Vertical project : designing fruit agroforestry systems for a renewed horticulture

Although it's addressing multiple issues for modern farming, agroforestry mixing fruit trees and annual crops (mainly vegetables) has not been so well documented under temperate climate. One expected amenity of agroforestry is to increase biodiversity and natural pest regulation within the plot. While fruit trees are among the crops that rely most on plant protection products, we made the hypothesis that introduction of annual crops in the perennial system can lead to effective biocontrol and to input reduction, while developing other synergies between crops (shadow beneficial effects, water limitation, ….) or social amenities. On two locations (Durette/TAB) in southern France, with different characteristics (crop rotation, marketing, surface...), the partners of a 6-years funded project called Vertical, designed in 2012 and 2013 innovative cropping systems addressing those specific constraints, in order to optimize their global performance. These systems have been implemented in 2013 and 2014. Sustainability indicators have been discussed and selected to (i) monitor and (ii) to assess these systems. An ex ante assessment tool has been developed under a participatory approach, to stimulate the co-design of new performant plots. This tool will shortly be adapted to ex-post assessment, so that advisors but also farmers dealing with fruit agroforestry systems can identify their main bottlenecks and assets. A link to the national bottom-up network of fruit agroforestry systems (called Smart) will be achieved this way

Vertical project : designing fruit agroforestry systems for a renewed horticulture

Although it's addressing multiple issues for modern farming, agroforestry mixing fruit trees and annual crops (mainly vegetables) has not been so well documented under temperate climate. One expected amenity of agroforestry is to increase biodiversity and natural pest regulation within the plot. While fruit trees are among the crops that rely most on plant protection products, we made the hypothesis that introduction of annual crops in the perennial system can lead to effective biocontrol and to input reduction, while developing other synergies between crops (shadow beneficial effects, water limitation, ….) or social amenities. On two locations (Durette/TAB) in southern France, with different characteristics (crop rotation, marketing, surface...), the partners of a 6-years funded project called Vertical, designed in 2012 and 2013 innovative cropping systems addressing those specific constraints, in order to optimize their global performance. These systems have been implemented in 2013 and 2014. Sustainability indicators have been discussed and selected to (i) monitor and (ii) to assess these systems. An ex ante assessment tool has been developed under a participatory approach, to stimulate the co-design of new performant plots. This tool will shortly be adapted to ex-post assessment, so that advisors but also farmers dealing with fruit agroforestry systems can identify their main bottlenecks and assets. A link to the national bottom-up network of fruit agroforestry systems (called Smart) will be achieved this way

Projected impacts of climate change on viticulture over French wine regions using downscaled CMIP6 multi-model data

Climate change is a major challenge for the French wine industry. Climatic conditions in French vineyards have already changed and will continue to evolve impacting viticulture. This study aims to analyse the evolution of agro- and eco-climatic indices based on phenology simulation of French wine-growing regions. This evolution was analysed on a recent-past period (1962–1991 to 1992–2021) using SAFRAN climate data and on a future projected period (1985–2014 to 2041–2070) with two SSP trajectories (SSP2-4.5 and SSP5-8.5). A set of 19 CMIP6 climate models downscaled at 8 km grid resolution over France coupled with three phenological and a water balance model were used. Phenological model parameters and training system characteristics were adapted to each region to match as much as possible current practices. Temperatures during the growing season have increased by +1 °C to +2.1 °C since the second half of the 20th century and could rise to +3.7 °C in regions around the Mediterranean by 2070. The inter-model variance concerning the precipitation is high, a significant change (decrease) in precipitation during the grapevine growing season is observed only for the regions of western France (Oceanic climate) over the period 2040–2071 with the SSP5 trajectory. All simulated phenological stages have shifted toward earlier dates. Their occurrence should be even earlier by 2070 with an average advance of up to 22 days for the mid-veraison of Pinot noir in eastern France. The theoretical maturity date (sugar content) should also be advanced from 19 to 30 days depending on the considered region and SSP. Thermal conditions closer to the photosynthetic optimum should promote onset by the early second half of the 21st century. The increase in both the number of hot days and grapevine water deficit during the period of fruit development should impact grape production in quality and quantity in all wine-growing regions. Spring frost projections show no significant change in risk for the second half of the 21st century, compared to current conditions

Dual role of striatal astrocytes in behavioral flexibility and metabolism in the context of obesity

Brain circuits involved in metabolic control and reward-associated behaviors are potent drivers of feeding behavior and are both dramatically altered in obesity, a multifactorial disease resulting from genetic and environmental factors. In both mice and human, exposure to calorie-dense food has been associated with increased astrocyte reactivity and pro-inflammatory response in the brain. Although our understanding of how astrocytes regulate brain circuits has recently flourish, whether and how striatal astrocytes contribute in regulating food-related behaviors and whole-body metabolism is still unknown. In this study, we show that exposure to enriched food leads to profound changes in neuronal activity and synchrony. Chemogenetic manipulation of astrocytes activity in the dorsal striatum was sufficient to restore the cognitive defect in flexible behaviors induced by obesity, while manipulation of astrocyte in the nucleus accumbens led to acute change in whole-body substrate utilization and energy expenditure. Altogether, this work reveals a yet unappreciated role for striatal astrocyte as a direct operator of reward-driven behavior and metabolic control

Postprandial hyperglycemia stimulates neuroglial plasticity in hypothalamic POMC neurons after a balanced meal

Mechanistic studies in rodents evidenced synaptic remodeling in neuronal circuits that control food intake. However, the physiological relevance of this process is not well defined. Here, we show that the firing activity of anorexigenic POMC neurons located in the hypothalamus is increased after a standard meal. Postprandial hyperactivity of POMC neurons relies on synaptic plasticity that engages pre-synaptic mechanisms, which does not involve structural remodeling of synapses but retraction of glial coverage. These functional and morphological neuroglial changes are triggered by postprandial hyperglycemia. Chemogenetically induced glial retraction on POMC neurons is sufficient to increase POMC activity and modify meal patterns. These findings indicate that synaptic plasticity within the melanocortin system happens at the timescale of meals and likely contributes to short-term control of food intake. Interestingly, these effects are lost with a high-fat meal, suggesting that neuroglial plasticity of POMC neurons is involved in the satietogenic properties of foods.Contrôle nerveux de la prise alimentaire et du métabolisme par une molécule neurale d'adhésion cellulaireISITE " BFCRéseau d'Innovation sur les Voies de Signalisation en Sciences de la Vi

The Addiction-Susceptibility TaqIA/Ankk1 Controls Reward and Metabolism Through D2 Receptor-Expressing Neurons

Background: A large body of evidence highlights the importance of genetic variants in the development of psychiatric and metabolic conditions. Among these, the TaqIA polymorphism is one of the most commonly studied in psychiatry. TaqIA is located in the gene that codes for the ankyrin repeat and kinase domain containing 1 kinase (Ankk1) near the dopamine D2 receptor (D2R) gene. Homozygous expression of the A1 allele correlates with a 30% to 40% reduction of striatal D2R, a typical feature of addiction, overeating, and other psychiatric pathologies. The mechanisms by which the variant influences dopamine signaling and behavior are unknown. Methods: Here, we used transgenic and viral-mediated strategies to reveal the role of Ankk1 in the regulation of activity and functions of the striatum. Results: We found that Ankk1 is preferentially enriched in striatal D2R-expressing neurons and that Ankk1 loss of function in the dorsal and ventral striatum leads to alteration in learning, impulsivity, and flexibility resembling endophenotypes described in A1 carriers. We also observed an unsuspected role of Ankk1 in striatal D2R-expressing neurons of the ventral striatum in the regulation of energy homeostasis and documented differential nutrient partitioning in humans with or without the A1 allele. Conclusions: Overall, our data demonstrate that the Ankk1 gene is necessary for the integrity of striatal functions and reveal a new role for Ankk1 in the regulation of body metabolism.Altérations du système de récompense dans l'anorexie mentaleRole du biostatus en acides gras polyinsaturés dans les troubles de contrôle exécuti

Exploring Functional β-Cell Heterogeneity In Vivo Using PSA-NCAM as a Specific Marker

BACKGROUND:The mass of pancreatic beta-cells varies according to increases in insulin demand. It is hypothesized that functionally heterogeneous beta-cell subpopulations take part in this process. Here we characterized two functionally distinct groups of beta-cells and investigated their physiological relevance in increased insulin demand conditions in rats. METHODS:Two rat beta-cell populations were sorted by FACS according to their PSA-NCAM surface expression, i.e. beta(high) and beta(low)-cells. Insulin release, Ca(2+) movements, ATP and cAMP contents in response to various secretagogues were analyzed. Gene expression profiles and exocytosis machinery were also investigated. In a second part, beta(high) and beta(low)-cell distribution and functionality were investigated in animal models with decreased or increased beta-cell function: the Zucker Diabetic Fatty rat and the 48 h glucose-infused rat. RESULTS:We show that beta-cells are heterogeneous for PSA-NCAM in rat pancreas. Unlike beta(low)-cells, beta(high)-cells express functional beta-cell markers and are highly responsive to various insulin secretagogues. Whereas beta(low)-cells represent the main population in diabetic pancreas, an increase in beta(high)-cells is associated with gain of function that follows sustained glucose overload. CONCLUSION:Our data show that a functional heterogeneity of beta-cells, assessed by PSA-NCAM surface expression, exists in vivo. These findings pinpoint new target populations involved in endocrine pancreas plasticity and in beta-cell defects in type 2 diabetes

Hypothalamic AgRP-neurons control peripheral substrate utilization and nutrient partitioning

Obesity-related diseases such as diabetes and dyslipidemia result from metabolic alterations including the defective conversion, storage and utilization of nutrients, but the central mechanisms that regulate this process of nutrient partitioning remain elusive. As positive regulators of feeding behaviour, agouti-related protein (AgRP) producing neurons are indispensible for the hypothalamic integration of energy balance. Here, we demonstrate a role for AgRP-neurons in the control of nutrient partitioning. We report that ablation of AgRP-neurons leads to a change in autonomic output onto liver, muscle and pancreas affecting the relative balance between lipids and carbohydrates metabolism. As a consequence, mice lacking AgRP-neurons become obese and hyperinsulinemic on regular chow but display reduced body weight gain and paradoxical improvement in glucose tolerance on high-fat diet. These results provide a direct demonstration of a role for AgRP-neurons in the coordination of efferent organ activity and nutrient partitioning, providing a mechanistic link between obesity and obesity-related disorders

Sois stage et tais-toi ? Le sous salariat démasqué

Contexte Les associations sont devenues des structures professionnelles importantes. Elles agissent également dans des domaines attractifs pour notre génération et leur éthique garantit a priori un cadre de travail à la fois valorisant et épanouissant pour leurs salariés. Pour autant, si ces structures recrutent, leur caractère sans but lucratif et la baisse des subventions publiques les condamnent à limiter leurs embauches, malgré une activité soutenue et souvent même croissante. Ainsi, en l..

Sociologie des professions et politiques publiques

5e édition entièrement revue et corrigéeInternational audienceDans cette notice, les auteurs appellent à un dialogue plus prononcé entre la sociologie des professions et l'analyse des politiques publiques. D'une part, les dynamiques professionnelles ont des effets sur la forme et le contenu des politiques publiques. D'autre part, les professions sont des cibles privilégiées des politiques publiques contemporaines, notamment dans le cadre du New Public Management. Cette notice présente aussi l'intérêt d'une perspective écologique de l'analyse des professions, telle que formulée par Andrew Abbott