bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple actions of dieldrin and lindane on the GABAA receptor‐chloride channel complex of rat dorsal root ganglion neurons
Authors: Nagata Keiichi , Narahashi Toshio
Published: November 2006

The GABAA receptor‐chloride channel complex is known to be the target of cyclodiene insecticides and of γ‐hexachlorocyclohexane (γ‐HCH, lindane). Dieldrin first enhances, then suppresses, γ‐aminobutyric acid (GABA)‐induced chloride currents, and the latter action results from the acceleration of desensitization. We now report more detailed analyses of the action of dieldrin and γ‐HCH on the GABAA receptor‐chloride channel complex of rat dorsal root ganglion, using whole‐cell and single‐channel patch clamp techniques. Pre‐application of dieldrin suppressed GABA‐induced chloride currents in a time‐and dose‐dependent manner. No enhancement of current was observed under these conditions, because the enhancing action of dieldrin, which is transient in nature, had ceased by the time GABA‐induced currents were recorded. Both transient and sustained components of chloride currents were suppressed by dieldrin. The effect was almost irreversible, and the current did not recover after 30 min of washout with dieldrin‐free solution. The currents activated by higher concentrations of GABA were more strongly suppressed by dieldrin. Co‐application of γ‐HCH with GABA caused an enhancement of the GABA‐induced chloride currents, which was followed by suppression. Single‐channel currents induced by 1 μM GABA were completely suppressed by 1 μM γ‐HCH. Hyper‐excitation of the nervous system and whole animal caused by dieldrin and γ‐HCH is the result of suppression of the GABA receptor‐chloride channel complex.
Phloem mobility of xenobiotics VI. A phloem‐mobile pro‐nematicide based on oxamyl exhibiting root‐specific activation in transgenic tobacco
Authors: Hsu Francis C. , Sun Kingmo , Kleier Daniel A. , Fielding Max J.
Published: November 2006

Phloem mobility is a desirable attribute for pesticides in many applications, and the physicochemical properties necessary for phloem mobility are now well understood. However, attempts to derivatize pesticides to make them phloem mobile are often frustrated by a concomitant loss of activity. This study describes a phloem‐mobile pro‐nematicide, a hydroxymethyloxamyl glucuronide (JR522) coupled with an in‐situ activation mechanism in transgenic tobacco expressing Escherichia coli β‐glucuronidase in its root tips. When applied foliarly to the transgenic tobacco, JR522 and its methyl ester (JM775) showed greater nematicidal activity than oxamyl against root‐knot nematodes. This example of combining pro‐pesticide chemistry with crop genetic engineering for site‐specific activation provides a model system for demonstrating how to circumvent the often mutual exclusivity of phloem mobility and pesticidal activity. Additional advantages of this scheme include the potential mammalian safety of the propesticide, as exhibited by JR522 in this study, and a high degree of site‐specific release of xenobiotics in plants.
Investigation of azole resistance in the Ustilago maydis sterol demethylase mutant erg 40
Authors: Joseph‐Horne Timothy , Carelli Angelina , Hollomon Derek , Kelly Steven L.
Published: November 2006

Resistance to azole fungicides in Ustilago maydis (DC) Corda has been examined using the mutant erg 40, a newly isolated mutant TriR‐1 and erg 40 revertants. Azole‐induced growth arrest of the wild type did not support an obvious role for 3,6‐diol in the mode of action has is clear for Saccharomyces cerevisiae Meyer ex Hansen. The level of microsomal P450 of erg 40 was identical to that of the parent, and reversion analysis showed no evidence of mutation in the sterol Δ5(6) desaturase, as would be expected for a S. cerevisiae mutant accumulating 14α‐methylfecosterol. Resistance appeared to be due to a single mutation in P450 14αdm. It is proposed that the orthologous forms of fungal sterol Δ5(6) desaturases have varied responses when attempting to utilise 14α‐methylated substrates.
Structure—activity relationships of pyridylcarbamates active against both benzimidazole‐sensitive and ‐resistant isolates of Botrytis cinerea
Authors: Akagi Toshio , Mitani Shigeru , Ito Keiichiro , Shigehara Itaru , Komyoji Terumasa , Matsuo Norifusa
Published: November 2006

A series of pyridylcarbamates showed high potency against cucumber gray mould (Botrytis cinerea Pers.). The most potent compound, propargyl‐N‐(6‐ethyl‐5‐iodo‐2‐pyridyl)carbamate was effective against an isolate sensitive to benzimidazole and dicarboximide fungicides as well as against an isolate resistant to both types of compound. QSAR analyses and molecular modelling studies were carried out to investigate the structural requirements for highly active compounds and the structural feature of the binding site of each strain. Significantly different QSAR equations were obtained only for substituents at the 6‐position of the pyridine ring. An ethyl‐sized pocket or an ethyl terminal recognition was suggested in the case of the sensitive or resistant isolate respectively. These results could explain the phenomenon of negatively correlated cross‐resistance between benzimidazoles and N‐phenylcarbamate fungicides. Substituent effects at the 5‐ or 2‐position were governed by steric factors. Substituent effects at the 3‐position were explained by steric hindrance or by conformational effects. The propargyl‐substituted compound above was the most desirable one from the viewpoint of QSAR.
Insecticidal isomers of 4‐tert‐butyl‐1‐(4‐ethynylcyclohexyl)‐2,6,7‐trioxabicyclo [2.2.2] octane and 5‐tert‐butyl‐2‐(4‐ethynylcyclohexyl)‐1,3‐dithiane
Authors: Weston John B. , Larkin John P. , Pulman David A. , Holden Ian , Casida John E.
Published: November 2006

4‐tert‐Butyl‐2,6,7‐trioxabicyclo[2.2.2]octanes and 5‐tert‐butyl‐1,3‐dithianes with the 4‐ethynylcyclohexyl substituent in the 1‐ and 2‐positions, respectively, are potent insecticides modeled on their 4‐ethynylphenyl and hex‐5‐ynyl analogs. The compounds were prepared from dimethyl 1,4‐cyclohexanedicarboxylate, 4‐(2,2‐dibromovinyl)cyclohexanecarboxylic acid, methyl 4‐(1‐chlorovinyl)cyclohexanecarboxylate, and 4‐ethynylcyclohexylmethanol by wellestablished chemistry. The cis and trans isomers of the 1‐cyclohexyl‐trioxabicyclooctane and all four geometric isomers of the 2‐cyclohexyl‐1,3‐dithiane were separated by chromatography of the final products or suitable intermediates. High levels of insecticidal activity were found against houseflies, German cockroaches and aphids for trioxabicyclooctanes and dithianes with the trans ethynylcyclohexyl configuration.
Water balance, respiration and immobilisation in relation to deltamethrin poisoning and physical conditions in the epigeal spider Oedothorax apicatus
Authors: Jagers Gerard A. J. M. , Akkerhuis Op , Westerhof Roelof , Van Straalen Nico M. , Koeman Jan H.
Published: November 2006

The effect of a pyrethroid insecticide, deltamethrin, on water loss, metabolic rate and immobilisation was studied, using the epigeal spider Oedothorax apicatus (Blackwall) (Linyphiidae) as a test species. Water loss was measured gravimetrically at different temperatures, air humidities, and doses of deltamethrin. Metabolic rate and immobilisation were measured at different temperatures and doses. Immobilisation was measured at different relative humidities and temperatures. Water loss due to evaporation increased linearly with vapour pressure deficit. The slope of the latter relationship increased with temperature, indicating an increase in cuticle permeability with temperature. In addition to water loss by evaporation, deltamethrin treatment induced water excretion. This was positively related to dose and temperature, but independent of air humidity. Metabolic rate increased with temperature and dose. Immobilisation was highest at low temperatures in combination with low air humidity. The consequences of pesticide‐induced water excretion are discussed with respect to field‐ and laboratory‐based dose‐effect relationships for pyrethroids presented in the literature. The present results seem to offer an explanation for hitherto unexplained minima in temperature‐response curves in pyrethroid toxicity in some arthropod species. It is concluded that simultaneous measurements of metabolic rate, water‐loss rate and pesticide effects are a prerequisite for an understanding of the effects of pesticides on arthropods.
Spectrophotometric determination of fenvalerate in a commercial formulation and as residues in water and soil
Authors: Naidu Rallapalle Raghava , Raju Raghava V. Prabhakara
Published: November 2006

Simple, rapid and sensitive spectrophotometric methods have been developed for the microdetermination of fenvalerate, based on the formation of red‐purple compounds when one of the hydrolysed products of fenvalerate is condensed with 4‐nitrophenylhydrazine (4‐NPH) in the presence of methanolic potassium hydroxide. With this reagent the colour development was instantaneous and was stable for 52 hours. The method has been successfully adapted to the determination of fenvalerate in its formulation and residues on water and soil.
A simplified method for measuring dilute emulsion stability
Authors: Wang Yiyan , Bian Shaozhuang , Wu Di
Published: November 2006

A simple and rapid method for the assessment of the stability of diluted pesticide emulsifiable concentrates has been developed for use in China. It gives results comparable to those obtained with FAO and WHO methods. The importance of some other physical characteristics such as contact angle, surface tension and wetted area in pesticide application are also discussed.
Extended summary SCI pesticides group/BCPC international symposium comparing glasshouse and field pesticide performance. Comparing glasshouse and field performance of pesticides: An appraisal
Authors: Finney John R.
Published: November 2006

The following is an extended summary based on a concluding paper presented at the above symposium, which was organised by G. Hewitt, D. Tyson, L. C. Copping, B. T. Grayson and J. C. Caseley on behalf of the British Crop Protection Council and the SCI Pesticides Group, and held at the University of Kent, Canterbury, on 12–14 April 1994. The summary is entirely the responsibility of the author, and does not necessarily reflect the views of the Editorial Board of Pesticide Science.
Effects of anti‐ecdysteroid azole analogues of metyrapone on the larval development of the fleshfly, Neobellieria bullata
Authors: Bélai Iván , Darvas Béla , Bauer Krisztina , El‐Din Mahmoud H. Tag
Published: November 2006

Based on our previous finding that PIM (phenyl‐imidazolyl‐metyra‐pon; 2‐(1‐imidazolyl)‐2‐methyl‐1‐phenylpropan‐1‐one, 1) is a strong inhibitor of ecdysone 20‐monooxygenase (IC50 = 7.89 × 10−7 M) from the fleshfly, Neobellieria bullata (Parker) and has also a good toxic action in vivo against this insect, 17 imidazole and 1,2,4‐triazole analogues of metyrapone were synthesized and evaluated for their action against N. bullata larvae in terms of toxicity, length of larval development, weight of the puparium as well as special symptoms, i.e. malformations of the anterior and posterior spiracles, and of the mandibles. The introduction of p‐methoxy (LC50 = 49 mg kg−1 in diet) or p‐chloro (LC50 = 97 mg kg−1) substituents on the benzene ring of PIM resulted in a significant increase in toxicity compared to that of metyrapone (LC50 = 561 mg kg−1) and PIM (LC50 = 148 mg kg−1). The hybridization state of the carbon atom adjacent to the benzene ring was not an important factor for toxicity because the acetoxy derivative (13) was almost as toxic as PIM. At least one methyl group was required on the carbon atom adjacent to the azole ring to maintain activity, while an ethyl group (4) enhanced the toxic effect. At the applied doses some compounds including metyrapone itself, extended the duration of the larval development. Only metyrapone and PIM decreased the puparium weight. Several derivatives induced lethal malformations of mandibles as well as the anterior and posterior spiracles.
In‐vivo efficacy and in‐vitro activity of tubercidin, an antibiotic nucleoside, for control of Phytophthora capsici blight in Capsicum annuum
Authors: Hwang Byung Kook , Kim Beom Seok
Published: November 2006

The antibiotic nucleoside tubercidin produced by Streptomyces viola‐ceoniger was evaluated for in‐vivo efficacy and in‐vitro activity against Phytophthora capsici, Magnaporthe grisea and Colletotrichum gloeosporioides. Tubercidin was more effective against P. capsici and M. grisea than against C. gloeosporioides in inhibiting mycelial growth. The bioassay on TLC plates was the most sensitive method and allowed the evaluation of antifungal activity of tubercidin even at a low concentration of 0.1 μgml−1. As compared to the systemic fungicide metalaxyl, tubercidin was similar or somewhat higher in inhibition of mycelial growth of P. capsici. When applied to pepper stems, tubercidin was equally as effective as metalaxyl in the control of phytophthora blight in pepper plants, irrespective of application time and concentration. The treatment with 1000 μg ml−1 tubercidin induced phytotoxicity in pepper plants. No control efficacy of phytophtora blight was observed in pepper plants supplied with a soil drench of tubercidin. Treatment with tubercidin at 500 μg ml−1 completely protected pepper plants at first branch stage from phytophthora blight until four days after application. The control efficacy of tubercidin drastically declined seven days after application.
The pyrethrins and related compounds part XXXIX— structure‐activity relationships of pyrethroidal esters with cyclic side chains in the alcohol component against resistant strains of housefly (Musca domestica)
Authors: Farnham Andrew W. , Khambay Bhupinder P. S.
Published: November 2006

Activities of a range of pyrethroidal esters, incorporating structural variations in all regions of the acid and alcohol components, have been measured against two fully characterised and homozygous resistant strains of Musca domestica L. (kdr and super‐kdr). The results, limited in this paper to esters of alcohols with cyclic side chains, indicate uniform resistance to the kdr strain across the whole range of structural variations. Against the super‐kdr strain, while variation in the acid component has little effect, the resistance factor is sensitive to the nature of the alcohol component, in particular on whether it contains an α‐cyano substituent.
Mechanisms conferring resistance of Western flower thrips to bendiocarb
Authors: Zhao Guangyu , Liu Wei , Knowles Charles O.
Published: November 2006

Mechanisms associated with bendiocarb resistance were examined in two strains of western flower thrips, Frankliniella occidentalis (Pergande), that differed in their susceptibility to this carbamate by 13.6‐fold. No appreciable differences between the two strains in [14C] bendiocarb penetration and excretion were detected; however, bendiocarb was metabolised substantially faster by the resistant KCM thrips than by the more susceptible UMC thrips. No appreciable difference between the two strains was found in the sensitivity of acetylcholinesterase activity to inhibition by bendiocarb. It was concluded that bendiocarb resistance in KCM western flower thrips was due to enhanced metabolism that probably was mainly oxidative in nature.
Microbial metabolism of fenoxaprop‐ethyl
Authors: Gennari Mara , Vincenti Marco , Nègre Michèle , Ambrosoli Roberto
Published: November 2006

Fenoxaprop‐ethyl was found to be metabolized by a mixed microbial population isolated from a leachate from a landfill. Fenoxaprop acid and 6‐chloro‐2(3H)‐benzoxazolone were detected as metabolic products in the culture broths. It was shown that the microbial population could utilize fenoxapropethyl as a source of carbon and nitrogen, but the presence of an additional source of carbon increased the metabolism rate.
Deposition and bioassay of insecticides applied by leaf dip and spray tower against Bemisia argentifolii nymphs (Homoptera: Aleyrodidae)
Authors: Liu Tong‐Xian , Stansly Philip A.
Published: November 2006

Two application methods, spray and leaf dip, were evaluated as bioassays for insecticides to nymphs of Bemisia argentifolii Bellows & Perring (formerly Bemisia tabaci Gennadius strain ‘B’). Sprays were applied at different volumes and pressures with the Potter Spray Tower®. Spray deposition was evaluated using a tracer dye, and also plain water in the case of the spray tower. Coverage on water‐sensitive paper was evaluated with a computerized imagescanning system. Insecticide efficacy was evaluated as mortality to whitefly nymphs. Materials assayed included ‘M‐Pede’® (an insecticidal soap), ‘Sunspray’® Ultra‐Fine Spray Oil (a mineral oil), ‘Margosan‐O’® (an extracted concentration of azadirachtin + 10% neem oil), and bifenthrin (‘Brigade’® 10WP), a pyrethroid, with purified water as a control.

Differing results were obtained with the two bioassay methods, depending on material tested. Mortality of whitefly nymphs from bifenthrin, and to a lesser extent neem extract, was largely independent of application method. In contrast, ‘Sunspray’ (mineral) oil, and to a lesser extent insecticidal soap, was more efficacious when applied as a dip than as a spray. Differences in respect of effects of application method on treatment mortality were attributed to differences between materials in mode of action.
Evaluation of cinnamamide as an avian repellent: Determination of a dose—response curve
Authors: Watkins Richard W. , Gill Elaine L. , Bishop Julie D.
Published: November 2006

The dose‐response curve was quantified for the avian repellency of cinnamamide, a derivative of the plant secondary compound cinnamic acid, using a three‐day, ‘short‐term no‐choice’ test. This test was designed to resemble more closely the availability of alternative food in the birds' natural environment than in previous no‐choice studies. Cinnamamide reduced food consumption by feral pigeons (Columba livia Gmelin) at concentrations as low as 6.17 μmole g−1 food (0.09% w/w) and this reduction increased with concentration. An R50 index, the concentration at which food consumption was reduced by 50% was interpolated from the dose‐response curve as 18.4 (±0.38) μmole g−1 food 10.26% w/w). This index can now be matched with those of related compounds in future structure‐activity studies. The birds' response to cinnamamide changed over the three‐day trial with respect to concentration. Repellency declined at concentrations < R50 and increased at concentrations > R50. This suggests that pigeons become habituated to cinnamamide at low concentrations but at high concentrations they may develop a conditioned aversion. This study provides quantitative confirmation of previous laboratory and field demonstrations of cinnamamide's effectiveness as a non‐lethal chemical repellent suitable for reducing avian pest damage.
A mechanistic approach towards surfactant/wax interactions: Effects of octaethyleneglycolmonododecylether on sorption and diffusion of organic chemicals in reconstituted cuticular wax of barley leaves
Authors: Schreiber Lukas
Published: November 2006

Mechanisms of surfactant/wax interactions which contribute significantly to the acceleration of rates of cuticular uptake of agrochemicals have been investigated. Experiments were carried out using isolated and subsequently reconstituted barley wax. As 14C‐labelled model compounds, the monodisperse alcohol ethoxylate octaethyleneglycolmonododecylether (C12E8), the aromatic compound, pentachlorophenol (PCP), and the aliphatic tetracosanoic acid (C24AC; representing a typical wax constituent) were used. Each of the three compounds represented one part of the complete interacting system: surfactant, pesticide and wax. Partitioning of PCP was independent of simultaneously present C12E8 below its critical micelle concentration (CMC), but decreased linearly above the CMC. The maximum increase in the mobility of PCP was by a factor of about four by C12E8, whereas the maximum increase of the mobility of C24AC was about forty‐fold. Effects on the mobility of PCP and C24AC were independent of C12E8 concentrations above the CMC, but they decreased significantly with decreasing C12E8 concentrations below the CMC. A common model usually applied in life sciences for the analysis for dose‐response curves, relating the observed effects to the logarithms of the applied concentrations, was successfully fitted to the results obtained here. This indicated that the observed effects were a function of the relative, rather than absolute, concentrations of the surfactant within the wax. Furthermore, it was discovered that surfactant‐induced acceleration of the diffusion of PCP and C24AC was completely reversible if C12E8 was removed from the system. Thus, accelerating effects on diffusion only occurred if distinct amounts of surfactant were present within the wax. This, finally, led to a tentative model, explaining the effect of C12E8 on wax structure as an unspecific plasticising interaction between surfactant and wax. Rapid induction and complete reversibility of the effects indicated that the assumption of irreversible alterations of the wax structure (e.g. solubilisation of wax or destruction of crystalline wax domains) was not necessary in order to explain the surfactant‐induced acceleration of rates of cuticular permeation of pesticides, when studying absorption/desorption from non‐evaporating aqueous solutions. However, such changes may still occur when evaporation of the water in spray deposits concentrates surfactants sufficiently for them to become wax solvents.
Detection, characterization and phytotoxic activity of AB021‐a and ‐b, two new macrolide polyene antibiotics
Authors: Scacchi Alessandro , Andriollo Nunzio , Cassani Giorgio
Published: November 2006

Screening for fungicidal activity carried out on culture broths of soil Streptomyces strains resulted in the isolation of two new macrolide polyene antibiotics. AB021‐a and AB021‐b, endowed with good protective activity against some plant diseases. These compounds had no effect on seed germination or seedling development, while they strongly inhibited the growth of rice, carrot and periwinkle cells in liquid suspension culture. This inhibition may be ascribed to the lack of the cuticular barrier in these materials. Within a short period of incubation, some parameters connected with membrane permeability of rice, carrot and periwinkle cells were affected. An increase of oxygen consumption also occurred. Incubation of beetroot discs with AB021 led to increased conductivity of the external medium. In addition, a leakage of betacyanin occurred, suggesting a modification of transport processes, also at the tonoplast.
Phloem translocation of pyridinecarboxylic acids and related imidazolinone herbicides in Ricinus communis
Authors: Chamberlain Keith , Tench Allen J. , Williams Roger H. , Bromilow Richard H.
Published: November 2006

The movement of [14C]pyridinecarboxylic acids was investigated in the castor bean plant Ricinus communis L. after application by petiole injection. The three isomeric unsubstituted acids appeared in similar concentrations in phloem sap taken from the upper main stem over a period of 6 h after application, but nicotinic acid occurred at higher concentrations than its isomers in phloem sap from the lower stem indicating better retention in the phloem sieve tubes. After 24 h, nicotinic acid had accumulated to a greater extent in the phloem sinks than had picolinic or isonicotinic acids. Phloem transport of substituted analogues, including dihalopyridinecarboxylic acids and imidazolinone herbicides, was measured in short‐term tests, and attempts made to relate such transport to the lipophilicity and pK,a of the compounds. Analogues of the imidazolinone, imazapyr, were less well transported than imazapyr itself, and were also much less well taken up by barley roots from nutrient solution compared to the herbicidal imidazolinone, and this could explain their low herbicidal efficacy despite a high intrinsic activity against the target enzyme acctolactate synthase.
Starch urea formaldehyde matrix encapsulation of solid agrochemicals: III. Studies and bioefficacy trials on double encapsulation
Authors: Rajagopalan Natarajan , Bhaskar Comandur , Bankar Vikas S. , Pokharkar Varsha B. , Shukla Parshuram G. , Regupathy Ayyappan , Khilar Kartic C.
Published: November 2006

A technique for the double encapsulation of carbofuran in starch urea formaldehyde (Starch‐UF) matrix has been developed. The solid particles of carbofuran were first microencapsulated with UF resin and these microcapsules were then dispersed in the Starch‐UF matrix to obtain a granular formulation. The rate of release of carbofuran from these granules was found to be governed by its diffusion through the solid UF resin shell and was significantly slower than from the single encapsulated granular formulation prepared by dispersing uncoated carbofuran in Starch‐UF matrix. The bioefficacy of these double encapsulated granules (Encecap‐D 3G), was evaluated for persistence against rice pests in paddy and against subterranean pests in potato, in comparison with conventional formulations of carbofuran, phorate, quinalphos, aldicarb and cadusafos. The persistence of Encecap‐D 3G was found to be better than that of the standard formulation in the cultivation of paddy under flooded conditions and in the cultivation of potato. The order of efficacy was found to be: White grubs—Encecap‐D 3G > quinalphos > cadusafos > aldicarb > phorate > Furadan 3G; Nematodes—cadusafos > Encecap‐D 3G > quinalphos > aldicarb > phorate > ‚Furadan’︁ 3G.
QSAR study of 4‐hydroxypyridine derivatives as inhibitors of the HILL reaction
Authors: Šoškić Milan , Sabljić Aleksandar
Published: November 2006

QSAR analysis has been performed for two sets of 4‐hydroxypyridine derivatives, i.e. phenol type inhibitors of photosystem II, to find accurate quantitative models for their inhibitory potency in the Hill reaction. Separate QSAR models based either on the structural descriptors (molecular connectivity indices and other topological features) or on the physicochemical constants (π, Vw, σ) have been developed for the two sets of 4‐hydroxypyridine derivatives. It was found that the size and lipophilicity of substituents at positions 2 and 5 are the most important for the activity of derivatives with a long side chain. The electron‐attracting capacity of these substituents might be an additional factor which increases the activity of 4‐hydroxypyridines in the Hill reaction. However, the inhibitory potency of tetrahalogenated 4‐hydroxpyridines depends on the type of halogen atom on the pyridine ring. The iodine substituent meets the receptor requirements best. The study suggests that the two groups of 4‐hydroxypyridines analyzed have overlapping binding sites on the receptor protein.
Effect of adjuvants on the performance of the new cereal fungicide, metconazole. II Field trials
Authors: Sampson Alan J. , Burnhams Adam F. , Grayson B. Terence
Published: November 2006

Glasshouse trials had shown that the activity of metconazole formulations against cereal foliar diseases could be enhanced by alcohol ethoxylate adjuvants. A series of soluble liquid (SL) formulations of metconazole had been prepared containing adjuvant: metconazole ratios of 5:1, 7.5:1, 10:1, 15:1 m/m (SL1, SL2, SL3, SL4) which glasshouse trials had shown could give equivalent performance to an emulsifiable concentrate formulation, (ECM) of metconazole at application rates up to three‐ or four‐fold lower than that of ECM alone.

A field trials programme was undertaken to compare the performances of these SL formulations with ECM at 120 g AI ha−1, through a range of application rates (48, 60, 72, 84 g AI ha−1), in a non‐orthogonal factorial trial design against diseases that occurred naturally (Septoria tritici Rob., Puccinia recondita Rob., Pyrenophora teres Drechs., Erysiphe graminis DC) or by artificial inoculation (Leptosphaeria nodorum Muell.), on either Triticum aestivum L. or Hordeum vulgare L.

The results from trials in three locations showed that the commercially acceptable performance of ECM at 120 g AI ha−1, in giving high levels of control of P. recondita, S. tritici and L. nodorum (both prophylactic and therapeutic activity) on T. aestivum. and of E. graminis and P. teres on H. vulgare, could be matched or improved by SL2, SL3 and SL4 at 72 g AI ha−1. Furthermore, control of E. graminis f. sp. tritici Marchal by these SL formulations at this application rate was better than that by ECM at 120 g AI ha−1, though the levels of control still remained below commercial acceptability for therapeutic activity. Nevertheless, substantial reductions in the application rate of metconazole have been achieved by using one‐pack adjuvant‐containing formulations in field trials, while still maintaining excellent control of a range of cereal foliar diseases. The choice between these SL formulations could therefore be made on other grounds such as cost/performance and ease of formulation.
Relating biological activity to chemical structure using neural networks
Authors: Manallack David T. , Livingstone David J.
Published: November 2006

In the last few years, neural networks have found increasing use in chemical applications, including their use in the analysis of quantitative structure‐activity relationships (QSAR) data. Networks are able to perform the equivalent of discriminant and regression analyses, in addition to providing a novel method for the low‐dimensional display of multivariate data. Experiments in our laboratories, using artificially structured data sets and real literature QSAR data with neural networks performing multiple linear regression, demonstrated their susceptibility to over‐fitting, resulting in poor predicted abilities. Other network algorithms and training regimes are emerging in the literature which address these particular problems.
The genetic algorithm in science
Authors: Cartwright Hugh M.
Published: November 2006

Algorithms developed for use in the study of artificial intelligence also show promise in such quite different fields as the physical and life sciences. These methods may have advantages in speed, scope, or both, over more conventional scientific methods, and expand the range of algorithmic techniques open to the scientist. The mechanism of one of these methods, the genetic algorithm, which is already finding application in a number of areas in science, is outlined.
Inhibition of thiazopyr metabolism in plant seedlings by inhibitors of monooxygenases
Authors: Feng Paul C. C. , Rao S. Raja , Schafer David E.
Published: November 2006

Metabolism of the herbicide thiazopyr [methyl 2‐(difluoromethyl)‐5‐(4, 5‐dihydroO‐lhiazo!vt)‐4‐(2‐methylpropy!)‐6‐(trinuorornethyl)‐3‐pyridinecarboxy‐late] was examined in young seedlings of redroot pigweed, grain sorghum, sunflower, corn and soybean. As previously observed with rat liver microsomes plants predominantly metabolized thiazopyr via oxidation reactions.

Sulfur and carbon atoms in the thiazoline ring were the primary sites of plant oxygenases. De‐esterification was also identified as an important pathway of transformations in plants. Although similar pathways of thiazopyr metabolism were observed among plants, our data indicated species differences in rates of thiazopyr degradation. Among species examined, pigweed (Amaranthus retroflexus L.) showed the fastest metabolism. Thiazopyr metabolism in pigweed was significantly inhibited by several cytochrome P450 monooxygenase inhibitors, among which tetcyclacis (TET) and piperonyl butoxide (PBO) were the most inhibitory. Thiazopyr metabolism in pigweed was not inhibited by organophosphates, known inhibitors of esterases. The results suggest that thiazopyr metabolism in plants is predominantly mediated via plant mono‐oxygenases.
Effect of UV irradiation on the degradation of methyl bromide in air. Role of moisture and oxygen concentration
Authors: Gennari Mara , Cignetti Alessandro , Gentile Irene Abbattista , Vindrola Daniela
Published: November 2006

This paper reports the effect of irradiation at wavelengths from 250 to 785 nm on methyl bromide disappearance from air with two different moisture contents (15 mg litre−1 and < 5 mg lire−1) and from a mixture of nitrogen, oxygen and water. In all cases, first‐order disappearance kinetics were observed. The half‐life varied from 22 min with irradiation at 250–420 nm to 326 h with irradiation at 366–750 nm. Increase in the half‐life was observed with reduction of the air moisture content. Negligible differences in the half‐life were found between air and the nitrogen mixture.
Studies on the insecticidal activities of some new N‐benzoyl‐N′‐arylureas
Authors: Carmellino Maria L. , Pagani Giuseppe , Pregnolato Massimo , Terreni Marco , Caprioli Vincenzo , Zani Franca
Published: November 2006

This paper reports the synthesis and the insecticidal activities of some N‐benzoyl‐N'‐arylureas 4‐arylsubstituted with alkylated or halogenated aroyl moieties. The compounds, tested against some representative insect species, displayed very high activity against Aedes aegypti, especially the halosubstituted derivatives. None of the newly synthesized compounds showed genotoxic activity in the Bacillus subtilis rec‐assay and in the Salmonella‐microsome test.
The mode of action of glufosinate in algae: The role of uptake and nitrogen assimilation pathways
Authors: Altenburger Rolf , Callies Rainer , Grimme L. Horst , Leibfritz Dieter , Mayer Adalbert
Published: November 2006

The purpose of this work was to investigate the in‐vivo mode of action of glufosinate in comparison with that of the known glutamine synthetase inhibitor, methionine sulfoxmine, in photoautotrophic microorganisms. Using the eukaryotic green alga Chlorella fusca (Shih. & Krauss) and the cyanobacterium Anacystis nidulans (Kratz & Myers), currently developed [15N]NMR pulselabelling techniques have been employed to study the inhibition of ammonia assimilation. The results show that, while methionine sulfoximine immediately blocks glutamine synthesis, glufosinate action requires an induction process in both organisms investigated, possibly indicating the de‐novo synthesis of an amino acid membrane carrier. In addition, the observed ability of C. fusca to incorporate nitrogen into glutamate under glutamine synthetase‐inhibiting conditions is explicable by an anabolic function of a glutamate dehydrogenase in this organism. This might explain the large differences in observed species sensitivity to glufosinate exposure.
The Stereochemistry of Sweetness
Authors: Birch G. G. , Lee C. K. , Lindley M. G.
Published: November 2006

Conformational analogies between sugars, deoxy sugars, substituted sugars, glycosides and cyclitols are examined in relation to current hydrogen bond theories of sweetness. Although the sensory properties of saporous molecules are probably multifunctional in origin, hydrophilic and lipophilic substituents vary in their effects. The former depend on configuration, whereas the latter may either enhance sweetness by strengthening binding to the taste bud protein, or cause re‐alignment of the molecule, eliciting a bitter response.
Study of the Effect of pH During Dialdehyde Starch (DAS) Adsorption on Cellulose
Authors: Bencheva S. , Nedelcheva M. , Valchev V.
Published: November 2006

The adsorption of dialdehyde starch (DAS) by its water solutions of different concentrations on sulphate and sulphite bleached cellulose is studied in the presence of aluminium sulphate depending on pH of the media. It was found that for both cellulose types the character of the change of the DAS adsorbed quantity depending on pH is similar and it is defined by the concentration of the solution. It was found that at the low DAS concentrations the interaction of the cellulose with aluminium sulphate appears as defining, and at the higher ones the interaction between DAS and aluminium sulphate. In the presence of aluminium sulphate the quantity of the adsorbed DAS increases slowly (sulphate bleached pulp) or has almost the same values, as in the case of adsorption when the aluminium sulphate is lacking (sulphite bleached pulp).
Crystallinity of Acid Treated Corn Starch
Authors: Komiya T. , Yamada T. , Nara S.
Published: November 2006

The hydrolysis of corn starch by 1N H2SO4‐30% ethanol aqueous solution at 45°C increased linearly with increasing of hydrolysis time for 20 d. The relative crystallinity of native corn starch showed 0.350 by X‐ray diffraction and it increased gradually with increasing of hydrolysis time up to 8 d. The increasing ratio of 1/hydrolysis residue to hydrolysis time increased more largely than that of relative crystallinity after 14 d. On the other hand, the relative crystallinity of native corn starch by deuteration showed 0.341 very near to the value by X‐ray diffraction. Moreover, this increasing ratio of the crystallinity accompanied by acid hydrolysis showed an inclination similar to that given by X‐ray diffraction. These facts suggest that the exchanging of OH for OD groups may be caused very a little in crystalline region of corn starch granules.
Application of Starch Hydrolyzate to the Production of Glucose Oxidase by Aspergillus niger G‐IV‐10
Authors: Rogalski J. , Dawidowicz A. L. , Jamroz J.
Published: November 2006

The study of starch hydrolysis conditions by immobilized α‐amylase and glucoamylase were carried out. The starch hydrolyzate was applied as a glucose source in the cultivation of Aspergillus niger. Fungus cells were immobilized on the sintered glass support. Such a biocatalizer was used for production of glucose oxidase under the stationary and repeated batch conditions. The results obtained in the cultivation with the immobilized cells were compared with those in the cultivation of the native cells.
Production of Single Cell Protein from Cassava Starch in Air‐lift Fermenter byCephalosporium eichhorniae
Authors: Varavinit S. , Srithongkum P. , De‐Eknamkul C. , Assavanig A. , Charoensiri K.
Published: November 2006

Batch and continuous cultivations were used to investigate the single cell protein (SCP) production byCephalosporium eichhorniae152 in an air‐lift reactor. The fungus was grown in an 8L air‐lift fermenter. The culture medium consisted of cassava as a sole‐carbon source, (NH4)2SO4as a nitrogen source and KH2PO4as a buffering agent. The pH of the medium was adjusted to 3.8 and was controlled during fermentation by using an automatic pH‐controller via 0.5 N NaOH. In batch fermentation, 1% of cassava gave the highest yield of 0.4. The optimum condition for continuous fermentation was 1% cassava in feed medium at a dilution rate of 0.4 h‐1(396 ml/h where 0.35 was the final yield. The productivity of continuous culture was found to be higher than that of the batch culture (0.135 g/l.h versus 0.04 g/lh).
Liver Tissue Dissection: Ultrasonic or RFA Energy?
Authors: Felekouras Evangelos , Prassas Evangelos , Kontos Michael , Papaconstantinou Ioannis , Pikoulis Emmanouil , Giannopoulos Athanasios , Tsigris Christos , Tzivras Michael , Bakogiannis Chris , Safioleas Michael , Papalambros Efstathios , Bastounis Elias
Published: November 2006

Background

Hepatic resection is the only potential curative treatment for a wide variety of conditions. However, liver surgery is technically demanding and closely associated with a number of serious complications. New devices and techniques are currently being applied in practice, which will improve the surgical outcome.

Methods

This retrospective study compares two methods of liver parenchymal division: ultrasound energy, a modern but already widely used technique, and radio‐frequency ablation (RFA), a completely novel method. The parameters investigated include the amount of blood transfused, the necessity of the Pringle maneuver, the length of time required for parenchymal division, and postoperative morbidity and mortality. The patients were divided into two groups. In one group (Group A), 15 patients underwent 17 ultrasound‐assisted liver resections, in which ten metastatic tumors, six hepatomas, and one cholangiocarcinoma were resected. In Group B, 21 patients underwent 22 RFA‐assisted hepatectomies in which 11 metastatic tumors, ten hepatomas, and two cholangiocarcinomas were removed.

Results

Thirteen patients (87%) in Group A and 11 (52%) in Group B received a transfusion, with an average of 3.5 and 1.6 units of red blood cells, respectively. The Pringle maneuver was necessary in two cases in Group A but was unnecessary in Group B. The mean length of time required for parenchymal dissection was 124 min in Group A and 93.18 min in Group B. One (6.7%) and four (19%) complications were observed in Group A and B, respectively (statistically not significant). Mortality remained zero in both groups.

Conclusions

RFA energy provides a novel reliable and safe alternative that can be used exclusively or as a supplement to the older techniques. Both resection time and amount of blood transfusion were reduced in the RFA group.
What are the illness perceptions of people with dysphonia: a pilot study
Authors: Buck F , Drinnan M , Wilson J , Barnard I S
Published: November 2006

Background: Patients do not respond to treatment in a predictable manner. Individual preconceptions determine help seeking, compliance and treatment outcome, yet clinicians rarely explore these issues. The illness perception approach sees the patient as an active participant in the healthcare process.

Aims: The aim of this study was to investigate the illness perceptions of people with dysphonia. The subsidiary aims were to correlate the Illness Perception Questionnaire with any psychological distress identified and a self-report measure of dysphonia, and to consider any potential implications for patient management.

Design: Prospective, cross-sectional observation.

Setting: Primary and secondary care, two general and four community hospitals.

Participants: Fifty adult patients with dysphonia due to benign disease completed three self-administered questionnaires, which investigated their illness perceptions, psychological distress and perceptions of the impact of the presenting ‘illness’.

Measures: The dysphonia was categorised as being due to functional (n=40) or organic (n=10) causes. All the voices were rated by an expert listener according to the GRBAS (grade, roughness, breathiness, aesthenia, strain) scale. Participants completed the Illness Perception Questionnaire, the Vocal Performance Questionnaire and the Hospital Anxiety and Depression scale.

Results: Patients showed a wide variation in perception of causation. They had no strong perceptions about the causes, consequences or duration of the presenting dysphonia. Functional dysphonics reported greater consequences, lower perceived control and increased anxiety when compared to patients with organic dysphonia. In terms of cure/control, all patients expected treatment to be helpful but this expectancy reduced as time increased. Anxiety was more associated with functional dysphonia, however, only 17 per cent of the subjects in this group showed clinically significant levels of signs of psychological distress.

Conclusions: Lay illness representations often diverge from the clinician's understanding of the presenting problem and strongly influence treatment behaviour. Early exploration of illness perceptions may enhance health behaviour and maximise the impact of intervention.
Correlates of length of stay, cost of care, and mortality among patients hospitalized for necrotizing fasciitis
Authors: MULLA Z. D. , GIBBS S. G. , ARONOFF D. M.
Published: November 2006

Several previous studies of necrotizing fasciitis (NF) have been single-institution investigations suffering from small samples sizes. This study of 216 NF patients hospitalized in Florida, USA, during 2001 was designed to identify risk factors for length of stay (LOS), total patient charges (TC), and mortality, using a statewide database. Robust gamma mixed regression was used to determine the predictors of LOS and TC while simultaneously accounting for outliers and the clustering of patients in 87 hospitals. Relative risks (RR) for hospital mortality were calculated using binomial regression. The NF hospitalization rate in Florida was 1·3/100 000. The median TC was US$54 533 and cumulative charges for all 216 patients were nearly US$20 million. Patients aged ⩾44 years at the time of admission were five times as likely to expire in the hospital than patients who were aged ⩽43 years (adjusted RR 5·08,P=0·03). Unexpectedly, diabetes was associated with a 61% reduction in the risk of hospital mortality (adjusted RR 0·39,P=0·04). Age ⩾44 years was the most powerful predictor of prolonged LOS, elevated TC, and an increased risk of hospital mortality in patients suffering from NF.
Atomic Scale Analysis of Planar Defects in Polycrystalline
Diamond
Authors: Erni Rolf , Freitag Bert , Hartel Peter , Müller Heiko , Tiemeijer Peter , van der Stam Michiel , Stekelenburg Mike , Hubert Dominique , Specht Petra , Garibay-Febles Vincente
Published: November 2006

Planar defects in a polycrystalline diamond film were studied by
high-resolution transmission electron microscopy (HRTEM) and
high-resolution scanning transmission electron microscopy (STEM). In both
modes, sub-Ångström resolution was achieved by making use of
two aberration-corrected systems; a TEM and a STEM
CS-corrected microscope, each operated at 300 kV. For
the first time, diamond in 〈110〉 zone-axis orientation was
imaged in STEM mode at a resolution that allows for resolving the atomic
dumbbells of carbon at a projected interatomic distance of 89 pm. Twin
boundaries that show approximately the Σ3 CSL structure reveal at
sub-Ångström resolution imperfections; that is, local
distortions, which break the symmetry of the ideal Σ3 type twin
boundary, are likely present. In addition to these imperfect twin
boundaries, voids on the atomic level were observed. It is proposed that
both local distortions and small voids enhance the mechanical toughness of
the film by locally increasing the critical stress intensity factor.
Local Measurement and Computational Refinement of Aberrations for
HRTEM
Authors: Kirkland Angus I. , Meyer Rüdiger R. , Chang Lan-Yun Shery
Published: November 2006

Methods for accurate and automated determination of the coefficients
of the wave aberration function are compared with particular emphasis on
measurements of higher order coefficients in corrected instruments.
Experimental applications of aberration measurement to the determination
of illumination isoplanicity and high precision local refinement of
restored exit waves are also described.
EDITORIAL
Authors: CARLOS DE BRITO MANUEL
Published: November 2006

The only acceptable ringtone on my new mobile phone is the overture to the Magic Flute, unfortunately in MIDI file. I guess this is Samsung’s modest tribute to the Mozart year, but as the mobile phone does not identify the tune, its significance will probably pass most people by. One Sunday some time ago a colleague of mine was cruising on his yacht Papageno on the river Tagus facing Lisbon; as he passed a schooner he heard someone whistle ‘Der Vogelfänger bin ich ja . . .’. He whistled back, and the man waved to him. The schooner, not surprisingly, had a German flag. On the other hand, in a remote corner of northern Portugal the petrol station shop is selling the Philips complete edition of Mozart’s recorded works (though I did not have the courage to ask the attendant how many collections, or even individual discs, he had sold).
JEAN PAUL’S LISTENERS
Authors: Bacht Nikolaus
Published: November 2006

This article moves the search for the ‘ period listener ’ into new terrain, bringing literary sources into play. The argument unfolds as a case study of the writings of Jean Paul, arguably the most radical, and most radically critical, among the early romantics. The purpose of the exercise is to demonstrate that literary sources, carefully decoded through philosophical analysis, can enhance and sharpen the knowledge provided by the kinds of sources upon which music historians traditionally rely.