Determination of detergents in washing machine wastewater with a voltammetric electronic tongue.

A voltammetric electronic tongue (ET) and a conductivity meter were used to predict amounts of detergents in process water from washing machines. The amount of detergent in over sixty samples was also determined by a HPLC reference method. Prediction was more accurate for the electronic tongue, but both techniques could be used. The composition of the detergent, e.g. supporting electrolyte, is an important factor for the ability to predict the detergent quantity by conductivity. Also two different surfactants, alkyl benzyl sulfonate (ABS) and etoxylated fatty alcohol (EOA), were fingerprinted by the HPLC. Their behaviour during the wash cycle differs from each other, ABS rinses away in the same proportions as the supporting electrolyte, but EOA appears to stay within the machine and laundry. Prediction models for ABS are accurate both with ET and conductivity meter, mostly due to the correlation with supporting electrolyte. The behaviour of EOA, with almost no correlation to the supporting electrolyte makes it difficult to predict using conductivity but ET prediction models give promising indications of its capabilities.

A model for peak and width of signaling windows: Ips duplicatus and Chilo partellus pheromone component proportions--does response have a wider window than production?

Pheromone communication systems have a reliable signal with a restricted window of amounts and ratios released and perceived. We propose a model based on a Gaussian response profile that allows a quantification of the response peak (location of optimum) and a measure of the peak width (response window). Interpreting the Gaussian curve, fitted by nonlinear regression (NLR), as a standard normal distribution, the peak location equals the mean (it) and the window width equals 2 x the standard deviation (2sigma). The NLR procedure can provide an objective measure for both peak location and width for a wide range of data sets. Four empirical data sets as well as 10 literature data sets were analyzed. The double-spined spruce engraver, Ips duplicatus, was field tested in four populations to find the optimum proportion for attraction to the two male aggregation pheromone components, ipsdienol (Id) and (E)-myrcenol(EM), ranging from 0 to 100% of Id. Tests in Norway and the Czech Republic confirmed the preference of western populations for a blend between 50 and 90% Id. A population in Inner Mongolia showed a preference for traps with the 10 and 50% Id baits. The NLR fitted values for response peak and width (mu; 2sigma) were: Norway 0.64, 0.73; Czech Republic 0.53, 0.73; NE China 0.77, 0.29; and Inner Mongolia 0.33, 0.50. The signal produced by Norwegian field-collected males had a narrower window width (2sigma = 0.12). Males of the maize stem borer, Chilo partellus, were tested in a flight tunnel for their response to variation in the two major female sex pheromone gland components, (Z)- l1-hexadecenal and the corresponding alcohol (OH). Variation of the alcohol in seven levels from 2 to 29% OH showed the highest male response for 17% OH. For all behavioral steps, the peak of male response was near mu = 0.14, while the window width fell from 2sigma = 0.5 to 0.2 for eight sequential behavioral steps from take-off to copulation. Female production had a similar peak location (mu = 0.13) but a narrower width, 2sigma = 0.14. Literature data from other moth species showed similar patterns, with a wider male response relative to the female production windows. Literature data on response to enantiomer ratios in a hymenopteran and to pheromone amounts in a dipteran were also described by our model. In a bark beetle population (Ips pini), with two hybridizing enantiomeric strains, the production peaks were narrower (0.1) than the response peaks (0.5). Thus, it in general, seems that in the pheromone systems analyzed, the width of the response window (2sigma = 0.1 to 0.8) is larger than that of the production window (2sigma = 0.03 to 0.14), irrespective of the sex of the sender.

Juvenile hormone regulation of HMG-R gene expression in the bark beetle Ips paraconfusus (Coleoptera: Scolytidae): implications for male aggregation pheromone biosynthesis.

Juvenile hormone III (JH III) induces acyclic isoprenoid pheromone production in male Ips paraconfusus. A likely regulatory enzyme in this process is 3-hydroxy-e-methylglutaryl-CoA reductase (HMG-R). To begin molecular studies on pheromone production, a 1.16-kb complementary DNA representing approximately one-third of I. paraconfusus HMG-R was isolated by polymerase chain reaction and sequenced. The predicted translation product is 59% and 75% identical to the corresponding portion of HMG-R from the fruit fly, Drosophila melanogaster, and the German cockroach, Blattella germanica, respectively. Northern blots show that topical application of JH III increases HMG-R transcript levels in male thoraces in an apparent dose- and time-dependent manner. These data support the model that JH III raises HMG-R transcript levels, resulting in increased activity of the isoprenoid pathway and de novo pheromone production.

The fern Polypodium decumanum, used in the treatment of psoriasis, and its fatty acid constituents as inhibitors of leukotriene B4 formation.

The fern Polypodium decumanum, commonly called Calaguala, has a clinically documented use in South America and Spain in the treatment of psoriasis. One of the inflammatory mediators isolated in abnormally high quantities in the psoriatic skin is leukotriene B4 (LTB4). Calaguala was tested in an in vitro model using human leukocytes for its ability to inhibit the LTB4 formation. The inhibition was found to be caused by the polyunsaturated fatty acids (PUFAs) linoleic, linolenic and arachidonic acid. IC50 values were determined for the isolated acids and compared to a group of closely related acids also commonly found in nature. The IC50 values for most acids tested were of the same magnitude (20-60 microM) except for arachidonic acid which showed stimulatory activity and 8(R) hydroxylinoleic acid which gave 30% inhibition with the highest dose tested (120 microM). The amounts of PUFAs in different Calaguala extracts were quantitatively analysed and it is concluded that the fatty acid constituents of Calaguala may contribute to the clinical effects of the extract.