bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adsorption‐leaching study of the herbicides metamitron and chloridazon
Authors: AráNzazu Goicolea M. , Arranz Juan F. , Barrio Ramón J. , de Balugera Zuriñe Gómez 
Published: November 2006

AbstractFreundlich isotherms were obtained for the adsorption equilibrium of the herbicides metamitron and chloridazon with the components of a representative soil in a pesticide concentration range of 10‐1000 γg ml−1 for metamitron and 10‐500 μg ml−1 for chloridazon.The mobility of these herbicides through soil columns was also studied using the displacement technique described by Davidson (Soil Sci. Soc. Amer. Proc., 32 (1968) 629). The experiment was carried out simultaneously in three columns, two of which were fed with solutions of the herbicides while the third was used as a control. The herbicide solutions flowed down by gravity and were collected at the outlet at different times. The herbicide content of these outlet solutions was determined by Differential Pulse Polarography.
Preliminary studies on the insecticidal activity and wash‐fastness of twelve pyrethroid treatments impregnated into bednetting assayed against mosquitoes
Authors: Lindsay Steven W. , Ismai Hossainl M. , Bennett Stephen , Curtis Christopher F. 
Published: November 2006

AbstractThe insecticidal properties of twelve pyrethroid preparations impregnated into polyester netting were compared, before and after washing, with a view to assessing their suitability for treating bednets (mosquito nets) in the field. Bioassays were carried out by exposing the mosquitoes, Anopheles gambiae Giles sensu stricto andAedes aegypti L. to netting with two concentrations of insecticide, on washed and unwashed samples, for 30 s and 3 min at different times after impregnation. Mortality was recorded after 24 h. Permethrin applied at 97°C at pH 3.4 resulted in increased uptake by polyester fibres. The performance of most insecticides on unwashed netting had not declined appreciably 12 weeks after impregnation. However, all the insecticides were depleted by washing. The treatments with best insecticidal activity after washing were cypermethrin, lambda‐cyhalothrin applied at ambient temperature and normal pH and permethrin applied in a hot acid solution.
Field effectiveness and biodegradation of cyclic imides in lettuce field soils
Authors: Martin Christian , Davet Pierre , Véga Danielle , Coste Camille 
Published: November 2006

AbstractWhen 42 field trials, carried out from 1975 to 1989 in the Perpignan region (France) for control of lettuce drop caused by Sclerotinia minor, were compared, a decrease in the field effectiveness of cyclic imides was perceptible, beginning approximately in 1985. Moreover, in 15 out of 46 commercial lettuce fields surveyed in 1988 and 1989, the effectiveness of iprodione was less than 80%, the level of acceptability for the growers. In these fields, fungicide degradation, estimated by 3,5‐dichloroaniline formation, was faster than in soils in which S. minor was adequately controlled. Statistical analyses showed that the iprodione degradation index was strongly linked to the history of fungicide treatment and was weakly correlated to soil pH or clay content. All the fields characterized by low iprodione effectiveness were associated with high levels of fungicide treatment and high degradation index. Moreover, we observed that soil from a field which had received iprodione for more than ten years did not degrade vinclozolin quickly, while soil from another part of the same field which had been treated with vinclozolin for eight years degraded vinclozolin faster than iprodione.
Automated quasi‐continuous immunoanalysis of pesticides with a flow injection system
Authors: Krämer Petra M. , Schmid Rolf D. 
Published: November 2006

AbstractChemical methods (HPLC, GC/MS) for the control of pesticides in water at low concentrations are time‐consuming, expensive and need sample pre‐concentration. Immunoassays offer the potential of rapid, inexpensive, sensitive and specific detection methods. This paper presents a flow injection system that is based on immunochemical reaction and which provides the opportunity for automated, quasi‐continuous measurements for screening water samples for the presence of pesticides.The method of flow injection immunoanalysis (FIIA) was compared with competitive ELISA (enzyme‐linked immunosorbent assay). It is possible to measure in the range of interest of 0·1 μg litre−1, which is the limiting value of the European drinking water directive.Measurements were made for the triazine herbicides atrazine and propazine, which both cross‐react with the polyclonal antiserum used.Furthermore, this device includes a new development of a membrane reactor for the exchange of used biological material, in this case antibodies. A brief comparison of ELISA and FIIA is presented, giving an overview of some aspects of the assays.
Automated conformational analysis and structure generation
Authors: Leach Andrew R. 
Published: November 2006

AbstractAn approach for automatically and rapidly searching a molecule's conformational space to determine low‐energy conformations is described. The method takes a simple 2D description of the molecule (atom types and connectivity), recognizes the presence of conformational units about which it has ‘knowledge’ and generates structures by template joining. Some of the algorithms which can be used to search the conformational space are described, as are methods to manipulate conformational information. Such an approach may be used to generate multiple conformations which may be further refined or stored in some form of 3D database.
GABA receptors of insects susceptible and resistant to cyclodiene insecticides
Authors: Anthony Nicola M. , Benner Eric A. , Rauh James J. , Sattelle David B. 
Published: November 2006

AbstractToxicity tests revealed up to 40‐fold resistance to a number of cyclodiene insecticides in a laboratory‐reared, cyclodiene‐resistant (CYW) housefly strain (Musca domestica L.). Using [35S] TBPS as a probe for convulsant sites in insects, saturable specific binding was detected in thorax and abdomen membranes prepared from housefly strains susceptible (CSMA) and resistant (CYW) to cyclodienes. Scatchard analysis of[35S] TBPS binding data to CSMA and CYW membranes failed to provide evidence for significant differences between the two strains in either the affinity (Kd) or density (Bmax) of saturable binding sites. For several polychlorocycloalkane insecticides, the ligand displacement profile of [35S] TBPS binding was almost identical for the CSMA and CYW houseflies. Therefore, using [35S] TBPS as a probe for convulsant sites, a 40‐fold resistance to cyclodienes in the CYW housefly strain cannot be accounted for only in terms of alterations in TBPS binding sites.
Development and assessment of a mathematical model to predict foliar spray deposition under laboratory track spraying conditions
Authors: Grayson B. Terence , Webb James D. , Pack Simon E. , Edwards Dean 
Published: November 2006

AbstractA mathematical model based on Young's equation of adhesion of liquids to solid surfaces has been developed to predict foliar spray deposition under track‐spraying conditions. The model incorporates the physical nature and morphological characteristics of the plant leaf surface and the physical properties of the spray solution. It was tested using experimental spray deposition measurements on four different plant species and an artificial target of glass rods with an array of forty‐eight solutions varying systematically in composition and properties. The morphological factors and regression coefficient of the model were calculated by a least‐squares multiple‐regression analysis of the observed spray deposition. The physical natures, wettabilities, of the target surfaces were estimated from contact angle measurements. The physical properties of the spray solutions, drop sizes and dynamic surface tensions were measured by a Malvern 2600 HSD particle size analyser and the maximum bubble pressure method respectively. Drop sizes were approximately constant through the series of solutions though dynamic surface tensions varied and form an important term in the model.The spray depositions predicted by the model were plotted as response surfaces against solution composition and compared with those from the observed spray depositions. Agreements were high (explained variances, wheat, 96.4%; green foxtail, 98.6%; pea, 98.9%; sugar beet, 98.6%; glass rods, 99.4%), giving confidence that the model had been correctly formulated.An explanation for the varying abilities of different plants to capture different volumes of spray solutions can now be expressed in qualitative and quantitative terms. Further validation of the model is in progress.
Quinone activation of protoporphyrinogen oxidase of barley plastids
Authors: Tietjen Klaus G. 
Published: November 2006

AbstractProtoporphyrinogen oxidase catalyzing the oxidation of protoporphyrinogen to protoporphyrin is the target enzyme for several highly active herbicides. The plastidic plant enzyme under normal conditions uses oxygen as electron acceptor. Duroquinone, however, can be an alternative electron acceptor of protoporphyrinogen oxidase of barley plastids. In this respect the enzyme from the plastids may be an evolutionary intermediate between bacterial enzymes coupled to ubiquinone and mammalian mitochondrial enzymes coupled to oxygen.
A modified clean‐up for the determination of glyphosate and its metabolite residues in lentils using high pressure liquid chromatography and post‐column fluorogenic labelling
Authors: Wigfield Yuk Y. , Lanouette Monique 
Published: November 2006

AbstractAn analytical method is presented for the analysis of glyphosate and its metabolite (aminomethyl)phosphonic acid (AMPA), in lentil samples. They were extracted from powdered samples with water and chloroform. The aqueous layer was acidified and passed through a cation exchange column. The eluate was made basic, passed through an anion exchange column in the hydroxide form and discarded. The latter column was eluted with hydrochloric acid (0.3 M) which was collected, evaporated under vacuum to 1 ml, diluted with water to 10 ml, filtered and analysed for glyphosate and metabolite using a liquid chromatograph with a post‐column reactor and a fluorescence detector. The limit of detection, average recovery and coefficient of variation (CV) were 0.08 μg g−1, 92.5% and 7.3% for glyphosate and 0.1 μg g−1, 92.5% and 8.3% for AMP A. The detector response was found to be linear within the range 20–400 ng.
Off‐target glyphosate deposits from aerial silvicultural applications under various meteorological conditions
Authors: Payne Nicholas J. , Thompson Dean G. 
Published: November 2006

AbstractAerial spray applications of the herbicide glyphosate were made over a forest canopy under various meteorological conditions. A ‘Thru Valve Boom’ dispersal system carried by a Cessna 188 fixed‐wing aircraft flying at 49 m s−1 was used to generate an aqueous spray cloud with a volume median diameter of 150 μm. Glyphosate deposits from multiple overlaid crosswind line sources released at 10 m above ground level were measured on ground sheets and artificial foliage at downwind distances between 50 and 400 m. Trials were conducted in stable, neutral and unstable atmospheric boundary layers with average wind speeds between 2·2 and 5·7 m s−1 and vertical intensities of turbulence between 0·07 and 0·16. Linear regression lines fitted to logarithmically transformed measurements and downwind distances (x) gave statistically significant correlation coefficients (P = 0·01), and were compared by ANOVA. Glyphosate deposits on ground sheets and artificial foliage were attenuated at rates inversely proportional to x to the power 1·7‐4·3. Regression line comparison showed that, in general, deposits on ground sheets decreased with increasing wind speed and intensity of turbulence, and some statistically significant differences were found in slopes and elevations of regression lines from different trials. However, deposits at the 50‐m station increased with wind speed due to the large‐drop cloud component. Regression line comparison for deposits on artificial foliage showed that, in general, they were highest in the intermediate wind speed‐neutral stability case and similar in the high wind speed‐unstable and low wind speed‐stable boundary layers, although deposits at the 50‐m station also increased with wind speed.
Solid‐phase extraction and gas chromatographic determination flumethrin residues in honey
Authors: De Paoli Mauro , Barbina M. Taccheo 
Published: November 2006

AbstractA gas chromatographic method to determine flumethrin (‘Bayvarol’) in honey samples is described. The method consists of solid‐phase extraction with RP C‐18 cartridges, clean‐up if required on silica cartridges, and quantitation of the active ingredient with an electron capture detector using deltamethrin as internal standard. Compared to previous methods it is very rapid, and a number of samples can be prepared simultaneously. The minimum detectable quantity is 0·005 mg kg−1 and mean recoveries are of the order of 95%.
Extraction of carbaryl from stored rice, maize, peas and sunflower seeds prior to chromatographic analysis
Authors: Brayan John G. , Haddad Paul R. , Sharp Gerald J. , Dilli Sergio , Desmarchelier James M. 
Published: November 2006

AbstractCarbaryl was extracted from aged samples of rice, maize, peas and sunflower seeds using hexane, acetone and methanol. The quantities of insecticide extracted from the grain by acetone and methanol were much higher than that extracted by hexane for all four products. Methanol extracted higher levels of carbaryl than acetone from maize and peas but for rice and sunflower seeds the results were similar for the two solvents. Extraction by simply standing the whole grain in solvent for 48 h generally resulted in similar extracted levels of carbaryl to those obtained using more exhaustive techniques, such as grinding the grain or Soxhlet extraction. However, grinding or Soxhlet extraction removed the pesticide from the grain more rapidly.
Synergism of teflubenzuron and chlorfluazuron in an acylurea‐resistant field strain of Plutella xylostella L. (lepidoptera: Yponomeutidae)
Authors: Ismail Fauziah , Wright Denis J. 
Published: November 2006

AbstractTopical application of the synergists piperonyl butoxide (PB) and S,S,S‐tributyl phosphorotrithioate (DEF) to second‐instar larvae of a standard laboratory strain (FS) and an unselected Malaysian field strain (CH) of the diamondback moth Plutella xylostella had no significant effect on the toxicity of the acylurea insecticides, chlorfluazuron and teflubenzuron, in a subsequent leafdip bioassay. In contrast, pre‐treatment with PB or DEF in acylurea‐selected subpopulations of the CH strain with varying levels of cross‐resistance to chlorfluazuron and teflubenzuron significantly increased (up to 34‐fold and 28‐fold, respectively) the toxicity of both compounds, suggesting that microsomal monooxygenases and esterases may be involved in resistance. The addition of a mineral oil, ‘Sunspray 6E’, to topically‐applied chlorfluazuron consistently reduced its LD50 value, and the effect of the oil appeared to be greatest on the most resistant population of P. xylostella. However, the effects of the oil were not significant (P > 0·05) and further studies are necessary to determine whether a penetration factor is present in the CH strain.
Photolysis of dimepiperate in aqueous solution
Authors: Pusino Alba , Gessa Carlo , Liu Weiping 
Published: November 2006

AbstractDimepiperate, S‐(1‐methyl‐1‐phenylethyl) piperidine‐1‐carbothioate (I) was degraded in aqueous solution by ultraviolet irradiation into piperidine (II), α‐methylstyrene (III), acetophenone (IV), and formaldehyde (V). The reaction followed first‐order kinetics. In sunlight the reaction occurred only in the presence of a sensitiser and afforded the same four photolytic degradation products. In the absence of oxygen the herbicide was converted much more rapidly, but yielded only (II) and (III) as products. A mechanism which accounts for the formation of the photoproducts is proposed.
Effect of abamectin on electrophysiological activity in the ventral nerve cord of Periplaneta americana L.: Correlation with symptoms of poisoning and levels of toxicant in vivo
Authors: Corbitt T. S. , Djamgoz M. B. A. , Wright D. J. 
Published: November 2006

AbstractTwenty‐four hours after injection of adult male Periplaneta americana with 36 ng [5‐3H]abamectin, when symptoms of poisoning were apparent in most individuals, similar levels of radioactivity were found in tissue samples from the ventral nerve cord, metathoracic muscle, fat body and testis of randomly‐selected insects. When insects injected with [5‐3H]abamectin (36 ng) were separated after 24 h into three groups showing varying symptoms, the level of radioactivity in the ventral nerve cord was found to be significantly greater in partially‐paralysed and paralysed groups (4‐ and 7‐fold respectively) than in a treated but non‐ paralysed group. The mean levels of abamectin in the nerve cords of unaffected, ‘partially‐paralysed’ and ‘paralysed’ insects were estimated to be 4, 23 and 37 nM respectively. Extracellular studies of the in‐vitro action of abamectin (10 nM and 1 μM) on the spontaneous activity of a picrotoxin‐sensitive, partially desheathed, ventral nerve cord preparation of adult male P. americana found the mean response time to be relatively slow (77 and 38 min respectively). In sheathed nerve cords, the mean response time to abamectin (1 μM) was 117 min. In all cases, treatment with abamectin increased the stimulus voltage required to evoke a response. Spontaneous activity was found to be progressively reduced in ventral nerve cord preparations from ‘partially‐paralysed’ and ‘paralysed’ insects compared with ‘non‐paralysed’ and untreated insects following dissection 24 h after injection of P. americana with unlabelled or labelled abamectin (36 ng), while the stimulus required to evoke activity in the ventral nerve cord showed the reverse trend. These differences in electrophysiological activity could be correlated directly with varying levels of abamectin in the nerve cords of ‘paralysed’ and ‘partially‐paralysed’ insects.
Quantitative structure–activity studies of optically active 2‐methoxy‐1,3,2‐oxazaphospholidine 2‐sulfides against Musca domestica L
Authors: Hirashima Akinori , Eto Morifusa 
Published: November 2006

AbstractThe quantitative relationship between the structure of optically active 4‐substituted 2‐methoxy‐1,3,2‐oxazaphospholidine 2‐sulfides (4‐RMOS) and their insecticidal activity on the house fly, Musca domestica L., was analysed using reported physicochemical parameters and regression analysis. The configuration at the C4 atom was more important for insecticidal activity than that at the phosphorus atom, since the coefficient of the dummy parameter for the C4‐ configuration was larger than that for the configuration of the phosphorus atom: (S)c(R)p diastereoisomers showed the highest insecticidal activity, and the activity decreased in the order of (S)c(R)p > (S)c(S)p > (R)c(R)p > (R)c(S)p. The electronic nature of the substituent at the C4 position was the most important, followed by the steric and hydrophobic effects: the more electron‐donating, the less bulky and the more hydrophobic the 4‐substituent, the higher the insecticidal activity. Thus the highest activity was obtained for the isopropyl derivatives, and the activity decreased in the order of isopropyl > isobutyl > ethyl > sec‐butyl > benzyl > phenyl > methyl > tert‐butyl.
Behaviour of ddt in three soils exposed to solar radiations under different conditions
Authors: Nair Amit , Samuel Thomas , Pillai Madathil K. K. 
Published: November 2006

AbstractVolatilization, mineralization, degradation and binding of soil‐applied [14C]DDT were studied in three different soils from a tropical region of southern India subjected to solar irradiation and flooding for a period of 42 days. The soil types–red cotton soil, nursery soil and canal bank soil–differed in their organic carbon content, pH and texture. Under unflooded conditions, volatile losses were highest in the sandy canal bank soil. Flooding significantly enhanced volatilization, and this effect was maximal in the nursery soil, which had the highest organic carbon. The soils fully exposed to solar radiations in quartz tubes registered 1.5‐1.8 times greater volatility. The volatilized organics contained appreciable quantities of DDE under both flooded and unflooded conditions. In addition, greater quantities of DDD volatilized from the flooded systems. The rate of formation of DDE was faster when soils were irradiated in quartz tubes. Mineralization remained minimal throughout the period of exposure and flooding the soil appeared to reduce further the [14C]carbon dioxide evolution. Canal bank soil exhibited the least mineralization and degradation. The data indicate that volatilization was significantly influenced by solar radiation and flooding to a much greater degree than by the differences in soil properties. Binding of DDT to soil was significantly increased by flooding the soil, thus leaving up to 33% of the initial DDT as bound residues in the nursery soil.
Preparation of controlled‐release formulations of 14C‐labelled thiobencarb herbicide and study of their environmental behaviour
Authors: Hussain Manzoor , Gant Jianying , Rathor M. Nasir 
Published: November 2006

AbstractControlled‐release formulations of 14C‐labelled thiobencarb herbicide were prepared in calcium alginate using kaolin as an inexpensive filler. The rates of release of the herbicide from these and from a commercial granular formulation were studied in static distilled water contained in open and closed vessels. The rate of release of the herbicide was much higher from the commercial formulation than from the controlled‐release formulations. Increasing the proportion of kaolin to calcium alginate in controlled‐release formulations reduced the rate of release of the herbicide. There was a significant loss of thiobencarb‐related radioactivity from the water solution when the vessels containing the solutions were left uncovered and exposed to light. The loss of the herbicide seemed to be due to degradation and evaporation.
Abiotic degradation pathways of isoxaben in the environment
Authors: Mamouni Abderrahim , Schmitt Philippe , Mansour Mohamed , Schiavon Michel 
Published: November 2006

AbstractPhotolysis of isoxaben [N‐[3‐(1‐ethyl‐1‐methylpropyl)isoxazol‐5‐yl]‐2,6‐dimethoxybenzamide] in dilute aqueous solutions, adsorbed on silica gel plates, has been investigated under natural and simulated solar light conditions. Eight photoproducts were isolated and identified by spectroscopic methods. Photo‐decomposition with sunlight led to the formation of three isomers, dimethoxy‐benzonitrile and dimethoxybenzamide as major photoproducts. The rearrangement has been shown to proceed in two photochemical steps by way of an azirine and a non‐identified photoproduct as stable intermediates. The azirine rearranges almost quantitatively to an oxazole and rearranges back to the starting isoxaben.