Analyse statistique correlative de l'influence des proprietes des sols sur l'adsorption d'herbicides et insecticides

A statistical correlative study (simple and multiple) between 14 herbicides and insecticides and composition of 51 soil samples has been performed by considering top- and sub-soil horizons, separately. Results point out the suitability of these regression models as a predictive tool to determine quantitatively the adsorption of numerous pesticides in soils mainly the more soluble compounds.     

Effet de l'EDTA sur l'accumulation et l'elimination du mercure par la moule Mytilus edulis

The effect of the presence of the chelating agent EDTA on the uptake and loss of mercury from the whole soft parts of the common mussel Mytilus edulis were investigated under laboratory conditions. It is concluded that the EDTA significantly increased mercury accumulation throughout 18 days exposure. During the elimination period the loss rates of mercury by the presence of EDTA were less important than those obtained in natural sea-water.     

Etude de l'accumulation du cadmium par une bacterie marine en fonction des conditions de cultures

The influence of different cultural conditions (temperature, salinity, pH, organic matter and cadmium concentration, presence of sulfhydryl groups) on the accumulation of cadmium by a Cd resistent marine bacterium was investigated. The results showed that each of these parameters modify to a certain extent both biomass production and cadmium accumulation. This work emphasizes the need for a higher standardization of toxicity tests to ensure a better reliability of results.     

Influence du volume d'inoculum dans la quantification des virus selon deux techniques comparees: Plages et N.P.P. utilisant un grand nombre d'inoculum par dilution

Viral particles can be quantified by two different titration methods which provided the same results: counting plates in solid medium and MPN method, using a large number of inocula for each dilution, in liquid medium. The accuracy of the two methods is a function of the volume of the inoculum used. The width of the confidence interval increases when the volume of the inoculum decreases.     

L'utilisation de souches de micro-organismes de collection pour l'etude de la biodegradabilite des pesticides

Use of Microbial strains from collection in the study of pesticide biodegradability. 5 different herbicides and 1 metabolite of herbicide were subjected to biodegradation by different microbial strains and simultaneously by soil suspensions.To take account of possible co-metabolisme a supplementary source of carbon was added in the culture media. Results were discussed.     

Microméthode de dosage simultané de l'alcool isopropylique et de son métabolite l'acétone

Simultaneous determination of Isopropyl Alcohol and Acetone prove to be necessary in cases of poisoning by this widely used alcohol. An aluminum capsule containing a sample of blood to be analyzed is introduced into a gas chromatograph equipped with a flameionization detector and a Carbowax 20 M - Chromosorb WHP column. Use of a small blood sample (0.50 μl) and high sensitivity of the method make it a selected procedure in the clinical diagosis of poisoning by Isopropyl Alcohol.     

Conditions d'acceptation ou de rejet des valeurs obtenues apres denombrement de virus ou bacteries sur milieux de culture solides

Enumeration of viruses or bacteria on solid culture media does not ever give statistically acceptable results. When counting is impossible, we must do it again. For accepting or not the counting, the authors established some probability Tables (95% and 99%) according to microbial densities.     

Influence de la pollution sur divers parametres electriques de l'atmosphere et notamment sur le champ electrique terrestre

We have shown, on the site of LACQ, the modification of atmospheric electric parameters in connection with the fall-outs of polluants for various meteorological conditions. For some of these conditions, it seems possible to predict pollution by plume localization and SO₂ detection on the ground.     

Photochimie et environnement X- evaluation de la toxicite des produits de phototransformation de l'hydroquinone et des chlorophenols en milieu aqueux

A test of acute toxicity on DAPHNIA MAGNA is suggested to evaluate the efficiency of the phototransformation as a route of abiotic degradation. This test is recommended for compounds phototransformed into a complex mixture of products. Hydroquinone, 2-chloro-, 4-chloro-, 2,4-dichloro-, 2,4,6-trichloro- and pentachlorophenol were studied as examples. In any case the phototransformation is an useful depollution technique on condition the irradiation to be completed as far as the ultimate step of phototransformation.     

Observation de la fluorescence sur feuille entiere et mise en evidence de la resistance chloroplastique a l'atrazine chez Chenopodium album L. et Poa annua L.

Within two plant species, Chenopodium album L. generally susceptible to atrazine, and Poa annua L. always reported as susceptible, atrazine tolerant populations were observed.This resistance is due to lower atrazine susceptibility of chloroplastic electron transfert. Oxygen evolution in isolated chloroplasts was mesured to determine the concentrations required for 50 % inhibition. They are similar in the two species for the susceptible and the tolerant chloroplasts 2 × 10^?7 M and 10^?4 M respectively.Differential chlorophyll fluorescence observed on whole leaf was used as a simple mean for detection of chloroplastic resistance.