Agroecology and ecological engineering for pest management. Cotton protection as a case study

This synthesis provides an annotated guide to the thinking and publications behind the evolution of concepts in cotton pest management over the last fifty years. The first movement was from the concepts of Pest Control to those of Integrated Pest Management (IPM). It was soon appreciated that advantage needed to be taken of the beneficial aspects of agro-ecological biodiversity, leading to concepts of Agro-Ecological Engineering. This required action beyond the immediate cotton field and of many players other than the recommending scientist. Area-wide and Community-based management, incorporating the lessons learnt from Farmer Field Schools (FFS) made this a more genuinely participatory process. It soon became apparent that biodiversity in itself does not deliver improved pest management and the practice of Landscape Farming came to involve the manipulation of spatio-temporal crop geometries, in turn leading to Better Cotton Management Practices (BMPs) aiming to capitalise on functionally useful biocomplexity rather than simple biodiversity as such and explicitly incorporating wider environmental concerns. More recent developments along this pest management continuum include the idea of New Cotton Cultivation (NCC) emphasising the interactions between the plant, the technical context and the natural and sociological environment of particular cultivators. With improvements in our understanding of the scale and complexity of the practices required to optimise cotton production systems we will continue to move towards more genuinely sustainable and lower physical-input systems. (Résumé d'auteur

Aphid and whitefly management in cotton growing: review and challenges for the future

In many cotton growing regions in the world, the phytosanitary situation of cotton has been marked in the past two decades by, among other things, a renewed increase in the populations of certain piercing-sucking insects and especially the aphid Aphis gossypii Glover and the whitefly Bemisia tabaci (Gennadius). These pests are polyphagous and display very special biological and ecological features causing damage with extremely serious economic consequences. The methods generally used to control these sucking insects were based mainly on the use of insecticides targeting aphids or whitefly, in most cases with the same spray procedures as for those used to control other major cotton pests such as bollworms. This chemical control has finally proved not very effective and its is expensive and forms a real danger for the conservation of biological diversity and for the environment as a whole. Alternative control methods that are better suited to the integrated management of aphid and whitefly populations are proposed within the framework of more rational and sustainable fanning. They are based on the principle of seeking a return towards a balance between these pests and the various accompanying indigenous beneficial insects. For this, a break with past practices is first recommended in order to prevent an aggravation of the phytosanitary situation, followed by the application of a new strategy based on the integrated pest management concept. The role of preventive measures would thus become preponderant. These are based on a strategy enabling plants to escape attacks by these pests thanks to various procedures such as early sowing, choice of varieties with short cycles, limited vegetative development and vegetation with low appetancy for the insects. Traditional agronomic techniques such as rotations and cropping patterns, rational combinations of crop plants, trap crops, etc., also have complementary effects by limiting pest outbreaks and enhancing populations of beneficials. The prospects opened up by genetically modified varieties are mentioned. The phytosanitary situations of the field are then monitored using population count techniques and the setting of economic thresholds. If it is then found to be essential to use curative control measures, priority should be awarded to alternative techniques and chemical spraying with active substances causing the least damage to the environment used only in the last resort. Appropriate agronomic techniques for the phytosanitary situations in cotton growing are mentioned. It is proposed that agronomists and crop protection specialists should adopt a concerted approach in this new pathways and report the results obtained in the medium term. (Résumé d'auteur

Santé des jeunes en rupture d'apprentissage: une recherche-action sur les modalités de soutien, les déterminants de la santé et les facteurs favorisant une réinsertion socio-professionnelle

Objectifs: -> identifier les déterminants des résiliations de contrats d'apprentissage dans les cantons de Vaud et du Valais romand, sur le plan de la santé, des comportements, et du parcours scolaire et professionnel; -> identifier les facteurs qui contribuent à la marginalisation et à l'abus de substances, ou au contraire à la réinsertion des jeunes; -> tester l'efficacité d'un programme d'accompagnement de ces jeunes

Evaluation des unités de prévention et de traitements pour jeunes suicidants à Genève: L'unité de crise pour adolescents des HUG : évaluation de son fonctionnement durant la première année ; Evaluation du programme d'étude et prévention du suicide rattaché à l'unité hospitalière pour jeunes suicidants à Genève

[Table des matières] 1. Synthèse et conclusion : Le projet; l'évaluation; résumé des premiers résultats; présentation de l'Unité; quelques chiffres; le vécu des adolescents / des soignants; le devenir des jeunes à trois mois; Conclusions et recommandations. 2. Introduction et méthodes : Le projet Children Action; évaluation de l'unité hospitalière; population cible; évaluation. 3. L'échantillon et son évolution : composition; données de tentative de suicide; données sur le séjour; évolution de la situation des adolescents enetre les deux bilans; gestion du temps libre; consommations, comportements à problème et santé subjective; image de soi; status psychiatrique; suivi thérapeutique et risque suicidaire; remarques. 4. Entretiens avec les infirmiers et les thérapeutes, l'assistante sociale. 5. Analyse des entretiens avec les adolescents : compliance; sorties, repas, soirées et nuits; vécu de l'hospitalisation; relations avec la famille..

The role of lubricant feeding conditions on the performance improvement and friction reduction of journal bearings

Most conventional hydrodynamic journal bearing performance tools can not suitably assess the effect of lubricant feeding conditions on bearing performance, even though these conditions are known to affect important performance parameters such as eccentricity and powerloss. A thermohydrodynamic analysis suitable to deal with realistic feeding conditions has been proposed. Special attention was given to the treatment of phenomena taking place within grooves and their vicinity,as well as to the ruptured film region. The effec to flubricant feeding pressure and temperature, groove length ratio,width ratio and number (single/twin) on bearing performance has been analyzed for a broad range of conditions.It was found that a careful tuning of the feeding conditions may indeed improve bearing performance.FCT - POCTI/EME/39202/200

Evaluation of the effects of hyaluronic acid-carboxymethyl cellulose barrier on ovarian tumor progression

BACKGROUND: Hyaluronic acid is a prognostic factor in ovarian cancers. It is also a component of Hyaluronic Acid-Carboxymethyl Cellulose (HA-CMC) barrier, an anti-adhesion membrane widely used during abdominal surgeries in particular for ovarian carcinosis. 70% of patients who undergo ovarian surgery will relapse due to the persistence of cancer cells. This study’s objective was to determine the oncological risk from use of this material, in the presence of residual disease, despite the benefit gained by it decreasing post-surgical adhesions in order to provide an unambiguous assessment of its appropriateness for use in ovarian surgical management. METHODS: We assessed the effects of HA-CMC barrier on the in vitro proliferation of human ovarian tumor cell lines (OVCAR-3, IGROV-1 and SKOV-3). We next evaluated, in vivo in nude mice, the capacity of this biomaterial to regulate the tumor progression of subcutaneous and intraperitoneal models of ovarian tumor xenografts. RESULTS: We showed that HA-CMC barrier does not increase in vitro proliferation of ovarian cancer cell lines compared to control. In vivo, HA-CMC barrier presence with subcutaneous xenografts induced neither an increase in tumor volume nor cell proliferation (Ki67 and mitotic index). With the exception of an increased murine carcinosis score in peritoneum, the presence of HA-CMC barrier with intraperitoneal xenografts modified neither macro nor microscopic tumor growth. Finally, protein analysis of survival (Akt), proliferation (ERK) and adhesion (FAK) pathways highlighted no activation on the xenografts imputable to HA-CMC barrier. CONCLUSIONS: For the most part, our results support the lack of tumor progression activation due to HA-CMC barrier. We conclude that the benefits gained from using HA-CMC barrier membrane during ovarian cancer surgeries seem to outweigh the potential oncological risks

Maitotoxin-4, a Novel MTX Analog Produced by Gambierdiscus excentricus

Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area

Rules Governing Selective Protein Carbonylation

BACKGROUND:Carbonyl derivatives are mainly formed by direct metal-catalysed oxidation (MCO) attacks on the amino-acid side chains of proline, arginine, lysine and threonine residues. For reasons unknown, only some proteins are prone to carbonylation. METHODOLOGY/PRINCIPAL FINDINGS:we used mass spectrometry analysis to identify carbonylated sites in: BSA that had undergone in vitro MCO, and 23 carbonylated proteins in Escherichia coli. The presence of a carbonylated site rendered the neighbouring carbonylatable site more prone to carbonylation. Most carbonylated sites were present within hot spots of carbonylation. These observations led us to suggest rules for identifying sites more prone to carbonylation. We used these rules to design an in silico model (available at http://www.lcb.cnrs-mrs.fr/CSPD/), allowing an effective and accurate prediction of sites and of proteins more prone to carbonylation in the E. coli proteome. CONCLUSIONS/SIGNIFICANCE:We observed that proteins evolve to either selectively maintain or lose predicted hot spots of carbonylation depending on their biological function. As our predictive model also allows efficient detection of carbonylated proteins in Bacillus subtilis, we believe that our model may be extended to direct MCO attacks in all organisms