bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicity of the chitin synthesis inhibitors, diflubenzuron and its dichloro‐analogue, to Spodoptera littoralis larvae
Authors: Ascher K. R. Simon , Nemny Nadia E.
Published: November 2006

The activities of the chitin synthesis inhibitors, diflubenzuron and PH 60–38, against Spodoptera littoralis larvae were assayed by feeding treated alfalfa or poisoned wheat bran baits, by allowing the larvae to imbibe sucrose‐containing aqueous dispersions of the compounds, and by injection into larvae. PH 60–38 was less active than diflubenzuron. On alfalfa, diflubenzuron had to be fed for at least 2 days to prevent formation of normal pupae and emergence of adults. For very big (480–540 mg) larvae, feeding diflubenzuron at concentrations of 50 mg/litre for 2 days or 2.5 mg/litre for 3 days prevented adult emergence. For 200–250 mg larvae, this was achieved by feeding concentrations of 100 mg/litre for 2 days, 5 mg/litre for 3 days or 3.5 mg/litre for 4 days. In all larvae > 150 mg, mortality in feeding experiments occurred in the prepupal or the pupal stage. Only with 30–50 mg and 100–150 mg larvae was there considerable mortality during moults between larval instars, the larvae being unable to liberate themselves from the old larval skins and head capsules. Diflubenzuron incorporated into wheat bran baits at concentrations of from 2.5 to 10 000 μg/g killed approximately 70–90% of the insects. When imbibed, diflubenzuron was much less toxic as a wettable powder than as a liquid formulation but the two formulations were equitoxic when injected into the larvae.
Cold storage degradation of the herbicide metribuzin in field soil samples awaiting analysis
Authors: Webster G. R. Barrie , Reimer Gerald J.
Published: November 2006

In conjunction with a study of herbicide degradation in the field, metribuzin (4‐amino‐6‐tert‐butyl‐4,5‐dihydro‐3‐methylthio‐l,2,4‐triazin‐5‐one) was shown to be degraded at‐37±5°C in soil samples awaiting analysis. Products of this degradation process include the known derivatives DADK (6‐tert‐butyl‐2,3,4,5‐tetrahydro‐l,2,4‐triazine‐3,5‐dione) and DK (4‐amino‐6‐tert‐butyl‐2,3,4,5‐tetrahydro‐l,2,4‐triazine‐3,5‐dione) and these products themselves have been shown to be degraded further under the same storage conditions. Loss of the herbicide can be approximated using half order kinetics with respect to metribuzin; however, loss of both previously identified metabolites is most rapid when metabolite concentrations are highest. Assuming half order kinetics, samples of Almasippi very fine sandy loam containing metribuzin (0.5 mg/kg) can be expected to lose 50% of the herbicide in 282 days at ‐ 37°, a period which is short enough to affect residue analysis results significantly should samples be stored for extended lengths of time prior to analysis. Implied in these results is the desirability of immediate analysis following collection of samples; otherwise rates of loss during storage must be determined to allow adjustment of results to compensate for residue losses in samples awaiting analysis.
The potential for pyrethroids as agricultural, veterinary and industrial insecticides
Authors: Breese Michael H.
Published: November 2006

The results of trials with some synthetic pyrethroids, especially cypermethrin and permethrin, against pests of cotton, various fruits, vegetables and brassicas are summarised. These compounds and cypermethrin in particular have given good results at low dosages against many insect species on these crops. Cypermethrin shows promise against ectoparasites attacking sheep and cattle and also is being evaluated for various non‐agricultural outlets.
Conversion rates of aldicarb and its oxidation products in soils. I. Aldicarb sulphone
Authors: Smelt Johan H. , Leistra Minze , Houx Norbert W. H. , Dekker Abraham
Published: November 2006

The rate of loss of aldicarb sulphone was studied in incubation experiments on soils from four plough layers and two deeper layers. In all instances the loss could be described by first‐order kinetics in the first period of two to three times half‐life. However, in a clay loam soil and a greenhouse soil a faster degradation rate was observed after the first 56 and 112 days of incubation respectively. The half‐lives of sulphone in plough layer soils at 15°C ranged from 18 days in a clay loam to 154 days in a peaty sand. Conversion in deeper layers was considerably slower than in the corresponding top layers of the soil profile. In a silty layer at 70 to 90 cm depth the half‐life at 15°C was 46 days, whereas in a sand layer at 90–110 cm no clear loss was found during the 294 days of incubation.
Conversion rates of aldicarb and its oxidation products in soils. II. Aldicarb sulphoxide
Authors: Smelt Johan H. , Leistra Minze , Houx Norbert W. H. , Dekker Abraham
Published: November 2006

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

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

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

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

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

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

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

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

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

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

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

A series of O,O‐diethyl O‐4‐(2,2‐disubstituted‐vinyl)phenyl phosphorothioates and phosphates was synthesised and examined for anticholinesterase activity to housefly and bovine erythrocyte ChE, and also for their toxicity to Musca domestica and Triatoma infestans. The synthesised phosphates were potent anticholinesterases and stronger inhibitors of housefly acetylcholinesterase than bovine erythrocyte acetyl‐cholinesterase. Satisfactory correlation was obtained between the anticholinesterase activity and the Hammett σ− constants against both enzymes, but it was not significantly improved by introducing a term for the Hansch π constant. The phosphorothioates showed poor and variable toxicity to M. domestica. On T. infestans, the only compound that showed some toxicity was the di(acetyl)‐substituted product [O‐4‐(2‐acetyl‐3‐oxobut‐1‐enyl)phenyl O,O‐diethyl phosphorothioate]. For comparative studies, some commercial products were also assayed on T. infestans.
Prospects for increasing photosynthesis by control of photorespiration
Authors: Keys Alfred J.
Published: November 2006

Photorespiration in plants is defined and discussed. The possibility of increasing crop yields by controlling photorespiration, particularly by inhibiting the initial reaction, is considered.
Dye‐sensitised photo‐oxidation of 2‐dimethylamino‐5,6‐ dimethylpyrimidin‐4‐01 in aqueous solution
Authors: Dixon Stephen R. , Wells Clifford H. J.
Published: November 2006

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

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

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

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

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

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

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

The above article (DOI: 10.1002/qre.795) was published online on 23 May 2006 in Wiley InterScience (www.interscience.wiley.com). An error was subsequently identified in the first paragraph. Please find the corrected paragraph below.

The recent paper by Wu et al.1 claims to have studied a new distribution (originally introduced by Chen2) that exhibits a bathtub‐shaped hazard rate function. The cumulative distribution function (CDF) of this new distribution is given as

for $x > 0$, $\lambda > 0$ and $\beta > 0$. It appears to us that the distribution given by (1) or a more general form of it has appeared before in at least three published papers.

The print publication will incorporate the amendments identified by this erratum notice.
The Yoix® scripting language: a different way of writing Java™ applications
Authors: Drechsler R. L. , Mocenigo J. M.
Published: November 2006

Our work led us to write a full‐featured, reliable and extensible scripting language implemented in Java and providing access to many Java capabilities. The result provides a mechanism for fast and efficient development, deployment and maintenance of client/server applications. The Yoix interpreter does not rely on Java reflection classes to access Java capabilities, but rather uses programmatic methods. This approach allowed us to deliver the complex aspects of Java functionality more simply and succinctly at the Yoix level as well as achieve consistent behavior and portability across platforms. We also included many practical functions and capabilities for application development. Indistinguishable from Java applications to end‐users, a Yoix application's interpreted nature allows scripts to be downloaded from a Web server and executed as needed by the application. This framework has been used successfully for mission critical applications within AT&T. The interpreter, its source, documentation, a completely functional application template and a large set of examples are freely available for download under open source licensing from the AT&T Labs—Research Web site at http://www.research.att.com/sw/tools/yoix/ or its alias http://www.yoix.org/. Yoix is a registered trademark of AT&T, Inc. Java is a trademark of Sun Microsystems, Inc. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and Molecular Structure of Tris[(trimethylsilyl)silyl](diisopropylamino)(diphenylphosphino)borane
Authors: Fan Maomin , Paine Robert T. , Duesler E. N. , Nöth Heinrich
Published: November 2006

The 1:1 reaction of [(Me3Si)3SiLi·3THF] with (iPr2N)BCl2 in hexane provides [{(Me3Si)3Si}·(iPr2N)BCl] (2) in good yield as a colorless crystalline solid. This compound combined in a 1:1 ratio with LiPPh2 in DME gives [{(Me3Si)3Si}·(iPr2N)B(PPh2)] (3) as a yellow crystalline solid. The new compounds were characterized by IR, MS and 1H, 13C{1H} and 11B NMR spectroscopy and the molecular structure of 3 was determined by X‐ray structure analysis.
Experimental and Theoretical Vibrational Study of the Oxotetrachlorochromate(V) Anion in [AsPh4][CrOCl4]
Authors: Roldán M. L. , Brandán S. A. , Varetti E. L. , Altabef A. Ben
Published: November 2006

Infrared and Raman spectra were obtained for tetraphenylarsonium oxotetrachlorochromate(V), [AsPh4][CrOCl4]. Equilibrium geometry and vibrational frequencies for the anion, CrOCl4−, were studied employing Density Functional Theory (DFT) methods. A comparative theoretical study was performed in order to determine the best level of theory and basis set to reproduce the experimental structure parameters and vibrational frequencies. Such frequencies served as a basis for the calculation of the scaled quantum mechanical (SQM) force field for the anion. The obtained results were compared with those obtained previously for the VOCl4− anion.
Changes in high density lipoprotein subfraction lipids during neutral lipid transfer in healthy subjects and in patients with insulin‐dependent diabetes mellitus
Authors: Ritter Mary C. , Bagdade John D.
Published: November 2006

While it is known that the transfer of cholesteryl ester (CE) from high density lipoprotein (HDL) to the apo B‐containing lipoproteins is increased in patients with diabetes, the extent to which the various lipoprotein fractions engage in neutral lipid exchange and the magnitude to which triglyceride (TG) is translocated is not known. To examine in greater detail neutral lipid net mass transfer in diabetes, the HDL subfractions and the apo B‐containing lipoproteins were separated, and the net mass transfer of CE and TG was compared to that of control subjects. In both groups, bidirectional transfer of CE from HDL3 to very low density lipoprotein (VLDL) + low density lipoprotein (LDL) and of TG from VLDL+LDL to HDL3, took place, but this process was significantly greater (P<.01) in insulin‐dependent diabetes mellitus (IDDM). In contrast, CE and TG accumulated in HDL2 to a similar degree in normal and IDDM subjects. In recombination experiments with each of the apo B‐containing lipoproteins, IDDM VLDL had a greater capacity to facilitate the exchange of core lipids from both IDDM and control HDL3: on the other hand, LDL from IDDM and control subjects both donated TG and CE to HDL2 and affected little change in HDL3. These findings indicate that all the major plasma fractions normally participate in the trafficking of CE and TG among the lipoproteins during neutral lipid transfer and show that the principal perturbation in cholesteryl ester transfer in IDDM involves altered interaction between VLDL and the HDL3 subfraction.
Separation and quantitation of mono‐, di‐, and triglycerides and free oleic acid using thin‐layer chromatography with flame‐ionization detection
Authors: Peyrou G. , Rakotondrazafy V. , Mouloungui Z. , Gaset A.
Published: November 2006

α‐Monoolein was prepared from glycidol and oleic acid by the regioselective opening of glycidol in the presence of an anionic resin. During the reaction, the lipochemical synthesis medium becomes enriched in monoolein, the effective emulsifying agent. This mixture can be analyzed by thinlayer chromatography coupled with flame‐ionization detection (FID). The products and reagents do not need to be derivatized. Diglyceride and triglyceride by‐products affecting the selectivity of the reaction also could be detected using this technique. Cholesterol was used as an internal standard. The factors influencing the separation, including the hydrogen flow rate, scan speed, and the composition of the developing solvent, were investigated. The degree of separation is highly sensitive to the hexane/diethyl ether ratio of the developing solvent. Good separation of triglyceride, oleic acid, the two diglycerides, cholesterol, α‐monoolein, and glycidol was obtained with the mixture hexane/diethyl ether/formic acid (65:35:0.04, by vol). Detector response, detection limits, and rod‐to‐rod variations also were examined. A range of rod loads giving a straightforward relationship between FID response and amount of compound loaded (relative to oleic acid and α‐monoolein) was defined. The accuracy of the quantification was illustrated by analysis of a mixture of oleic acid and α‐monoolein standards of known composition.
Arachidonic acid supply and metabolism in human infants born at full term
Authors: Koletzko Berthold , Decsi Tamás , Demmelmair Hans
Published: November 2006

Infants need arachidonic acid (AA; C20:4n‐6) for eicosanoid synthesis and deposition in growing tissues, including brain. Human milk supplies performed AA in amounts considered to meet accretion in membrane‐rich tissues, but vegetable oil‐based infant formulas do not contain AA. We studied two groups of ten healthy infants, each fed human milk or formula, and analyzed plasma lipid composition. Percentage contributions of AA to plasma phospholipids were stable over two months after birth in breast‐fed infants, but infants fed formula developed significantly (P<0.05) lower levels at the ages of two weeks (formula 6.9% vs. breast 9.4%, w/w), one month (6.2 vs. 9.1%), and two months (5.7 vs 8.4%). In a second trial, we randomized infants to receive (from birth to age four months) formula without or with both AA and docosahexaenoic acid (DHA; C22:6n‐3) at levels typical for mature human milk. Infants fed conventional formula showed a continuous decrease of phospholipid AA over time, whereas feeding of formula supplemented with AA and DHA led to significantly higher AA levels, similar to those in breast‐fed infants (two months: supplemented 9.6% vs. unsupplemented 7.1%; four months; 8.7 vs. 6.6%). In order to estimate infantile capacity for endogenous synthesis of AA, we fed four term neonates with newly diagnosed phenylketonuria (mean age 18 d) a formula with all fat contributed by corn oil, which has a higher natural13C‐enrichment than European human milk or formula. Analysis of13C‐enrichment in plasma fatty acids over four days allowed us to estimate infantile AA synthesis. We found an increased13C‐value in plasma AA of all infants, which indicates that term neonates can synthesize AA. However, with a simplified isotope balance equation, we estimate that endogenous synthesis contributed only about 23% of total plasma arachidonic acid by day four. We conclude that full‐term infants fed formula may require a dietary supply of some preformed AA if the biochemical status of breast‐fed infants is to be achieved.
A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until two months
Authors: Carlson Susan E. , Werkman Susan H.
Published: November 2006

This was a randomized, double‐blind trial to determine if a nutrient‐enriched (preterm) formula supplemented with 0.2% docosahexaenoic acid (DHA, 22∶6n−3) from a low eicosapentaenoic acid (0.06%) source of marine oil would enhance visual novelty preference and attention of preterm infants. Both the standard and experimental formulas contained 3% of total fatty acids as linolenic acid (18∶3n−3) and were fed from approximately three days of age to two months past term. After two months, both diet groups were fed a commercially‐available term formula with linolenic acid as the only source of n−3 fatty acid. At 12 mo visual recognition memory (novelty preference) and visual attention (number and duration of discrete looks) were determined with the Fagan Test of Infant Intelligence. The DHA‐supplemented group compared with the control group had more and shorter duration looks in comparisons of familiar and novel stimuli, confirming earlier evidence that DHA can increase information processing speed of preterm infants who otherwise are receiving good intakes of linolenic acid. Because supplementation was stopped at two months and the effects seen at 12 mon, this study demonstrates for the first time that a relatively short period of DHA supplementation can produce significant effects on later visual attention.
Determination of hydroperoxides and structures by high‐performance liquid chromatography with post‐column detection with diphenyl‐1‐pyrenylphosphine
Authors: Ohshima Toshiaki , Hopia Anu , German J. Bruce , Frankel Edwin N.
Published: November 2006

A high‐performance liquid chromatographic method, using post‐column detection with diphenyl‐1‐pyrenyl‐phosphine (DPPP), was developed for the quantitative and qualitative determination of isomeric lipid hydroperoxides (OOH). The OOH eluted from a normal‐phase column were passed through a photodiode array detector and then mixed with DPPP solution in a reaction coil heated at 80°C. DPPP oxide formed by the reaction with OOH was determined by monitoring the fluorescence intensity at 380 nm and excitation at 352 nm. The conjugated diene OOH (13‐cis, trans‐ and 9‐cis, trans‐OOH) and nonconjugated OOH (12‐cis‐trans‐ and 10‐cis, trans‐OOH) from photosensitized oxidation of methyl linoleate were determined in a molar ratio of 31∶29∶19∶21, respectively. However, only the two conjugated hydroperoxides were detected by ultraviolet absorption at 234 nm. Further applications were carried out for the determination of OOH of methyl oleate and methyl linolenate. This method proved to be useful for the determination of the OOH containing both conjugated and nonconjugated diene structures.
Stearic acid unlike shorter‐chain saturated fatty acids is poorly utilized for triacylglycerol synthesis and β‐oxidation in cultured rat hepatocytes
Authors: Pai Tonkun , Yeh Yu‐Yan
Published: November 2006

Utilization of stearate as compared to various saturated fatty acids for cholesterol and lipid synthesis and β‐oxidation was determined in primary culture of rat hepatocytes. At 0.5 mmol/L in the medium, stearate (18:0) adequately solubilized by albumin was less inhibitory to cholesterol synthesis from [2‐14C] acetate than myristate (14:0) and palmitate (16:0) (68% vs. 91 and 88% inhibition, respectively). The rate of incorporation into cholesterol from [1‐14C] stearate (3.0±0.6 nmol/mg protein/4 h) was 37‐, 1.8‐, and 7.8‐fold of that from myristate, palmitate, and oleate, respectively. Conversely, the rate of [1‐14C] stearate incorporation into total glycerolipids was 88–90% lower than that of labeled palmitate, myristate, and oleate. The rate of [1‐14C] stearate incorporation into triacylglycerol (3.6±0.4 nmol/mg protein/4 h) was 6–8% of that from myristate, palmitate, oleate, and linoleate. The rate of stearate incorporation into phospholipids was the lowest among tested fatty acids, whereas the rate of mono‐ and diacylglycerol synthesis was the highest with stearate treatment. The rate of β‐oxidation as measured by CO2 and acid soluble metabolite production was also the lowest with [1‐14C] stearate treatment at 22.7 nmol/mg protein/4 h, which was 35–40% of those from other [1‐14C] labeled fatty acids. A greater proportion of stearate than other fatty acids taken up by the hepatocytes remained free and was not metabolized. Clearly, stearate as compared to shorter‐chain saturated fatty acids was less efficiently oxidized and esterified to triacylglycerol in cultured rat hepatocytes.
Identification of noveltrans isomers of 20∶5n−3 in liver lipids of rats fed a heated oil
Authors: Chardigny Jean‐Michel , Sébédio Jean‐Louis , Grandgirard André , Martine Lucy , Berdeaux Olivier , Vatèle Jean‐Michel
Published: November 2006

Trans polyunsaturated n−3 fatty acids are formed as a result of the heat treatment of vegetable oils. It was demonstrated previously that the 18∶3 Δ9cis, 12cis, 15trans containing acis Δ9 ethylenic bond was converted to a geometrical isomer of 20∶5n−3, the 20∶5 Δ5cis, 8cis, 11cis, 14cis, 17trans. In the present study, we have identified two new isomers of eicosapentaenoic acid, the Δ11 monotrans and the Δ11, 17 ditrans isomers in liver of rats fed a heated oil. These are formed as a result of the conversion of two of the main isomers of linolenic acid which are present in refined and frying oils, the 18∶3 Δ9trans, 12cis, 15cis and the 18∶3 Δ9trans, 12cis, 15trans.
Dihydro‐vitamin K1: Primary food sources and estimated dietary intakes in the American diet
Authors: Booth Sarah L. , Pennington Jean A. T. , Sadowski James A.
Published: November 2006

Dihydro‐vitamin K1 was recently identified as a dietary form of vitamin K produced during the hydrogenation of vitamin K1‐rich vegetable oils. Dihydro‐vitamin K1 is absorbed, with measurable levels in human plasma following dietary intake. To determine the primary food sources of dihydro‐vitamin K1 in the American diet, 261 foods from the U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) were analyzed by high‐performance liquid chromatography. Of these foods, 36 contained dihydro‐vitamin K1. Fast‐food items that were otherwise poor sources of vitamin K1, such as french fries and fried chicken, contained appreciable amounts of dihydro‐vitamin K1 (36 and 18 μg/100 g, respectively). These nutrient values were then applied to the FDA TDS consumption model to determine average dietary intake of dihydro‐vitamin K1 in 14 age‐gender groups. With the exception of infants, all age‐gender groups had estimated mean daily dihydro‐vitamin K1 intakes of 12–24 μg, compared to mean daily vitamin K1 intakes of 24–86 μg. The vitamin K1 and dihydro‐vitamin K1 intakes were summed, and the dietary contribution of dihydro‐vitamin K1 was expressed as a percentage of total vitamin K intake. Children reported the highest intakes of dihydro‐vitamin K1 (30% of total vitamin K intake), followed by a progressive decrease in percentage contribution with age. There are currently no data on the relative bioavailability of dihydro‐vitamin K1 but, given its abundance in the American diet, this hydrogenated form of vitamin K warrants further investigation.
Quantitative31P nuclear magnetic resonance analysis of the phospholipids of erythrocyte membranes using detergent
Authors: Nouri‐Sorkhabi M. Hossein , Wright Lesley C. , Sullivan David R. , Kuchel Philip W.
Published: November 2006

31P Nuclear magnetic resonance (NMR) spectra of human erythrocyte lysates dissolved in sodium cholate were acquired. The narrow resonances of phospholipids were mostly well resolved, allowing identification and accurate quantitative analysis of phospholipid classes of the erythrocyte membranes. The ether‐linked phosphatidylethanolamine components of the erythrocyte membranes were identified, based on the removal of plasmalogens by acidolysis and of diacyl phospholipid species by degradation using phospholipase A1. It was also shown that the introduction of double bonds on the acyl chains of phosphatidylcholine shifted the31P NMR resonances to lower frequencies. Quantitative analyses of phospholipids from the spectra were based on their apparent molar concentrations. The recoveries of phospholipids from erythrocytes were significantly higher than those using conventional extraction procedures.
Docosahexaenoic acid‐rich fish oil does not enhance the elevation of serum transaminase and liver triacylglycerol induced by carbon tetrachloride in mice
Authors: Yasuda Satoshi , Watanabe Shiro , Kobayashi Tetsuyuki , Okuyama Harumi
Published: November 2006

Carbon tetrachloride (CCl4) is metabolized to trichloromethyl radical and induces liver injury with elevated serum transaminase and increased hepatic triacylglycerols (TG). To answer the question whether dietary polyunsaturated fatty acids (PUFA) enhance free radical‐mediated liver injury, a docosahexaenoic acid (DHA)‐rich fish oil (FO) or a saturated and monounsaturated fatty acid‐rich beef tallow diet was fed to mice for 4 wk and then CCl4 was administered. When thiobarbituric acid‐reactive substances (TBARS) were measured in the absence of antioxidant, the FO diet and CCl4 treatment markedly increased liver TBARS values synergistically, apparently supporting the interpretation that the highly autoxidizable DHA accelerates lipid peroxidation induced by CCl4. However, no such marked interaction was observed between diet and CCl4 treatment in liver TBARS values measured in the presence of an antioxidant in the assay mixtures as well as in conjugated diene contents. Furthermore, the FO diet did not enhance CCl4‐induced elevation of serum transaminase but lowered liver TG levels. The proportion of DHA, the most easily autoxidizable among common PUFA, was increased but those of eicosanoid precursors were decreased in liver phospholipids by CCl4 treatment, possibly reflecting the inflammation‐related mobilization of eicosanoid precursors but not lipid peroxidation. These results indicate that dietary enrichment with DHA does not enhance CCl4‐induced liver injury through the so‐called free radical‐mediated propagative autoxidation of DHA in mice.
Identification of milk fat triacylglycerols by capillary supercritical fluid chromatography‐atmospheric pressure chemical lonization mass spectrometry
Authors: Laakso Päivi , Manninen Pekka
Published: November 2006

Identification of milk fat triacylglycerols was accomplished by capillary supercritical fluid chromatography (SFC) combined with atmospheric pressure chemical ionization mass spectrometry [(APCI)MS]. Supercritical carbon dioxide was the carrier fluid in SFC. Ionization was achieved by introducing vapor of ammonia in methanol into the ionization chamber, which resulted in the formation of abundant [M+18]+ and [M‐RCOO]+ ions of triacylglycerols. These ions defined both the molecular weight and the fatty acid constituents of a triacylglycerol, respectively. SFC on a nonpolar stationary phase provided an efficient separation of triacylglycerols according to the combined number of carbon atoms in the acyl chains of a molecule. In addition to the identification of the major chromatographic peaks representing molecules with 26–54 acyl carbons, minor peaks representing triacylglycerols with an odd number of acyl carbons were separated and identified. Furthermore, compositional information on partially separated isobaric triacylglycerols, which differed substantially in the chain length of the fatty acyl residues, was achieved within some of the peaks. A new finding of the present study was the formation of abundant [M+18]+ ions of saturated triacylglycerols in addition to diagnostic fragment ions, being of primary importance in structure elucidation. This extends the applicability of capillary SFC‐(APCI)MS in the analysis of both saturated and unsaturated triacylglycerols.