VictorJuiz/thesis huggingface dataset:
Has the use of statins increased in Ontarians 65 years old and older post-myocardial infarction since the publication of the landmark 4S lipid lowering trial?

This thesis compared the use of lipid lowering agents in patients 205 years old post myocardial infarction (MI), before and after the publication of the first landmark statin trial, the Scandinavian Simvastatin Survival Study (4S), using the Ontario Myocardial Infarction Database. The regression analysis found a significant 3.6-fold increase in the rate of use of statins after the trial publication (0.144%/month pre-4S vs 0.508%/month post-4S). Pre-4S, the rate of increase in statin use was 2.7-fold higher in younger (65-74 years) patients, while post-4S, the rate of increase in use in the younger group was only 1.8-fold higher. The rate of increase in statin use was 1.6-fold higher in males than in females post-4S. Specialists had 2-fold higher rate of increased statin use than non-specialists. Overall, prescription rates of statins remain lower than might be optimal in a post-Ml population.
Changes in acoustic parameters at 30 MHz of human and bovine articular cartilage following experimentally-induced matrix degradation to simulate early osteoarthritis

Matrix degradation and proteoglycan loss in articular cartilage is a feature of early osteo-arthritis. To determine the effect of matrix degradation and proteoglycan loss on ultrasound propagation in cartilage, we used papain and interleukin-1Ã to degrade the matrix proteoglycans of human and bovine cartilage samples respectively. There is also minor collagen alteration associated with these chemical degradation methods. We compared the speed of sound and frequency dependent attenuation (20 to 40 MHz) of control and experimental paired samples. We found that a loss of matrix proteoglycans and collagen disruption resulted in a 20-30% increase in the frequency dependent attenuation and a 2% decrease in the speed of sound in both human and bovine cartilage. We conclude that the frequency dependent attenuation and speed of sound in articular cartilage are sensitive to experimental modification of the matrix proteoglycans and collagen. These findings suggest that ultrasound can potentially be used to detect morphologic changes in articular cartilage associated with early osteoarthritis.
In vitro endothelial wound repair, characterization and regulation of early repair during the conversion of resting to migrating endothelial cells

During re-endothelialization, the endothelial cell (EC) must undergo a transition from a resting cell with a cytoskeleton organized for barrier function to a migrating cell with a cytoskeleton that promotes cell translocation. Since the mechanisms which regulate the above transition are not well understood, I characterized and studied the regulation of the actin and microtubule cytoskeletons, with an emphasis on the former, during early endothelial repair in which the transition occurs. Within 6 hours following an 'in vitro' 1.0-1.5mm wound in a confluent porcine aortic endothelial monolayer, ECs at the wound edge underwent 3 sequential stages of actin microfilament bundle reorganization to become migrating cells. Centrosome redistribution to the front of the cell occurred within 2-3 hours as previously reported. Progression through the 3 stages was associated with endothelial elongation and specific changes in phosphotyrosine localization at vinculin cell-cell and vinculin/talin cell-substratum adhesion sites associated with microfilament bundles. Focal adhesion kinase (FAK) and paxillin localized at the ends of central microfilament bundles oriented parallel and perpendicular to the wound. Increased tyrosine phosphorylation and expression of paxillin occurred during stages II and III. When tyrosine phosphatase or kinase activity was inhibited by sodium orthovanadate or genistein, respectively, microfilament bundle reorganization and subsequent progression through the 3 stages was disrupted. This resulted in decreased EC elongation, which consequently inhibited wound closure 16 to 48 hours after wounding. To elucidate the upstream signaling mechanisms, the effects of basic fibroblast growth factor (bFGF) and Rho activity were studied. Addition of exogenous bFGF increased central microfilament bundles orientated perpendicular to the wound edge at 3 hours following wounding, suggestive of Rho activity. Addition of the specific Rho inhibitor, exoenzyme C3, resulted in the reduction of phosphotyrosine, paxillin, and central microfilament bundles. Centrosome redistribution and cell elongation were inhibited by C3, but, were restored upon co-incubation of bFGF with C3 which subsequently increased the rate of endothelial wound closure. RhoA localized with the centrosome and alongside some microtubules. Thus, during early endothelial wound repair resting ECs undergo 3 stages of microfilament bundle reorganization and centrosome redistribution, which may be regulated by Rho and tyrosine phosphorylation, to become migrating cells.
Disposition and anticancer effects of flaxseed lignans in the rat

The inhibitory effect of flaxseed and secoisolariciresinol diglycoside (SDG) on mammary carcinogenesis may be due to antagonism of hormone action. Therefore, it was hypothesized that flaxseed lignans inhibit mammary tumour development by targeting tissues that synthesize or metabolize estradiol and insulin-like growth factor I (IGF-I), reducing their circulating levels, and lowering their stimulatory effect on tumour growth. The overall objective was to determine lignan disposition and if dietary lignans reduce plasma levels of estradiol and IGF-I at different stages of rat mammary carcinogenesis, consequently reducing tumour growth. Metabolites of 3H-SDG—determined to be mainly enterodiol, enterolactone, and secoisolariciresinol by urine analysis—targeted the cecum, liver, kidney, and uterus. Chronic SDG exposure delayed fecal excretion and increased levels of 3H-SDG metabolites in the cecal tissue and contents, liver, adipose, ovaries and uterus, tissues involved in estradiol and IGF-I synthesis and/or metabolism. Although most of the 3H-SDG dose was excreted (feces = 60%, urine = 30%) regardless of exposure by 48 h, tissue (3%) and blood (0.3%) levels indicated that lignans take >48 h to be removed. Flaxseed (5%) or its SDG (1.5 mg/d) decreased plasma estradiol and/or IGF-I during the pre-initiation (21 to 50 days of age) and early promotion (50 to 80 days of age) stages of carcinogenesis. During the pre-initiation period, plasma levels of estradiol and IGF-I were reduced to a greater extent, and both hormones were inversely related to urinary lignan excretion. Flaxseed (2.5% and 5%) and SDG (0.7 mg/d and 1.4 mg/d) feeding during the promotion phase of N-methyl-N-nitrosourea (MNU)-induced mammary tumourigenesis lowered tumour invasiveness and grade in comparison to control but had no effect on plasma estradiol or IGF-I. Low dose SDG promoted whereas high dose SDG inhibited tumour multiplicity. In conclusion, the anticancer activity of flaxseed lignans during the early stages of mammary carcinogenesis might involve lower plasma levels of estradiol and IGF-I as a result of interference with estradiol and IGF-I synthesis in tissues targeted by lignan metabolites. However, circulating levels of estradiol or IGF-I was not related to the effect of flaxseed or its SDG at later stages of mammary carcinogenesis.
Oral delivery of glucagon-like peptide-1 using PLGA-COOH microspheres

The insulinotropic hormone, glucagon-like peptide-1 (GLP-1), has been proposed for the treatment of patients with type II diabetes. Since GLP-1 is rapidly inactivated by dipeptidyl-peptidase IV (DP IV), a DP-IV degradation-resistant analog of GLP-1, D-ala2-GLP-1, was tested and found to exhibit enhanced bioactivity when administered subcutaneously to mice. However, the glycemic-lowering effects of this peptide are lost within 4 hour of injection, thus necessitating frequent and invasive administration if it is to be used as a treatment for type II diabetes. To circumvent these problems, we have designed a therapeutic microsphere that is prepared by encapsulating 2% D-ala 2-GLP-1 in microspheres made of 50% Olive Oil-48% poly(lactide-co-glycolide)-COOH (PLGA-COOH). The PLGA-COOH microspheres we developed released most of their peptide over a 9 h period 'in vitro'. These D-ala2-GLP-1-microspheres were also effective in delivering therapeutic levels of GLP-1 over a 10 hour period to non-diabetic and diabetic mice, thereby reducing both basal blood glucose levels and the glycemic response to repeated oral glucose tolerance test (OGTT).
Standing out across cultures, personal distinctiveness in Canada and Japan

Many have argued that the Japanese do not strive for personal distinctiveness or separation from others. Alternatively, the Japanese may pursue indirect or masked forms of distinctiveness that do not mirror the typical expression of this motive in the West. To explore this possibility, a distinction is drawn between 'horizontal' and 'vertical' distinctiveness. Horizontal distinctiveness refers to standing out from others by appearing different in a manner that is not inherently good or bad. Vertical distinctiveness refers to standing out from others by being clearly superior or inferior in an activity domain that is itself normative. The hierarchical, tight structure of Japanese society suggests that vertical forms of positive differentiation and horizontal forms of negative differentiation may be more pronounced than in the West. These predictions were tested by comparing the distinctiveness-related experiences recollected by Canadian and Japanese students. As predicted, the Japanese reported a greater proportion of horizontal (rather than vertical) negative events than did the Canadians, suggesting that standing out for its own sake is more costly for the Japanese. Contrary to prediction, however, the Japanese also reported a greater proportion of horizontal (rather than vertical) positive events than did the Canadians. The latter finding is considered in relation to the potential influence of modesty bias.
Inactivation of Cryptosporidium parvum oocysts and Bacillus subtilis spores by chlorine dioxide in laboratory reagent and natural waters

The chlorine dioxide inactivation of 'Cryptosporidium parvum' oocysts (Iowa isolate, genotype 2 (C)) was measured at bench scale in various water matrices using 'in vitro' excystation and a most probable number cell culture infectivity assay. 'In vitro' excystation underestimated inactivation compared to the infectivity assay. There was a significant difference (Ã = 0.05) in the inactivation of oocysts among the diverse water matrices measured by the infectivity assay but not by ' in vitro' excystation. A 'Ct' of 1000 mg·min/L was necessary for 2.0 log10 inactivation in type I deionised-distilled water adjusted to pH 8 at 22°C. This degree of resistance to chlorine dioxide by 'C. parvum' oocysts has not been quantified previously in the literature. 'Bacillus subtilis' spores (ATCC 19659) were found to be an unsuitable surrogate for 'C. parvum' oocysts in bench- and pilot-scale chlorine dioxide inactivation studies, but could function as a surrogate in pilot scale filtration removal studies.
Nonlinear finite element analysis of the coupled thermomechanical behaviour of turbine disc assemblies

Comprehensive two and three-dimensional finite element studies are made of the effect of the critical geometric features and interface conditions in the fir-tree region of a gas turbine disc upon the resulting thermomechanical contact stress distribution at the blade-disc interface. In addition to the rotational body forces, the thermal state of a turbine disc made from nickel based super alloy, was determined using realistic boundary temperatures and the assembly was treated as a coupled boundary value problem. Three aspects of the work were accordingly examined. The first was devoted to the validation of the basic finite element model using convergence tests and photoelastic stress analysis. The second was concerned with examining the effect of the flank length and flank angle, inner radius of disc and interfacial friction upon the thermomechanical stress-state of an insulated disc. The third was concerned with the determination of the influence of the skew angle upon the triaxial state of stress and load sharing between the teeth in the turbine disc assembly. Contact between the disc and the blades was modelled using contact elements and the analysis pertain to an insulated disc, with heat conduction being the main form of heat flow. The outcome of the study reveals: (i) the important role played by the temperature and rotation upon the induced thermomechanical contact stresses at the blade-disc interface, and (ii) the effect of the skew angle upon the resulting three dimensional thermomechanical stress state, and the inability of the two-dimensional finite element model to accurately capture the stress gradients at the fir-tree interface and through the thickness.
Arrival, survival, and beyond survival, the Indo-Trinidadian journey to political and cultural ascendancy

This dissertation presents a socio-historical and contemporary case study of the East Indian community in Trinidad. It fulfils three objectives: (1) It examines the ways in which the current, Afro-defined 'national culture' of Trinidad is being challenged by the Indo-Trinidadians at the popular level. Here, it demonstrates the fluidity and dialectical nature of such seemingly 'fixed' concepts as national identity and national culture. A close examination of the post 1980s era shows that the intensive popular nationalism of the Indo-Trinidadians has resulted in an incursion of Indo-Trinidadian cultural elements in the official definition of the nation. Today, Trinidad's official national 'we-culture' of calypso, carnival and steelpan has been forced to include the uniquely Indo-Trinidadian elements, such as Indian Arrival Day, Divali, and Chutney. (2) It examines some of the contemporary boundary maintenance mechanisms employed by the Indo-Trinidadian leadership in their effort to sustain group distinctiveness in Trinidad's Creole society. It will demonstrate that the process of boundary maintenance in Trinidad's plural society, where the forces of assimilation are strong, and many, is a particularly problematic one for the Indo-Trinidadian community. Often, it is in these very processes of boundary maintenance that one sights the inherent contradiction of 'sameness' with the Creole 'other'. (3) It examines the current Hindu resurgence in Trinidad, and the ways in which it continues to fuel the larger Indo-Trinidadian ethnonational contestation for 'equal space'. The relationship between religion and nationalism as one of a dialectic interplay, is analyzed. I also argue that while organized Hinduism in Trinidad--with its full cultural force of rich symbolism, myths, and values--has tremendously boosted the larger ethnic struggle, it has also conversely harmed intra-group affiliations. The shift from a 'cultural' to a 'religious ethnonationalism' has meant the deliberate appropriation of all things "Indian" as "Hindu", and vice versa, resulting in deeper schisms between the Hindu, and the Christian and Muslim Indo-Trinidadian community.
Human pulmonary function response to a controlled exposure to fine urban particulate matter

There is growing evidence that fine particulate matter may have adverse effects on respiratory health, but convincing human exposure studies are lacking. The present thesis describes preliminary research in which four human subjects were exposed for two hours on four separate occasions each to particle-filtered air and to three target levels of concentrated ambient fine particles (20, 40, and 60 [mu]g/m3) in a human exposure facility using a new and innovative particle delivery method. Diffusing capacity for CO, body plethysmography, and spirometry when carried out before and after exposure. Spirometry was also carried out during each exposure. Results suggested that the facility could effectively be used for human exposures to concentrated fine ambient particles while maintaining adequate conditions of safety and comfort, and that two-hour exposures up to target concentrations of 60 [mu]g/m3 did not adversely alter lung function in the subjects tested.
The evolution and evaluation of a 3D input device

A novel input device--the Rockin'Mouse--is described and evaluated. The Rockin'Mouse is a four degree-of-freedom input device that is similar to a regular two degree-of-freedom mouse except that the bottom is rounded so that it can be tilted. This tilting can be used to control two extra degrees of freedom, making it suitable for manipulation in 3D environments. The Rockin'Mouse can mimic the performance of a regular mouse. However, in a 3D scene a mouse can only operate on two dimensions at a time and therefore manipulation in 3D requires a way to switch among dimensions. With the Rockin'Mouse, however, four degrees of freedom can be simultaneously controlled. In this thesis, we describe the design rationale behind the Rockin'Mouse, its evolution through a series of prototypes, and an experiment that shows it performing 30% faster than a mouse in a 3D translation task.
c-Kit signalling pathways and survival signals in a factor-dependent leukemia

I have investigated the role of phosphatidylinositol-3-kinase (PI3-kinase) and phospolipase-C-ã (PLC-ã) stimulation by Steel factor (SLF) through the c-Kit receptor, and the dependence of c-Kit induced leukemogenesis on these enzymes. c-KitWT and c-Kit mutants YF719 and YIF728 were expressed in 32D myelomonocytic cells. KitYF719 fails to recruit PI3-kinase following stimulation with SLF while KitYF728 fails to stimulate PLC-ã phosphorylation. These cells were separately injected into mice, and the presence of 32D cells was evaluated by colony assays and FACS analysis 6 weeks later. While both KitWT and KitYF719-expressing cells could be readily detected in spleen and bone marrow, recovery of KitYF728 cells from these organs was severely reduced. These results indicate that Kit tyrosine 728 is of particular importance for full maintenance of cells 'in vivo', likely through activation of PLC-ã. We have also investigated the leukemic potential of Bcl-2 by overexpressing this anti-apoptotic survival factor in factor-dependent murine 32D myelomonocytic cells. (Abstract shortened by UMI.)
Sexuality and containment, Ling Mengchu's erotic stories

This thesis is a cultural study of a group of stories about illicit sex in the short story collections 'Pai'an jinqi' and ' Erke pai'an jingqi', both of which were written by the late Ming writer Ling Mengchu (1580-1644). The whole thesis consists of two parts: introduction and translation. The translation includes four erotic stories selected from these two collections and these four stories have never been rendered into English before (though some of them have French and German versions). The introduction, instead of a potpourri of rudimentary generalizations about the author and his works, is a monograph mainly focussed on a paradox of these stories, i.e., the tension between the presentation of sexual pleasure and its containment for a moral purpose. To give a convincing explanation to this tension, the thesis examines the context--the life of the author and the society in which he lived as much as it analyses the text--the aspects of sexuality and the repressive mechanisms the author imposed on his erotic descriptions. In so doing, it tries to demonstrate the eroticism in the way that may help understand not only how the principle of pleasure is related to the economic base of the late Ming but also how, owing to the functioning of the state ideology, it is morally contained, contrary to what has been assumed by some Western scholars (e.g. Foucault) that "pleasure is not considered in relation to an absolute law of the permitted and the forbidden, nor by reference to a criterion of utility, but first and foremost in relation to itself." And it is the conclusion of this thesis that these stories about illicit sex, erotic as they are, are actually mildly explicit in terms of sexual description, belonging, in its three-tier typological schema (i.e., the schema that divides late Ming erotic fiction into three basic kinds: lust, lust-love and lust-sex) of the late Ming erotica, to the category of "lust."
Two clusters of acidic amino acids at the NH¦2-terminus of complement component C4 Ã'-chain are important for C2 binding

Cleavage of complement component C3 into C3a and C3b is a critical step in the activation of the complement system and consequently the role of this system in host defense. The reaction is catalyzed by two homologous enzymes, the classical and alternative pathway C3 convertases, which have the compositions C4b2a and C3bBb, respectively. The goal of this thesis was to identify sequences in human complement component C4 that contribute to the binding of C2. Previous mapping studies using monoclonal antibodies have suggested that the 738-826 segment at the NH2-terminus of C4 Ã'-chain is involved in the interaction with C4BP, a ligand of C4b which is antagonistic to the binding of C2. Mapping studies on C3, particularly using the site-directed mutagenesis approach, have also identified an acidic amino acid segment at the NH2-terminus of C3 Ã'-chain as being essential for the interaction with factor B, the alternative pathway C2 analogue. Due to the functional similarity between C4 and C3 and the significant sequence similarity at the NH2-termini of their respective Ã '-chains, this segment of C4 was therefore hypothesized to contribute to the binding of C2. (Abstract shortened by UMI.)
A spatial analysis of the relationship between respiratory health and motor vehicle emissions amongst small urban areas

This study assesses the relationship between exposure to particulate matter (PM) from motor vehicle emissions and hospital admission rates for respiratory illness among enumeration areas (EAs) in Southeast Toronto (SETO). Exposure is modelled from traffic count data using a geographical information system, and census data is used to control for the effect of socioeconomic status. Spadal relationships of variables are assessed, and Poisson regression is used to estimate the effect of exposure on hospitalization. Exposure to PM from motor vehicles has a statistically significant effect on hospitalization rates for selected respiratory conditions, with a relative risk of 1.39 in the highest exposure quintile. The effect of exposure on non-respiratory hospitalization rates is weaker, but also significant. The non-specific effect of exposure suggests that control for confounders may have been incomplete. Some variables are positively spatially autocorrelated, but this does not appear to influence the results of the multivariate model.