Construction d'une démarche de pilotage d'un système de polyculture-élevage

National audiencePas de résum

Typologie des ripisylves des rivières de Guadeloupe, un premier pas vers le développement de techniques de génie végétal avec des espèces locales

National audienceThe PROTÉGER project aims to promote soil bioengineering techniques to preserve the extreme biodiversity of Guadeloupe's riparian environments, while protecting the population and their property from the risks incurred during river floods and cyclonic events. The first phase of the project consisted in describing the archipelago's riparian zones, in order to know their natural patterns and to be able to draw inspiration from them to develop nature-based solutions. Out of the 270 banks sampled, 302 species, 231 of which were native, were encountered, representing 10% of the local flora, reflecting the highly forested nature of the archipelago and its exceptional diversity. The analysis of these surveys allowed us to define 12 types of riparian vegetation, and to document 80 species that could potentially be used in soil bioengineering. The study presents 30 of them in the form of individual sheets available on the project website with their description, phenology, protection status, ecology, use and conditions of implementation. Beyond the typology and the specific sheets, this work also showed the alarming state of the Guadeloupe’s riparian forests, in particular on the downstream part of the rivers, with habitats degraded by pollution and the presence of invasive alien species.Le projet PROTÉGER vise à promouvoir les techniques de génie végétal pour préserver l’extrême biodiversité des milieux rivulaires de Guadeloupe, tout en protégeant la population et leurs biens, des risques encourus lors des crues de rivière et des évènements cycloniques. La première phase du projet a consisté à décrire les ripisylves de l’archipel, afin d’en connaitre les modèles naturels et de pouvoir s’en inspirer pour développer des solutions fondées sur la nature. Sur les 270 berges échantillonnées, 302 espèces dont 231 indigènes ont été rencontrées, soit 10 % de la flore locale, reflétant la nature très forestière de l’archipel et son exceptionnelle diversité. L’analyse de ces relevés a permis de définir 12 types de ripisylves, et de documenter 80 espèces potentiellement utilisables en génie végétal. L’étude présente 30 d'entre elles sous forme de fiches individuelles disponibles sur le site internet du projet avec leur description, leur phénologie, leur statut de protection, leur écologie, leur usage et leur condition d’utilisation. Au-delà de la typologie et des fiches spécifiques, ce travail a aussi montré l’état alarmant des ripisylves de Guadeloupe, notamment sur la partie aval des cours d‘eau, avec des habitats dégradés par la pollution et la présence d’espèces exotiques envahissantes

Platelet function and microparticles levels for patients with paroxysmal and persistent atrial fibrillation including during acute episodes

International audienc

Platelet function and microparticle levels in atrial fibrillation: Changes during the acute episode

Background: Thrombotic risk constitutes a major complication of atrial fibrillation (AF). Platelets and microparti-cles (MPs) are important for hemostasis and thrombosis, however their participation during AF is not well known. The aim of this study was to characterize platelet function and MPs procoagulant and fibrinolytic activity in AF patients and to determine the effects of an acute-AF episode. Methods: Blood was collected from paroxysmal (21) and persistent (16) AF patients referred for AF catheter ab-lation. Ten patients in sinus rhythm for 10 days were induced in AF allowing comparisons of left atrium samples before and after induction. Platelet aggregation with ADP, TRAP, collagen, and ristocetin was studied. Platelet surface expression of PAR-1, αIIbβ3, GPIb and P-selectin were evaluated by flow cytometry, and MPs-associated procoagulant and fibrinolytic activity levels were determined by functional assays. Results: A specific reduction in platelet aggregation to TRAP, activating the thrombin receptor PAR-1, was found in all AF patients. No differences in platelet receptor expression were found. Yet, after acute-induced AF, the platelet response was improved. Furthermore, a significant decrease of left atrium tissue factor-dependent procoagulant activity of MPs was observed. Conclusion: Acute episodes of AF results in a decrease in MPs-associated tissue factor activity, possibly corresponding to consumption, which in turn favors coagulation and the local production of thrombin. A decreased platelet basal aggregation to TRAP may result from PAR1 desensitization, whereas the improved response after an induced episode of AF suggests activation of coagulation and PAR1 re-sensitization

Potentiels et verrous d'une filière protéagineuse pour une agriculture durable en Bourgogne

International audienc

Distinct Substrates of Idiopathic Ventricular Fibrillation Revealed by Arrhythmia Characteristics on Implantable Cardioverter-Defibrillator.

BACKGROUND Idiopathic ventricular fibrillation (IVF) can be associated with undetected distinct conditions such as microstructural cardiomyopathic alterations (MiCM) or Purkinje (Purk) activities with structurally normal hearts. OBJECTIVE This study sought to evaluate the characteristics of recurrent VF recorded on implantable defibrillator electrograms, associated with these substrates. METHODS This was a multicenter collaboration study. At 32 centers, we selected patients with an initial diagnosis of IVF and recurrent arrhythmia at follow-up without antiarrhythmic drugs, in whom mapping demonstrated Purk or MiCM substrate. We analyzed variables related to previous ectopy, sinus rate preceding VF, trigger, and initial VF cycle lengths. Logistic regression with cross validation was used to evaluate the performance of criteria to discriminate Purk or MiCM substrates. RESULTS Among 95 patients (35 women, age 35 ± 11 years) meeting the inclusion criteria, IVF was associated with MiCM in 41 and Purk in 54 patients. A total of 117 arrhythmia recurrences including 91% VF were recorded on defibrillator. Three variables were mostly discriminant. Sinus tachycardia (≤570 ms) was more frequent in MiCM (35.9% vs 13.4%, P = 0.014) whereas short-coupled (80%). Ectopy were inconsistently present before VF. CONCLUSIONS Characteristics of arrhythmia recurrences on implantable cardioverter- defibrillator provide phenotypic markers of the distinct and hidden substrates underlying IVF. These findings have significant clinical and genetic implications