bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conversion rates of aldicarb and its oxidation products in soils. II. Aldicarb sulphoxide
Authors: Smelt Johan H. , Leistra Minze , Houx Norbert W. H. , Dekker Abraham 
Published: November 2006

AbstractThe loss of aldicarb sulphoxide was studied in incubation experiments with soil from four plough layers and two deeper layers. The loss during the 111 days of the experiment could be described by first‐order kinetics. The half‐lives at 15°C ranged from 20 days in a clay loam to 46 days in a peaty sand. The loss of sulphoxide in deeper layers was considerably slower than in the corresponding top layers of a soil profile. In soil from a silty layer at 70–90 cm depth the half‐life was about 53 days. In soil from a sand layer at 90–110 cm depth a loss of only about 15% was measured after 111 days of incubation. First‐order rate constants for sulphoxide conversion in a clay loam at 6, 15 and 25°C were found to be 0.009, 0.033, and 0.05 day−1 respectively; in a greenhouse soil these rate constants were 0.0052, 0.019 and 0.04 day−1 respectively. The fractions of aldicarb sulphoxide that were oxidised to sulphone at 15°C in soil from plough layers were computed to range from 0.52 to 0.76.
Uptake of aminotriazole from humectant‐surfactant combinations and the influence of humidity
Authors: Cook Gordon T. , Duncan Henry J. 
Published: November 2006

AbstractUptake of aminotriazole (3‐amino‐1,2,4‐triazole) by bean leaves (Phaseolus vulgaris var. Canadian Wonder) was not greatly influenced by the addition to the spray solution of dimethylformamide (DMF), ethylene glycol and polypropylene glycol 400 (PPG 400) over the concentration range 1.0–50.0 ml litre−1. However, the addition of polyoxyethylene 20 sorbitan monolaurate (polysorbate 20) (0.2–1.0 g litre−1) to spray solutions of the above additives and glycerol (5.0 ml litre−1; except for DMF, 50.0 ml litre−1) substantially increased uptake to 80–100% in all cases at 50 ± 10% relative humidity (r.h.). Similar penetration figures were recorded when a range of polysorbate surfactants (polysorbate 20, 40, 60, 80 and 85; 0.2 g litre−1) were applied to spray solutions containing either dimethyl sulphoxide (DMSO) or glycerol (5.0 ml litre−1). Humidity was found to have a critical effect upon the humectant‐surfactant combinations tested, i.e. DMSO + polysorbate 20, ethylene glycol+ polysorbate 20 and PPG + 400‐polysorbate 20 (5.0 ml litre−1+0.2 g litre−1). With DMSO + polysorbate 20 the following uptake figures were recorded: < 30% r.h., 3.1 %; 45 ± 10% r.h., 86.8%; 55–65% r.h., 48.2 % and 100% r.h., 0.3%. Similar trends were recorded with all three humectant‐surfactant combinations. Further studies revealed that the adverse effect of humidity on DMSO‐polysorbate mixtures could be at least overcome partially by regulating the DMSO concentration.
Chemical hydrolysis of 2‐chloro‐4,6‐bis(alkylamino)‐1,3,5‐triazine herbicides and their breakdown in soil under the influence of adsorption
Authors: Burkhard Niklaus , Guth Johann A. 
Published: November 2006

AbstractThe determination of rate constants and the calculation of the activation parameters [activation energy (Ea), free energy of activation(ΔG≠)and entropy of activation (ΔS≠)] demonstrated the identity of the reaction kinetics of chemical hydrolysis of the chlorinated triazine herbicides simazine, atrazine, propazine and terbuthylazine. Persistence in soil could be estimated, from the hydrolytic half‐life time, only in pH regions where these compounds were also sensitive to chemical hydrolysis. In general, the rate of hydrolysis increased in the presence of soil as the result of a catalysing effect of the soil in their breakdown. When half‐lives in soil of these triazine herbicides were compared with adsorption constants, a functional relationship was observed in both soil types; as adsorption increased the half‐life in soil also increased.
Measurement of the bioconcentration factors of pesticides by freshwater fish and their correlation with physicochemical properties or acute toxicities
Authors: Kanazawa Jun 
Published: November 2006

AbstractThe bioconcentration factors (BCF) for 15 pesticides by a freshwater fish (topmouth gudgeon) were measured under continuous flow conditions in water containing 5 to 20 μg litre−1 of each pesticide at the equilibrium condition. A significant correlation was found between the BCF by the fish and the water solubility of the pesticide or its partition coefficient (PC) between octan‐1‐01 and water. Moreover, a significant correlation was also found between the BCF by topmouth gudgeon and the acute toxicities to carp, rainbow trout and water flea. It would therefore appear that the bioconcentration potential of a pesticide by a fish may be predicted from knowledge of its solubility or PC, and that the acute toxicity of a pesticide to a fish may be predicted from knowledge of the BCF.
The algaecidal activities of some sulphonyl derivatives of polychlorobenzenes and diphenyll Ethers
Authors: Goulding Kenneth H. , Cronje Theo , Cremlyn Richard J. W. 
Published: November 2006

AbstractSix sulphonyl derivatives of polychlorobenzenes and 15 sulphonyl derivatives of diphenyl ethers were tested as potential algaecides against two species of algae, Chlorella fusca and Anabaena variabilis. The most algaecidal compounds were the nitrophenyl sulphonylphenyl ethers and the chloronitrophenyl sulphonylphenyl ethers, some of which compared well with the known herbicide nitrofen by the screening method used.
A method for determining the volatility of active ingredients used in plant protection. Part III: The temperature relationship between vapour pressure and evaporation rate
Authors: Gückel Walter , Kästel Roland , Lewerenz Johann , Synnatschke Gotthard 
Published: November 2006

AbstractHitherto it has been possible to determine vapour pressures only at a temperature of 20°C when using the method previously described for measuring the evaporation rate. The scope of application of the method has now been extended to temperatures of 30, 40, 50 and 60°C; because of the known temperature dependence of the vapour pressure, the vapour pressures at all the intermediate temperatures can then be calculated from these values.
Stability of pyrethroids on wheat in storage
Authors: Noble Robert M. , Hamilton Denis J. , Osborne William J. 
Published: November 2006

AbstractThe four pyrethroids, permethrin, phenothrin, fenvalerate and deltamethrin were applied to wheat which was stored for 52 weeks at 25 or 35°C, and either 12 or 15% moisture content. Rates of loss were calculated from residue analyses of the wheat at five intervals during storage. Calculated half‐lives (weeks) for the pyrethroids at 25°C (12% moisture) and 35°C (15% moisture) were: permethrin 252 and 44, phenothrin 72 and 29, fenvalerate 210 and 74, and deltamethrin 114 and 35, respectively.
Morphological and physiological variability in black nightshade (Solanum spp.)
Authors: Vandeventer John W. , Meggitt William F. , Penner Donald 
Published: November 2006

AbstractPlants from two black nightshade (Solanum spp.) seed sources were compared for differences in morphology at seedling and mature plant stages, flowering and physiological responses to pre‐germination seed treatment, growth responses to temperature, and response to herbicides. Differences in the morphology of the two Solanum spp. were evident from seedling to maturity. The plants grown from the Michigan (MI) seed source had a deep purple abaxial leaf surface at the three to four‐leaf stage, a yellow anther column, and toothed proximal half in the mature leaf, whereas the plants grown from the California (CA) seed source had no unusual abaxial coloration or toothed proximal margin and had a dark brown anther column. Differences in response to herbicides were seen between plants grown from the two seed sources following pre‐plant‐incorporated, pre‐emergence, and post‐emergence herbicide applications. The plants from the MI seed source were up to five times more susceptible to chloramben, applied pre‐plant‐incorporated at 1.68 kg ha−1, and to ethalfluralin, applied preemergence at 1.12 kg ha−1, than plants from the CA seed source. Plants from both seed sources have been described as Solanum nigrum L. The plants from MI have been identified elsewhere as Solanum ptycanthum Dun. and those from CA as Solanum scabrum Mill. This identification could resolve conflicting reports among researchers regarding chemical control measures.
Parasitism and host–plant relationships in the dipterous stem borer complex of ryegrass
Authors: Howell James 
Published: November 2006

AbstractSamples taken from a ryegrass variety trial at the Grassland Research Institute, Hurley, and examined at the Welsh Plant Breeding Station, showed that the dominant stem borer species in the overwintering generation were Geomyza tripunctata Fall. and Oscinella frit L. The rate of parasitisation of stem borers, largely by species of Hymenoptera, ranged from 15 to 43%. There were differences in host plant selection by Geomyza compared with Oscinella spp. The numbers of both stem borer groups were significantly associated with the total number of tillers per sample; however, this relationship was found to differ markedly between varieties.
Measurement and simulation of the movement and degradation of atrazine and metribuzin in a fallow soil
Authors: Nicholls Peter H. , Walker Allan , Baker Robert J. 
Published: November 2006

AbstractThe movement and persistence of atrazine and metribuzin, in a sandy loam soil following application in spring, was simulated using two models. The first model, based on the physical laws describing water and solute movement and using measured values of soil hydraulic properties, underestimated herbicide mobility in the soil and predicted too rapid drying of the deeper soil layers. The accuracy of the simulations was improved by empirically reducing the measured hydraulic conductivities by a factor of 4. This probably reflects the difficulties of obtaining reliable measurements of soil hydraulic properties. A second and simpler model, which simulated water and herbicide movement using mobile and immobile water categories, accurately predicted soil water contents. It tended to underestimate herbicide movement at short times after application, and to overestimate movement later in the experiments. A comparison of different methods of simulating herbicide degradation showed that prediction of degradation rates in the field from laboratory data can be unsatisfactory with some compounds.
Relationships between lipophilicity and root uptake and translocation of non‐ionised chemicals by barley
Authors: Briggs Geoffrey G. , Bromilow Richard H. , Evans Avis A. 
Published: November 2006

AbstractThe uptake by roots from solution, and subsequent translocation to shoots in barley, of two series of non‐ionised chemicals, O‐methylcarbamoyloximes and substituted phenylureas, were measured, Uptake of the chemicals by roots was greater the more lipophilic the chemical, and fell to a lower limiting value for polar chemicals. Translocation to the shoots was a passive process, and was most efficient for compounds of intermediate polarity. Both processes had reached equilibrium within 24h of treatment. The reported behaviour of many pesticides in various plant species agrees with the derived relationships, but the detailed mechanisms of these processes are unknown.
The insecticidal and anticholinesterase activities of O,O‐diethyl O‐4‐(2,2‐disubstituted vinyl)phenyl phosphates and phosphorothioates
Authors: de Licastro Susana A. , Zerba Eduardo N. , Wood Edgardo , de Villar Maria I. P. 
Published: November 2006

AbstractA series of O,O‐diethyl O‐4‐(2,2‐disubstituted‐vinyl)phenyl phosphorothioates and phosphates was synthesised and examined for anticholinesterase activity to housefly and bovine erythrocyte ChE, and also for their toxicity to Musca domestica and Triatoma infestans. The synthesised phosphates were potent anticholinesterases and stronger inhibitors of housefly acetylcholinesterase than bovine erythrocyte acetyl‐cholinesterase. Satisfactory correlation was obtained between the anticholinesterase activity and the Hammett σ− constants against both enzymes, but it was not significantly improved by introducing a term for the Hansch π constant. The phosphorothioates showed poor and variable toxicity to M. domestica. On T. infestans, the only compound that showed some toxicity was the di(acetyl)‐substituted product [O‐4‐(2‐acetyl‐3‐oxobut‐1‐enyl)phenyl O,O‐diethyl phosphorothioate]. For comparative studies, some commercial products were also assayed on T. infestans.
Dye‐sensitised photo‐oxidation of 2‐dimethylamino‐5,6‐ dimethylpyrimidin‐4‐01 in aqueous solution
Authors: Dixon Stephen R. , Wells Clifford H. J. 
Published: November 2006

AbstractThe sensitisation by Rose Bengal of the photo‐oxidation of 2‐dimethylamino‐5,6‐ dimethylpyrimidin‐4‐01 (I) has been studied in aqueous solution by monitoring the rate of oxygen consumption in the system. The results are in accord with a mechanism whereby I is oxidised via a reaction with singlet oxygen. Values for the rate constant for the reaction of I with singlet oxygen have been determined over the temperature range 279‐296 K, and the energy of activation and entropy of activation for the reaction have been evaluated as 71.9 kJ mol−1 and 150.5 J K−1 mol−1, respectively. The positive value for the entropy of activation suggests that the reaction intermediate could have a zwitterionic form. The effect of pH on the reaction rate has been investigated, and the increased rate at high pH has been attributed to an increase in singlet oxygen production as the pH is raised.
Adsorption, decomposition and movement of oxamyl in soil
Authors: Gerstl Zev 
Published: November 2006

AbstractA study was conducted of the behaviour of oxamyl in Israeli soils of varying clay and organic matter contents. The adsorption isotherms for oxamyl were linear, and the adsorption coefficient (Kd) could be correlated to the clay content of the soils, as well as to the organic matter content of the soil. Oxamyl adsorption was underestimated by using published correlations between the adsorption and the chemical properties of pesticides, such as their solubility or octan‐1‐ol‐water partition coefficient. The decomposition of oxamyl in soils followed first‐order kinetics. The half‐life ranged from 4 to 33 days in a Bet Dagan soil. The reaction rate increased with increasing moisture content of the soil until field capacity was reached, at which point it levelled off. The Arrhenius relationship was followed, with degradation proceeding more rapidly at higher temperatures. In several soils of varying composition, which were kept at field capacity, no difference in the degradation rates was observed. Oxamyl was applied to a Bet Dagan soil from a point source in a single pulse, as a split application, and on a continuous basis. The distribution patterns of oxamyl under the various treatments differed significantly. After the single‐pulse application, oxamyl was leached out of the emitter zone. While the split application decreased the oxamyl‐free zone, the best results were obtained by continuous application, which gave a nearly uniform distribution of oxamyl in the soil.
Quantitative structure‐activity relationship studies of acute toxicity (LD50) in a large series of herbicidal benzimidazoles
Authors: Adamson George W. , Bawden David , Saggers David T. 
Published: November 2006

AbstractQuantitative structure‐activity relationship (QSAR) studies have been carried out on oral rat LD50 values, for 129 herbicidal (trifluoromethyl)benzimidazoles, by multiple regression analyses, using computer‐generated descriptors to represent chemical structure, at several levels of specificity. The results permit rationalisation of the structure‐toxicity relationship, particularly the effect of substituent interactions, and allows reliable ‘rough estimate’ prediction of toxicity. However, reliable predictions of high accuracy are not feasible, even from analysis of this large, consistent, congeneric set of data, thus casting doubt on the suitability of the LD50 as a biological end‐point for a QSAR.
The enantiomeric composition of triadimenol produced during metabolism of triadimefon by fungi. Part I: Influence of dose and time of incubation
Authors: Deas Adrian H. B. , Clark Terence , Carter Geoffrey A. 
Published: November 2006

AbstractBotrytis cinerea, grown in shake culture in a liquid nutrient medium containing different amounts of triadimefon (4–40 mg litre−1), produced triadimenol as the sole major metabolite. Analysis by gas‐liquid chromatography (g.l.c.) showed the presence of (1R,2S) and (1S,2S)‐triadimenol, but no (1S,2R) or (1R,2R)‐enantiomer. The proportion of (1R,2S) to (1S,2S)‐triadimenol decreased over the period 6 to 168 h and with increased amounts of applied triadimefon. The implications of these patterns of metabolism are discussed in terms of overall fungitoxicity, the stereospecificity of the reduction process and the shortcomings of conventional, non‐chiral analysis of diastereoisomers by g.l.c. for assessing the sensitivity of fungi to such fungicides as triadimefon.
Molecular basis for the antimycotic and antibacterial activity of N‐substituted imidazoles and triazoles: The inhibition of isoprenoid biosynthesis
Authors: Bossche Hugo Vanden , Lauwers Wim , Willemsens Gustaaf , Marichal Patrick , Cornelissen Frans , Cools Willy 
Published: November 2006

AbstractThe antimycotic N‐substituted imidazoles and triazoles, such as imazalil, ketoconazole and itraconazole, interfere selectively at low concentrations (≥0.01nm) with the 14α‐demethylase system (which is dependent on cytochrome P‐450) of fungal cells, for example, Candida albicans and Penicillium italicum. This results in a decreased availability of ergosterol and the accumulation of 14α‐methyl‐sterols such as lanosterol. Cholesterol synthesis in a subcellular fraction of rat liver, in intact fibroblasts, and in vivo in rat liver, was much less sensitive, for example, to ketoconazole. The imidazole derivatives imazalil, miconazole, ketoconazole and parconazole, and the triazole derivatives propiconazole, terconazole and itraconazole affect the cytochrome P‐450 species of microsomal fractions from Saccharomyces cerevisiae and rat liver. Cytochrome P‐450 of rat‐liver microsomes was much less sensitive to these azole derivatives, in parallel with the lower sensitivity of cholesterol synthesis. Using unilamellar vesicles composed of phosphatidylcholine, phosphatidyl‐ethanolamine and diphosphatidylcholine, multilamellar vesicles of dipalmitoylphos‐phatidylcholine, and intact S. cerevisiae, it was shown that the substitution of ergosterol by lanosterol leads to functional changes in the membranes. It is speculated that the selective interaction of the azole derivatives with the yeast microsomal cytochrome P‐450 leads to the accumulation of 14a‐methyl‐sterols and results in changes in the permeability of the membranes and leakages. The observed inhibition of growth may have its origin in these changes. Miconazole, ketoconazole and deacylated ketoconazole (R‐39519) also affect the growth of Staphylococcus aureus, miconazole being 12.5 and 14 times, respectively, more active than R‐39519 and ketoconazole. The greater antibacterial activity of miconazole coincides with its greater inhibition of the biosynthesis of C‐55 isoprenoid alcohol and vitamin K. The phosphorylated derivative of C‐55 isoprenoid alcohol has functional importance in the biosynthesis of bacterial cell wall and membrane polymers, and the menaquinone vitamin K plays a role in the electron transport of Gram‐positive bacteria. The reduced synthesis of these vital compounds may contribute to the antibacterial activity of miconazole.
Ultrastructural changes induced by the systemic fungicides triadimefon, nuarimol and imazalil nitrate in sporidia of Ustilago avenae
Authors: Hippe Sigrun 
Published: November 2006

AbstractThe effects of the systemic fungicides triadimefon, nuarimol, and imazalil nitrate (5 μg ml‐1 for 8 and 16 h) on the ultrastructure of sporidia of Ustilago avenae were studied using transmission and scanning electron microscopes. Thin‐section and freeze‐fracture techniques demonstrated fine structural alterations to the cytology of the fungus. Compared with untreated controls, in which the cells were generally unicellular and uniform in shape and ultrastructure, fungicide‐treated cells exhibited considerable thickening of peripheral cell walls and septa, an increased number of mitochondria that were enlarged and irregular in shape, greater amounts of endoplasmic reticulum, and extensive vacuolisation and accumulation of lipid bodies. The vacuoles were filled with membrane‐like aggregates and vesicles, which could be extruded by exocytosis. The plasmalemma ultrastructure of fungicide‐treated sporidia, observed by scanning electron microscopy after freeze‐fracture was significantly different from that of control cells. The antifungal agents caused hemispherical pits, protrusions, invaginations, and aggregation of intramembrane particles on the membrane fracture faces. Specific structures, on the plasmalemma of plasmatic and extraplasmatic fracture faces, support the assumption of exocytosis. The ultrastructural changes were more pronounced after triadimefon and nuarimol treatment than after imazalil nitrate treatment. An extended incubation time (16 h) with triadimefon and nuarimol resulted in complete destruction of the cellular system of most sporidia.
Structure‐activity relationships in triorganotin biocides: The influence of the anionic radical
Authors: Blunden Stephen J. , Smith Peter J. , Sugavanam B. 
Published: November 2006

AbstractBioassay data are reported for seven triorganotin compounds (R3SnX), in which R=phenyl, cyclohexyl, or 2‐methyl‐2‐phenylpropyl, and × is the anionic form of the organic chelating ligands quinolin‐8‐ol, quinoline‐8‐thiol, 1,3‐diphenylpropane‐1,3‐dione, or 3‐hydroxyflavone, when tested against an organophosphorus‐resistant species of the two‐spotted spider mite (Tetranychus urticae), the potato blight fungus (Phytophthora infestans), and the vine downy mildew fungus (Plasmopara viticola). The relationship between the activity and the co‐ordination number of the tin atom is discussed, and it is shown that the anionic group × can, in some instances significantly affect the biological properties.
The two‐parameter bathtub‐shaped lifetime distribution
Authors: Nadarajah Saralees , Kotz Samuel 
Published: November 2006

AbstractThe above article (DOI: 10.1002/qre.795) was published online on 23 May 2006 in Wiley InterScience (www.interscience.wiley.com). An error was subsequently identified in the first paragraph. Please find the corrected paragraph below.The recent paper by Wu et al.1 claims to have studied a new distribution (originally introduced by Chen2) that exhibits a bathtub‐shaped hazard rate function. The cumulative distribution function (CDF) of this new distribution is given as

for $x > 0$, $\lambda > 0$ and $\beta > 0$. It appears to us that the distribution given by (1) or a more general form of it has appeared before in at least three published papers.The print publication will incorporate the amendments identified by this erratum notice.