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Joseph V. Paukstelis

Bio: Joseph V. Paukstelis is an academic researcher from Kansas State University. The author has contributed to research in topics: Hadamard transform & Reagent. The author has an hindex of 10, co-authored 30 publications receiving 522 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a stationary two-dimensional Hadamard encoding mask was used for 3D imaging of a thin-layer chromatography plate using laser-induced fluorescence and surface-enhanced Raman scattering.
Abstract: Spatial imaging of thin-layer chromatography plates using laser-induced fluorescence and surface-enhanced Raman scattering has been accomplished with a stationary two-dimensional Hadamard encoding mask. Detection of three nanograms of pararosaniline hydrochloride on a thin-layer chromatography plate was made possible by means of the surface-enhanced Raman phenomenon. The imaging capabilities of the stationary two-dimensional Hadamard encoding mask coupled with the depth profiling ability of photoacoustic detection allows for the three-dimensional photoacoustic imaging of a multiple analyte sample.

25 citations

Patent
17 Jan 1989
TL;DR: In this article, 3-Methyl-2-benzothiazolinone acetone azine and 2-phenylphenol in 1:4 molar solid mixture reacts specifically with ozone at concentrations of environmental interest to produce a red-violet color.
Abstract: 3-Methyl-2-benzothiazolinone acetone azine and 2-phenylphenol in 1:4 molar solid mixture reacts specifically with ozone at concentrations of environmental interest to produce a red-violet color. The response is proportional, but not rectilinearly, to ozone concentration at constant exposure time and to time of exposure at constant ozone concentration. The reagent is intended for use with visual comparison standards in passive monitoring devices. No interference was observed from atmospheric oxygen, nitrogen dioxide, sulfur dioxide, or bromine or iodine vapor. Chlorine produced a light yellow color.

20 citations


Cited by
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Journal ArticleDOI
TL;DR: A general trend was apparent between the hydrogen cyanide potential and cyanide metabolizing activity, in that the higher the hydrogen Cyanide potential, in general, thehigher the cyanide metabolites activity.
Abstract: A survey has been made of the occurrence and distribution of three enzymes which metabolize cyanide in a variety of higher plants including both cyanogenic and non-cyanogenic species. The enzymes investigated were β-cyanoalanine synthase, rhodanese and formamide hydrolyase. β-Cyanoalanine synthase was found to be present in every higher plant tested whereas rhodanese was found to occur far less commonly in plants. Formamide hydrolyase activity was not detected in any of the higher plants tested. In addition, quantitative analyses have been made of the potential hydrogen cyanide content of each plant investigated. A general trend was apparent between the hydrogen cyanide potential and cyanide metabolizing activity, in that the higher the hydrogen cyanide potential, in general, the higher the cyanide metabolizing activity.

231 citations

Journal ArticleDOI
TL;DR: The results suggest that HCN produced in the rhizospheres of seedlings by selected rhizobacteria is a potential and environmentally compatible mechanism for biological control of weeds.
Abstract: Rhizobacteria strains were characterized for ability to synthesize hydrogen cyanide and for effects on seedling root growth of various plants. Approximately 32% of bacteria from a collection of over 2000 isolates were cyanogenic, evolving HCN from trace concentrations to >30 nmoles/mg cellular protein. Cyanogenesis was predominantly associated with pseudomonads and was enhanced when glycine was provided in the culture medium. Concentrations of HCN produced by rhizobacteria were similar to exogenous concentrations inhibiting seedling growth in bioassays, suggesting that cyanogenesis by rhizobacteria in the rhizosphere can adversely affect plant growth. Growth inhibition of lettuce and barnyardgrass by volatile metabolites of the cyanogenic rhizobacteria confirmed that HCN was the major inhibitory compound produced. Our results suggest that HCN produced in the rhizospheres of seedlings by selected rhizobacteria is a potential and environmentally compatible mechanism for biological control of weeds.

194 citations

Journal ArticleDOI
TL;DR: Volatile metabolites from a number of rhizosphere pseudomonads prevented lettuce root growth in a seedling bioassay and one of these metabolites was identified as cyanide, which was related to consistently higher levels ofrhizosphere cyanide in comparison with S97-treated plants and control soils.
Abstract: Volatile metabolites from a number of rhizosphere pseudomonads prevented lettuce root growth in a seedling bioassay. One of these metabolites was identified as cyanide. Direct contact between rhizobacteria and plant roots produced, with one exception, similar responses. However, not all cyanogenic isolates were plant-growth-inhibitory rhizobacteria. When grown in liquid culture, cyanogenic strains produced an average of 37 nmol HCN ml−1 over a 36-h period and inhibition of root growth occurred at concentrations as low as 20 nmol ml−1. Cyanogenic strains introduced into sand or soil also produced HCN. Two cyanogenic strains ofPseudomonas fluorescens, one (5241) a plant-growth inhibitory rhizobacterium and the other (S97) a plant-growth-promotory rhizobacterium, were used to treat bean and lettuce seedlings prior to planting in soil. Lettuce dry weight was reduced by 49.2% (day 28) and 37.4% (day 49) when inoculated with S241 whereas S97 increased growth initially (+64.5% at day 28, no difference from control at day 49). Equivalent figures for inoculated bean plants were: −52.9% and −65.1% (5241); +40.7% and +23.3% (S97). A more detailed experiment using only bean plants confirmed these contrasting affects. Inhibition by S241 was related to consistently higher levels of rhizosphere cyanide in comparison with S97-treated plants and control soils. S241 also survived in the rhizosphere at higher densities and for a longer period of time than S97. The possible contribution of rhizobacterial cyanogenesis to plant growth inhibition is discussed.

194 citations

Journal ArticleDOI
TL;DR: It is argued that, when in sufficiently high concentrations, DFPs determine the level of food intake by these animals irrespective of other questions of nutritional quality of the leaves.
Abstract: Traditional approaches to the question of the effects of plant secondary metabolites on the feeding choices of folivores of Eucalyptus have focused on the tree species level, although numerous field studies of foraging behaviour have identified selection at the level of the individual trees. Attempts to relate these decisions to deterrency resulting from secondary leaf chemistry have been inconclusive because assays used have focused on broad groups of compounds such as "total" phenolics. In this study we have conducted no-choice feeding trials with two arboreal mammalian folivores, the common ringtail possum (Pseudocheirus peregrinus) and the koala (Phascolarctos cinereus), to measure deterrency of individual trees of two species of Eucalyptus, E. ovata and E. viminalis. Average daily intakes of E. ovata foliage by common ringtail possums ranged from 2.5 to 50 g kg-0.75 body mass. Koala intakes of foliage from the same individual trees ranged from 22.4 to 36.3 g kg-0.75 body mass. When fed foliage from different individual E. viminalis trees, common ringtail possums ate between 1.26 and 6.28 g kg-0.75 body mass while koalas ate from 14.3 to 45.9 g kg-0.75 body mass. Correlative analyses showed no relationships between feeding and several measures of nutritional quality, nor with total phenolics or condensed tannins. They did, however, identify two groups of plant secondary metabolites that may cause deterrency: terpenes, and a defined group of phenolic compounds, the diformylphloroglucinols (DFPs). Further bioassay experiments with common ringtail possums showed that only the DFPs could cause the effects seen with the foliage experiments at concentrations similar to those found in the leaves. We argue that, when in sufficiently high concentrations, DFPs determine the level of food intake by these animals irrespective of other questions of nutritional quality of the leaves.

183 citations

Book ChapterDOI
01 Jan 1991

170 citations