No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Biliary diseases are uncommon, potentially fatal causes of acute abdomen in dogs. Little information is present comparing the performance of computed tomography (CT) to ultrasound in identifying canine biliary pathology. Thirty-five client-owned dogs presenting for acute abdomen signs received an abdominal ultrasound and contrast-enhanced abdominal CT. Two authors reviewed the randomized, anonymized CT and ultrasound studies. Twenty-eight dogs had biliary pathology and seven dogs serving as controls had no evidence of biliary disease. The final diagnoses of patients with biliary pathology included cholelithiasis, gallbladder mucoceles, cholangiohepatitis/cholangitis, extrahepatic biliary obstruction, gallbladder wall edema, gallbladder wall mass, and cystic mucosal hyperplasia. Computed tomography was more accurate in identifying cholelithiasis than ultrasound. No statistical difference in the odds to identify other biliary pathology was identified between ultrasound and CT. Findings from this study suggest CT may be used in place of ultrasound in canine patients presenting for acute abdominal signs of biliary origin.

There are many reports indicating the presence of emerging contaminants such as: estrogen hormones, 1,4-dioxane and perfluoro-octanoic acids in the natural environment. Estrogen hormones are considered important emerging class of contaminants due to their endocrine disrupting effects. These compounds are invariably found in the environment originating mostly from natural sources. Trace concentrations of estrogen hormones (low µg/L concentrations) have been detected in municipal wastewater treatment plants and observed in receiving water bodies. 1,4-Dioxane (C4H8O2) is used as an organic solvent and solvent stabilizer numerous in chemical processes. The United States Environmental Protection Agency (US-EPA) has recognized 1,4-dioxane as a toxic chemical and a possible human carcinogen. 1,4-dioxane has been detected as a contaminant in the natural environment, drinking water supplies, superfund sites, public groundwater sources in the United States, Canada and Japan at concentrations greater than the permissible standards. Perfluorinated chemicals such as perfluoro-octanoic acid (PFOA) and perfluorooctane-sulfonate (PFOS) have been manufactured for use in a variety of industrial and consumer applications. Due to their environmental persistence, PFOAs have been detected in surface waters at a number of locations at concentrations ranging from pg/L to ng/L. Elevated concentrations of PFOAs have been measured in surface and ground waters near specific point sources. Through this project, successful attempts have been made for the destruction of emerging contaminants using ultrasound. This study deals with the optimization of various process parameters for the destruction of estrogen hormones. The influence of process parameters such as power density, reactor geometry, power intensity, ultrasound amplitude, and external mixing was investigated. Artificial neural network (ANN) approach was used to describe the interactions between optimized parameters. The important findings obtained in the present work for the optimized estrogen degradation can help tackle the challenges of scale up such as operational optimization and energy consumption. The effect of process conditions such as pH and presence of oxidizing agents on the ultrasonic destruction of 1,4-dioxane and PFOA was studied. Acidic conditions favored the destruction of both the compounds. The presence of activated sulfate radicals enhanced the reaction rate kinetics. An innovative technology using electric potential and ultrasound for the removal organic contaminants was developed. The existence of organic contaminants in ionic form under certain process conditions has led to the development of this technology. Applying a low electric potential across the probe enhances the mass transfer of the contaminants into effective reaction zone, thereby enhancing the total destruction. A two-fold increase in the reaction rates was observed. This study shows ultrasound as an efficient and effective treatment technology for the destruction of emerging contaminants. / Civil Engineering

The carotid artery wall moves longitudinally along the length of the vessel, although little is known about what causes this motion, or what health information it represents. The overarching purpose of this dissertation was to investigate the regulation of carotid artery longitudinal wall motion (CALM) in humans, as well as how CALM can be used to infer information about arterial health. Through observational and experimental designs, we tested evidence for a structural ventricular-vascular coupling effect, which postulates that systolic anterograde CALM is influenced by the forward blood shear rate while systolic retrograde CALM is influenced by left ventricular rotation, although the data suggests a moderate influence of left ventricular rotation, and minimal influence of shear rate. In cross-sectional analyses, we demonstrated that diastolic CALM variables are better related to age and health status compared to systolic CALM displacement and that this relationship was independent of traditional measures of arterial stiffness. These experimental and observational results directed the use of diastolic CALM as a potential indicator of arterial health in subsequent studies, due to the relative independence from systolic events. While there was no effect of 12-weeks of exercise training in healthy men on diastolic CALM variables, we observed increased systolic retrograde CALM and diastolic CALM acceleration in men with a history of resistance exercise training compared to sedentary men, suggesting an effect of habitual exercise training. Our novel findings suggest that CALM is regulated by a complex system, in part related to both arterial wall structure and ventricular-vascular coupling, and may have clinical value in complimenting measures of traditional arterial stiffness in humans. Future studies should examine whether local changes to arterial wall structure or indirect changes in regulatory control dictate differences in CALM with aging and with chronic exercise training, before integrating CALM into routine measurement of arterial health. / Thesis / Doctor of Philosophy (PhD) / We have known for a long time that arteries expand in order to absorb pressure; however, only recently have we identified that arteries also move longitudinally along the length of the arterial wall. The overarching purpose of this dissertation was to study what causes carotid artery longitudinal wall motion (CALM), and how we can use this information to understand arterial health. We demonstrated that CALM is partly controlled through the forward blood velocity wave and left ventricular rotation of the heart, and that diastolic CALM is uniquely related to aging and health status, but is not impacted by exercise training in healthy men. There are many aspects of CALM that need to be examined before wide-spread use, though our results indicate that CALM represents a new way of studying arterial health, which has the potential to complement traditional measures of cardiovascular disease risk in humans.

Background: At the time of endobronchial ultrasound (EBUS) staging, ultrasonographic features can be used to predict mediastinal lymph node (LN) malignancy. Predictive tools have been developed, however they have not gained widespread use due to lack of research demonstrating validity and reliability. We sought to develop a novel predictive tool, the Canada Score, capable of predicting malignancy and potentially guide LN biopsy decision making. Methods: We prospectively analyzed the ultrasonographic features of LNs from patients with NSCLC. Ultrasonographic features were identified by a single experienced endoscopist, this data was used to develop the Canada Score. Pathological specimens were used as the gold standard for determination of malignancy. Videos were then circulated to endoscopists across Canada, who were also asked to identify ultrasonographic features for each LN. Hosmer- Lemeshow test, logistic regression, receiver operator characteristic (ROC) curve, and Gwet’s AC1 analyses were used to test the performance, discriminatory capacity, and inter-rater reliability of the Canada Score. Results: A total of 300 LNs from 140 patients were analyzed by 12 endoscopists across 7 Canadian centres. Backwards elimination was used to create a multivariate model. Hosmer-Lemeshow test and ROC curves indicated the model was well-calibrated (chi2=11.86, p=0.1567) with good discriminatory power (c- statistic= 0.72 ±0.042, 95%CI: 0.64-0.80). Beta-coefficients were used to create a simplified score out of four. Evaluation of the tool showed that LNs scoring 3 or 4 had odds ratios of 15.17 (p<0.0001) and 50.56 (p=0.001), respectively for predicting malignancy. A score of 4/4 was associated with 99.59% specificity and a positive likelihood ratio of 22.78. Inter-rater reliability for a score ≥ 3 was 0.81 ± 0.02 (95%CI: 0.77-0.85). Conclusions: The Canada Score shows excellent performance in identifying malignant LN at the time of EBUS. A cut-off of ≥ 3 has the potential to inform decision-making regarding biopsy or repeat/mediastinoscopy if the initial results are inconclusive. / Thesis / Master of Science (MSc) / During lymph node staging for lung and esophageal cancer, specific features of lymph nodes can be seen. Using diagnostic tools these features can be used to predict whether a lymph node is cancerous or benign. However, many of these diagnostic tools are inaccurate or unreliable. To address this, this thesis aimed to develop a novel diagnostic tool based on lymph node features seen during staging procedures and determine its clinical usefulness and application to the wider lung and esophageal cancer population. This thesis also aimed to use improved methods to develop this diagnostic tool such that patient and clinician experiences would be significantly improved. The results of this thesis may contribute to a reduction in the number of repeat procedures required for patients undergoing staging prior to their treatment for lung and esophageal cancers.