In the present study, the corrosion behaviour of several magnesia-chrome (MC) and magnesia-alumina spinel (MA) bricks against fayalite type slags was investigated and the role of the spinel phases was highlighted . The experimental results revealed that the corrosion resistance of the MC bricks was superior to the MA bricks against KIVCET slags in static and dynamic conditions . As a result of the interaction between MgO from MC bricks and the slag, a modified forsterite phase (Mg, Fe, Zn, Ca)₂SiO₄ was formed, which destroyed the precipitated complex spinel bonds at the grain boundaries of periclase and magnesia-chromia spinel . Furthermore, both MgO and MgO-MgAl₂O₄ spinel in the MA brick dissolved into the slag, which resulted in modified forsterite phases of (Mg, Fe, Zn, Ca)₂SiO₄ and (Mg, Fe, Zn)(Fe, Al)₂O₄ complex spinels, respectively. In addition, the accretion formation in the KIVCET furnace was investigated through solubility experiments of Cr₂0₃ in the KIVCET slag with various amounts of lead, which revealed that the net contribution of Cr₂0₃ to the spinel formation is the highest in the barren (no Pb) slag, followed by high-lead (11% Pb) and it is the lowest for the low-lead (6% Pb) slag. The amount of spinel solid solution increased consistently with increasing Cr₂0₃ dissolved and the PbO existent in the slag. From examinations of several used bricks from the tuyere area of a Peirce Smith nickel converter, it was found that the corrosion is due to the interaction of the partially oxidized matte penetrating deep into the brick and the magnesia grains forming (Mg, Fe, Ni, Co) xOy spinels . Analyses of brick samples used in the KIVCET Electric Furnace roof identified deep reaching sulphation, which weakened the bonding phase between coarse magnesia grains. In the Bottom Blown Oxygen Converter, a highly aggressive lead and bismuth oxide rich slag penetrated deep into the brick, which destroyed the grain boundaries, causing the refractory to be easily eroded at the refractory-slag interface. Our studies concluded that the spinel phases, either as magnesium chromate, magnesium aluminate or complex spinel [(Mg, Fe)(Cr, Al, Fe)₂O₄], enhanced the corrosion resistance of a basic refractory to fayalite type slags from the non-ferrous smelting and converting furnaces.

The literature comparing macronutrient metabolism in healthy and diabetic subjects is abundant; however, little data exists on how non-diabetic subjects with insulin resistance handle macronutrient. We did two studies to investigate the postprandial responses to macronutrient in healthy, hyperinsulinemic and type 2 diabetic (T2DM) subjects. In the first study, twenty-five healthy, non-diabetic subjects [9 with fasting serum insulin (FSI) <40pmol/L; 8 with 40 ≤ FSI < 70pmol/L; and 8 with FSI ≥ 70 pmol/L] were fed eleven test meals (50g oral glucose with 0-30g doses of canola oil or whey protein) after an overnight fast. There were no significant FSI × fat (p=0.19) or FSI × protein (p=0.08) interaction effects on glucose response, suggesting that the effects of fat or protein on glycemia were independent of FSI of the subjects. In addition, the changes in relative glucose response per gram of fat (r = -0.05, p = 0.82) or protein (r = 0.08, p = 0.70) were not related to FSI of the subjects. In the second study, Healthy (FSI < 40pmol/L), Hyperinsulinemic (FSI ≥ 40pmol/L), and T2DM were fed five foods with 50g available carbohydrate. Among the subject-groups, the Glycemic Index (GI) values were not significantly different for each food, and the mean (±SEM) GI values of all foods were not significantly different (p>0.05). However, the mean (±SEM) Insulinemic Index of the foods was higher in T2DM (100±7, n=10) than those of Healthy (78±5, n=9) and Hyperinsulinemic subjects (70±5, n=12) (p=0.05). The Insulinemic Index was inversely associated with insulin sensitivity (r=-0.66, p<0.0001), positively related to fasting- and postprandial-glucose (both r=0.68, p<0.0001) and hepatic insulin extraction (r=0.62, p=0.0002). The oral-glucose data were pooled from the two studies to investigate whether there was any relationship between GLP-1 and insulin sensitivity, β-cell function and hepatic insulin extraction. No significant correlation was observed (p>0.05). The results suggest that the glucose-lowering effect of fat and protein is not affected by insulin sensitivity. GI is independent of the metabolic status of the subjects; however, unlike GI, Insulinemic Index is influenced by the metabolic status of the subjects, and thus may have limited clinical utility.

The purpose of this research is to examine past and present Indigenous music and how both interconnect in a continuum of sound and meaning. This research is intended to address the value and benefits of Indigenous music in today’s society based on the past practice of music as an integral aspect of all elements of life. With a main focus on Northern Plains knowledge of music, elements of continuity illustrate how Indigenous music promotes resistance, social change and healing for both rural and urban Indigenous peoples. The research methodology is based on an Indigenous knowledge framework that prioritizes the study of Indigenous music through an Indigenous lens. Interviews with musicians and ceremonialists confirm that Indigenous music relates to and is embedded in the physical, political, economical and spiritual worlds. Through a trans-disciplinary approach, this thesis allows reconsideration of the place and space in which Indigenous music dwells within our current culture. By reassessing the limited definitions of traditional, this study shows that the idea of Indigenous music becomes an emancipatory, evolving and constant stream of consciousness embedded in the adaptations of our people. With the interviewees’ knowledge, I have constructed a unique understanding of Indigenous music, how it adapts with modernization, yet maintains an original intention, purpose, meaning and message. Indigenous worldview, consisting of ceremonies, protocols, teachings and knowledge of history, ensures continued existence through song and music. I focused on the drum, women’s roles, prayers, language and hip hop as examples of resistance within Indigenous nations. As we begin to consider decolonization strategies within Indigenous communities, musicians and ceremonialists serve an essential role in this process.

The rapid and wide scale environmental spread of multi-drug resistant bacteria is a seriousissue in recent years. Drug resistant bacteria have already occupied different ecologicalniches in many places, from wilderness to densely populated urban areas. To investigate theecological niches in Bangladesh samples were collected from wild migratory bird speciesOpen Bill Stork (Anastomus oscitans) and from the nearby water sources where these birdsvisited. A total of 76 E. coli isolates from the 170 OBS (Open Bill Stork) fecal samples and8 E. coli isolates from 3 river sources were isolated. Disk diffusion was used for checking thesusceptibility of the isolates against antibiotics that are common in human and veterinarymedicine in Bangladesh. It was found that 28.95%OBS and all water E. coli isolates wereresistant to at least one of the tested antibiotics. Common resistant phenotypes wereAmpicillin, Tetracycline, Aztreonam, Nalidixic Acid and Ciprofloxacin. Multi-drugresistance identified from 2.63%OBS and most of the water isolates. Very fewESBL(Extended Spectrum Beta-Lactamase) producing E. coli were found from OBS,whereas 50% of E. coli water isolates were ESBL producer, with all the ESBL producerspossessing the CTX-M-15 gene. The most concerning aspect of our findings was the presenceof human associated E. coli sequence types in water samples, for example ST156-complex156, ST10-complex10 and ST46. This study concludes the contaminationof environmental niches in Bangladesh by resistant bacteria.

Multidrug resistance protein 1 (MRP1) is an integral membrane protein belonging to the ATP-binding cassette (ABC) superfamily that utilizes ATP binding and hydrolysis to transport various endogenous substrates and/or xenobiotics across membranes against a concentration gradient. The overall goal of my research was to examine the nucleotide and protein interactions of MRP1 using various biochemical methods. In the first study, Cu2+(Ph)3 which promotes cross-linking of two nearby Cys residues and limited proteolysis were used to study conformational changes of MRP1 at different stages of ATP binding and hydrolysis at the nucleotide binding domains (NBDs). The limited trypsin digestion patterns indicated that some Cys residues of MRP1 could be cross-linked in the nucleotide-free state and that the Cys cross-linked MRP1 was more susceptible to trypsinolysis. Furthermore, binding of ATP, AMP-PNP, and trapping of ADP by MRP1 prevented the cross-linking events from occurring, but binding of ATPγS did not. However, the ATPγS-bound MRP1, like nucleotide-free MRP1, showed enhanced sensitivity towards trypsinolysis. These studies show that the two ATP analogs, AMP-PNP and ATPγS, interact with MRP1 in different ways. In the second study, the interaction of MRP1 with other cellular proteins was examined. An in vivo chemical cross-linking approach combined with affinity purification and MS analysis was initially used to identify protein partners directly interacting with MRP1. When this approach proved unsuccessful, a second approach involving immunoaffinity purification of MRP1-containing complexes followed by MS analysis was adopted. Six potential candidate interacting protein partners of MRP1 were identified via this approach and two of them, FUS and drebrin, were further characterized by co-immunoprecipitation and colocalization experiments. FUS seems unlikely to be an important binding partner of MRP1 since confocal and subcellular fractionation studies showed it to be exclusively localized in the nucleus. On the other hand, drebrin depletion by siRNA knock-down resulted in a moderate decrease in MRP1 overall expression levels although the membrane localization of MRP1 remained unchanged. / Thesis (Master, Pathology & Molecular Medicine) -- Queen's University, 2008-12-08 17:44:52.767

The purpose of this study was to determine if, after adjusting for the contribution of exercise dose, exercise intensity was associated with the improvement of insulin sensitivity. Abdominally obese, sedentary men (n = 16, [mean±SD] age: 45.0±7.5 yr; waist circumference: 108.6±5.3 cm) and women (n = 18, [mean±SD] age: 42.3±6.2 yr; waist circumference: 100.1±8.2 cm) performed daily, supervised exercise for 3 and 4 months, respectively. Exercising at a self selected exercise intensity, men were required to expend expended 700 kcal per session and women 500 kcal per session. Exercise intensity and dose were determined using heart rate and oxygen consumption data obtained from repeated graded exercise tests. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. Insulin sensitivity improved in both men and women (change score: men = 7.2±5.4 mg/kgskm/min, women = 5.8±7.1 mg/kgskm/min) (p < 0.05). Exercise intensity was associated with the improvements in insulin sensitivity in men (unstandardized regression coefficient (β) = 0.43, p = 0.02). Adjusting for exercise dose, the change in abdominal adipose tissue (AT), or the change visceral AT did not alter this association (p < 0.05). Exercise intensity was not associated with the improvement of insulin sensitivity in women (β = - 0.11, p = 0.7). Adjusting for exercise dose, the change in abdominal or visceral AT did not change the association in women (p > 0.05). Our findings suggest that exercise intensity is independently associated with the improvement of insulin sensitivity in abdominally obese men but not women. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2011-06-13 19:56:40.465

Fibre reinforced polymer (FRP) materials have been a material of interest in the field of structural engineering due to their superior mechanical properties such as high strength to weight ratios and resistance to environmental degradation and corrosion. Even though research has established the material to be a viable option for construction they are highly susceptible to elevated temperatures. There are several systems available on the market and a great deal of research needs to be conducted to investigate the change in properties and different behaviour at elevated temperature to serve as a better basis for design. The main objective of this project and the experimental program presented in this thesis is to study the thermo mechanical properties of the available systems on the market. A summary of the previous research done in the area covering other materials is presented providing an introduction to the behaviour of different systems under elevated temperature. Then, two different experimental programs are presented. The first considers the glass transition temperature and thermal decomposition of the different systems and the second examines the tensile strength of the different systems under different temperature regimes. The results of both experimental programs are presented and then a connection between the thermo mechanical properties of the resins and the overall strength of the system is established. The research demonstrates that the glass transition temperature of the resin used for an FRP strengthening system is the main determinant of the performance at high temperatures. / Thesis (Master, Civil Engineering) -- Queen's University, 2011-06-16 09:21:32.228

Pseudomonas aeruginosa is an opportunistic pathogen found in soil and aquatic environments that possesses a broad range of intrinsic antibiotic resistance mechanisms, including a highly impermeable outer membrane and several RND-type efflux pumps that export a number of clinically relevant antibiotic classes. Chronic P. aeruginosa infections in cystic fibrosis (CF) patients gradually develop high levels of resistance to antimicrobial therapy due to conditions that favour the acquisition and selection of numerous chromosomal mutations, the nature of which are poorly understood. To identify chromosomal contributors to aminoglycoside resistance a P. aeruginosa transposon mutant library was screened for increases in aminoglycoside susceptibility. Six genes of interest (pstB, lptA, faoA, amgR, PA0392, and PA2798) were identified, the deletion of which meaningfully decreased aminoglycoside minimum inhibitory concentrations in wild-type P. aeruginosa. Combinations of gene deletions were constructed to determine if any of these genes contributed to aminoglycoside resistance via a common mechanism or whether they operated independently to promote intrinsic aminoglycoside resistance. In all cases, double deletion had an additive impact on aminoglycoside susceptibility, suggesting that each gene of interest contributes to resistance through an independent mechanism. Deletions in pstB, lptA, faoA, amgR, PA0392, and PA2798 were introduced into pan-aminoglycoside-resistant CF-lung isolates where they dramatically compromised aminoglycoside resistance, indicating that these genes also contribute to acquired aminoglycoside resistance in chronic P. aeruginosa infections. A fluorimetric assay was developed to measure aminoglycoside-induced membrane depolarization using the voltage sensitive probe DIBAC4(3). Gentamicin-induced membrane depolarization was found to be substantially increased in the amgR, pstB, and PA0392 mutant strains when compared to wild-type P. aeruginosa. These increases in depolarization paralleled declines in cell viability as measured by a gentamicin killing assay, suggesting that the cytoplasmic membranes of these mutant strains are more sensitive to the membrane perturbing effects of aminoglycoside-induced mistranslated proteins, and supporting a role for the disruption of the selective barrier of the cytoplasmic membrane in the bactericidal activity of the aminoglycosides. This study describes novel contributors to intrinsic and acquired aminoglycoside resistance in P. aeruginosa, and highlights the importance of membrane functions in resisting these activities. / Thesis (Master, Microbiology & Immunology) -- Queen's University, 2012-09-21 21:27:23.303

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