In this study we determined the effect of nitrous oxide (N2O) on homocysteine concentrations in children and whether blood levels of folate, vitamin B12, B6, methylmalonic acid (MMA) and methylenetetrahydrofolate reductase C6777T genotype affected this relationship. Homocysteine was measured before and after N2O. Vitamin levels, MMA and genotype were determined preoperatively. Median age of the 32 participants was 11 months (3-126 months). All children had folate and B6 levels above deficiency values (7.4, 20nmol/L respectively). Five children had MMA levels indicating deficiency (≥0.21µmol/L). Post-exposure homocysteine concentrations increased by 25% (P= <0.001). Duration of exposure and initial homocysteine concentrations were predictors of the increase (r2= 0.821, P= <0.001). Vitamin B12 and initial homocysteine concentrations were inversely associated (r2 = 0.277, P= 0.004). Folate, vitamin B6 and genotype showed no effect. In conclusion, N2O exposure leads to increased homocysteine in children. Studies investigating benefit of pre-surgical vitamin B12 supplementation may prove worthwhile.

No description available.

Atmospheric nitrous acid (HONO) is a significant and sometimes dominant OH source at polar region. An improved method of detecting HONO is developed using photo-fragmentation and laser-induced fluorescence (LIF). The detection limit of this method is 2-3 pptv for ten-minute integration time with 35% uncertainty. The abundance of laser-induced fluorescence (LIF) HONO measurements during ANTCI (Antarctic troposphere chemistry investigation) 2003 exceeds the pure gas phase model predictions by a factor of 1.92±0.67, which implies snow emission of HONO. A 1D air-snowpack model of HONO was developed and constrained by observed chemistry and meteology data. The 1D model includes pure gas phase chemical mechanisms, molecular diffusion and mechanical dispersion, windpumping in snow, gas phase to quasi-liquid layer phase HONO transfer and quasi-liquid layer nitrate photolysis. Based on the air-snowpack model, snow emission of HONO is highly likely and will be transported to place of the measurements. The pH, thickness of quasi liquid layer and contineous nitrite measurement are key factors to calibrate and validate the air snowpack model.

No description available.

In recent decades the knowledge of nitrous oxide (N2O) emissions after the application of nitrogen (N) fertilizers in agriculture soil has improved. However the understanding of emissions of N2O from Canadian organic agricultural systems has not been developed. The Glenlea Long Term Crop Rotation is the longest running organic conventional comparison study in western Canada and was used here to compare N2O emissions between the systems. In organic cropping systems forage legumes such as alfalfa are incorporated into the soil as an N source. The amount of N2O that is emitted after the incorporation and during the subsequent crop is not well known. The wheat and legume phases (alfalfa (Medicago sativa) in organic system and soybean (Glycine max L.) in the conventional) of the rotation were monitored for N2O. In 2014, 2015, and spring 2016 (data still being analysed) emissions of N2O were monitored using the vented static chambers method as well, soil conditions (temperature, moisture, inorganic N and extractable carbon) and yields were measured. Typical N2O emissions from spring applied urea were observed after application in the conventional system however no emission episode was seen after the fall alfalfa plough down or during spring thaw in the organic system. Greater NO3- accumulation was observed in the organic treatments however low emissions were observed. The organic system resulted in lower yields for both years, but still resulted in lower emissions per amount of grain produced (yield-scaled emissions) than the conventional system. This study adds to the knowledge that N2O emissions from organic systems do differ from conventional however yields need to be improve to fully exploit the benefits. / February 2017

Knowledge of the relationship between rate of nitrification and nitrous oxide (N2O) emission, and between cumulative nitrification and N2O emission is important for developing N2O emission mitigation strategies. Gross nitrification and N2O from nitrification were determined using 15N labelling of inorganic N. N-Serve was added to delay nitrification and results showed an increase in rate of N2O emission with that of apparent nitrification in absence of N-Serve, but there was no relation in its presence. Same amount of cumulative N2O was emitted for same amount of nitrogen (N) apparently nitrified, regardless of N-Serve addition. There was no relation between N2O emission attributed to nitrification and gross nitrification with and without N-Serve. Again, same amount of cumulative N2O was emitted for same amount of gross nitrified N, regardless of N-Serve addition. These results imply that the amount of N nitrified dictates eventual cumulative N2O emitted, regardless of rate of nitrification. / February 2017

No description available.

Psychological and physiological effects of nitrous oxide resemble those of eight other drug categories. Lipid solubility or hydrate microcrystal theories correlate behavioral measures with measurable parameters of the molecule N20. N20, a spindle poison, halts mitosis in metaphase, producing widespread physiological consequences. N20 affects the microtubules of the spindle in a number of specific ways. Microtubules are utilized in other parts of eukaryotic cells, in a wide variety of functions. In neurons, microtubules build and maintain dendritic sensory processes. Since microtubules are built of two dissimilar proteins, constantly assemble and disassemble, and maintain a more negative interior potential, they would be responsive to changes in summed post-synaptic dendritic potential. Microtubules respond to N20 with a loss of communication between subcellular components, and between cells. Chromosomes, proteins, and ATP are no longer transported efficiently. Such fundamental changes might explain nitrous oxide's effects in "potentiating" other drugs, and upon perception and memory.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 169-180).

Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Netzer, D.W. Second Reader: Shreeve, R.P. "September 1990." Description based on title screen as viewed on December 17, 2009. DTIC Identifier(s): Nitrogen oxide, NOx control, gas turbine combustors, gas turbine fuel additives, soot control, pollution control. Author(s) subject terms: NOx control, gas turbine combustors, gas turbine fuel additives, soot control, pollution control. Includes bibliographical references (p. 65-66). Also available in print.