Quelle place pour les adventices dans l’épidémiosurveillance ? Rapport au Comité National d’Epidémiosurveillance

La gestion des adventices est à juste titre considérée comme un frein majeur à l’adoption deméthodes intégrées de conduite des cultures peu dépendantes en produits phytosanitaires.Leur dynamique d’infestation se construisant sur plusieurs saisons culturales du fait du stock desemences dans le sol, les plantes adventices ne peuvent être gérées comme le seraient d’autresravageurs dépendant des seuls paramètres saisonniers pour déclencher leur épidémie. Pourautant notre groupe conclut que l’épidémiosurveillance des adventices peut être utile à unerationalisation des moyens de lutte. Elle peut permettre, sur le pas de temps court, d’optimiseren saison le choix tactique et le timing des interventions de tout ordre ayant un impact sur lesadventices et doit pour cela apparaître clairement dans les Bulletins de Santé du Végétal (BSV).Sa compilation sur plusieurs saisons permettra de mieux saisir l’évolution de la flore et depointer du doigt les facteurs responsables sous-jacents. Ceux-ci constituent autant d’éléments àintégrer dans l’analyse du risque et les préconisations stratégiques qui peuvent en découler. (...

The measures implemented to reduce the impact of plant protection products on pollinators in France

Shortly after the introduction of systemic insecticides, new problems were observed by beekeepers on honeybee colonies. The studies carried out under laboratory conditions have shown sublethal effects on honeybee behavior. However, it was not possible to reproduce under natural conditions the effects described by beekeepers on bee colonies. In addition, studies have revealed that many other factors could also be responsible for the dysfunction of honeybee colonies. Scientists agree that problems observed on the hives are the result of multifactorial effects. Measures concerning apicultural and agricultural practices are therefore necessary to improve honeybee colonies' health and to preserve the diversity of pollinators in France

Nouvelles règles d’évaluation des produits phytopharmaceutiques : conséquences pour les oléagineux

At the beginning of 2009, Parliament has adopted two directives to reduce utilizations of pesticides in Europe. Some Cut off criteria will be used after 2011 for the approval of active substances. This decision will affect the possibilities of chemical protection for the oilseed. A Pesticides Safety Directorate study shows that several herbicides, fungicides and insecticides actually used will be suspended, but without major impact for the crop protection, especially if expected innovations will be available next years

Perturbateurs endocriniens et relations dose-effet non monotones (état des lieux, mécanismes impliqués et conséquences en toxicologie)

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Le raisonnement et les avancées techniques permettent de réduire la fertilisation azotée : le cas de Farmstar-colza®

The practices of nitrogen fertilization are really changing, due to the new farming context including environmental, economical, and energetic constraints. In 2005, 90% of the producers said they used a method to adapt nitrogen supplies in their fields and more than 40% among them used the CETIOM method “réglette azote”. Since 2004, a new system, called Farmstar-colza® based on satellite observation has been developed by Infoterra France, a subsidiary of the EADS group. With this technology, it’s possible to draw a map of the fields with nitrogen supply advices and to practice modular apply on the crops. Moreover, this technology increases the precision of the crop nitrogen absorption assessment. Therefore, in the future it seems possible to improve the estimated need of nitrogen to grow oil seed rape in order to get a good energetic balance with an optimum oil rate as well as high yields

Les urgences au cabinet dentaire

Afin d'assurer la sécurité de ses patients le chirurgien-dentiste doit savoir gérer les situations d'urgences. Après un rappel diagnostic des principales urgences rencontrées en odontologie sont décrits les différents moyens permettant de prévenir leur apparition. Une conduite à tenir est ensuite exposée dans l'hypothèse de la survenue d'un accident malgré une bonne attitude préventive. Les gestes et les thérapeutiques devant être adaptée d'une part, à l état général du patient et d'autre part, à la pratique quotidienne du chirurgien-dentiste.NANTES-BU Médecine pharmacie (441092101) / SudocPARIS-BIUM (751062103) / SudocNANTES-Bib.Odontologie (441092219) / SudocSudocFranceF

Non-monotonic dose-response relationships and endocrine disruptors: a qualitative method of assessment

International audienceExperimental studies investigating the effects of endocrine disruptors frequently identify potential unconventional dose-response relationships called non-monotonic dose-response (NMDR) relationships. Standardized approaches for investigating NMDR relationships in a risk assessment context are missing. The aim of this work was to develop criteria for assessing the strength of NMDR relationships. A literature search was conducted to identify published studies that report NMDR relationships with endocrine disruptors. Fifty-one experimental studies that investigated various effects associated with endocrine disruption elicited by many substances were selected. Scoring criteria were applied by adaptation of an approach previously used for identification of hormesis-type dose-response relationships. Out of the 148 NMDR relationships analyzed, 82 were categorized with this method as having a " moderate " to " high " level of plausibility for various effects. Numerous modes of action described in the literature can explain such phenomena. NMDR can arise from numerous molecular mechanisms such as opposing effects induced by multiple receptors differing by their affinity, receptor desensitization, negative feedback with increasing dose, or dose-dependent metabolism modulation. A stepwise decision tree was developed as a tool to standardize the analysis of NMDR relationships observed in the literature with the final aim to use these results in a Risk Assessment purpose. This decision tree was finally applied to studies focused on the effects of bisphenol A

Unraveling the Role of Zinc Complexes on Indium Phosphide Nanocrystal Chemistry

International audienceThe addition of zinc complexes to the syntheses of indium phosphide nanocrystals (InP NCs) has become commonplace, due to their ability to alter and significantly improve observed optical properties. In this paper, the role of zinc complexes on the synthesis and observed properties of InP is carefully examined. Produced InP and InP:Zn2+ NCs are thoroughly characterized from both structural (core and surface) and optical perspectives over a wide range of Zn2+ compositions (0%-43% atomic content). We find no differences in the physical (NC size and polydispersity) and structural properties (crystallographic phase) of InP and InP:Zn2+ NCs. Optically, significant changes are observed when zinc is added to InP syntheses, including blueshifted absorption edges and maxima, increased quantum yields, and the near elimination of surface state emission. These improved optical properties result from surface passivation by zinc carboxylate moieties. Changes to the optical properties begin at zinc concentrations as low as 5%, demonstrating the high sensitivity of InP optical properties to exogenous species