VictorJuiz/thesis huggingface dataset:
A finite element groundwater flow model analysis of the glacial stratigraphy of the Greater Toronto Area

The Greater Toronto Area is the most rapidly urbanizing region in Canada. A key concern in the area is the long-term viability of groundwater resources under increased demand. The sustainable exploitation of these resources is limited by an evident lack of knowledge about deep groundwater flow. WATFLOW/3D, a 3D finite element groundwater flow code, was selected for the flow analysis. Point water level data, kriged heads and stream gauge measurements were used to calibrate the numerical model which has been solved for steady state. The model accurately predicts hydraulic heads and baseflow quantities throughout the region verifying hydrogeologic parameters and recharge estimates derived by previous studies. Bedrock topography was determined to be a primary control on deep groundwater flow while aquifer thickness plays an important secondary role. The results of the work have important implications for future development in the region, particularly the management and protection of groundwater resources.
Paleoecological assessment of Mirror Lake, Oregon, United States of America

A multi-proxy paleoecological analysis was performed on sediments recovered from high elevation Mirror Lake, Oregon, (45° 10' 45€ N; 117° 18' 26€ W) in order to establish its baseline environmental conditions. Multivariate analysis of the 55 abundant diatom taxa, delimited three successive lake biozones spanning the ca. 2000 years sampled. The increased abundance of 'Cyclotella stelligera' and 'C. pseudostelligera ', and a general increase in the proportion of planktonic diatom taxa in zone 2 possibly indicate a slight nutrient increase. Loss on ignition analysis revealed a relatively stable profile with a high proportion of silicates. The charcoal record revealed that the lake area had been subject to numerous fire events. Neither proxy could be used to explain the diatom trends. A preliminary pollen analysis indicated an early 19 th century disturbance event, with a trend towards the gradual replacement of pine by spruce and fir. Generally, Mirror Lake has remained relatively stable.
Exploring age and maturity in youth justice

This thesis examines the ways in which decisions made about youths in conflict with the law are based upon, or affected by, notions of their chronological age and apparent maturity. An empirical examination of youth court hearings, youth court data, and a survey of the Ontario public was undertaken in order to explore this question. The findings reveal that age and apparent maturity appear not to be related to decisions made about youthful offenders. However, 'youthful' status was recognized in the courts when it came to the level of supervision that was necessary to manage youths. This study provides a view to understanding the social construction of adolescence and the underlying ambivalence toward youth who come in conflict with the law. The following account of decision-malting about young offenders by court practitioners and members of the public reveals the arbitrary nature and fluidity of categories of age, and also allows us to explore how 'youth' plays out in the youth justice system.
Effects of polyethylene glycol on colon carcinogenesis in rodents

The effects of 5% dietary polyethylene glycol (PEG) on colon carcinogenesis in rodent models are reported here. First, it was hypothesized that 5% dietary PEG decreases colon carcinogenesis in rodent models of colon cancer. Second, it was hypothesized that PEG decreases carcinogenesis by decreasing insulin resistance. Dietary PEG decreased aberrant crypt foci growth in the azoxymethane-induced F344 rat without affecting glucose tolerance. PEG did not affect aberrant crypt foci growth in the SWR mouse, but increased carcinogenesis in the genetically susceptible Min mouse. It was concluded that PEG does not decrease carcinogenesis in all rodent models of colon cancer.
An environmental feminist analysis of Canada/Costa Rica debt-for-nature investment, a case study of intensifying commodification

This thesis analyzes Canadian debt-for-nature investment in Costa Rica in the context of development and the historical relationships of power between industrial countries and colonies, between the state and the people, between men and women, and between human beings and nature. The stated aim of Canadian debt-for-nature investment in Costa Rica is to develop a model of environmental management which reduces poverty and environmental degradation. This is done through funding the activities of two non-governmental organizations (NGOS): the National Institute of Biodiversity INBio and the World Wildlife Fund-Canada (WWF-C). INBio is the debtor NGO using debt-for-nature funds in eleven nationally-designated conservation areas throughout Costa Rica to identify and access the resources of biodiversity for the international market. WWF-C is the creditor NGO using debt-for-nature funds to create micro-enterprises in the same eleven conservation areas. (WWF-C). is based in the Arenal Conservation Area (ACA) where it has initiated a unique land management and planning project including, at its core, the microenterprise Abanico Medicinal Plant and Organic Agriculture Project (the Abanico Project). This thesis presents a close analysis of the structure and functioning of the complex Canada-Costa Rica debt-for-nature investment relationship and the projects developed by INBio and (WWF-C). In this context, the thesis highlights the micro-enterprise Abanico Medicinal Plant and Organic Agriculture Project. Micro-enterprises, such as this one, are income-generating units for low-income people promoted by public policies and developed by NGOS using international aid funds such as debt-for-nature investments. This research, at both the macro and the micro level, shows that the environmental economic model of debt-for-nature investment does not depart from the neoclassical models of economic development that underlie the current environmental, social, and cultural crisis. Both INBio and WWF-C activities operationalize the commitment of the World Bank, the International Monetary Fund, and many large environmental NGOs to pursue sustainable development and gender equity by means of the market. In documenting these practices and their consequences for local populations, this study challenges the claims that debt-for-nature investment reduces poverty and ecological destruction and, instead, uncovers the inadequacy of market-based solutions for these kinds of problems.
Restoration of degraded soils under red pine plantations on the Oak Ridges Moraine

A soil chronosequence was studied on the Oak Ridges Moraine to validate a model of soil degradation induced by deforestation, pioneer agriculture and subsequent abandonment, followed by restoration after planting with red pine ('Pinus resinosa' Ait.) in the 1920s. Key pedogenic processes were identified and rates and magnitude of recovery were quantified in terms of morphological, physical and chemical soil characteristics. Soil degradation generally involved reduced fertility with profile haploidization on non-eroded, fallowed fields, and deflation on more exposed, eroded fields. After reforestation soil restoration was characterized by: cessation of erosion, differentiation and development of soil horizons, reductions in bulk density, increased fertility and acidification. Chronofunctions revealed that on non-deflated, fallowed sites substantial recovery of bulk density, soil organic C, total N, available P, and exchangeable K, Ca and Mg occurred within 75 years of reforestation. In contrast, estimated recovery of these parameters on severely deflated sites was delayed far beyond plantation maturity.
Should all patients having elective first-time coronary bypass grafting surgery be crossmatched for blood?

Currently blood is reserved (crossmatched) for all patients having coronary artery bypass grafting (CABG) surgery. Many patients, however, will not require any blood and are therefore unnecessarily crossmatched. This practice reduces the general pool of blood in blood banks, increases costs, and leads to wastage of blood. In this study, a clinical prediction rule was developed on 737 patients having elective first- time CABG surgery that allows physicians to predict which patients will need blood during surgery, and only crossmatch blood for these patients. The rule includes four commonly available preoperative patient variables: preoperative haemoglobin, weight, age, and sex. The rule, which was validated on another 296 patients, is accurate (sensitivity = 87.4%, specificity = 57.8%), and should perform well on other patient populations. Application of this rule will eliminate crossmatching in about 50% of patients having elective first-time CABG surgery.
Genetic markers and breeding success, theoretical and empirical investigations in fish

One of the most active research areas in population biology is genetic relatedness and gene flow in mating systems. This thesis examines genetic relatedness and gene flow in fish mating systems using microsatellite DNA markers, and contains four sections. The first section shows how to quantify microsatellite variation, and tests assumptions made by genetic distance estimators that have long been problematic. The results enable the widespread application of microsatellites in genetic models of population biology and are important in evolutionary and conservation biology for calculating genetic distances and identifying evolutionarily significant units. The second section develops mathematical models for calculating genetic relatedness among parents and offspring using both genetic and behavioural data. The models calculate the confidence in the parentage assignments and the optimum number of loci and offspring required to provide accurate parentage inference, and enable analysis of previously intractable mating systems. The third section quantifies gene flow within a major social unit of bluegill reproduction, the colony. Higher quality parental males attain higher paternity by avoiding parasitism during spawning by small precociously maturing males called cuckolders and adaptively allocate more parental care to their young. Cuckolder success is determined by their size and reproductive behavior with small sneakers and large females mimics attaining the highest reproductive success. Females make complex mate choice decisions, adaptively trading-off direct benefits from parental male care with good genes of cuckolders. The fourth section addresses the conservation biology practice of producing hatchery fish for wild supplementation, and its effects on the genetics, behaviour and reproductive success of wild populations. Independent of hierarchy position, hatchery males obtain lower paternity, possibly due to inferior sperm or reproductive ability, and overall obtain about half the success of their wild counterparts. Hatcheries have the potential to reduce effective sizes and genetically pollute wild populations, increase extinction probabilities, and in general may be an ineffective conservation approach. Overall, this thesis provides both innovative models to understand the breeding biology and evolution of natural populations, and novel empirical results that have important consequences for the conservation and effective management of wild fish populations.
Family-based caregiving of cognitively impaired members, the case of Chinese immigrants in Toronto

This study explores the caregiving process of eighteen Chinese immigrant families whose older relatives were afflicted by Alzheimer's Disease and related disorders. The carers and their relatives were all ethnic Chinese who had immigrated to Canada and had settled in Toronto. The study is qualitative in nature and the long interview method was chosen to examine how family carers perceive, interpret and derive meaning from the care commitment. This in-depth analysis enables the researcher to uncover the intricacies of the process of caregiving. The sample was drawn from those living in the community as well as those residing in institutions. The carers' experience revealed a paradox consisting of five recurrent themes: learning to value the new, impaired character of the care recipient; accepting the altered relationship with the relative; managing their own emotional responses; maintaining a balance between caregiving and their own life demands; and, finally, developing the capacity to absorb stress while appreciating the rewards of the caregiving process. Other broad themes which emerged from the findings included: the significance of family identity, rules, themes, and constructs in care apportioning decisions; the gradual evolution of functional and dysfunctional family care patterns; the mediating role of family and kinship support resources and the positive aspects of care. The study also examined the respondents' utilization of informal and formal support systems. They acknowledged that their own immediate family members and close kin provided a great variety of support assistance. Respondents would, however, turn to formal help when informal assistance was deficient or when the caring demands exceeded their capacity to care. To address effectively the needs of family carers, the study suggests that intervention strategies should be developed at the micro, mezzo and macro levels. But for social work professionals, the greatest challenge is to transform the way dementia care is conceived, so that both caregivers and recipients maintain their distinctive individuality in the face of a cruel and exhausting affliction.
Vocal function in subjects with compensated unilateral vocal fold paralysis pre- and post-medialisation thyroplasty

Unilateral vocal fold paralysis is a condition that can cause significant vocal dysfunction. Treatment options include behavioural therapy or surgical procedures. The purpose of the present study was to investigate specific vocal function parameters in subjects with a compensated unilateral vocal fold paralysis, and to investigate the effects of medialisation thyroplasty on these parameters. The pathophysiology of the voice abnormality associated with a unilateral vocal fold paralysis and the relevant literature regarding treatment has been reviewed. Measurements included indirect laryngoscopy, acoustic data (fundamental frequency, percent jitter and shimmer), fundamental frequency and intensity range, voice range profile, phonation threshold pressure, perceptual evaluation and a reading task. Results indicated that most subjects exhibited a reduced fundamental frequency and intensity range compared to normal values prior to surgery. A comparison of data from before and after medialisation thyroplasty indicated that most subjects showed improvements in the vocal parameters evaluated.
The effects of terrain discrepancy and the role of texture in enhanced/synthetic vision systems

This thesis presents the results of a study conducted at the University of Toronto Institute for Aerospace Studies Flight Simulation Laboratory, investigating the effects of terrain discrepancies due to navigation error and texture patterns on pilot performance while using an Enhanced/Synthetic Vision System (E/SVS). Flights in a Bell 205 helicopter simulator incorporating Enhanced/Synthetic Vision were performed. Analysis of the results revealed that in maintaining a target altitude and velocity a plaid texture pattern resulted in the best pilot performance. Also shown was that terrain discrepancy in pitch caused the greatest deviation from the desired velocity and altitude. Pilots performed equally well in comparing slopes independent of the navigation error or texture selection. Navigation error and texture did not affect the ability of pilots to fly constant altitude above sloping terrain or to match their mean heading with the up-slope direction, but roll navigation error resulted in a greater standard deviation in heading.
Real-time face detection on a configurable hardware platform

Automated object detection is desirable because locating important structures in an image is a fundamental operation in machine vision. The biggest obstacle to realizing this goal is the inherent computational complexity of the problem. The focus of this research is to develop an object detection system that operates on real-time video data in hardware. Using human faces as the target object, we develop a detection method that is both accurate and efficient, and then implement it on a large programmable hardware system. Using a programmable system reduced the time and cost required to create a working hardware prototype. The implementation runs at 30 frames per second, which is approximately 1000 times faster than the same algorithm running in software and approximately 90 to 6000 times faster than the reported speed of other software algorithms.
The development and use of cobalt hexammine as a tool to study the tertiary structure of the Neurospora VS ribozyme

A prerequisite to understanding how ribozymes function is an understanding of their three-dimensional structure. Until now, there was no method by which to examine the tertiary structure of the VS ribozyme precursor RNA because it self-cleaves immediately upon folding into its tertiary structure. Under most conditions, a divalent metal such as magnesium is required to induce VS ribozyme structure and function. My research shows that cobalt hexammine can induce almost the same VS ribozyme structure as magnesium does but at a 33-fold lower concentration. Moreover, VS ribozyme cleavage does not occur in the presence of cobalt hexammine alone making it a valuable tool for studying the structure of the VS ribozyme precursor RNA. I have used cobalt hexammine as such a tool and have discovered that helix Ia inhibits the formation of a long-range pseudoknot as well as a secondary structure rearrangement in helix Ib.
Norms and nature, resituating the mental causation debate

Non-reductive accounts of the mind appear to run into difficulties when it comes to accommodating our common sense intuitions about the nature of mental causation. Using Donald Davidson's response to his critics' charge of epiphenomenalism as my starting point, I argue that many non-reductive positions (Davidson's included) are still grounded on residual naturalistic presuppositions, and that our recognizing that such presuppositions are in fact groundless constitutes a first step towards the development of a sustainable non-reductive account of mental causation. I then make efforts to draw connections between this issue and recent work in perception by 'natural realists' such as John McDowell and Hilary Putnam, arguing that in both cases it is a particular conception of what it is to be natural which is the source of our philosophical puzzlement about the mind.
Facilitating organizational knowledge work through Web information systems, an investigation of the information ecology and information behaviours of users in a telecommunications company

This dissertation outlines an exploratory research investigation of Web information systems (WIS), such as departmental intranets, corporate portals, and the World Wide Web, and their capacity to facilitate organizational knowledge work--a set of knowledge creation, distribution, and use processes in which information plays a primary role. As a means of investigating this phenomenon, a case study evaluation of Web information systems usage was conducted on five major sets of users at a large telecommunications company. Emphasis was placed on examining the information needs and uses of participants and the information ecology in which Web information systems were utilized. Data collection involved a wide variety of techniques, namely interviews, Web tracking, field observations, document review, and questionnaires. A modified version of grounded theory served as the primary mode of data analysis; descriptive statistics helped triangulate research results. Field work findings suggest that WIS do support knowledge work, but in a limited way: primarily for knowledge creation only; and to a lesser extent knowledge distribution and use. Different WIS are utilized for knowledge work in varying ways to resolve diverse problem situations and support disparate information behaviours. Information politics, the WIS development process, and the organization's information culture impact the use of WIS for knowledge work. Further, a person's functional role, general motivation to learn, perception and interest in WIS technology influences the extent to which WIS are adopted and utilized. Findings also suggest that to foster knowledge work, WIS need to: support the tailorability and organization of information; deliver relevant, reliable and timely information; provide collaborative tools; and promote user engagement with these systems. The central contribution of this research is a model of Web use showing the organizational, user, and interface factors that promote or inhibit the use of Web information systems for knowledge work. Moreover, these factors co-exist in mutual bi-directional relationships with one another. Implications include the need for firms to pay attention to the salient attributes of these shaping factors when constructing Web information systems to help organizational participants create, distribute, and utilize knowledge more effectively.
Injection drug users in Toronto: Gender differences and HIV risk taking

'Objective'. To examine the importance of gender in the HIV epidemic in injection drug users (IDU's) in Toronto. 'Methods'. This was an analysis of secondary data collected as part of the 'Toronto Study of Injecting Drug Use and Risk of HIV Infection'. Differences between male and female IDUs were compared using Pearson Chi squared and t-tests. Predictors of HIV risk taking were evaluated by univariate and multivariate logistic regression. 'Results'. Female IDUs differ from males on a number of demographic and drug taking measures. Female IDUs were more likely to both give and take injection equipment. Females were more likely to have a regular sexual partner who injects, and were less likely to use condoms with a regular partner. Females were more likely than males to use condoms during intercourse with a client of the opposite sex. 'Conclusion'. Male and female IDUs differ in risk taking that may lead to HIV infection.