bluuebunny/crossref_metadata_2025_split huggingface dataset:
Baculoviruses as vectors for foreign gene expression in insect cells
Authors: Atkinson Allan E. , Weitzman Matthew D. , Obosi Louis , Beadle David J. , King Linda A. 
Published: November 2006

AbstractRecombinant DNA technology has enabled the expression of a large number of eukaryotic genes in vitro. There has been growing interest in recent years in the development of baculovirus expression vectors as an easily manipulated gene expression system. Both virus and insect cell culture are relatively easy to handle, and biologically active proteins have been produced abundantly from a variety of eukaryotic, prokaryotic and viral genes. This review describes the molecular biology of baculoviruses and some of the current applications of the baculovirus expression system in insect cells. Specific emphasis is placed on those features relevant to the use of this system in pesticide research.
Microdroplet application for determination of comparative topical and residual efficacy of formulated permethrin to two populations of diamond back moth (plutella xylostella L.)
Authors: Hall Franklin R. , Adams Andrew J. 
Published: November 2006

AbstractAn on‐demand, uniform droplet generator was used to apply 120 μm diameter drops of formulated permethrin either directly onto 3rd‐instar Plutella xylostella, of two Ohio populations, or onto the abaxial surface of leaf discs (1‐1000 drops cm−2) to which those larvae were subsequently exposed. Incorporating a fluorescent tracer (Saturn Yellow GT‐17N) in the spray mixture confirmed that „direct hit”︁ larvae had received a topical dose from a single droplet. There was little difference in the LC50/LD50 for either population of P. xylostella when 24 and 48 h mortality assessments from direct hits were compared, but the LD50 of Celeryville larvae was 6‐8 times greater than that of Fremont larvae. Residual deposits of 120 μm drops containing approximately the LC50, based on the topical assays, revealed that a droplet density providing a dose per cm2 leaf surface of more than 1000 times the LD50 was required to cause median mortality. The efficiency of utilisation, based on the topical LD95 values, was 0.0006% and 0.072% for Fremont and Celeryville larvae, respectively.
Non‐destructive method for estimating methyl bromide residues in apples during aeration following fumigation
Authors: Sell Charles R. , Moffitt Harold R. 
Published: November 2006

AbstractA method is presented for estimating the persistence and concentration of residual free methyl bromide (MB) present in apples during the aeration period following fumigation. The method is based on determining the rate of decline in concentration of methyl bromide in the exhaust air stream during aeration. The rate was shown to follow two consecutive pseudo‐first‐order decay curves. The first component of the curve resulted primarily from removal of MB from the free air space in the chamber, and the second component resulted from the desorption of MB from the apples. Estimates of the concentration of MB residue in apples were obtained from the regression parameters for the second decay curve. The technique gave good estimates of the residue concentration over a wide range of fumigation conditions and ventilation rates, and may be useful for determining the duration of aeration period required to achieve a proposed residue tolerance of 0.2 mg kg −1 methyl bromide.
The degradation of diflubenzuron and its chief metabolites in soils. Part III. Fate of 2,6‐difluorobenzoic acid
Authors: Nimmo Wijnand B. , Joustra Kees D. , Willems Antonius G. M. 
Published: November 2006

Abstract2,6‐Difluorobenzoic acid, one of the two primary diflubenzuron metabolites, is rapidly and completely degraded in soil. Times to 50% disappearance were 9 and 12 days in two agricultural soils. [14C]Carbon dioxide was an ultimate product of the ring‐14C‐labelled compound. A part of the radioactivity, increasing with time to one third of the applied dose of 1 mg kg−1, could not be extracted from the soil.
The toxicity of phosphine, methyl bromide, 1,1,1‐trichloroethane and carbon dioxide alone and as mixtures to the pupae of red flour beetle, Tribolium castaneum herbst
Authors: Rajendran Somiahnadar 
Published: November 2006

AbstractThe toxicity of phosphine, methyl bromide, 1,1,1‐trichloroethane (methyl chloroform) and carbon dioxide and mixtures of phosphine + methyl bromide, methyl bromide + methyl chloroform, phosphine + carbon dioxide, and methyl bromide + carbon dioxide to one‐ to two‐day‐old pupae of Tribolium castaneum Herbst was studied. Joint action ratios estimated at LD50 and LD90 for a 24‐h exposure indicated no enhancement of toxicity for mixtures of phosphine and methyl bromide, or methyl chloroform and methyl bromide on the pupae. Carbon dioxide up to 40% in air enhanced the toxic action of phosphine as well as of methyl bromide. Higher levels of carbon dioxide, however, failed to improve the toxicity of phosphine or methyl bromide proportionately. Carbon dioxide used alone produced a maximum of 11% mortality of the pupae exposed to 10–70% levels for 24 h. The order of toxicity of the fumigants both at LD50 and LD90 was phosphine > methyl bromide > methyl chloroform.
Measurement of simazine residues in chickpeas, Cicer arietinum, by gas–liquid chromatography
Authors: Allender W. J. 
Published: November 2006

AbstractA method is described for the measurement of simazine [2‐chloro‐4,6‐bis(ethylamino)‐1,3,5‐triazine] residues in chickpeas (Cicer arietinum). Ground chickpea samples were extracted with dichloromethane, followed by clean‐up on alumina. Gas‐liquid chromatography using metribuzin [4‐amino‐ 6‐tert‐butyl‐4,5‐dihydro‐3‐methylthio‐1,2,4‐triazin‐5‐one] as internal standard with thermionic detection was used to quantify simazine residues. The limit of detection was 0.02 mg kg−1 and the recoveries of simazine from chickpea samples (0.1–4 mg kg‐1) averaged 92%.
Herbicide penetration across isolated and intact leaf cuticles
Authors: Baker Edward A. , Chamel Andre R. 
Published: November 2006

AbstractPenetration of four herbicides (atrazine, diclofop‐methyl, dinoseb and glyphosate‐mono(isopropylammonium) salt) was followed through isolated pear leaf cuticles into agar and across intact cuticles of Argenteum (ARG) mutant pea leaves from monosized droplets (300 μ diam.) during 48 h following application. Penetration into pea leaves ranged from low for glyphosatemono(isopropylammonium) (5% of amount applied) and atrazine (14%) to rapid for dinoseb (91%) and diclofop‐methyl (82%). A major proportion (90%) of the dinoseb retained in the tissues underlying the site of droplet application migrated across the cuticle and the epidermal layer of cells. In contrast, only a small proportion (13%) of the dinoseb entering the leaf was transported to the tissues surrounding the treatment zone. Corresponding values for diclofop‐methyl were 61% and 4% respectively. Initially, dinoseb also penetrated rapidly through isolated pear leaf cuticles, 36% of the applied dose being recovered in an agar receiver disc 4 h after treatment, but subsequent uptake was slower. Penetration of glyphosate‐mono(isopropylammonium) also decreased after 4 h whereas atrazine and diclofop‐methyl diffused steadily through isolated cuticles up to 216 h after treatment. The incorporation of ‘Tween 20’ or ‘Agral 90’ (1 g litre−1) into the formulation reduced the penetration of glyphosate‐mono(isopropylammonium) through isolated pear leaf cuticles.
Uptake and metabolism as mechanisms of selective herbicidal activity of the 1,2,4‐triazolo[1,5‐a] pyrimidines
Authors: Hodges Craig C. , De Boer Gerrit J. , Avalos Javier 
Published: November 2006

AbstractIn order to identify the factors providing the triazolopyrimidines with a wide range of selectivity amongst agriculturally important plant species, studies were made on the uptake and metabolism of a representative compound, N‐(2,6‐dichlorophenyl)‐5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine‐ 2‐sulfonamide. This compound is much more phytotoxic to dicots than to monocots. Experiments showed that variations in leaf morphologies and geometries relative to spray applications resulted in different herbicide dosages applied to plant species used in selectivity evaluations. However, this parameter did not have a statistically significant correlation to herbicide selectivity measurements. Characterization of the metabolic pathways showed that the major herbicide metabolites involved methyl hydroxylation or hydroxylation of the aniline ring followed by glucose conjugation. Since these metabolites were not exclusive to either monocots or dicots, herbicide selectivity does not appear dependent on the pathway of metabolism. Studies on the kinetics of metabolism suggest instead that metabolic rate was important. Monocots metabolized the herbicide rapidly and generally were tolerant while the opposite was true of dicots.
Use of gas chromatographic retention indices for quantitative structure activity relationship studies of dialkyl phenyl phosphates
Authors: Gandhe Balkrishna R. , Purnanand  , Prasad Rameshwar , Danikhel Rajinder K. , Shinde Shankarrao K. , Srivastava Rajendra K. , Batra Balwant S. , Rao Karumuru M. 
Published: November 2006

AbstractThirty‐five dialkyl phenyl phosphates analogous to methyl and ethyl paraoxon were synthesized and their insecticidal activity against house fly (Musca nebulo) determined. Gas chromatographic retention indices (GCRI) at 200°C for all the phosphates were determined on OV‐101, DB‐1701 and DB‐WX fused‐silica capillary columns. The retention indices on polar and nonpolar columns (DB‐1701 and OV‐101, DB‐WX and OV‐101) considered together were shown to be related to the Hansch hydrophobic constant (II). Multiple regression analysis using the least‐square method was carried out to establish the linear relationships between insecticidal activity and GCRI along with the Hammett constant, (σ).The multiple correlation coefficients (r) of various parameters obtained using GCRI were found to be as significant as those obtained using II values. It was found that both hydrophobic and electronic effects made a significant contribution to the insecticidal activity of dialkyl phenyl phosphates. It is concluded that GCRI on two columns can be used directly as an indicator for hydrophobicity in QSAR studies provided that a suitable pair of polar and nonpolar columns is used for this purpose.
Recent development in suspoemulsions
Authors: Mulqueen Patrick J. , Paterson Eric S. , Smith Geoffrey W. 
Published: November 2006

AbstractSuspension emulsions or suspoemulsions result from the combination of an emulsion phase, containing one or more active ingredients, with a continuous phase also containing active ingredients but in the form of a solid dispersion. Advantages of such products, which can contain as many as four complementary biologically active ingredients, are elimination of tank mixing; a reduced inventory of products; reduction in the number of applications to a given crop; and savings in time and money. The development of suspoemulsions is discussed and a novel, easy method for their preparation, using latexes, is described. Such products are also useful as feedstock emulsions for other suspension emulsions as well as constituting a stable oil‐in‐water emulsion delivery system in their own right.
Phloem mobility of xenobiotics. IV. Modelling of pesticide movement in plants
Authors: Grayson B. Terence , Kleier Daniel A. 
Published: November 2006

AbstractA model is described that accounts for the effect of physical properties on the mobility of a xenobiotic within the phloem tissue of a plant. This model builds on the intermediate permeability hypothesis by incorporating the effect of acid dissociation. The relative importance of lipophilicity and acid‐base properties of compounds is discussed. The sensitivity of the model predictions to plant parameters such as the nature of the sieve tube membranes is also explored. Experimental support for the model is presented using examples from the literature. The systematic behaviour of mobility as a function of physical properties for both non‐ionized and acidic compounds is well accounted for by the model with only rare exceptions. Application of the model to commercial plant‐protection chemicals is generally consistent with experimental observations. Thus, many of the herbicides that are known to be phloem‐mobile are predicted to be so by the model. However, none of the selected fungicides and only a few of the insecticides are predicted to be phloem‐systemic, again in general agreement with observation.
Fate of carbendazim in rice tissues after seed or foliage treatments
Authors: Parida Tarulata , Nayak Mandakini , Sridhar R. 
Published: November 2006

AbstractCarbendazim was quantified employing reversed‐phase high‐performance liquid chromatography in rice coleoptiles, radicles and shoot portions of seedlings of different ages grown from seeds treated with the fungicide, and in shoot portions of adult plants at different times after foliar treatment with the fungicide. The highest levels of carbendazim were detected in the coleoptiles four days after germination of seeds and the radicals contained the lowest concentrations. Carbendazim residues declined with time in the shoot portions of seedlings and of adult plants. However, the levels of carbendazim detected in the shoot tissues of 21‐day‐old seedlings grown from treated seeds [recommended dose of 10 mg a.i. 10g−1 seeds] and in adult plants 35 days after treatment (recommended dose of 0.25 g a.i. litre−1 spray fluid) correspond to the reported lasting ability of the fungicide in terms of protection against blast of rice.
An electrophysiological study of susceptible (cooper) and resistant (kdr; super‐kdr) strains of the adult housefly (Musca domestica L.) using an isolated mesothoracic leg preparation
Authors: Gibson Amanda J. , Osborne Michael P. , Ross Hamish F. , Sawicki Roman M. 
Published: November 2006

AbstractSensory fibres in the isolated metathoracic leg of houseflies were used as a neurophysiological assay to investigate nerve insensitivity factors in knockdown‐resistant strains (kdr, super‐kdr) against DDT, the pyrethroids deltamethrin and RU15525, and the N‐alkyl amide BTG502. Several neurophysiological effects were induced by these compounds, but the only consistent one was an elevation of the spontaneously occurring firing rate. Whilst both resistant strains possess a nerve insensitivity factor, that of the more resistant super‐kdr flies appeared to be weaker than that of kdr. When probed with BTG502, super‐kdr nerves were no more resistant to this compound than those of the susceptible Cooper strain. Kdr nerves were considerably less sensitive (at least 100‐fold) than either of these other two strains. These results indicate that the voltage‐dependent sodium channels are different in all three strains and that the higher resistance shown by super‐kdr over kdr flies cannot be accounted for by simple enhancement of the kdr nerve‐insensitivity factor. Therefore, target sites other than the voltage‐dependent sodium channel have to be considered to account, fully for super‐kdr resistance. Such sites could occur at synaptic contacts, possibly involving phosphorylation of proteins and/or calcium‐ion regulation.
An investigation of the non‐solvent‐extractable residues of [14C]chlorpyrifos‐methyl in stored wheat
Authors: Matthews Wendy A. 
Published: November 2006

AbstractThe residues of [14C] chlorpyrifos‐methyl remaining in wheat after solvent extraction accounted for 28% of the applied dose after an extended period of storage. A bioassay of these residues was carried out using Tribolium castaneum and a significant reduction in the numbers of adults reaching maturity was observed. Attempts to release the non‐solvent‐extractable residues using an enzymic digestion procedure were unsuccessful, as were several of the chemical solubilisation procedures investigated. A water/methanol extraction system was successful in releasing up to 86% of the radioactivity leaving 10% still non‐extractable. Analysis of this solubilised residue revealed that 59% was present as the pyridinol metabolite of chlorpyrifos‐methyl and 26% was a polar material composed of two main components. Bioassay tests of these metabolites revealed that the reduction in the number of insects reaching maturity could be associated with the pyridinol metabolite.
Photolysis of flucythrinate
Authors: Chattopadhyaya S. , Dureja P. 
Published: November 2006

AbstractPhotolysis of flucythrinate ((RS)‐α‐cyano‐3‐phenoxybenzyl (S)‐2‐(4‐difluoromethoxyphenyl)‐3‐methylbutyrate) in solution (methanol) by UV light (> 290 nm) and as a thin film on glass by exposure to sunlight yields products resulting from ester cleavage. The major product in solution is formed via photo‐induced decarboxylation. When thin films are exposed to sunlight, flucythrinate has a half life of 8 days on glass and 3 days on a leaf surface.
Sensitivity analysis of a mathematical model for pesticide leaching to groundwater
Authors: Boesten J. J. T. I. 
Published: November 2006

AbstractThe sensitivity of pesticide leaching to pesticide/soil properties and to meteorological conditions was assessed by calculations with an existing convection—dispersion model. The model assumes equilibrium sorption (Freundlich equation), first‐order transformation kinetics and passive plant uptake. The extent of pesticide leaching was characterized by the percentage of the dose leached below 1 m depth. The calculations were carried out for a humic sand soil cropped with maize and exposed to Dutch weather conditions.In general, the percentage leached was found to be very sensitive to the sorption coefficient, the Freundlich exponent (describing the curvature of the isotherm) and the transformation rate. The percentage leached was moderately sensitive to weather conditions (wet/dry years), long‐term sorption equilibration and the relationship between transformation rate and temperature. Sensitivity to the extent of plant uptake was only significant for pesticides with low sorption coefficients. Sensitivity to soil hydraulic properties was small. The effect of application in autumn instead of in spring was found to be very large for non‐sorbing pesticides with short half‐lives. The sensitivity to spatial variability in sorption coefficient and transformation rate was found to be substantial at low percentages leached.
Pharmacological properties of presynaptic muscarinic receptors in the sixth abdominal ganglion of the cockroach, Periplaneta americana L.
Authors: Le Corronc Hervé , Hue Bernard 
Published: November 2006

AbstractThe effects of muscarinic agonists on acetylcholine (ACh) release in the cercal‐afferent giant‐interneuron synapses of the cockroach have been studied using the single‐fibre oil‐gap method. Decrease in amplitude of the cEPSP was induced by pressure ejection of arecoline (ARE), carbachol (CCh) and oxotremorine free base (OXO) within the sixth abdominal (A6) ganglion. This depressive effect was dose‐dependent without any effect at the post‐synaptic site in the range of concentrations used. The concentration for 50% of cEPSP inhibition of the most commonly used muscarinic agonists was determined. The rank order of potencies was: ARE > CCh > OXO > McN‐A‐343 > bethanechol (BET). Plateau levels of 56%, 54% and 68% were reached when increasing the concentration of ARE, CCh and OXO respectively. McN‐A‐343 and BET had an inhibitory effect on ACh release but higher doses also acted at the postsynaptic level. Furthermore, muscarinic agonists were able to evoke uIPSP and a smaller inhibitory effect of ARE and OXO was observed in presence of picrotoxin.It is concluded that the ACh release in the cockroach A6 ganglion is modulated by presynaptic muscarinic receptors which are possible target sites for insecticides. The presence of putative muscarinic receptors on inhibitory GABAergic interneurons, involved in pre‐ and postsynaptic inhibition is suspected.
Cross‐resistance between acylurea insect growth regulators in a strain of Plutella xylostella L. (Lepidoptera: Yponomeutidae) from Malaysia
Authors: Ismail Fauziah , Wright Denis J. 
Published: November 2006

AbstractThe activities of the acylurea insect growth regulators, chlorfluazuron, teflubenzuron and difubenzuron, and the neurotoxic macrocyclic lactone, abamectin were assessed against a laboratory susceptible (FS) strain and a field (Cameron Highlands, Malaysia (CH)) strain of the diamondback moth, Plutella xylostella L. using a leaf‐dip bioassay at 20°C. The time taken to achieve end‐point mortality was found to vary considerably (9–17 days), being fastest with abamectin against the FS strain and slowest with difubenzuron against the CH strain. The order of activity (LC50 at F6/7) against second‐instar larvae of both strains was: abamectin > chlorfluazuron = teflubenzuron ⋙ difubenzuron. Subsequent assays (F14) with the acylureas, flufenoxuron and hexaflumuron against the FS strain suggested that the former was slightly more active than chlorfluazuron or teflubenzuron, the latter slightly less active. The CH population was found to be 12.6‐, 6.7‐, 6.4‐ and 2.3‐fold less sensitive to difubenzuron, teflubenzuron, chlorfluazuron and abamectin respectively than the FS strain. Selection of sub‐populations of the CH strain with chlorfluazuron (CHL‐SEL) and teflubenzuron (TEF‐SEL) for six generations (F6‐11), resulted in LC50 resistance ratios of 109‐ and 315‐fold respectively when compared with the FS strain, equivalent to an 18‐ and a 46‐fold increase in resistance compared with the unselected CH strain. Marked cross‐resistance was also demonstrated between chlorfluazuron and teflubenzuron in both sub‐populations. However, there was no evidence of cross‐resistance to dijlubenzuron and abamectin and little or no cross‐resistance to flufenoxuron and hexaflumuron. Resistance to chlorfluazuron and teflubenzuron appeared to be relatively unstable in the TEF‐SEL compared with the CHL‐SEL sub‐population (over 6–9 generations). However, reselection of the TEF‐SEL population with chlorfluazuron (F18–20) led to a very rapid increase in resistance to chlorfluazuron and particularly teflubenzuron. For the latter compound, resistance factors of about 1000000 were obtained (F19, 21). Such values are probably only semi‐quantitative, as above a certain level of resistance feeding bioassays with acylureas (compounds which are active to a significant extent by ingestion) are likely to become rate‐limiting.
Isolation of microsomal cytochrome‐p450 isozymes from Ustilago maydis and their interaction with sterol demethylation inhibitors
Authors: Kapteyn Johan C. , Pillmoor John B. , De Waard Maarten A. 
Published: November 2006

AbstractA procedure for the isolation of microsomes containing cytochrome‐P450 isozymes from Ustilago maydis is described. Yields of P450 amount to approximately 19(±+ 6) pmol mg−1 of microsomal protein. The wavelength of maximum absorbance of the reduced carbon monoxide difference spectrum is 448‐449 nm. The azole fungicides prochloraz, etaconazole, imazalil, triadimefon and 3‐(2,4‐dichlorophenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)‐4(3H)‐quinazoline, which differ markedly in toxicity to U. maydis, all induce type II binding difference spectra at extremely low concentrations (10−9‐10−8 M). The DMI concentrations which cause half saturation of type II binding difference spectra (IC50) do not correlate with the fungicidal activities of the azoles. Binding of carbon monoxide to ferrous cytochrome‐P450 was only slightly inhibited to different degrees by the DMIs tested. However, the inhibition of carbon monoxide binding also does not correlate with fungitoxicity of the DMIs. The results in this paper suggest that the spectrophotometric studies with this preparation are not useful for evaluating selective toxicity of DMIs to intact sporidia of U. maydis.