percentage was significantly increased in the peripheral blood lymphocytes collected from the two patients upon diagnosis. Moreover, in contrast with normal sera, both patients' sera significantly increased the percentage of IgG4-expressing cells when incubated with CD40-stimulated normal B lymphocytes. Similar effects were obtained with the culture supernatants of the patients' activated T cells. Anti-interleukin (IL) 4 and/or anti-IL-13 antibodies were unable to antagonize the IgG4 production. IL-4 and IL-13 serum concentrations were found to be normal in the two patients. The increased IgG4 production was found to be mediated by soluble factor(s), most probably secreted by activated T cells, which did not require the signal transducer and activator of transcription 6 signaling pathway

Critical steps for initiating an animal uterine transplantation model in sheep: experience from a case serie.

International audienceRecent reports have demonstrated uterus transplantation as a relevant solution to treat absolute uterine infertility. Training on animal models is a prerequisite to set up a uterine transplantation program in humans. Sheep have been used as an optimal model for training and research as they display similar vessels size to human. While the ovine model might seem easy there are many difficulties in performing this complex surgery. In this study we describe through our experience the critical initial steps toward building a learning curve toward an optimal ovine uterine transplantation model. We performed nine orthotopic uterine autotransplantations using end-to-side anastomoses to the external iliac vessels in sheep. We recorded the duration of all surgical steps and pointed out specific difficulties and solution found. We were able to perform optimal uterine dissection after the first 5 cases and optimal bilateral arterial and venous anastomoses, after 7 and 9 cases respectively. The main factors associated to success rate were optimal exposure, appropriate equipment, careful vessel preparation and modification of the anastomosis technique. As uterine transplantation research programs are expanding, setting up an ovine model to train and perform research is critical. Such model is complex and requires optimized multidisciplinary approach to build an efficient learning curve

Analysis of time-series of total and plant water stress levels using a dual-source energy balance model over agricultural crops and medium to low resolution thermal infra red remote sensing data

International audienc

Added value to local breeds through goods and services: a diversity of ways of valorisation

International audienc

Is the ecosystem services concept relevant to capture the multiple benefits from farming systems using livestock biodiversity? A framework proposal

Local breeds are key components of livestock farming systems. They are part of livestock biodiversity and this diversity has been threatened since the second half of the 20th century by their replacement with animals from specialized breeds. The multiple benefits of farming systems using local breeds – provision of goods, landscape and environmental management, and uses related to cultural and heritage dimensions – have long been recognized and used to argue for their conservation. However, the notion of ecosystem services is rarely used to analyze those benefits. This article presents a qualitative approach to the provision of ecosystem services by farming systems that use livestock biodiversity. Based on diverse case studies of breeds from several species, we propose an analytical framework that accounts for how a service is qualified, who is concerned by the services identified, the role of the breed in the process of service provision, and interactions between services. Finally, the framework considers the links between the provision of services and the management of the breeds. We discuss to what extent the notion of ecosystem services is useful in dealing with the multiple benefits from farming systems using local breeds

Heterozygous LmnadelK32 mice develop dilated cardiomyopathy through a combined pathomechanism of haploinsufficiency and peptide toxicity.

International audienceDilated cardiomyopathy (DCM) associates left ventricular (LV) dilatation and systolic dysfunction and is a major cause of heart failure and cardiac transplantation. LMNA gene encodes lamins A/C, proteins of the nuclear envelope. LMNA mutations cause DCM with conduction and/or rhythm defects. The pathomechanisms linking mutations to DCM remain to be elucidated. We investigated the phenotype and associated pathomechanisms of heterozygous Lmna(ΔK32/+) (Het) knock-in mice, which carry a human mutation. Het mice developed a cardiac-specific phenotype. Two phases, with two different pathomechanisms, could be observed that lead to the development of cardiac dysfunction, DCM and death between 35 and 70 weeks of age. In young Het hearts, there was a clear reduction in lamin A/C level, mainly due to the degradation of toxic ΔK32-lamin. As a side effect, lamin A/C haploinsufficiency probably triggers the cardiac remodelling. In older hearts, when DCM has developed, the lamin A/C level was normalized and associated with increased toxic ΔK32-lamin expression. Crossing our mice with the Ub(G76V)-GFP ubiquitin-proteasome system (UPS) reporter mice revealed a heart-specific UPS impairment in Het. While UPS impairment itself has a clear deleterious effect on engineered heart tissue's force of contraction, it also leads to the nuclear aggregation of viral-mediated expression of ΔK32-lamin. In conclusion, Het mice are the first knock-in Lmna model with cardiac-specific phenotype at the heterozygous state. Altogether, our data provide evidence that Het cardiomyocytes have to deal with major dilemma: mutant lamin A/C degradation or normalization of lamin level to fight the deleterious effect of lamin haploinsufficiency, both leading to DCM

Approche multi-échelle du fonctionnement des éco-agrosystèmes d'Afrique de l'Ouest dans le cadre du projet AMMA

6 pages, octobre 2005Rapport de restitution comité ECCO

Overview of research activities at the Gourma meso-scale site (Mali)

Within the AMMA project, the Gourma site in Mali is one of the 3 densely instrumented meso-scale sites dedicated to the study of the climatic and vegetation gradient over West Africa. The Gourma belongs to the Sahel and represents the northernmost site of the sub-regional AMMA window. It is mainly a pastoral region bracketed by the isohyets 500 and 100 mm. The Gourma window (14.5 - 17.5 ̊N; 1 - 2 ̊W) was chosen to be representative of sahelian and saharo-sahelian conditions that can be observed in Sahel. Desert-like conditions prevail in its northern part whereas savannah grasslands are present in its southern part. We present the overall strategy aimed at characterizing the vegetation dynamics, the spatio-temporal variation of soil moisture and the associated energy fluxes from the surface to the atmosphere, at different spatial scales from local- to meso-scale. Combined field measurements, modelling and assimilation of multi-spectral satellite data into a coupled vegetation - SVAT model is the chosen methodology to achieve this goal. This approach uses forcing variables that are acquired through a network of automatic systems (weather stations, raingauges) and/or derived from satellite remote sensing. Vegetation, soil moisture, sap flow measurements as well as radiation data are used for model evaluation and for the validation of available satellite products. For the local intensive site, named ‘Agoufou’, automatic weather systems are complemented by the IDAF and AERONET stations allowing a long term survey of atmospheric chemistry and aerosols. Compared to the two other meso-scale sites, emphasis is put on vegetation studies including long term monitoring of vegetation dynamics