1,788 research outputs found

    Leases: Farmland Lease Provisions in Oklahoma

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    Cerumen Composition by Flash Pyrolysis-Gas Chromatography/Mass Spectrometry

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    Objective: To assess the chemical composition of cerumen by flash pyrolysis-gas chromatography/mass spectrometry. Study Design: Collected earwax specimens were fractionated into residue and supernatant by means of deoxycholate. This natural bile acid produces significantly better disintegration of earwax in vitro than do presently available ceruminolytic preparations, and also has demonstrated excellent clinical results in vivo to date. Patients: The sample for analysis was obtained from a patient with clinical earwax impaction. Results: The supernatant is composed of simple aromatic hydrocarbons, C5-Cl 7 straight-chain hydrocarbons, a complex mixture of compounds tentatively identified as diterpenoids, and steroids, in particular cholesterol. The residue, on the other hand, produced simple aromatic compounds (including benzenes, phenols, and benzonitriles), C5-C25 straight-chain hydrocarbons, greater relative quantities of nitrogen compounds and phenol, and lesser importance of the (tentatively identified) diterpenoids. Conclusions: Through the use of the detergent deoxycholate, squalene and a tentatively identified diterpenoid were revealed to be present in a free, unbound state, whereas some steroids and hydrocarbons appeared to be bound to a macromolecular structure by nitrogen linkages or other bonds. Additionally, this study reintroduces detergents as a viable method of earwax removal, specifically the bile acids

    Transitioning from wild collection to forest cultivation of indigenous medicinal forest plants in eastern North America

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    Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.The forest flora of eastern North America includes many herbaceous plant species traded in domestic and international medicinal markets. Conservation concerns surrounding wild-collection exist and transitioning to cultivation in agroforestry systems has potential economic and ecological benefits. Costs and revenues associated with adopting forest cultivation were modeled for eight North American medicinal forest plants. Sensitivity analysis examined profit potential in relation to (1) discount rates; (2) propagation methods; (3) prices; (4) growing period; (5) production costs; and (6) yields. Results indicate that intensive husbandry of six of eight species would be unprofitable at recent (1990-2005) price levels. Exceptions are American ginseng (Panax quinquefolius L.), and under certain circumstances (e.g., maximum historic prices, low production costs) goldenseal (Hydrastis canadensis L.). Direct marketing to consumers and retailers might improve grower profits, but is undermined by the availability of cheaper, wild-collected product. We suggest that the North American medicinal plant industry could play a key role in facilitating any transition from wild to cultivated product, perhaps through development of a certification and labeling program that brands "forest cultivated" products. This could generate price premiums, to be passed along to growers, but must be accompanied by aggressive consumer education. A "forest cultivated" certification and labeling program has potential to benefit industry and consumers if assurances regarding product identity and quality are a central feature. Plant species that are not viable candidates for commercial cultivation due to limited consumer demand (i.e., species with "shallow," erratic markets) are best addressed through proactive government and industry initiatives involving targeted harvester education programs.Eric P. Burkhart (1) and Michael G. Jacobson (2) ; 1. Shaver's Creek Environmental Center, the Pennsylvania State University, Petersburg, PA 16669, USA. 2. School of Forest Resources, the Pennsylvania State University, University Park, PA 16802, USA.Includes bibliographical references

    Molecular Composition of the Louse Sheath

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    Flash pyrolysis-gas chromatography/mass spectrometry was used to assess the chemical composition of the head louse\u27s nit sheath. The pyrolyzate of the female insect\u27s secretions, which form a cement-like cylinder holding the egg onto the hair, is dominated by amino acid derivatives and fatty acids. No chitin-specific compounds were detected in the sheath. These results, contrary to previous reports, show that the polymeric complex of the sheath is composed of proteinaceous moieties, possibly cross-linked to aliphatic components. This study constitutes the first chemical characterization of the pyrolysis products of insect (louse) glue and unequivocally confirms that louse sheaths are not chitinous, as suggested by earlier histochemical studies. Development of agents that might loosen nits from the hair shaft is dependent on research that addresses the chemical composition of the nit sheath

    Abundances in HD27411 and the helium problem in Am stars

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    We analyze a high-resolution spectrum of the A3m star HD27411. We compare abundances derived from ATLAS9 model atmospheres with those using the more computationally-intensive ATLAS12 code. We found very little differences in the abundances, suggesting that ATLAS9 can be used for moderate chemical peculiarity. Our abundances agree well with the predictions of diffusion theory, though for some elements it was necessary to calculate line profiles in non-thermodynamic equilibrium to obtain agreement. We investigate the effective temperatures and luminosities of Am/Fm stars using synthetic Stromgren indices derived from calculated spectra with the atmospheric abundances of HD27411. We find that the effective temperatures of Am/Fm stars derived from Stromgren photometry are reliable, but the luminosities are probably too low. Caution is required when deriving the reddening of these stars owing to line blanketing effects. A comparison of the relative proportions of pulsating and non-pulsating Am stars with delta Scuti stars shows quite clearly that there is no significant decrease of helium in the driving zone, contrary to current models of diffusion.Comment: 10 pages, 8 figures, 6 tables, accepted for publication in MNRA

    Current and Average Prices for Use in Farm Planning, Ohio, 1967

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