bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of hexachlorocyclohexane isomers and carbofuran applied to surface and sub‐surface layers of a flooded soil
Authors: Panda Soudamini , Sharmila M. , Ramanand K. , Panda D. , Sethunathan N. 
Published: November 2006

AbstractThe persistence of carbofuran (2, 3‐dihydro‐2, 2‐dimethylbenzofuran‐7‐yl methylcarbamate) and the β‐ and γ‐isomers of HCH (hexachlorocyclohexane) applied to surface (oxidised) and sub‐surface (reduced) layers of a flooded soil was studied using radiolabelled insecticides. In one experiment, these compounds were placed in the surface (2–5 mm) and sub‐surface (10–15 cm) layers of 10‐day flooded soil columns. HCH isomers were unstable under flooded soil conditions irrespective of their placement, but disappeared slightly faster when applied to the sub‐surface layer, possibly due to the more reduced conditions prevailing. In contrast, sub‐surface‐applied carbofuran was more stable than surface‐applied carbofuran. The decreased stability of surface‐applied carbofuran may be due to a relatively higher pH in the surface layer and in the flood water which was in immediate contact with the surface layer. In another experiment, surface and sub‐surface soil samples were collected from a rice field which had been flooded for 30 days. These soils were then again flooded under laboratory conditions prior to addition of carbofuran and β‐HCH. Upon submergence, both surface and sub‐surface soil samples attained almost equally reduced conditions. In flooded surface soil samples, more rapid degradation not only of carbofuran but also of β‐HCH occurred, compared with similarly incubated sub‐surface soil samples.
The susceptibility of the Indian field mouse, Mus booduga gray, to anticoagulant rodenticidal baits
Authors: Balasubramanyam M. , Purushotham K. R. 
Published: November 2006

AbstractThe baseline susceptibility of the Indian field mouse, Mus booduga was established for warfarin, bromadiolone and brodifacoum by means of nochoice feeding tests. The mice were found to be more susceptible to the second generation anticoagulants bromadiolone (0.005 g kg−1) and brodifacoum (0.002 g kg−1) than warfarin (0‐25 g kg−1). They required 8–10 days feeding on warfarin (0.25 g kg−1) diet for complete mortality. A feeding period of 8 days corresponding to 99% mortality was suggested as a checking test for registering future warfarin resistance in suspect samples of M. booduga.
Virus recognition and pathogenicity: Implications for resistance mechanisms and breeding
Authors: Fraser Ronald S. S. 
Published: November 2006

AbstractThe major method of control of virus diseases in crop plants is breeding for resistance. The genetics of resistance, and of matching virulence (the ability of a virus strain to overcome a specific host resistance gene) have been studied less for viruses than for fungal and bacterial pathogens. This paper draws on a survey of the genetics of resistance to a large number of viruses in cultivated crops, and makes some generalisations and predictions about mechanisms.Most resistance to viruses in crops is monogenic. Dominant alleles are associated with virus‐localisation mechanisms, which are induced after infection. The nature of the ‘recognition event’ between plant‐ and virus‐coded functions, which triggers resistance plus a cascade of secondary responses, is not yet known. Gene dosage‐dependent alleles tend to be associated with non‐localising resistance, which allows some virus spread, but inhibits multiplication. Recessive alleles may involve a negative type of resistance mechanism, whereby the resistant plant lacks some function normally required by the virus for pathogenesis. Such resistance tends to be expressed as complete immunity.Many resistance genes have been overcome by virulent isolates of viruses; only 10 % of the sample of resistance genes have proved exceptionally durable. Virulence may involve different viral functions. The production of infectious cDNA clones, and construction of chimaeric recombinants between clones of virulent and avirulent isolates, is now allowing detailed mapping of virulence determinants.Transformation of plants with ‘novel’ genes for virus resistance, based on coat proteins and viral satellites, may allow construction of more robust resistance systems.
An electrophysiological investigation of the susceptible (cooper) and resistant (kdr; super‐kdr) strains of the adult housefly, Musca domestica L
Authors: Gibson Amanda J. , Osborne Michael P. , Ross Hamish F. , Sawicki Roman M. 
Published: November 2006

AbstractThe electrical activity of abdominal nerves of the housefly, Musca domestica L., was used as a bioassay to study nerve sensitivity to DDT and deltamethrin in susceptible (Cooper) and resistant (kdr, super‐kdr) strains. By this technique the resistant strains were less sensitive (approximately 10 000‐fold) than Cooper, but the bioassay could not distinguish between super‐kdr and kdr in their responses to either compound and so could not account for the greater resistance shown by flies with super‐kdr above kdr flies when these insecticides are applied topically. Although factors other than nerve insensitivity may be involved, the compounds were applied to the preparation in aqueous saline solutions at, or close to, their solubility limits and this could have masked differences in responses of nerves from the resistant strains.
Degradation of carbetamide and its chief metabolites in alkaline soil
Authors: Cantier Jean Michel , Bastide Jean , Yan Zhixing , Coste Camille 
Published: November 2006

AbstractThe degradation kinetics of carbetamide D‐(−)‐N‐ethyl‐2(phenylcarbamoyloxy) propionamide and its potential metabolites have been measured at different temperatures in both unsterilized and sterilized alkaline soil. A very large difference in both rates and processes of degradation between compounds was found. The kinetic studies were conducted by quantitative and qualitative analysis of the transformed product using [14C]‐labelled compounds. Good radioactivity recovery was obtained and the existence of an important non‐extractable fraction was detected in all cases. This soil‐bound fraction is attributed to either conjugation of aniline with soil organic matter or aromatic ring cleavage to give amino acid precursors.
Degradation of ethylenethiourea on lettuces
Authors: Smith Roger M. , Madahar Kirpal C. , Salt W. G. , Smart Nigel A. 
Published: November 2006

AbstractThe rates of uptake and loss of ethylenethiourea (ETU) in lettuces were studied following the application of ethylenethiourea or selected ethylenebisdithiocarbamate fungicides to the soil or to the leaves of potgrown plants. Analyses were carried out using high performance liquid chromatographic analysis of ETU. The amounts of ETU residues on leaves decreased rapidly and were negligible within a week, unless ethylenebisdithiocarbamate fungicides had been applied to the soil, as the latter were degraded simultaneously to give additional ETU which was then taken up by the plants.
The influence of volume rates on the activity of glyphosate and difenzoquat assessed by a parallel‐line assay technique
Authors: Kudsk Per 
Published: November 2006

AbstractThe influence of volume rate and nozzle size on the activity of difenzoquat and glyphosate against outdoor, pot‐grown wild oats and barley plants, respectively, was assessed using a parallel‐line assay technique. The results showed that the assumption of parallel dose‐response curves for difenzoquat and glyphosate was not rejected in either experiment. An inverse relationship between herbicidal activity and volume rate was found with both herbicides, but volume rate had a more pronounced impact on glyphosate activity than on difenzoquat activity. For a given spray volume, no impact of nozzle size on the activity of glyphosate was found. The advantages of applying the parallelline assay in studies of the influence on herbicide activity of factors not supposed to affect the mode of action of the herbicide are discussed.
Inhibition of insect cytochrome P‐450 by some metyrapone analogues and compounds containing a cyclopropylamine moiety and their evaluation as inhibitors of juvenile hormone biosynthesis
Authors: bélai Iván , Matolcsy GyöRgy , Farnsworth Dan E. , Feyereisen René 
Published: November 2006

AbstractTwo metyrapone analogues, 2‐(l‐imidazolyl)‐2‐methyl‐l‐phenyl‐l‐pro‐panone (A‐phenyl‐B‐imidazolyl‐metyrapone; III) and 2‐methyl‐l‐phenyl‐2‐{1,2,4‐triazol‐l‐yl)‐l ‐propanone (A‐phenyl‐B‐triazolyl‐meiyrapone; IV) as well as two cyclopropylamine derivatives. N‐cyclopropyl‐4‐icrt‐butylbenzylamine (V) and N‐cyclopropyl‐4‐(3,7‐dimethyl‐7‐methoxy‐octyloxy)benzamide (cyclopropylamine acylated with a JH analogue acid of known structure; VI) were synthesized and evaluated in biological assays for JH biosynthesis on cockroach, Diploptera punctata corpora allata and egg growth in adult cockroach as well as for mixed function oxidase activities, i.e. epoxidation of aldrin to dieldrin and O‐demethylation of 7‐methoxy‐4‐methylcoumarin to 7‐hydroxy‐4‐methylcoumarin on microsomes from housefly, Musca domestica, abdomen and from cockroach midgut.Compound VI was a good in‐vitro inhibitor of JH biosynthesis, but it had significantly lower activities in the assays for inhibition of microsomal cytochrome P‐450. Compound IV and metyrapone had moderate activity as inhibitors of oocyte growth. Compounds III, IV and V were more potent inhibitors of housefly aldrin epoxidation than metyrapone and they inhibited the enzyme activity by almost 100% at 02mM, while in cockroach midgut microsome assay metyrapone was more potent than these three compounds.
Deltamethrin raises potassium activity in the microenvironment of the central nervous system of the cockroach: An assessment of the potential role of the blood‐brain barrier in insecticide action
Authors: Hendy Christopher H. , Djamgoz Mustafa B. A. 
Published: November 2006

AbstractThe effect of deltamethrin (10μm) on extracellular K+ activity in the micro‐environment of the central nervous system of the cockroach has been studied. At normal room temperature, deltamethrin induced a rise in the K+ concentration of about 3 mM, representing some 75% increase from normal Deltamethrin also caused a transient surge in the frequency of spontaneous activity, which preceded the K+ effect. At a lowered temperature, the final value of the deltamthrin‐induced rise in extracellular K+ concentration was very similar to normal. However, when the structural component of the blood‐brain barrier was disrupted, the effect of deltamethrin was much reduced. Possible consequences of the deltamethrin‐induced rise in extracellular K+ concentration and the potential role of the blood‐brain barrier in insecticide action are discussed.
Quantitative autoradiography of GABA receptors in locust (Schistocerca americana) brain
Authors: Schouest Leo P. , Miller Thomas A. , Olsen Richard W. 
Published: November 2006

AbstractConventional film autoradiography was used at the light microscopic level for the localization and quantization of 4‐aminobutyric acid (GABA) receptors in the locust brain (Schistocerca americana). Localization of the receptor site was achieved via binding with the receptor‐ligand probe [3 H]muscimol. Frozen sections were cut and subsequently incubated either in 40 nM [3H]muscimol or by coincubating sections with [3H]muscimol and one of the following: GABA (50 μM)], a receptor specific agonist [muscimol (1 μM) or isoguvacine (1 μM)], an uptake inhibitor [nipecotic acid (50 μM)], or a noncompetitive channel modulator [avermectin B1a, (1 μM) or aldrin (50 μM)]. Through computer image enhancement and densitometric analysis of the optical density of [3H]muscimol binding sites, the interaction of the above compounds with the putative GABA receptor was determined for various anatomical regions of the locust brain. By comparing the differently treated, but adjacent sections, GABA receptor distribution was quantitated and mapped. Receptor sites were found distributed in the antennal lobes, central body, β‐lobe and β‐lobe of the corpus pedunculatum, protocerebral bridge, and calyx as well as the optic lobe regions.
Pharmacological differentiation of responses to dopamine, octopamine and noradrenaline recorded from a cockroach motoneurone
Authors: Pitman Robert M. , Davis Julian P. L. 
Published: November 2006

AbstractRecordings have been made from the soma of a cockroach common inhibitory motoneurone. Locally applied dopamine, octopamine or noradrenaline all depolarised the neurone and produced a modest increase in membrane conductance. Under voltage‐clamp, currents evoked by these amines showed considerable voltage dependence. The current‐voltage relationships for dopamine and octopamine responses were similar, but differed from that for noradrenaline. The unusual voltage‐dependent characteristics of these responses suggest that these compounds may serve a modulatory function in the insect CNS.The effects of a range of pharmacological antagonists indicate that dopamine acts upon a class of receptors distinct from those mediating responses to octopamine, noradrenaline and acetylcholine (ACh). Dopamine currents were abolished by SCH 23390 or cis‐(Z)‐flupenthixol, which did not depress responses to the other agonists. Octopamine and noradrenaline currents were selectively blocked by metoclopramide and ergometrine respectively, while β‐bungarotoxin and gallamine preferentially suppressed ACh responses.At the present time the ionic basis of dopamine responses is unclear. Dopamine‐evoked currents were totally abolished by application of Cd22+ or verapamil or when the preparation was bathed in Ca2+ free external solutions. Changes in the external concentrations of Na+, K+ or Cl−, however, also had some effect upon dopamine currents.
Impact of two synthetic pyrethroids and methomyl on management of the cabbage aphid, brevicoryne brassicae (L.) and its associated parasitoid, diaeretiella rapae (M'Intosh)
Authors: Abo El‐Ghar Gamal E. S. , M. El ‐Sayed Abd El‐Ghany 
Published: November 2006

AbstractThe effectiveness of two synthetic pyrethroids, cypermethrin and fenvalerate, and of methomyl applied to cabbage plants was tested against the cabbage aphid, Brevicoryne brassicae (L.), and its parasitoid, Diaeretiella rapae (M'Intosh). Dosage rates chosen were equivalent to the manufacturer's maximum and minimum recommendations. Methomyl was considerably more toxic to B. brassicae adults than the two synthetic pyrethroids used. Fenvalerate, at the lowest rate used (71 g ha−1), showed satisfactory effectiveness in reducing aphid adult population on treated plants by c. 77% below that of the control. All insecticides and rates used significantly reduced the emergence of parasitoid adult D. rapae from mummified aphids compared to the control. Fenvalerate clearly had less impact on emergence than cypermethrin or methomyl at any dosage used, while methomyl has appeared to be the most toxic compound in this respect. Longevity of parasitoid adults was highly affected by insecticide application, particularly those adults emerging from mummified aphids exposed to methomyl or cypermethrin. However, only a slight difference in longevity was seen at the lower rate of 71 g ha−1 of fenvalerate. At the lowest dosage rates used, methomyl and cypermethrin reduced the F1‐progeny of adult parasitoid females by 70.5% and 58.3%, respectively, of the control, whereas fenvalerate reduced the progeny by only 36.4%.
Response of the german cockroach Blattella germanica (L.) to a light source following exposure to surface deposits of insecticides
Authors: Miall Stephanie M. , Le Patourel Geoffrey N. J. 
Published: November 2006

AbstractAdult male German cockroaches were exposed to surface deposits of insecticides for 5 min in the central compartment of a three‐compartment choice chamber illuminated at one end. They were then allowed access to the escape compartments and their distribution recorded over the subsequent 60 min. Cockroaches exposed to pyrethroid insecticides rapidly accumulated in the escape compartment closest to the light source; the same effect was observed to a lesser extent following exposure to propoxur. Boric acid and bendiocarb deposits inhibited the movement of the cockroaches away from the light source, and fenitrothion deposits delayed it. Dieldrin had no effect on the distribution of cockroaches within the choice chamber. The reversal of the normal tendency of German cockroaches to move from a light area to a dark harbourage following exposure to pyrethroids may contribute to the flushing action observed when these chemicals are used for control of B. germanica populations.
Simultaneous determination of benzimidazole fungicides by HPLC on apples, pears and their pulps
Authors: Bicchi Carlo , Belliardo Flavio , Cantamessa Liliana , Gasparini Gianfranco , Icardi Marisa , Sesia Elio 
Published: November 2006

AbstractThe simultaneous HPLC determination of carbendazim, thiabendazole and thiophanate‐methyl in apples, pears and their pulps is described. The method is based on a clean‐up procedure carried out on an Extrelut 20 cartridge followed by HPLC analysis on a Diol column using hexune+isopropanol as mobile phase. Average recoveries of 83.8% for carbendazim, 82.9% for thiabendazole and 68.8% for thiophanate‐methyl on apple matrix were obtained; recoveries on pear matrix were in the same range. Detection limits with UV detection at 285 nm of 100 ng ml−1 for carbendazim, 140 ng ml−1 for thiabendazole and 500 ng ml−1 for thiophanate‐methyl were achieved.
Effects of the experimental fungicide RH 886 on Mucor piriformis
Authors: Spotts Robert A. , Dobson Robin L. 
Published: November 2006

AbstractNo registered fungicide controls Mucor piriformis, a cause of severe postharvest storage rot in pears, but the experimental fungicide RH 886 (active ingredients: 77% 5‐chloro‐2‐methylisothiazol‐3‐(2H)‐one and 23% 2‐methylisothiazol‐3‐(2H)‐one) has an ED50 of 23.1 μg ml−1 in 5 min exposure for germination of sporangiospores of M. piriformis and an ED50 of 9.9 μg ml−1 for mycelial growth. Mixing RH 886 into infested, amended soil at 8 mg g−1 soil or mixing copper sulfate into soil at 1 mg g−1 soil prevented sporulation of M. piriformis. Application of RH 886 to pear fruits prior to inoculation, or immersion of fruits in solutions of RH 886 containing sporangiospores of M. piriformis significantly reduced fruit infection.
Colloidal aspects of pesticidal and pharmaceutical formulations—An overview
Authors: Tadros Th. F. 
Published: November 2006

AbstractIn this overview, the colloidal aspects of pesticidal and pharmaceutical formulations of the dispersion type are described. The nature and magnitude of the interaction forces between particles or droplets in a dispersion are briefly described. These include double‐layer, steric and van der Waals' interactions. Combinations of these interaction energies govern the stability/instability of dispersions. The various states of suspensions and emulsions can be described in terms of energy‐distance curves. Particular attention is given to the various break‐down processes, such as flocculation, coalescence, Ostwald ripening and phase inversion. Some guidelines for the stabilisation of suspensions and emulsions are given. The following practical aspects of dispersion and emulsion formulation are discussed: (a) creaming, sedimentation and their prevention; (b) the assessment of the state and long term physical stability of suspensions, including particle and droplet size analysis and rheology. In the latter case, both steady‐state shear stress–shear rate and low deformation (oscillatory, constant stress and shear wave propagation) are very useful in the control and assessment of the long term physical stability; (c) mixed suspensions and emulsions i.e. suspoemulsions. The possible interactions between suspension particles and emulsion droplets are briefly described; (d) multiple emulsions that can be applied for sustained release; (e) microemulsions, their formation and characterisation illustrating the potential application of these systems in formulations: (f) microencapsulation, describing the most common procedures for preparation of such systems. These include interfacial polymerisation and condensation and coacervation techniques.
Mycoherbicides: Opportunities for genetic manipulation
Authors: Greaves Michael P. , Bailey John A. , Hargreaves John A. 
Published: November 2006

AbstractPossibilities of using genetic manipulation to improve the effectiveness of mycoherbicides are discussed. Particular emphasis is given to fungal genes involved in the production of specialised structures essential for colonisation and reproduction in pathogenesis and in regulating pathogen specificity. Example are given of relevant genetic transformations in fungi which have already been achieved. In the short term, manipulation of genes encoding for specific enzymes or toxins is considered to be the most promising approach for improving mycoherbicide performance.
The biological activity of acifluorfen‐sodium and its relationship to wetting, penetration and wax composition in four species
Authors: Willingham Gary L. , Graham Linda L. , Westmoreland David G. 
Published: November 2006

AbstractThe biological activity of the sodium salt of acifluorfen was determined for velvetleaf (Abutilon theophrasti), cocklebur (Xanthium pensylvanicum), morning‐glory (Ipomoea sp.), and soybean (Glycine max) in greenhouse tests and by a leaf‐disc efflux assay which bypasses cuticular penetration. The greenhouse activity in order of decreasing control was morning‐glory > cocklebur > velvetleaf > soybean. Activity in the efflux assay in order of decreasing control was velvetleaf ≈︁ morning‐glory > cocklebur > soybean. Leaf wetting was determined by contact angle measurements. Cocklebur wets very readily, and this was attributed partly to its more polar wax content. Soybean wets very poorly, primarily due to its large leaf hairs, which accounts for part of acifluorfen selectivity. Surfactants and inorganic salts increased penetration in a species‐specific manner, and as penetration increased, so did activity. Acifluorfen‐sodium is more active on velvetleaf than on cocklebur in a leaf‐disc efflux assay, but in the greenhouse the reverse is true. This may be explained by the fact that penetration is eight times greater in cocklebur than in velvetleaf.The chemical composition of the leaf waxes was determined for each species by gas chromatography–mass spectroscopy (GC/MS). Morning‐glory and velvetleaf waxes consist mainly of long‐chain esters. Soybean wax is primarily a C‐30 alcohol. Cocklebur wax is primarily composed of one material which is not a typical leaf wax. This component could not be conclusively identified, but contains several carbonyls, several vinyl groups, and possibly a hydroxyl group. This wax is more polar than the other leaf waxes and seems to account for the extremely good wetting and high degree of penetration in cocklebur compared to the other species. Wax composition does not relate to penetration or activity in the other three species tested. More complex differences in cuticle structure and biological sensitivity probably account for differences in penetration and activity.