The synthesis of14C- and3H-labeled glycerol ethers

The racemic¹⁴C-and³H-labeled alpha and beta derivatives of octadecyl glycerol ether (batyl alcohol) and of hexadecyl glycerol ether (chimyl alcohol) of high specific activity were synthesized by treating the appropriate alkyl halides with a large excess of the potassium salts of isopropylidene or benzylidene glycerol. By use of the trifluoroacetic anhydride esterification procedure, the labeled diesters of alpha and beta octadecyl and hexadecyl glycerol ethers were prepared. The labeled monoesters of beta octadecyl and of beta hexadecyl glycerol ethers were isolated from the reaction mixtures by silicic acid column chromatography. Work done in partial fulfillment for PhD Degree, Department of Biochemistry, University of North Carolina.     

Productivity of algae in sewage disposal

One of the highly significant and rapidly developing methods of applying solar energy to environmental problems is that of waste disposal. Many of the liquid wastes from our residences, industries and farms provide a suitable medium for micro-algae in the environment to proliferate with extreme rapidity converting solar energy to the energy in their cellular matter and to heat. The efficiency of conversion of solar energy to plant tissue often reaches 5 per cent, and the efficiency of conversion of solar energy to heat apparently reaches in excess of 90 per cent. The heat so produced is beneficial to waste disposal in several ways: for example, it accelerates both aerobic and anaerobic microbiological waste oxidation and reduction and hastens the death of pathological organisms which may be present in the waste. The release of oxygen from water during photosynthesis provides aerobic microbiological waste oxidation; and the absorption of carbon dioxide which also accompanies photosynthesis raises the p^H of the waste to a point which may be lethal to any pathogenic bacteria and viruses. Depending upon the availability of solar energy and the efficiency attained, production rates for oxygen may reach 500 pounds per acre per day-a rate sufficient to continuously and fully oxidize the wastes of more than 2500 persons. Under average environmental conditions, oxygen production rates of 200 lb/day may be dependably produced.     

Fumonisin B1 alters cell cycle progression and interleukin-2 synthesis in swine peripheral blood mononuclear cells

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium verticillioides, a fungus that commonly contaminates maize. In the present study, we investigated the effects of FB1 on swine peripheral blood mononuclear cells (PBMC) by measuring cell proliferation, cell cycle progression and interleukin (IL)-2 production. Forty-eight hours after treatment in vitro, FB1 induced a decrease of PBMC proliferation as measured by cell counting and dehydrogenase enzyme activity. This effect was observed starting with 10 microM FB1. The effect of FB1 on cell cycle progression was analyzed by flow cytometry. Incubation of PBMC with FB1 increased the percentage of cells blocked in G0/G1 phase of the cell cycle. Treatment with 200 microM FB1 induces a high blockade of the cell cycle, with 92.4% of cells in G0/G1 phase. This blockade was observed in all lymphocyte subsets tested (CD2+, CD4+, CD8+ and Ig+) as evidenced by dual staining for DNA and membrane surface molecules. A significant decrease of IL2 production was also observed in the supernatants of ConA stimulated PBMC treated with 100 or 200 microM FB1. In conclusion, these data suggest that FB1 may affect immune functions by inhibiting lymphocyte proliferation and IL2 production, suggesting a possible role of FB1 exposure during infectious disease and cancer.     

Soybean unsaponifiables: Hydrocarbons from deodorizer condensates

Molecular distillation of deodorizer condensates followed by chromatography on alumina, gave substantial quantities of hydrocarbons free of other unsaponifiable constituents. Squalene comprised 50% of the hydrocarbon fraction and contained practically all the unsaturation. A crystalline, saturated hydrocarbon fraction of 4.2% was composed primarily of C₂₉ and C₃₁ paraffins. An unresolved fraction was composed of two major components, each estimated to contain about 30 or 35 carbon atoms. Minor amounts of many hydrocarbons with chain lengths of 15\s-35 carbon atoms were present but not completely identified. C¹⁴ analysis showed that the hydrocarbons are natural to soybean oil and they are not artifacts arising from petroleum solvent residues. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, USDA.     

Using discrete optimization for designing dental shade guides

A key criterion in the design of dental shade guides used for matching tooth color is that the shade tabs cover the natural tooth color space as completely as possible with a manageable number of tabs. Earlier studies have designed hypothetical shade guides from a given population of tooth colors described in the CIELAB system using the goal of minimizing the mean coverage error. In this study, we investigate this topic using the goal of maximizing coverage, meaning that as many measured colors as possible were within a given color difference from the nearest shade tab of the guide. We use techniques of linear discrete optimization to determine the positions of the shade tabs and consider both color difference formulas, CIELAB and CIEDE2000, in an exemplary tooth color population. We obtain coverage error and coverage figures for hypothetical shade guides of various numbers of tabs designed with the goal of either minimizing coverage error or maximizing coverage. Results show that discrete optimization and the goal of maximizing coverage could be used to improve shade guide development. The described technique could be used not only for dental shade guides development, but also for any purpose requiring coverage of as many colors as possible while keeping the number of reference colors manageable. © 2009 Wiley Periodicals, Inc. Col Res Appl, 2010     

Effectiveness of daylighting design and occupant visual satisfaction in a LEED Gold laboratory building

Using daylight as primary light source has been widely recognized as an important strategy to reduce building energy demand and enhance indoor environment quality. However, to design and operate a building to make full use of daylight, which is a dynamic light source, to meet diverse occupant needs remains a challenge. This paper reports a post-occupancy study of the visual environment in a laboratory building on a university campus, and puts a spotlight on the building occupants as it examines the effectiveness of the daylighting design and systems integration in creating a visual environment to support occupant comfort and satisfaction while reducing artificial lighting demand. Results show generally high satisfaction with daylit work environment and positive effect of the horizontal shading strategy. Issues about the integration between daylighting and electric lighting systems and level of occupant control are identified and discussed for improving the effectiveness of daylighting and enhancing the quality of the visual environment in the building of study. A multiple-tool methodology is developed and tested, which included occupant surveys, interviews, illuminance measurements, continuous data loggers, fisheye-lens camera and glare-identifying software, and documentation of spatial settings, systems features, and user behavior.