bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectroscopic investigation of electron donor‐acceptor processes involving organic free radicals in the adsorption of substituted urea herbicides by humic acidsa
Authors: Senesi Nicola , Testini Ciro 
Published: November 2006

AbstractProducts of the interaction between soil humic acids and substituted‐urea herbicides were prepared in the laboratory and subjected to elemental, functional group, differential thermal, infrared spectroscopic and electron‐spin resonance analysis, in order to examine the various chemical mechanisms that may take place upon adsorption. The results indicate that, besides the involvement of hydrogen bonding, a prominent role is played by electron donor‐acceptor processes involving organic free radicals, which leads to the possible formation of charge‐transfer complexes. The phytotoxicity of the urea herbicides, expressed as the inhibition potency towards the Hill reaction (pl50 values), appeared to be correlated with their capacity to interact with soil humic components, and it is suggested that these two processes depend upon the same molecular parameters.
Evaluation of inexpensive thin‐layer chromatographic procedures for the estimation of some organophosphorus and carbamate insecticide residues in fruit and vegetables
Authors: Wood Alan B. , Kanagasabapathy Lalitha 
Published: November 2006

AbstractModified versions of previously published procedures for the extraction and clean‐up of some organophosphorus insecticide residues in fruits and vegetables are described, and their usefulness in combination with selected thin‐layer chromatographic procedures is experimentally assessed for several pesticides in apples, oranges, tomatoes, carrots and peas. A simple extraction procedure for insecticidal carbamates is similarly evaluated for carbaryl and propoxur residues in apples, carrots and peas. Semi‐quantitative estimation, by visual comparison with standards, is shown to be possible in many cases at residue levels as low as 0.4 mg kg−1, and the combined procedures should be useful in the screening of fruits or vegetables for compliance with maximum residue limits.
Chemical control of soil‐borne pathogens in tuff medium for strawberry cultivation
Authors: Sneh Baruch , Katan Jaacov , Abdul‐Raziq Ali 
Published: November 2006

AbstractThe phytopathogenic fungi Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani were completely eradicated after exposure for 30 min to a 0.4‐0.5 % aqueous solution by weight of formaldehyde. With metham‐sodium, higher concentrations or longer exposures were needed to obtain similar results. When tested in tuff (a granular plant growth medium of volcanic rock origin), the toxicity of formaldehyde was lower and that of metham‐sodium was higher, compared with the corresponding toxicities in aqueous solutions. Both fungicides eradicated the two fungi, as well as Pythium myriotilum, when tested under practical conditions in vertical aluminium tubes filled with tuff. No detrimental effect could be observed on strawberry plants subsequently grown in these columns.
The effects of temperature and humidity on the toxicity of three organophosphorus insecticides to adult Oryzaephilus surinamensis (L.)
Authors: Barson Graham 
Published: November 2006

AbstractThe toxicities, to a laboratory susceptible strain and to a resistant strain of Oryzaephilus surinamensis (L.), of water‐dispersible powder formulations of pirimiphos‐methyl, fenitrothion or chlorpyrifos‐methyl under constant conditions of 25°C and 70% r. h. were compared to the toxicities when the insects were exposed to a diurnal cycle of 12.5–20–12.5°C and 70–50–70% r. h. to simulate grain store conditions in the UK during spring and autumn. All the insecticides were more effective at 25°C and 70% r. h. The LD50 values for the susceptible strain were low, being 4.4 and 1.4 mg m−2 at 12.5‐20°C and 25°C, respectively, for chlorpyrifos‐methyl, 18.3 and 4.1 mg m−2, respectively, for pirimiphos‐methyl, and 4.0 and < 1.O mg m−2, respectively, for fenitrothion. The LD50 values obtained from the two sets of environmental conditions for a resistant strain (484) differed by factors of 1.8 for chlorpyrifos‐methyl, 4.8 for pirimiphos‐methyl, and 7.3 for fenitrothion.Toxicity studies were also made with chlorpyrifos‐methyl under various constant conditions of temperature and humidity from 5–30°C (5°C intervals) and 30, 50, 70 and 90% r. h., and also at O°C and 60% r. h.Chlorpyrifos‐methyl was very effective and there was little or no cross resistance to chlorpyrifos‐methyl in the resistant strain. From 15 to 30°C, mortality was high, and differences in mortality at the LD50 level for the various humidities were slight, but there was a decrease in mortality with decreasing humidity at any one temperature, in particular, at 5°C, 50 and 70% r. h., and 10°C and 50% r. h. Chlorpyrifosmethyl was more toxic to both strains at the highest humidity (90%) throughout the whole temperature range. The LD50 values for each strain decreased at each temperature as the water vapour concentration was increased. At O°C and 60% r. h., all the insects from both strains died but the cause of death was not clear.
A test for repellency to non‐biting flies and a comparison of repellents using Musca domestica L.
Authors: Campbell Malcolm M. 
Published: November 2006

AbstractA system for testing the effect of a repellent against nonbiting flies attracted to man was developed for Musca domestica L. and Musca vetustissima Walk., and was used to compare the repellency of a range of chemicals against the former. Both arms of one person were simultaneously exposed to large numbers of the test insect in a cage, with repellent applied to a 45 cm2 area on one arm, and the solvent to an identical area on the other arm. By varying the dose of repellent, a dose‐to‐repellency relationship was established and evaluated using probit analysis to determine 50% (RD50) and 90% (RD90) repellency. Both values were required to characterise a repellent. Greatest uniformity of results was obtained with even illumination of the cages from above and exclusion of side lighting. RD50 and RD90 values were not affected by prior exposure of the flies in a cage and did not change with time. Of the repellents tested, dipropyl isocinchomeronate was the most effective against M. domestica. The repellent effect of mixtures of the compounds was tested against M. domestica and was less than expected by summation of the components acting alone, suggesting that to minimise the total dose of chemical applied to skin, single compounds are preferable to mixtures.
New possibilities for controlling foliar absorption via stomata
Authors: Mansfield Terence A. , Pemadasa Malawara A. , Snaith Paul J. 
Published: November 2006

AbstractStomatal guard cells are known to be preferential sites for foliar absorption. Uptake of herbicides has been shown to increase when the stomata are open, probably because the pore provides access for solutions to areas where the cuticle is thinner and where less wax is deposited. Stomatal closure in dry seasons has been suggested as a reason for reduced herbicide uptake in those periods. New evidence is presented that indol‐3‐ylacetic acid can overcome the influence of natural agents causing stomatal closure, thus providing the possibility of regulating stomatal aperture in the field to facilitate the uptake of applied chemicals.
Phytotoxicants from microorganisms and related compounds
Authors: Fischer Hans‐Peter , Bellus Daniel 
Published: November 2006

AbstractPhytotoxic compounds produced by microorganisms are reviewed. Their utilisation as leads to new herbicides is explored in three chemical classes : 2‐aminoalk‐3‐enoic acids, ether derivatives of 3‐hydroxycyclobut‐3‐ene‐1,2‐diones, and 2‐(acylaminooxy)acetic acid derivatives. It is concluded that some bacteria and fungi yield compounds possessing sufficient herbicidal activity to be valuable as herbicides as such, or as leads for chemical optimisation.
Effect of fungicides on stages of the life cycle of Phytophthora cinnamomi
Authors: Geissler Art E. , Katekar Gerard F. 
Published: November 2006

AbstractAn assessment was made of the effects of several fungicides on the formation of zoosporangia, the release of zoospores from zoosporangia, zoospore motility, germ tube formation and mycelial growth, by Phytophthora cinnamomi Rands. Compounds active against mycelial growth (such as metalaxyl and furalaxyl), as well as those active against zoospores (such as captafol and zineb), could be detected by a lupin (Lupinus angustifolius L.) assay which has been developed. This assay may be useful as a screening procedure to detect new fungicides.
Atrazine hydrolysis. Part I: Proton catalysis at 25°C
Authors: Gamble Donald S. , Khan Shahamat U. , Tee Oswald S. 
Published: November 2006

AbstractSix new results have been obtained in an investigation of the catalysed hydrolysis of atrazine. A procedure was developed for determining rate constants from the first 20 mol% of the reaction. The reduced length of the experiments increased the experimental productivity and minimised the risk of sample deterioration. The proton catalysis rate was measured at 25°C, over the H+ concentration range of 1 to 10 mmol litre−1. This shortened the extrapolation to the pH values of field conditions, and guaranteed the absence of doubly‐protonated atrazine. Because spectrophotometry has been regarded as a controversial method for studying the hydrolysis kinetics of the 1,3,5‐triazine herbicides, this method was re‐examined. Excellent agreement was obtained from a comparison of the gas‐liquid chromatographic and spectrophotometric methods of monitoring the kinetics experiments. Of the widely diverging relationships found in the literature for the extrapolation of laboratory half‐lives to the pH range of field conditions, the one deduced from the reaction scheme of Plust et al. was found to be theoretically correct. Its parameters have been calibrated with several hundred experimental measurements. The proton is not the dominant catalytic agent in soils, but its calibration is essential for identifying those catalytic agents that are dominant. It has been deduced that the temperature dependence of the experimental rate constant is governed by the temperature responses of two parameters.
Synthesis, fungicidal activity and structure‐activity relationships of a series of 1‐(3‐pyridyl)‐1‐substituted‐but‐3‐yn‐1‐ols
Authors: Arnoldi Anna , Betto Eliseo , Ceresa Lucia , Farina Gandolfina , Formigoni Attilio , Galli Remo , Scaglioni Leonardo 
Published: November 2006

AbstractA series of 1‐(3‐pyridyl)‐1‐substituted‐but‐3‐yn‐1‐ols and some related compounds were synthesised and tested for antifungal activity against eight phytopathogenic fungi of different taxonomic classes. High activity was shown in particular against Sphaerotheca fuliginea on Cucumis sativus. The compounds containing aromatic substituents gave the best results, not only in protectant but also in systemic and eradicant tests. The quantitative structure‐activity relationship suggests that steric effects play an important role in determining fungicidal activity.
Persistence on cotton foliage of insecticide residues toxic to Heliothis larvae
Authors: Wilson Angus G. L. , Desmarchelier James M. , Malafant Kim 
Published: November 2006

AbstractControl measures for Heliothis spp. on cotton are usually applied against eggs and newly hatched larvae that infest plant terminal growth. In order to investigate the rate of degradation of a range of insecticides, leaf disc samples were collected, at intervals after application, from both fully expanded cotton leaves and unfolding terminal leaves. The samples were subjected separately to bioassay with newly hatched larvae, and to chemical analysis of the surface deposits.On old leaves, larval mortality caused by two biological insecticides declined by half after field exposure for 36 h, but for the synthetic insecticides, the interval ranged from 4.5 days with endosulfan to 18 days with fenvalerate. On new leaves, the longest interval was 7 days with fenvalerate. Chemical half‐life on old leaves ranged from 1 day with endosulfan to 12 days with DDT, and was also shorter on young leaves than the equivalent biological half‐life. Bioassay appears to be the most reliable method of assessing insecticidal activity over time. Dosage/mortality data were integrated to give LC50 and LC90 values.Leaf expansion may have the greatest effect on insecticide persistence during the 6 week period of rapid growth commencing 2 months after sowing. Expansion was slower when plants were water stressed, and accelerated following irrigation. The implications of the above findings for cotton pest management are discussed.
The enantiomeric composition of triadimenol produced during metabolism of triadimefon by fungi. Part II: Differences between fungal species
Authors: Deas Adrian H. B. , Clark Terence , Carter Geoffrey A. 
Published: November 2006

AbstractThe fungi Coriolus versicolor, Cladosporium cucumerinum, Botrytis cinerea and Fusarium culmorum, in shake culture, metabolised triadimefon to triadimenol. Analyses by gas–‐liquid chromatography of the triadimenol showed that the fungi produced different qualitative and quantitative combinations of the four possible enantiomers, and that these differences were reproducible. The relationship between the enantiomeric composition of the triadimenol produced and the sensitivity of the test fungi to triadimefon, is discussed in the light of published data on the differences in antifungal activity shown by these enantiomers.
Fluorescence microscope studies of Ustilago maydis and Penicillium italicum after treatment with imazalil or fenpropimorph
Authors: Kerkenaar Antonius , Barug Daniel 
Published: November 2006

AbstractImazalil and fenpropimorph caused morphological changes in sporidia of Ustilago maydis and in germinating conidia of Penicillium italicum, as observed by fluorescence microscopy using an optical brightener. Sporidia of U. maydis appeared swollen, distorted, multicellular and, sometimes, branched; conidia of P. italicum swelled in size, and extension of the germ tubes was strongly inhibited. Mycelium of P. italicum, treated with fenpropimorph, showed much enlarged hyphal diameters and relatively short distances between septa. Imazalil and fenpropimorph also caused an irregular deposition of β–1,3 and β‐1,4 polysaccharides, probably chitin, in U. maydis and P. italicum. The latter phenomenon is discussed in relation to the following observed effects of fungicides that inhibit ergosterol biosynthesis: differences in effect on the morphology of budding and filamentous fungi; preferential inhibition of yeast‐hypha conversion in dimorphic fungi; disorganisation of septum formation in budding fungi; and inhibition of spheroplast formation from budding fungi.
Structure‐activity relationships in a group of azoles, with special reference to 1,3‐dioxolan‐2‐ylmethyl derivatives
Authors: Heeres Jan 
Published: November 2006

AbstractSubstituted imidazoles and substituted 1,2,4‐triazoles are active to varying degrees in the control of fungi pathogenic to plants, animals and man. The relationship between chemical structure and their antifungal activity, both in‐vitro and in‐vivo, is reviewed.
Synthesis and fungicidal activity of a series of 1,1‐disubstituted‐but‐3‐yn‐1‐ols
Authors: Arnold Anna , Betto Eliseo , Farina Gandolfina , Formigoni Attilio , Galli Remo , Merlini Lucio 
Published: November 2006

AbstractTwenty‐three aromatic or heterocyclic 1,1‐disubstituted‐but‐3‐yn‐1‐ols were prepared by the reaction between prop‐2‐ynylmagnesium bromide and suitable ketones. They were tested in vivo for antifungal activity against eight phytopathogenic fungi of different taxonomic classes. Four compounds had noteworthy activity on Sphaerotheca fuliginea in protectant, systemic and eradicant assays. The relationship between structure and activity is discussed on the basis of the recent hypotheses on the mechanism of action of ergosterol biosynthesis inhibitors.
Structural studies in azolylmethanes
Authors: Anderson Nicholas H. , Branch Sarah K. , Loeffler R. S. Thomas , Mann Brian E. , Nowell Ian W. , Walker Philip E. 
Published: November 2006

AbstractThe crystal structures of a number of fungicidal azolylmethanes are compared. In the benzyl compounds [1‐aryl‐4,4‐dimethyl‐2‐(1,2,4‐triazol‐1‐yl)pentan‐3‐ones, the corresponding pentan‐3‐ols, and 1‐(4‐chlorophenyl)‐3‐(2‐fluorophenyl)‐2‐(1,2,4‐triazol‐1‐yl)propan‐1‐one], the benzyl and tert‐butyl groups (or 4‐chlorophenyl group) are trans, whereas in the analogous phenoxy compounds [1‐(4‐chlorophenoxy)‐3,3‐dimethyl‐1‐(1,2,4‐triazol‐1‐yl)butan‐2‐one and the corresponding butan‐2‐ol], the tert‐butyl groups are trans to the triazole and gauche to the phenoxy group. Coupling constants, determined by nuclear magnetic resonance (n.m.r.) spectroscopy, suggest that for some compounds there is one dominant solution conformation. Intramolecular hydrogen bonding, observed by infrared spectroscopy in two of the compounds, supports the findings by n.m.r. For some compounds, the crystal and solution conformations appear to be very similar, whereas in others they are quite different. Published data on the relative activity of the enantiomers of the benzyl‐ and phenoxy‐compounds are discussed, but differences in the relative activity of enantiomers in the two series cannot be readily rationalised. It is concluded that different enantiomers may have different modes of binding at the active site.
Development of a packaging material using antistatic ionomer part 2: charge distributions of potassium ionomer
Authors: Maki Nobuyuki , Tajitsu Yoshiro , Sasaki Haruo 
Published: November 2006

AbstractGenerally, plastics and plastic films are low in moisture absorption and high in electric insulation. They are inherently easy to be charged with static and can cause a variety of static troubles. We developed a functional packaging material to solve these static problems, by using potassium ionomer. We reported good antistatic performance (e.g. short static decay time, and excellent ash test) of potassium ionomer films in a previous paper. However, a mechanism underlying the antistatic property of potassium ionomer has not yet been fully elucidated. In this study, we measured the space charge distributions of potassium ionomer using the pulsed electro‐acoustic method. As a result of the space charge measurements, we found characteristic charge distribution of potassium ionomer film. On the basis of the existence of this characteristic charge distribution, we speculate that the space electric charge distribution of a potassium ionomer film under a direct current electric field shows apparent electric charge movement. Copyright © 2006 John Wiley & Sons, Ltd.
Efficient implementation of Aho–Corasick pattern matching automata using Unicode
Authors: Nieminen Janne , Kilpeläinen Pekka 
Published: November 2006

AbstractWe study different efficient implementations of an Aho–Corasick pattern matching automaton when searching for patterns in Unicode text. Much of the previous research has been based on the assumption of a relatively small alphabet, for example the 7‐bit ASCII. Our aim is to examine the differences in performance arising from the use of a large alphabet, such as Unicode that is widely used today. The main concern is the representation of the transition function of the pattern matching automaton. We examine and compare array, linked list, hashing, balanced tree, perfect hashing, hybrid, triple‐array, and double‐array representations. For perfect hashing, we present an algorithm that constructs the hash tables in expected linear time and linear space. We implement the Aho–Corasick automaton in Java using the different transition function representations, and we evaluate their performance. Triple‐array and double‐array performed best in our experiments, with perfect hashing, hashing, and balanced tree coming next. We discovered that the array implementation has a slow preprocessing time when using the Unicode alphabet. It seems that the use of a large alphabet can slow down the preprocessing time of the automaton considerably depending on the transition function representation used. Copyright © 2006 John Wiley & Sons, Ltd.
Protection by multiple antioxidants against lipid peroxidation in rat liver homogenate
Authors: Chen Hao , Tappel Al 
Published: November 2006

AbstractThe purpose of this study was to test the hypothesis that multiple antioxygenic nutrients provide increased protection against lipid peroxidative damage to rat liver. Rats were fed diets (i) deficient in vitamin E and selenium (Diet 1), (ii) supplemented with vitamin E and selenium (Diet 2), (iii) supplemented with (ii) and in addition trolox C,N‐acetylcysteine, coenzyme Q0, and (+)‐catechin (Diet 3), or (iv) supplemented with (iii) and in addition β‐carotene, ascorbic acid palmitate, canthaxanthin, and coenzyme Q10 (Diet 4). Liver homogenates were obtained from three rats fed each of the diets for six weeks and were incubated at 37°C up to two hours with and without exogenous tertiary‐butyl hydroperoxide (TBHP) or Cu2+. Lipid peroxidation was determined by measurement of thiobarbituric acid substances. Diets 2 and 3 significantly protected againstin vivo hepatic lipid peroxidation, and this protection was augmented by Diet 4. Diets 2, 3, and 4 were protective against mild oxidation induced by TBHP or Cu2+. During incubations with exogenous TBHP and Cu2+, there were only small differences between diets supplemented with antioxidants in inhibition of lipid peroxidation, indicating that diets supplemented with vitamin E and selenium (Diet 2) may have provided the maximal protection for liver. The possible mechanisms of protection provided by multiple antioxidants in diets were discussed. Protection by multiple antioxidants against lipid peroxidation may translate to prevention of peroxidative damage to human tissue, a factor in human disease.
A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until nine months
Authors: Werkman Susan H. , Carlson Susan E. 
Published: November 2006

AbstractThis randomized, double‐blind trial tested the hypothesis that the addition of 0.2% docosahexaenoic acid (DHA, 22∶6n−3) from marine oil to commercially‐available preterm and term formulas with ≥3% linolenic acid (18∶3n−3) would enhance novelty preference and visual attention of preterm infants. Among preterm infants cared for in our center, study infants were a select group considered to be at lower risk for developmental delay. Study infants received their assigned diet (control, DHA‐supplemented) from a mean postnatal age of 25 d until 9 mon past term. At 6.5, 9, and 12 mon past term, they were tested for visual recognition memory (novelty preference) and attention with the Fagan Test of Infant Intelligence. The effects of DHA supplementation were analyzed by repeated measures analysis of variance. In paired comparisons of novel and familiar stimuli, DHA‐supplemented and control infants had the same novelty preference, but supplemented infants had more discrete looks to both novel (P<0.03) and familiar (P<0.02) stimuli and a shorter overall look duration (P<0.03). These data are analogous to those from n−3‐deficient and n−3‐fed monkeys in that the group with better DHA status had shorter overall look duration. Because shorter look duration has been associated with more rapid information processing, preterm infants fed formulas with only linolenic acid may have had slower information processing than those fed DHA.