Search results for " PES"
showing 10 items of 388 documents
La dérive pédagogique parallèle. Un fil éducatif invisible entre Porto et Paris à travers des récits personnels
2019
Partimos de la deriva como práctica artística contemporánea, con reconocidos antecedentes históricos. El objetivo principal es experimentar las potencialidades pedagógicas de la observación de entornos urbanos de forma colaborativa y mediada por las TIC a través de la deriva, como artistas/investigadores/docentes encargados de la formación del profesorado, para poder introducir este tipo de iniciativas en el entorno educativo. La A/R/Tografía como método de Investigación Basada en las Artes facilita usar la deriva simultáneamente como práctica artística, proceso investigador y experiencia de aprendizaje docente. Los resultados se exponen a través de narrativas personales que muestran reflex…
Degradation and acute toxicity of Methidathion and Trichlorfon onProcambarus clarkii,in experimental conditions
1991
Routine applications of organophosphate pesticides may adversely affect many nontarget organisms. Static toxicities in mature crayfish Procambarus clarkii were determined, in laboratory, for two organophosphate insecticides using 24, 48, 72 and 96‐h static tests. Three groups of 10 crayfish were exposed to 0.75 to 6 ppm for Trichlorfon and 0.2 to 0.9 ppm for Methidathion. The 24 to 96‐h LC50 values for Trichlorfon and Methidathion were from 5.14–0.99 ppm and 0.73–0.28 ppm respectively. Studies of degradation of Methidathion and Trichlorfon have been made using 1 ppm for Methidathion and 0.1 ppm for Trichlorfon. Both insecticides were degradated gradually until 96‐h. Results show that Methid…
Vers des systèmes viticoles économes en pesticides
2022
L’utilisation de produits phytosanitaires (cuivre, soufre et produits de synthèses) est à ce jour le moyen de lutte le plus efficace pour garantir une vendange qualitative et quantitative (Pujol, 2017). Face aux préoccupations sociétales croissantes concernant l’impact des pesticides sur l’environnement et la santé, la viticulture se doit pourtant de réduire sa dépendance aux produits phytosanitaires. Une transition agroécologique est ainsi nécessaire et implique de changer les pratiques afin de parvenir à diminuer l’utilisation des produits phytosanitaires. Le réseau DEPHY-Ferme a été créé en 2010 afin d’initier et stimuler cette transition agroécologique et répondre aux enjeux ambitieux i…
Proteolytic Processing ofBacillus thuringiensisCryIIIA Toxin and Specific Binding to Brush-Border Membrane Vesicles ofLeptinotarsa decemlineata(Color…
1996
Abstract The mode of action of Bacillus thuringiensis insecticidal proteins in lepidopteran insects is known to involve five steps: ingestion, solubilization, protease activation, binding to midgut membrane receptors, and disruption of the intestinal membrane. Two of these steps, protease activation and binding to midgut membrane receptors, have been analyzed in the major potato pest, the coleoptera Leptinotarsa decemlineata (Colorado potato beetle). Unlike recently proposed, after treatment of the coleopteran-specific B. thuringiensis toxin CryIIIA with gut content from the Colorado potato beetle, a 42-kDa processing polypeptide has been identified. The study of binding to midgut membrane …
Microbiological control of soil-borne phytopathogenic fungi with special emphasis on wilt-inducing Fusarium oxysporum
2009
Contents Summary 529 I. Biological control of plant diseases: state of the art 530 II. Main modes of action of biological control agents 530 III. The protective strains of F. oxysporum: an unexplored model 532 IV. Future directions for the study of the protective capacity of strains of F. oxysporum 539 V. How to make biological control successful in the field? 540 References 541 Summary Plant diseases induced by soil-borne plant pathogens are among the most difficult to control. In the absence of effective chemical control methods, there is renewed interest in biological control based on application of populations of antagonistic micro-organisms. In addition to Pseudomonas spp. a…
Quantitative structure-activity relationships for the toxicity of organophosphorus and carbamate pesticides to the Rainbow trout Onchorhyncus mykiss.
2006
This study has investigated the development of quantitative structure-activity relationships (QSARs) for the toxicity to rainbow trout Onchorhyncus mykiss Walbaum of 75 organophosphorus and carbamate pesticides. The toxicity data were obtained from an openly available toxicological database and were selected to be representative of a single endpoint. A large number of physicochemical and structural descriptors were calculated for the pesticides. QSAR models were developed using multiple linear regression and partial least-squares analyses. Following the removal of a small number of outliers, predictive QSARs were developed on small numbers of mechanistically relevant descriptors. Applying m…
Invasive and native populations of common ragweed exhibit strong tolerance to foliar damage.
2013
8 pages; International audience; Tolerance and resistance are defence strategies evolved by plants to cope with damage due to herbivores. The introduction of exotic species to a new biogeographical range may alter the plant herbivore interactions and induce selection pressures for new plant defence strategies with a modified resource allocation. To detect evolution in tolerance to herbivory in common ragweed, we compared 3 native (North America) and 3 introduced (France) populations, grown in a common garden environment. We explored the effect of leaf herbivory on plant vegetative and reproductive traits. Plants were defoliated by hand, simulating different degrees of insect grazing by remo…
Bacillus thuringiensis treatment modulate the HSP70 expression in larva and adult brain of Rhynchophorus ferrugineus
2013
To study the pathogen-host relationship, we used the model of the entomopathogenic bacterium Bacillus thuringiensis (Bt) and Rhynchophorus ferrugineus, a quarantine pest that attacks palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval and adult growth, and on the expression of the heat shock proteins (HSPs), rapidly synthesized in the cell after exposure to stress including pathogens. Bt has negative effects on larval and adult growth, on total hemocytes counts and on the hemocyte type. HSP70 was evaluated in the supernatant of the brain lysate obtained from larvae and adults fed with sublethal doses of Bt. HSP70 expression was mo…
Analysis of Pesticide Residues in Milk, Eggs, and Meat
2009
This handbook provides a systematic description of the principles, procedures, and technology of the modern analytical techniques used in the detection, extraction, clean up, and determination of pesticide residues present in the environment. This book provides the historical background of pesticides and emerging trends in pesticide regulation. The text discusses various techniques for analysis, including supercritical fluid extraction, disposable electrochemical biosensors, matrix solid-phase dispersion, volatmetric methods, and liquid chromatography. The authors also address the scope and limitation of NEEM products in plant protection as well as the analysis of medicinal plants.
Antimicrobial activity of the red palm weevil Rhynchophorus ferrugineus
2011
The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera Dryophthoridae), is an important pest of palms. Knowl- edge of both its natural enemies and its defensive mechanisms against predators and microorganisms is important to develop methods for an integrated pest control. Antimicrobial activity of the cuticular surface of adults and larvae, as well as of eggs, of this invasive species was investigated. This activity was tested against the Gram-positive bacteria Bacillus subtilis (Ehrenberg) Cohn and Bacillus thuringiensis Berliner, the Gram-negative bacterium Escherichia coli Escherich, and the entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium aniso…