<p> The East South C (E.S.C.) ore zone at the Dickenson Mine, Red Lake, is a major auriferous banded sulphide orebody which cross-cuts sulphide facies banded iron formation (S.F.B.I.F.) near its eastern termination. Pyrite was obtained from sulphide-rich portions of the ore zone as well as from sulphide-poor E.S.C. mineralization not spatially associated with S.F.B.I.F., S.F.BI.F., shear zone hosted mineralization such as the 1492 and F ore zones, and from quartz-carbonate vein mineralization in the South C ore zone. Forty-three pyrite separates from the zones were analyzed by Atomic Absorption Spectrophotometry for Co and Ni, in order to determine the origin of the E.S.C. ore zone. The average Ni and Co content of these pyrites are as follows: S.F.B.I.F.,7.9 and 13.6 ppm respectively; remobilized S.F.B.I.F. 10.3 and 13.6; carbonatized S.F.B.I.F. 10.9 and 22.6; South C 14.9 and 50.6; 1492 zone 34.1 and 28.4; F-zone 11.2-27.6; sulphide-poor E.S.C. 26.2 and 48.4 and sulphide-rich E.S.C., 17.91 and 16.63.</p> <p> High and variable Co values were found to be associated with carbonate-rich samples, irrespective of the type of mineralization and low and similar Co values were found in all carbonate-poor samples irrespective of their origin. Therefore, the Co content of pyrite cannot be used as a discriminant of genetically dissimilar pyrite. The Ni content in pyrite from S.F.B.I.F. is low and constant, while in shear zone and vein mineralization it is higher and more variable. The E.S.C. ore zone has similar values to that found in the epigenetic mineralization, however, a few sulphide-rich samples are similar to those found in S.F.B.I.F., suggesting a bimodal source of sulphide for the E.S.C.. It is proposed that the hydrothermal system which produced the E.S.C., 1492, F and South C ore zones, locally incorporated sulphides from the S.F.B.I.F. to produce the sulphide-rich mineralization found at the eastern extremity of the E.S.C. ore zone.</p> / Thesis / Bachelor of Science (BSc)

Consensus in scientific literature is that hyperglycemia, which is a condition that manifests in individuals with uncontrolled diabetes, causes compromised bone growth, but the exact mechanisms of are unknown. It has been estimated that 5% of dental implant failures that have previously been linked to unknown causes may be associated with undiagnosed diabetes. It is important to study the early stages of bone growth as it is accepted that they are critical in the long-term success rate of endosseous implants. This study aimed to investigate the bone healing seen in the hyperglycemic group compared to the normal (i.e. control) group, at an early time point, using high-resolution microscopy techniques. Ten young (200-250gram) male Wistar rats were used for this study with five rats assigned to the control group and the other five rats intravenously injected with 65 mg/kg of streptozotocin (STZ) to induce diabetes. An osteotomy model was used to make a 1.3mm defect in the diaphysis of the rat femurs. After five days, the femurs were removed, fixed in glutaraldehyde, dehydrated, and embedded in resin. Structural and chemical analyses were conducted on the samples using a variety of microscopy techniques to examine various factors of bone quality including: bone porosity, relative mineralization level, and the arrangement of collagen and mineral. When analyzing the micro-structure, the hyperglycemic group showed increased porosity in the newly formed bone as compared to the control group. However, no significant differences were found in the nano-structure when analyzing the arrangement of collagen and mineral.Therefore, the results in this thesis suggest that alterations in micro-architecture rather than nano-architecture may play a pivotal role in the compromised bone healing in uncontrolled diabetes at this five-day time point. Future work should investigate additional time points in the bone healing process. / Thesis / Master of Applied Science (MASc) / According to the International Diabetes Federation, 387 million people worldwide are living with diabetes of which 46.3% are undiagnosed. Uncontrolled diabetes results in hyperglycemia, which is a condition where there is an increased level of glucose in the blood. When diabetes is not regulated correctly with medication, it leads to problems in the long-term success rate of dental implants. The objective of this thesis was to investigate the early stages of bone formation, which are accepted to be critical in the long-term success rate of dental implants, in hyperglycemic animal models compared to control groups using various microscopy techniques. The different techniques used allowed for the structural and elemental compositions of bone to be studied on the micro-scale and nano-scale. It was shown that at the 5-day healing time point studied, the micro-structure, rather than the nano-structure, was negatively altered in the hyperglycemic group compared to the control group.

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The present work deals with capture and storage of carbon dioxide from biogases by bond- ing to alkaline earth metals from power plant ashes. The aim is to achieve the feed-in standard in Germany for the natural gas grid by binding CO2 in a long-term stable and environmentally compatible manner. In addition, the ash quality is to be improved by reduced mobility of critical metals such as lead, zinc and cadmium, and calcium carbonate is to be recovered as a valuable material in addition to the biomethane. In several experimental setups from laboratory scale to pilot plant, it was shown that both carbon dioxide and hydrogen sulfide can be captured and stored in large quantities of ash residues. Both the use of a packed column to compensate for the poor absorption and reaction kinetics and the use of ammonium chloride as an extraction agent proved to be particularly effective for biogas upgrading to biomethane level. In contrast, both the absorption and reaction temperature, as well as gas-specific influencing factors such as carbon dioxide concentration and volume flow rate, had little to no influence. With regard to ash quality, an improvement of the landfill class from IV to 0 was achieved with respect to lead, from II to 0 for zinc and from III to I for cadmium. A significant improvement was also achieved for chlorine, but this did not result in a reduction of the landfill class. The ash quantity could be reduced by more than 50 %, among other things, by dissolving out the alkaline earth metals for the carbon dioxide reaction. As further research steps, it remains to further reduce the metal mobility with respect to the ash eluate in order to better optimize the process water quality. This could be achieved, for example, by a controlled pH value.

Connective tissue growth factor (CTGF/CCN2) and bone morphogenetic protein (BMP)-2 are both produced and secreted by osteoblasts. Both proteins have been shown to have independent effects in regulating osteoblast proliferation, maturation and mineralization. However, how these two proteins interact during osteoblast differentiation remains unknown. In Chapters 2 and 3, we utilized two cell culture model systems, osteoblasts derived from CTGF knockout (KO) mice and osteoblasts infected with an adenovirus, which over-expresses CTGF (Ad-CTGF), to investigate the effects of CTGF and BMP-2 on osteoblast development and function in vitro. To observe differences in osteoblast maturation and mineralization, we performed alkaline phosphatase (ALP) staining and activity and alizarin red staining, respectively. Contrary to a previously published report, osteoblast maturation and mineralization were similar in osteogenic cultures derived from KO and wild type (WT) calvaria in the absence of BMP-2 stimulation. Interestingly, in KO and WT osteoblast cultures stimulated with BMP-2, the KO osteoblast cultures exhibited increased alkaline phosphatase staining and activity and had larger, fused nodules stained with alizarin red than WT osteoblast cultures. This increase in osteoblast differentiation was accompanied by increased protein levels of phosphorylated Smad 1/5/8 and mRNA expression levels of bone morphogenetic protein receptor Ib. These data confirm enhanced osteoblast maturation and mineralization in BMP-2 induced KO osteoblast cultures. We also examined osteoblast differentiation in cultures that were infected with Ad-CTGF and in control cultures. Continuous over-expression of CTGF resulted in decreased ALP staining and activity, alizarin red staining, and mRNA expression of osteoblast markers in both unstimulated and BMP-2 stimulated cultures. Impaired osteoblast differentiation in cultures over-expressing CTGF was accompanied by decreased protein levels of phosphorylated Smad 1/5/8. In addition to the functional assays that we performed on WT and KO osteoblast cultures, we performed ChIP assays to investigate differences in binding occupancy of transcription factors on the Runx2 and Osteocalcin promoters in BMP-2 induced WT and KO osteoblast cultures. We demonstrate that in BMP-2 induced WT and KO osteoblast cultures, there was greater Smad 1 and JunB occupancy on the Runx2 promoter and Runx2 occupancy on the Osteocalcin promoter in BMP-2 induced KO osteoblast cultures compared to WT cultures. Collectively, the data demonstrate that CTGF acts to negatively regulate BMP-2 induced signaling and osteoblast differentiation. In Chapter 4, we synthesized an active His-tagged BMP-2 recombinant protein to track surface binding of BMP-2 in CTGF WT and KO osteoblasts. We amplified mature BMP-2 in genomic DNA, which was inserted correctly into a pET-28b(+) vector. We ran a SDS-PAGE gel and stained with Coomassie blue to show that we successfully induced BMP-2 in bacteria cells, extracted the protein using urea, and purified and eluted the protein using Nickel charged agarose beads and imidazole elution buffer. Furthermore, by Western blot analysis using anti-His antibody, we confirmed the presence of the His-tag on the BMP-2 protein. Lastly, ALP staining on osteoblast cultures stimulated with our synthesized BMP-2 exhibited increased staining compared to the unstimulated osteoblast cultures, which confirmed the activity of our His-tagged BMP-2 protein. Future studies utilizing this protein will demonstrate that CTGF acts as an extracellular antagonist by limiting the amount of BMP-2 available for receptor binding. / Cell Biology

Application of biosolids as an alternative source of Nitrogen (N) is becoming a common silviculture practices on loblolly pine forest. However, little is known about how biosolids type, application rate, and timing affect forest floor and soil N availability in pine plantations. The objectives of this study were to determine the effect of different types, rates, and season of application of biosolids on forest floor and soil N. The study was established in a 17-year-old loblolly pine plantation in Amelia County, VA. Anaerobically digested (AD225), lime stabilized (LS225), and pelletized (Pellet225) biosolids and a conventional inorganic urea plus diammonium phosphate fertilizer (U+DAP225) were surface applied at a rate of 225 kg ha-1 based on Plant Available Nitrogen (PAN) between March 5th and 10th, 2006. Anaerobically digested biosolids were also surface applied at the rates of 900 kg PAN ha-1 and 1800 kg PAN ha<sup>-</sup¹ (AD900 and AD1800). Anaerobically digested biosolids at the rate of 900 kg PAN ha⁻¹ were also applied on November 5th, 2005 (AD900F). Surface application of different type of biosolids in a loblolly pine plantation increased soil N availability and mineralization when biosolids were applied at the permitted rate of 225 kg PAN ha⁻¹. Surface soil NH₄-N and NO₃-N availability and N mineralization was significantly different among biosolids type over time. N release from different type of biosolids depends on the initial inorganic N content, and N mineralization in biosolids. The average soil N availability and mineralization was significantly greater in the Pellet225 treatments than in all the other treatments. Soil N availability decreased in winter in all the treatments but remained generally higher than the control until the end of the second growing season. Nitrate-N concentrations in lysimeters were below water quality standard limits in all the treatments applied at the rate of 225 kg PAN ha⁻¹. Accumulation of N, C, and Ca in the forest floor was well correlated with the amount of biosolids applied on each treatment. The surface application of different type of biosolids had minimal impact upon total N and C in the mineral soil. Increasing application rates of anaerobically digested biosolids directly increased soil N availability and mineralization. Nitrate-N concentrations in lysimeters were above water quality standards limits during several months in the AD900 and AD1800 treatments. Significant differences in the forest floor total N, C and Ca were observed with increasing application rates of biosolids. Total C accumulation was significantly higher in the forest floor in the AD1800 treatment. However, we observed no effect on soil total C with increasing application rates of biosolids. We found that biosolids application during spring significantly increased soil extractable N, N mineralization, NO₃-N leaching, and total C in the mineral soil in comparison to the fall application. Fall application significantly increased NH₄-N leaching and soil extractable Ca. We observed no significant effect on ion exchangeable N measured on membranes, total N, C, Ca, and pH measured in the forest floor, and soil total N and pH in the mineral soil. Our results demonstrated that permitted surface application of biosolids at the rate of 225 kg PAN ha⁻¹ in a loblolly pine plantation increased surface soil N availability without increasing the potential for NO₃-N groundwater pollution. / Ph. D.