No description available.

Thesis (Master's)--Scott Polar Research Institute, University of Cambridge, 1989. / Includes bibliographical references (leaves 86-92).

Thesis (M.A.)--The University of North Carolina at Greensboro, 2010. / Directed by Roy Stine; submitted to the Dept. of Geography. Title from PDF t.p. (viewed Jul. 19, 2010). Includes bibliographical references (p. 89-93).

Thesis. 1975. Sc.D.--Massachusetts Institute of Technology. Dept. of Meteorology. / Vita. / Bibliography: leaves 164-170. / by Gerald F. Herman. / Sc.D.

No description available.

No description available.

The effect of pH, temperature, substrate concentration, and orthophosphate on abiontic phosphomonoesterase activity was examined in disturbed and undisturbed Arctic soils with variable moisture content and in Virginia forest, grassland and agricultural soils. Distribution of acid and alkaline phosphatases was related to soil pH. The pH optimum for enzyme activity was near 5.5 in all soils except agricultural soil where it was 11. The pH of all soils except agricultural soil was between 4.7 and 6.6. At pH 5.5 enzyme activity was 10 to 20 fold greater in O_e - O_i horizon Arctic soils than in Ap horizon Virginia soils. Undisturbed Arctic soils had 30-40% greater activity than disturbed soils. Phosphomonoesterase activity in each soil was 10 fold greater than either phosphodiesterase or phosphotriesterase activity in the same soil. Three hundred to 700 µg p-nitrophenol ·g⁻¹ h⁻¹ were released by Arctic soils incubated at 0°C; levels increased as temperature increased. K_{m_app} (v: v/S regression analysis) ranged from 1.57 to 2.91 mM (Arctic) and 2.11 to 3.23 mM (Virginia). V_max’ expressed as µmoles·g⁻¹ h⁻¹, ranged from 17.6 to 23.2 (Arctic) and 0.52 to 3.66 (Virginia). Orthophosphate inhibition of p-nitrophenyl phosphatase activities was competitive or mixed in Arctic soils and competitive in Virginia soils. K_i ranged from 3.4 to 11.7 mM (Arctic) and 4.12 to 15.6 mM (Virginia). Data suggests that the potential for phosphatase catalyzed phosphate hydrolysis is greatest in the organic Arctic soils (gram dry weight basis) and activity in those soils is influenced by disturbance and moisture. / Master of Science

The Arctic has long been considered to be a pristine environment, far from population centers and pollution sources. The detection of synthetic organochlorine compounds in various elements of the Arctic food web has confirmed the global dispersion of pollutants, particularly of persistent compounds such as organochlorines and heavy metals. Levels of heavy metals, although elevated, appear to be naturally so throughout much of the Arctic. Arctic pollution is both a humanitarian and ecological concern. Many arctic coastal communities depend heavily on marine mammal fat for sustenance, and are therefore potentially exposed to high levels of organochlorines and some metals. From an ecological perspective, the structure of arctic food webs, the importance of lipid mobilization for winter survival, and the adaptive physiologies of arctic organisms may result in an enhanced response to contaminant exposure. This thesis assesses the exposure and effect of organochlorine and heavy metal exposure in inland freshwater ecosystems of Arctic Alaska, and evaluates the physiological response of arctic grayling to experimental polychlorinated biphenyl (PCB) exposure. / Graduation date: 1995

This thesis discusses the impact of the snowmobile on the Inuit society in northern Canada and more specifically in Kangiqsualujjuaq (Nunavik). By drawing the portrait of traditional and modern habits of mobility, it is possible to understand the influence of the snowmobile--considered as micro-technology--on the fundamental structures of the Inuit society. More generally, the research illustrates the evolution of the means of transportion starting from the pre-contact period to the 1990's. / Westernization of the Inuit society is not the consequence of only one item but the combination of many. Even if it is difficult to evaluate the influence of a particular technology on a cultural system, snowmobile has had an important impact on the social, cultural and economic values of the Inuit society. The results of the introduction of this vehicle are not only the consolidation of the westernization way of living, because the snowmobile also gives to the Inuit society, the technology needed to practice traditional activities in a contemporary context.

Thesis (M.S.)--Eastern Connecticut State University, 2004. / Website for materials: http://www.geocities.com/bobbyn18/Thesis.html?1074876403923 (viewed 12-29-2005). Bibliography: leaves 93-97. Thesis also available via the World Wide Web.