Étude des complémentarités entre gestion dynamique à la ferme et gestion statique en collection: Cas de la variété de blé Rouge de Bordeaux

National audienceWhile on-farm conservation was considered minor in the development of the National Charter on Genetic Resources in 1998, there is increasing recognition of its important role in the conservation of genetic diversity. In addition to amateur gardening associations that save and exchange seeds, farmers in France have formed networks around systems of shared seed conservation and exchanges, with the goal of protecting the diversity of cultivated species. Parallel to this, the contribution of farmers to the dynamic management of agricultural biodiversity has been recognized by many scientific studies and in international treaties. These developments led us to examine the complementary nature of on-farm and gene-bank conservation efforts in terms of the management of genetic resources. This study, which combines ethnobotanical and genetic approaches, was conducted on bread wheat, for which France has a national collection of 10 000 accessions. There is also an active network of farmers who cultivate historic varieties and landraces, including the Rouge de Bordeaux, which was chosen for a detailed study. By conducting individual interviews with farmers, we were able to understand better their management practices, seed exchanges with other farmers and with the national collection, and strategies for maintaining and selecting this variety on their own farms. We characterized the genetic diversity conserved by several farmers and in the samples preserved in the national collection for Rouge de Bordeaux by using a comparative genetic analysis of samples obtained from farmers and from the collection, in light of the management practices and exchange networks that exist among farmers and between farmers and the national collection. Our results demonstrate that the diversity of these populations is far from being redundant. While certain samples are quite homogeneous and similar to samples from the national collection, others are highly heterogeneous. There is also a high degree of genetic differentiation among populations, with clear groupings of populations identified. The structure of the diversity may be explained by the structure of exchanges and the development of local adaptation within the populations to environmental conditions and management practices, and by differing strategies of selection and conservation. Further analysis will help us understand more precisely what defines a variety and what type of genetic diversity or phenotypic traits are conserved with different management strategies. Our results also support a greater degree of seed circulation between farmers' fields and the national collection, to conserve the adaptive potential and a broader range of genetic diversity for each variety.Considérée comme mineure lors de la rédaction de la Charte nationale des ressources génétiques en 1998, la gestion à la ferme a depuis gagné en importance et en reconnaissance. En effet, après les associations de jardiniers amateurs, des réseaux d'agriculteurs se sont fédérés en France autour de systèmes mutualistes de sélection/conservation de la diversité cultivée. Parallèlement, la contribution des paysans à la gestion dynamique de l'agrobiodiversité a été scientifiquement et institutionnellement reconnue. Ces éléments nous ont conduit à examiner les complémentarités dans la gestion des ressources génétiques à la ferme et en collection. Cette étude, qui croise des approches ethnobotanique et génétique, a été menée sur le blé tendre pour lequel il existe en France une collection nationale de 10 000 accessions et un réseau actif d'agriculteurs-collectionneurs de variétés. Pour la variété Rouge de Bordeaux, nous avons tenté de caractériser la diversité dans les champs et en collection, en procédant à une analyse génétique d'échantillons obtenus auprès d'agriculteurs et auprès de la collection. Nos résultats montrent que les ressources génétiques conservées dans les deux compartiments sont loin d'être redondantes. La structuration de la diversité s'explique par les réseaux d'échanges de semences (entre paysans, et entre les paysans et la collection), par l'adaptation locale des populations aux conditions du milieu et aux pratiques de culture, et par les pratiques de sélection/conservation. Ces résultats appellent des analyses complémentaires pour comprendre précisément ce qui est conservé/cultivé sous un nom variétal donné, et plaident en faveur d'une circulation accrue des semences entre champs et collection

Expertise médico-militaire et avis sapiteur spécialisé : état des lieux d’une pratique et perspectives

Le service de santé des armées (SSA) termine en 2020 une restructuration qui se caractérise par une diminution de sa composante hospitalière au profit de la médecine des forces. La médecine d'unité est une des composantes de cette transformation et doit être le pivot autour duquel s'organise le parcours de soins des militaires, avec notamment une place privilégiée dans la filière d'expertise médico-statutaire. En effet, alors que jusqu'à présent les décisions médico-militaires relevaient d'un avis spécialisé, la responsabilité de ces dernières est désormais transférée au médecin d'unité qui peut solliciter ou non un avis sapiteur. L'impact de ce changement a été évalué via un auto-questionnaire distribué aux médecins du SSA participants. Au terme de notre étude, nous avons pu décrire que les avis sapiteurs représentent un outil précieux pour les médecins d'unité. En outre, les spécialistes militaires continuent d'avoir la confiance des médecins des forces et ce malgré l'éloignement géographique et les délais. Les participants ont rapporté un manque de pertinence occasionnel lorsque les avis émanent de spécialistes ayant une connaissance plus limitée de l'institution, que qui souligne le fait qu'une bonne connaissance du milieu semble être indispensable pour émettre un bon avis sapiteur. Ce travail propose plusieurs solutions, comme réduire les délais de réponse en favorisant les avis à distances (sur pièce ou par appel téléphonique) ou favoriser les échanges avec le milieu civil

Comparison of Static and Dynamic Land Use-Transport Interaction Models: Pirandello and UrbanSim Applications

International audienceThe paper addresses comparability of two urban modeling frameworks: the static equilibrium Pirandello and the dynamic disequilibrium UrbanSim. The two frameworks, though conceptually different, contain some common features in their transportation and land use models. An empirical test includes the long-term effect of an urban toll implementation in the Lyon urban area in France. The conclusion is that the static and the dynamic urban modeling frameworks, despite their fundamental differences, can generate, in most cases, comparable empirical results, which are intuitively logical and can be used for policy scenario evaluations

Temperature measurement using infrared thermography of the dielectric in a DBD plasma actuator dedicated to subsonic airflow control

Présentation oral

Experimental study of the flow induced by a sinusoidal Dielectric Barrier Discharge actuator and ist effects on a flate natural boundary layer

International audienceSince the mid-1990s, electrohydrodynamic actuators have been developed for modifying on subsonic airflows. The principle of plasma action is the use of the direct conversion of electrical energy into kinetic energy in order to act on the flow boundary layer. This paper presents our contribution to such an investigation concerning an electrohydrodynamic actuator consisting of several sinusoidal dielectric barrier discharges. First, the ionic wind induced by this actuator was measured with a pressure sensing probe. The induced flow velocity increased with the applied voltage and frequency. The particle image velocimetry system without external airflow showed the presence of induced swirls, generated by the ion movement in plasma. Then the action of this actuator on a flat plate boundary layer in parallel flow at zero incidence was studied in a subsonic wind tunnel. Experiments were performed for 15 m/s and 22 m/s. They showed that electric discharges (8 kV, 1 kHz) acting on a laminar flow tripped the laminar-to-turbulent transition. Moreover, higher applied voltages (up to 12 kV, 1 kHz) were necessary for modifying turbulent boundary layers

Utilisation digestive des graines protéagineuses traitées et leur valorisation par les vaches laitières

National audienc

Effects of high-intensity interval training associated with a complementation of flaxseed oil on body composition and metabolic profile in obese rats

International audienc

Beneficial Effects of High Intensity Interval Training and/or Linseed Oil Supplementation to Limit Obesity-Induced Oxidative Stress in High Fat Diet-Fed Rats

International audienceHigh-intensity interval training (HIIT) and linseed oil (LO) supplementation are effective strategies to reduce obesity-induced oxidative stress. Our aim was to determine whether the HIIT + LO combination prevents obesity-induced oxidative stress in high fat diet (HFD)-fed rats. HFD-fed 8-week-old, male, Wistar rats were subdivided in four groups: HFD, LO (2% of sunflower oil replaced with 2% of LO in the HFD), HIIT (4 days/week for 12 weeks), and HIIT + LO. Wistar rats fed a low-fat diet (LFD) were used as controls. Epididymal and subcutaneous adipose tissue, gastrocnemius muscle, liver, and plasma samples were collected to measure oxidative stress markers (AOPP, oxLDL), antioxidant (SOD, CAT, and GPx activities) and pro-oxidant (NOx and XO) enzyme activities. Compared with the LFD, the HFD altered the pro/antioxidant status in different tissues (increase of AOPP, oxLDL, SOD and catalase activities in plasma, and SOD activity increase in liver and decrease in adipose tissues) but not in gastrocnemius. LO upregulated CAT activity and decreased NOx in liver. HIIT alleviated HFD negative effects in liver by reducing SOD and NOx activities. Moreover, the HIIT + LO combination potentiated SOD activity upregulation in subcutaneous tissue. HIIT and LO supplementation have independent beneficial effects on the pro/antioxidant balance. Their association promotes SOD activity in subcutaneous adipose tissue