Liver fatty acid binding protein (L-FABP) binds and translocates many lipophilic substrates within the cytoplasm including long chain fatty acids. Moreover it was reported that L-FABP possesses antioxidative properties within hepatocytes. However, the mechanism of L-FABP’s antioxidative activity remains to be determined. Peroxisome proliferator activated receptor (PPAR) agonists and antagonists can regulate L-FABP levels. However, it needs to be investigated how PPAR agonists and antagonists regulate L-FABP expression. And whether the altered expression of L-FABP by these agents will affect its antioxidative properties within hepatocytes remains unclear. In this thesis we employed clofibrate (PPARα agonist), MK886 (PPARα antagonist), and GW9662 (PPARγ antagonist) to elucidate the mechanism whereby PPAR regulate L-FABP expression and what effect such expression has on the antioxidant activity of L-FABP in CRL-1548 hepatoma cells. Clofibrate served to upregulate L-FABP expression while MK886 and GW9662 were employed to inhibit L-FABP expression. The principal findings revealed that clofibrate treatment enhanced L-FABP mRNA stability and transcription, which resulted in increased L-FABP levels, while MK866 and GW9662 reduced these levels. We also demonstrated that increases in L-FABP levels were associated with reduced cytosolic reactive oxygen species (ROS), while L-FABP siRNA knockdown resulted in a decrease in L-FABP expression and an associated increase in ROS levels. The antioxidant mechanism of recombinant rat L-FABP in the presence of a hydrophilic (AAPH) and lipophilic (AMVN) free radical generators was also evaluated. Recombinant rat L-FABP was produced in E. coli and its amino acid sequence was confirmed by MALDI QqTOF MS. Antioxidant activity was assayed using the thiobarbituric acid method. Ascorbic acid served as a positive control for the AAPH reaction while α-tocopherol was used as a positive control for the AMVN reaction. The antioxidant activity of recombinant L-FABP was greater when free radicals were generated with AAPH than AMVN. Oxidative modification of L-FABP included up to five methionine oxidative peptides with a total of 80 Da mass shift compared to native L-FABP. These findings suggest that the mechanism of L-FABP’s antioxidant activity involved the reaction of methionine with free radicals. In conclusion, L-FABP expression is regulated by PPAR agonists and antagonists through transcription and mRNA stability. Moreover, methionine residues appear to play an important role in the antioxidative activity of L-FABP.

The local livelihood systems of Tam Giang Lagoon, Central Vietnam have shifted since the policy changes of 1986. Aquaculture has replaced capture fishing as the most important livelihood activity in the lagoon. Aquaculture is governed by both customary and legal access rights. The move from a centrally-planned (collectivization) economy to a market-oriented economy in conjunction with the development of the aquaculture sector has had significant impacts. This change has reduced the available lagoon areas for mobile-gear fishers, polarized different user-groups, and raised the issue of resource access inequity. The overarching objective of this thesis is to understand the complexity and influence of property rights on local livelihood systems; specifically: (1) to examine changes in resource access and various types of resource use in the lagoon; (2) to analyse the effects of aquaculture and changes in resource access on local livelihood systems; and (3) to assess the resilience of livelihood systems and identify the essential elements that contribute to resilience in livelihood systems. Qualitative and quantitative research methods were used for data collection. Sixty-five semi-structured interviews were conducted and fourteen households were selected for an additional in-depth livelihood analysis. Focus group discussions were one of the most important methods used for data collection. Fifteen formal focus groups and several informal discussions were organized. Both types of focus groups were used in conjunction with a number of participatory methods, such as seasonal calendar, participatory mapping, and well-being ranking. The field work was conducted over twenty-nine months between December, 2005 and April, 2008. The research examined the evolution of property rights and the complexity of resource access in Thuy Dien village. The research investigated seven types of resource use which are associated with “bundles of rights” and discussed the dynamics of property rights governed by both laws and customs. De jure and de facto rights were classified in different time periods by using Schlager and Ostrom’s framework. By applying a sustainable livelihood framework, the research presented overview of livelihood systems and discussed the influence of property rights on household livelihoods. Households in the village were classified into four groups: (1) earth pond, (2) net-enclosure; (3) mobile fishing; and (4) non-fishing households. Attention was paid to the disparity between these household types in term of livelihood strategies and opportunities for livelihood development. The research applied a resilience approach to the analysis of the local livelihood systems. Resilience is an inherent attribute of sustainable livelihood systems because it implies the flexibility and availability of options. If resilience is lost, livelihood systems may cross a threshold and shift to a different regime or alternative equilibrium. In Tam Giang Lagoon, a shift to a different regime seemed to have occurred over the last two decades.

Cadmium (Cd) is a potentially toxic trace element. Two growth chamber studies were conducted to understand how: i) mono-ammonium phosphate affects durum wheat, flax or canola Cd uptake due to fertilizer induced changes in soil solution and plant; ii) preceding canola and barley affect the Cd uptake of subsequent durum wheat or flax. Durum wheat and flax shoot Cd concentrations were greater when grown on previous crop canola soil than when grown on previous crop barley soil regardless of what type of crop residue, if any, was added. The increase in Cd uptake for durum wheat and flax when on canola soil was probably due to increased availability of Cd in soil. Conversely, the application of mono-ammonium phosphate – reagent grade and the incorporation of preceding crop residue did not increase the crop Cd uptake of canola, durum wheat or flax and durum wheat or flax, respectively.

Crude gliadins were extracted from Canada Western Red Spring (CWRS) wheat flour with 70% (v/v) aqueous ethanol solutions and then lyophilized. Lyophilized crude gliadins were dissolved in 70% (v/v) aqueous ethanol (EtOH) or 4 mM acetic acid (HAc) and the density and ultrasound properties were measured at 20 °C. Good linear relationships of density, ultrasound velocity and ultrasound attenuation with solution concentrations were found. Solvent and sonication effects on the crude gliadins were discussed in terms of the values of the partial specific volume and the partial specific adiabatic compressibility coefficient for crude gliadins. The ethanol soluble crude gliadins had a larger partial specific volume and larger partial specific adiabatic compressibility coefficient than those for acidic soluble crude gliadins. These large values for the physical properties of ethanol soluble crude gliadins were thought to be evidence for the existence of complexes formed by some proteins (ethanol soluble LMW-glutenins and gliadins) and lipids in ethanol solutions and it was also found that the protein-lipid complexes were not destroyed by sonication treatment. Besides, there was no evidence showing that gliadins change with different wheat flours and cause different volume and compressibility properties of crude gliadins.

Introduction: The ideal timing to initiate orthodontic treatment is an important, yet controversial issue. The purpose of this study was to investigate the provision of orthodontic care for 7 types of skeletal dysplasia by paediatric dentists and orthodontists in Canada. Methods: A questionnaire was distributed to randomly selected orthodontists (N=140) and paediatric dentists (N=132) throughout Canada. Surveys returned within 8 weeks were included for c2 statistical analysis. Results: The response rate was 59% for orthodontists and 54% for pediatric dentists. Orthodontists and pediatric dentists differed significantly in the timing of their first orthodontic consultation (p < 0.01). More pediatric dentists used to the dental age to determine the appropriate time to initiate treatment (p < 0.01), whereas more orthodontists relied on the pubertal indicators (p < 0.01). More orthodontists would intervene in the early mixed dentition for moderate mandibular prognathia (p < 0.01); mid-mixed dentition for severe mandibular retrognathia (p < 0.01), late mixed dentition for moderate mandibular retrognathia (p < 0.01) and permanent dentition for skeletal openbite and severe mandibular prognathia (p < 0.01). Most pediatric dentists would intervene in the early and mid-mixed dentition for the specified cases of skeletal malocclusions (p < 0.05). Conclusions: The results of this investigation indicate both consistencies and variation between orthodontic and paediatric practitioners with regard to preference in treatment timing, and the factors that influence these decisions.

Purpose: To evaluate the in vitro shear bond strength (SBS) of orthodontic attachments using 2 self-etching primers (SEP): iBOND and G-Bond. Methods: 180 molars were randomly divided into 12 groups. Teeth were bonded with a stainless steel button using Transbond XT composite. The bonding agents were iBOND, G-Bond, Transbond Plus SEP and Transbond XT primer (control). SBS’s immediately, 24hours and 3months were measured with their Adhesive Remnant Index (ARI). Results: Transbond XT primer (11.22MPa) had a significantly higher immediate SBS than Transbond Plus SEP (5.32MPa), iBOND (6.69MPa) and G-Bond (8.30MPa). 24 hours, Transbond XT primer (16.65MPa) and Transbond Plus SEP (13.20MPa) had a significant increase in their SBS. No difference was observed at 3 months. ARI were significantly different between the groups at all time points. Conclusions: iBOND and G-Bond yielded sufficient SBS’s over the three time points that may be sufficient to withstand occlusal and light archwire forces.

Objective: To collect data regarding Canadian laypersons perceptions of smile esthetics and compare these data to US data in order to evaluate cultural differences. Methods: Using Adobe® Photoshop® 7, a digital image of a posed smile of a sexually ambiguous lower face was prepared so that hard and soft tissue could be manipulated to alter Buccal Corridor (BC), Gingival display (GD), Occlusal Cant (OC), Maxillary Midline to Face Discrepancy (MMFD) and Lateral Central Gingival Discrepancy (LCGD). Adult Canadian laypersons (n=103) completed an interactive computer-based survey of 29 randomized images to compare smile preferences for these variable. The custom survey was developed to display fluid, continuously appearing modifiable smile variables using MATLAB® R2008 for presentation. These data were compared to previously published data for US laypersons. Statistical inference was determined using Wilcoxon Rank Sum tests. Results: Canadian laypersons were more sensitive in detecting deviations from ideal and had a narrower range of acceptability thresholds for BC, GD, OC, MMFD and LCGD. Ideal esthetic values were significantly different only for BC. Conclusions: It appears cultural differences do exist related to smile characteristics. Clinically significant differences in the preference of the smile characteristics were found between Canadian and US laypersons. Canadian laypersons, on average, were more discriminating to deviations from ideal and had a narrower range of acceptability.

Overhead transmission lines are prone to undergo large amplitude, low frequency vibrations when exposed to freezing rain and steady side winds. These vibrations are referred to as galloping. They involve a dominant vertical motion in addition to twisting and horizontal swaying. Field reports indicate that the majority of galloping cases are associated with lightly-iced lines with thin ice accretions. Previous studies have failed to explain this trend satisfactorily. The present thesis involves a series of wind tunnel experiments to understand the rotational effects in lightly-iced transmission line galloping. The work to restore and upgrade the wind tunnel used for the experiments are also reported. Aerodynamic loads are measured first on a stationary model of a short, representative section of a lightly-iced conductor. Subsequently, automated controls force the model to undergo rotational oscillations, and the aerodynamic loads measured from these dynamic tests are compared to the stationary results. The airflow in both sets of experiments is visualised by using a laser-based system. The stationary test shows that the well-established den Hartog criterion for predicting vertical galloping does not explain why lightly-iced lines gallop. The dynamic experiments however confirm the presence of rotation-induced lift, unaccounted for by quasi-steady theory and the den Hartog criterion. This additional lift force increases the coupling between the rotational and vertical directions and may promote coupled aerodynamic instability. Visualisations indicate that the surface irregularities of the ice and the rotational motion are jointly responsible for the rotation-induced lift forces observed in the aerodynamic measurements.

Fourteen varieties of wheat grown in western Canada were assessed for differences in starch content and structure. Physicochemical properties of starch such as amylopectin to amylose ratio, starch granule morphology, and thermal and pasting properties were all found to vary significantly between varieties. Enzymatic susceptibility was measured using industrial α-amylase to hydrolyze gelatinized starches and resultant reducing sugar content ranged from ~407−500mg glucose equivalents per gram starch, indicating different patterns of oligosaccharide chain lengths present after hydrolysis. During fermentation striking differences in glucose generation were observed, the high glucose cohort averaged 1.21 g/g-starch for the initial time point, compared to a range of 0.83−1.05 g/g-starch for the low glucose cohort. In general, the pattern of glucose generation appears to be consistent with ethanol and biomass production. Correlating structural attributes with fermentation performance suggests that amylopectin to amylose ratio is the most predictive factor in the pattern of wheat starch hydrolysis.

Atmospheric icing is a major design factor for guyed lattice masts and transmission lines in Canada and many others countries with cold climate. Tall and slender guyed lattice towers are particularly sensitive to ice accretion, wind or combination of both, as they are often located in remote areas, where meteorological data are limited. The variation of local topography and seasonal climate affects icing conditions and complicates standardization of icing accretion design guidelines. Icing design criteria was evaluated in this study through an extensive literature review of current design standards for latticed structures subjected to ice and wind load and/or a combination of both, field and laboratory work.