Osteoporosis is caused by loss of bone mineral content, which leads to bone fractures or structural deformations of bone. Osteoporosis usually occurs when people get older, after menopause in women, or it can be caused by a lack in the intake of a sufficient amount of calcium and vitamin D. Until recently, osteoporosis was considered to be an unavoidable part of aging, but today, approved and effective treatments can be used to deal with the consequences. At present, determination of risk of bone abnormalities is done by measuring the density of bone (largely determined by calcium content). Dual energy X-ray Absorptiometry (DXA) is the gold standard technique for measuring bone mineral density (BMD). Even though BMD is one of the principal determinants of bone strength, BMD measurements do not give information about variation of trabecular structure of bone. That's why DXA alone has limited ability to predict who will sustain an osteoporotic fracture. To predict fracture risk of patients, the texture analysis of the DXA images is of interest as a measure to predict fracture in addition to BMD. This thesis focuses on the application of texture analysis to digital images of bone scans of patients at risk of fracture and osteoporosis. Texture analysis was performed by analyzing the variation of grey level patterns of pixels of DXA images. Texture analysis of such images will give an idea of the variation of grey scale patterns of pixels between normal and osteoporotic DXA images of bone. Existing texture analysis measures such as contrast measures of co-occurrence matrices and mean slope value of fractal dimension based measure are used to analyze the texture of DXA images. An alternative partitioning technique is proposed as a measure of the texture analysis.

The existence of anchor ice in supercooled water can have a profound impact on the management of water resource infrastructures in cold regions. For example, it can raise a tailrace water level and cause significant losses in generation revenue. So far, there have been limited studies on anchor ice, therefore, many problems still exist and much more study is needed. In the present research, experimental and mathematical studies of anchor ice were carried out. Experiments were conducted in a counter-rotating flume, located in a cold room at the University of Manitoba. The experiments were mainly focused on anchor ice evolution around rocks and on gravel beds under different hydro-meteorological conditions. The results are compared to a mathematical model developed herein and some important parameters such as anchor ice porosity and frazil ice deposition coefficient are examined. The growth process of anchor ice was monitored by two CCD cameras. A digital processing program was developed to analyze anchor ice images and determine the growth rate of anchor ice. In addition, anchor ice density, an important factor when studying anchor ice, was estimated and the effect of air temperature, Froude number and Reynolds number is explored. By analyzing torque load signals from the counter-rotating flume, the variation of bed roughness with the growth of anchor ice is elucidated. The deposition coefficient of anchor ice growth was also determined from the experiments. A mathematical model was developed based on a two-stage method to simulate the process of frazil ice transportation and deposition. Both frazil ice attachment and heat transfer between the supercooled water and ice crystals are considered in the model. Four governing equations related to the distribution of velocity and frazil ice transportation and deposition inside and outside the roughness layers were built. A fourth-order Runge- Kutta numerical method was used and programmed in Matlab to solve the governing equations. The growth rate of anchor ice under different hydro-meteorological conditions can be simulated by this numerical model. The proposed experimental and mathematical studies of anchor ice are presented intuitively in this paper and the results from this study contribute to a better understanding of the anchor ice growth mechanism. This study will help to develop better management strategies to mitigate ice related complications associated with hydroelectric generating stations and other hydraulic structures in cold regions.

The focus of this research is on a tolerance space-based approach to image analysis and correspondence. The problem considered in this thesis is one of extracting perceptually relevant information from groups of objects based on their descriptions. Object descriptions are represented by feature vectors containing probe function values in a manner similar to feature extraction in pattern classification theory. The motivation behind this work is the synthesizing of human perception of nearness for improvement of image processing systems. In these systems, the desired output is similar to the output of a human performing the same task. Thus, it is important to have systems that accurately model human perception. Near set theory provides a framework for measuring the similarity of objects based on features that describe them in much the same way that humans perceive the similarity of objects. In this thesis, near set theory is presented and advanced, and work is presented toward a near set approach to performing content-based image retrieval. Furthermore, results are given based on these new techniques and future work is presented. The contributions of this thesis are: the introduction of a nearness measure to determine the degree that near sets resemble each other; a systematic approach to finding tolerance classes, together with proofs demonstrating that the proposed approach will find all tolerance classes on a set of objects; an approach to applying near set theory to images; the application of near set theory to the problem of content-based image retrieval; demonstration that near set theory is well suited to solving problems in which the outcome is similar to that of human perception; two other near set measures, one based on Hausdorff distance, the other based on Hamming distance.

The overall context of this thesis research is to explore natural language as a medium to interact with computer software in the graphics domain, e.g. programs like MS Paint or OpenGL. A core element of most natural language understanding systems is an ontology, which represents concepts and items of the underlying domain of discourse. This thesis presents an ontology for the graphics domain based on several resources, including documentation and textbooks on graphics systems, existing ontologies, and - most importantly - a collection of natural language instructions to create and modify graphic images. The ontology was developed in several phases, and finally tested as part of a complex natural language interface. This natural language interface accepts verbal instructions in the graphics domain as input and creates matching graphic images as output. The results of our tests indicate an accuracy of the system in the area of 80%.

To improve our understanding of how environmental mercury (Hg) concentrations influence Hg in fish, I conducted a field experiment to quantify the relative contributions of dietary and aqueous exposure to Hg levels in fish. To further assess the importance of water as a source of Hg to fish, a long-term dataset from the Mercury Experiment to Assess Atmospheric Loading in Canada and the United States was used as input data for two Hg bioaccumulation models: OneFish (accumulation from food and water) and Wisconsin (accumulation from food). Both approaches used enriched stable isotopes of Hg. Yellow perch accumulated 10-21% of their Hg directly from water. Wisconsin model predictions were significantly lower than observed fish Hg concentrations and OneFish predictions. These results suggest that waterborne Hg is an important contributor to Hg in fish and that the exclusion of water in bioaccumulation models may produce underestimates of fish Hg concentrations.

The research work presented in this thesis investigates the mechanistic details of conventional as well as electrochemically directed self-assembly of alkylthiosulfates and explores the use of conjugated semiconducting polymers for organic electronic applications. Here, the significance of the use of conjugated polymers is twofold; first, to explore their applications in nanoelectronics and second, the possibility of using them as a top contact on the self-assembled monolayers (SAMs) for molecular electronic applications. Throughout this work, deposition of the organic materials was performed on prefabricated device structures that required no further lithographic or metal deposition steps after modification of the electrodes with the organic molecules. Self-assembly of alkylthiosulfates on gold are reported to form monolayers identical to those formed from the corresponding alkanethiols. However, these self-assembly processes follow more complex mechanisms of monolayer formation than originally recognized. Studies on the mechanism of alkylthiosulfate chemisorption on gold shows that the self-assembly process is influenced by electrolyte and solvent. Plausible mechanisms have been proposed for the role of trace water in the solvent on conventional as well as electrochemically assisted self-assembly of alkylthiosulfates on gold. Electroanalytical and spectroscopic techniques have been used to explore the mechanistic details of electrochemically directed self-assembly of alkylthiosulfates on gold. It has been found that the self-assembly process is dynamic under electrochemical conditions and the heterogeneous electron transfer process between the organosulfur compound and gold is mediated through gold surface oxide and accompanied by corrosion. Conducting polymers are serious candidates for organic electronic applications since their properties can be controlled by the manipulation of molecular architecture. Unique electronic properties of conjugated polypyrrole hybrid materials (PPy0DBS-Li+) with immobile dopant anions and mobile cations have been observed and explained on the basis of movement of the cations in an applied electric field. Based on this principle, functioning polymer resistive memory devices have been demonstrated which can be scalable to lower dimensions for nanoelectronics applications. Finally, proof of concept for using a conducting polymer as a top contact in molecular electronic devices created using electrochemically directed self-assembly is demonstrated.

Computational tools such as finite element analysis and simulation are commonly used for system performance analysis and validation. It is often impractical to rely exclusively on the high-fidelity simulation model for design activities because of high computational costs. Mathematical models are typically constructed to approximate the simulation model to help with the design activities. Such models are referred to as “metamodel.” The process of constructing a metamodel is called “metamodeling.” Metamodeling, however, faces eminent challenges that arise from high-dimensionality of underlying problems, in addition to the high computational costs and unknown function properties (that is black-box functions) of analysis/simulation. The combination of these three challenges defines the so-called high-dimensional, computationally-expensive, and black-box (HEB) problems. Currently there is a lack of practical methods to deal with HEB problems. This dissertation, by means of surveying existing techniques, has found that the major deficiency of the current metamodeling approaches lies in the separation of the metamodeling from the properties of underlying functions. The survey has also identified two promising approaches - mapping and decomposition - for solving HEB problems. A new analytic methodology, radial basis function–high-dimensional model representation (RBF-HDMR), has been proposed to model the HEB problems. The RBF-HDMR decomposes the effects of variables or variable sets on system outputs. The RBF-HDMR, as compared with other metamodels, has three distinct advantages: 1) fundamentally reduces the number of calls to the expensive simulation in order to build a metamodel, thus breaks/alleviates exponentially-increasing computational difficulty; 2) reveals the functional form of the black-box function; and 3) discloses the intrinsic characteristics (for instance, linearity/nonlinearity) of the black-box function. The RBF-HDMR has been intensively tested with mathematical and practical problems chosen from the literature. This methodology has also successfully applied to the power transfer capability analysis of Manitoba-Ontario Electrical Interconnections with 50 variables. The test results demonstrate that the RBF-HDMR is a powerful tool to model large-scale simulation-based engineering problems. The RBF-HDMR model and its constructing approach, therefore, represent a breakthrough in modeling HEB problems and make it possible to optimize high-dimensional simulation-based design problems.

Acute infectious diarrhea (AcID) causes a significant health burden on the population of developed countries, and even a higher burden in the developing world. The only investigation into the causes of AcID in Winnipeg was conducted in the late 1970s. That study determined that 3%-5% of Children’s Hospital Emergency Room (CHER) visits were due to AcID, and about 50% of those were due to rotavirus infections. We conducted a prospective case-control study to reveal the current spectrum of viral pathogens associated with AcID and the distribution and frequency of their occurrence among the pediatric population of Winnipeg. In this study, nucleic acid detection (NAD) and genome sequence information confirmed the presence and identity of each pathogen, and established whether an etiological shift in the distribution of pathogens, both between families and strains of specific pathogens, occurred. Stool samples were collected from pediatric cases with AcID at the ER along with asymptomatic cases for control. A panel of viral nucleic acid detection (NAD) assays was established by the Viral Gastroenteritis Study Group for human astro, calici (Noro and Sapo), entro, polio, hepA, rota and reo viruses according to the published procedures. A new assay for Aichivirus was developed, and the VGSG has established a novel rotavirus assay which is capable of detecting rotavirus from at least 4 different host species (Human, bovine, porcine and simian). Amplified viral targets were sequenced and the information submitted to GeneBank to confirm the strain of each isolate. A total of 1128 patients visited WCHER and WC during the study period and among them 242 patients were enrolled. In 104 cases viruses were identified. A total number of 114 viruses were identified either by NAD or EM assay. Out of 114 viruses, prevalence of HAdV, NoV GI/II and HRV were 44%, 23% and 23% respectively. Mixed infections were found in 4% of cases.This knowledge of pathogen distribution will facilitate design of effective methods for prevention, treatment and intervention in the spread of AcID pathogens.

Many medical imaging applications have been developed so far; however, many of them do not support collaboration and are not remotely accessible (i.e., Telemedicine). Medical imaging applications are not practical for use in clinical workflows unless they are able to communicate with the Picture Archiving and Communications System (PACS). This thesis presents an approach based on a three-tier architecture and provides several components to transform medical imaging applications into collaborative, PACS-based, telemedical systems. A novel method is presented to support PACS connectivity. The method is to use the Digital Imaging and COmmunication in Medicine (DICOM) protocol and enhance transmission time by employing a combination of parallelism and compression methods. Experimental results show up to 1.63 speedup over Local Area Networks (LANs) and up to 16.34 speedup over Wide Area Networks (WANs) compared to the current method of medical data transmission.

Objectives: Inadequate maternal vitamin D (25(OH)D) levels during pregnancy may affect primary tooth calcification predisposing enamel hypoplasia (EH), a risk factor for Early Childhood Caries (ECC). The purpose of the study was to determine the relationship between 25(OH)D status of expectant mothers and the incidence of EH and ECC among their infants. Methods: This prospective study recruited expectant mothers during their second trimester of pregnancy. A prenatal questionnaire was completed and serum sample drawn for a 25(OH)D assay. Infant dental exams, scheduled at approximately 12 months of age, determined EH and ECC, at which time the mother completed a second questionnaire. The dental examiner was blinded to each mother's prenatal vitamin D status. Results: 207 women, 90% of whom self-declared Aboriginal heritage, were enrolled at a mean age of 19.0 ± 4.7 years. The mean serum 25(OH)D was 48.1 ± 24.4 nmol/L. 35% had levels ≤ 35 nmol/L, a formerly-defined threshold of deficiency. Only 10% of women had concentrations ≥ 80 nmol/L, denoting adequacy. 135 infants were examined at 16.1 ± 7.4 months of age. EH was identified in 22% of infants, 23% had ECC and (36% ECC when white spot lesions were included). Mothers of children with EH had lower mean serum 25(OH)D concentrations during pregnancy than mothers of children without EH (43.2 ± 21.1 vs. 51.4 ± 27.4 nmol/L, p=.072). Mothers of children with ECC had lower 25(OH)D levels than mothers whose children were caries-free (41.4 ± 20.4 vs. 52.4 ± 27.4 nmol/L, p=.045). The rate of untreated decay was inversely related with maternal vitamin D concentrations (p<.001). Infants with EH were significantly more likely to have ECC (p<.001). Logistic regression identified low maternal calcium levels (p=.034), not having heard of vitamin D (p=.036), and not using margarine daily (p=.024) as being significantly associated with EH in the primary dentition of infants. Backwards logistic regression revealed that EH (p<.001), infant age (p=.002), and lower 25(OH)D levels during pregnancy (p=.019) were significantly associated with ECC. Conclusions: This study shows for the first time that maternal vitamin-D levels may influence primary dentition and the development of ECC in their babies.