VictorJuiz/thesis huggingface dataset:
Understanding adolescent cannabis use, a stress process model application

Cannabis use remains an unresolved social problem in Canada. Widespread adolescent cannabis use is a particularly troublesome reality both in terms of criminal labelling and possible adverse health effects. The empirical focus of this research is to develop an understanding of factors that predict differential levels of cannabis use. Particular attention is devoted to adolescents who use cannabis at problem levels. This research is set in the context of the criminal and health related consequences associated with cannabis use. The historical background of cannabis prohibition is reviewed and the literatures on social, health and legal impacts are summarized. Within this backdrop, the conceptual framework is guided by the stress process model situating a criminalized behaviour within a health oriented framework. In addition to estimating the effects of individual family and school stressors this research evaluates the effects of cumulative stressors on cannabis use. While much attention has been given to the association between formal social control and cannabis use, the influence of various social relationships (informal social control) on this behaviour remain largely unexplored. A particular contribution of this research is evaluating the extent to which informal social control influences cannabis use patterns among adolescents. Finally, policy implications and future research directions are discussed.
Children's and adolescents' understandings of society and government

The present study explored the possibility of integrating global developmental and domain-specific theoretical orientations using Case's theory of Central Conceptual Structures (Case & Okomoto, 1996), to provide a more comprehensive account of children's understandings in this domain. Understandings of (a) society and government, (b) individual social roles, and (c) relations between individual roles were assessed in three different age groups: 6-7 years, 11-12 years and 16-18 years. Participants in the youngest age group understood the individual roles in terms of their actions. Participants in the middle age group related the individual roles to the government and noted their importance in society. Participants in the oldest age group perceived the individual roles as representatives of societal functions. With age, children showed a greater ability to relate the individual roles through their significance for society. The results corresponded with Case's theory, providing evidence for a Central Conceptual Structure in this domain.
A class of fair queueing based medium access control protocols for wireless ATM local area networks, implementation and simulation

This thesis deals with the traffic scheduling of multimedia services in the wireless ATM networks. In particular, fair queueing based traffic scheduling is explored in centralized TDMA networks. The concept of fair queueing and related theories are reviewed. Three different fair queueing scheduling approaches implemented on top of centralized TDMA MAC protocols are introduced. Simulations are performed, and the results are analyzed.
Ties that bind, farming, Agrarian ideals, and life in Ontario, 1890-1930

Historians have rightly regarded the period from 1890 to 1930 as the time when Ontario emerged as an urban and industrial province. But their acceptance of the idea that this development was accompanied by a crisis of "rural depopulation" in the countryside has led them to dismiss the life of the farm, and ideas about that life, as anachronistic. The prevailing assumption of rural decline in the face of steady urbanization has also meant that little attention has been paid to the interaction between the country and the city, save perhaps to present urban areas as the final destinations of migrating farmers. This study contends that there was no crisis in Ontario's farming communities in this period. The adult farming population remained stable and relatively prosperous. Farm children left home because of the lack of available land in their neighbourhoods, not out of any widespread rejection of their parents' occupation. Their departures were neither sudden nor disruptive, but rather undertaken in stages and negotiated in the context of the family farm economy. The existence of prosperous fanning districts and a large urban population with roots in the countryside ensured that farming and conceptions of farming played a central role in the province's society and culture even as towns and cities expanded and the proportion of people engaged in agriculture declined. Public defences of farming were creative and vibrant, and rooted in contemporary ideas about history, racial decline, science, gender, art, and literature. The thesis presents an overview of these agrarian ideas, and then traces their influence over individual lives, educational institutions, and the home front in the First World War. A final chapter details the first challenge to the idealization of farming in Ontario, at the hands of sociologists and public health officials in the 1910s and 1920s. Through an examination of census material, personal papers, the farm press, and government records, this work argues that the history of Ontario from the 1890s through to the Depression should not be seen primarily as an era of urban triumph, but rather one of the complicated intermingling of rural and urban worlds.
Genomics-based characterization of tumor suppressor genes in the cardiovascular system, a role for adenomatosis polyposis coli gene in human cardiovascular development and disease

Advances in sequence-based genome research using expressed sequence tag (EST) technology offers the opportunity for large-scale gene discovery. Complementing the EST technology, the rapidly developing area of bioinformatics devoted to the collection, organization and analysis of DNA and protein sequences has advanced significantly our understanding of gene regulation during development and in disease states. The EST data can be analyzed in silico (computer based) to establish expression profiles of cDNA libraries derived from specific tissues or organs. Expression profiles of different cDNA libraries can be compared by ' in silico' Northern analysis as a tool to identify differentially expressed genes and to predict their functional roles in regulation of biological processes. In the current study, 'in silico' Northern analysis of cardiac-derived EST's was employed to identify differentially expressed genes during cardiac development and in disease. Large scale expression profiling of EST's from cDNA libraries created from human fetal, normal adult and adult hypertrophic hearts revealed developmentally and disease-dependent differential expression of several genes involved in regulation of cell number and growth, including tumor suppressor and apoptosis-related genes, leading to the hypothesis that temporal changes in expression of these growth regulating genes may underlie developmental- and disease-specific alterations in cardiac growth phenotype. The tumor suppressor adenomatosis polyposis coli (APC) and its interacting protein ß-catenin were found to be differentially expressed during cardiac development and in hypertrophic disease, resulting in higher abundance of APC in normal adult heart relative to hypertrophied and fetal hearts, and in reciprocal changes in ß-catenin protein levels. Loss of function studies using antisense inhibition of APC translation in murine C2C 12 myoblasts inhibited cell proliferation and myotube formation and led to an increase in cell death, in parallel with an increase in basal ß-catenin protein levels. Three novel APC protein isoforms were found to be expressed in the heart in a developmental- and disease-specific manner, and commensurate with this, expression levels of alternatively spliced brain-specific (BS)- and exon-1 containing APC gene isoforms were also found to vary in developmental- and disease-specific manner. We conclude that APC plays a direct role in cardiac myocyte growth and differentiation and that differential and switching of alternatively spliced and/or post-translationally modified APC isoforms may underlie, at least in part, some of the developmental- and disease-dependent alterations in cardiac growth phenotype.
The reproducibility and accuracy of cephalometric analysis using different digital imaging modalities and image compression

This study evaluated and compared the reproducibility and accuracy of cephalometric landmarks and measurements between conventional radiographic film and the corresponding indirect, JPEG compressed or direct digital images (DI). Twenty-one conventional films were indirectly digitized using a scanner, and TIFF images were converted to JPEG files using 2 levels of compression (12:1 and 25:1). Simultaneous acquisition of conventional and direct DI (stimulable-storage phosphor (SPP)) was obtained for thirty patients. Three observers for the indirect and one observer for the direct DI identified 17 and 22 landmarks respectively on the computer monitor. X and y-coordinates were recorded and cephalometric measurements calculated. Statistical analysis involved use of the paired samples t-tests and ANOVA models. The results showed that indirect DI have equivalent landmark reproducibility with conventional film. JPEG compression of indirect DI at 25:1 level results in loss in accuracy of cephalometric measurement when compared to non-compressed DI, whereas, JPEG at 12:1 did not. Direct DI were less accurate for 8 out of 21 landmarks but clinical accuracy of cephalometric measurement was equivalent to conventional film.
Differential infrared radiometer-based thermometric instrument for non-contact temperature and friction measurements

The design of a novel thermometric instrument featuring thermal-emission-intensity harmonic modulation, non-contact infrared radiation and stray background suppression is described. The instrumental principle depends on thermal (blackbody) emission of Planck radiation from a heated surface. It was developed to measure small temperature rises caused by frictional heating. By using a thin-film/ceramic strip heated with AC, the instrument was adjusted to optimum positions and alignments. A low-power He-Ne heating laser was used to investigate the sensitivity and estimate a figure-of-merit (FOM) for the instrument. The FOM at the laser of point 0 mW of the non-contact thermometric instrument was 159.9 ± 8.5 and the sensitivity for the particular thin-film/ceramic material was estimated to be 0.18-0.23 K. The instrument was applied to measure friction with a friction rig system. The friction was produced through a moving sample sliding on a stationary sample and measured at different normal loads and speeds. The tests were processed with Al-on-Al and Steel-on-part-lubricated Steel model and the correlation between normal loads, speeds and lock-in amplifier amplitude was established.
The relational goals of children with externalizing and internalizing symptoms

Relational goals relate to people's goals in relationships. Drawing from cognitive theories of emotion (e.g., Oatley & Johnson-Laird, 1987) and attachment theory (e.g., Bowlby, 1971), the association between four different relational goals in children and long-term patterns of emotional organization, operationalized as internalizing and externalizing symptoms, was explored. The goals examined in the present investigation included dominance, affiliation and two protection goals: perception of threat from the environment ("world threat") and the need to receive comfort from others. Two hundred and eighteen children (117 girls and 101 boys) ages 10 to 14 from diverse cultural backgrounds participated in this study. Information about relational goals was obtained from the participants and from inferences made about the participants' goals by their peers. Both self- and peer-report relational goal measures were developed and evaluated. The measures contained multiple statements pertaining to each goal domain. Teachers completed behavioural ratings of externalizing and internalizing symptoms. As expected, there was a positive relationship between relational goals as reported by the participants and by their peers. Direct relationships between goals and externalizing and internalizing symptoms were also predicted. Externalizing symptoms were positively related to dominance goals and negatively related to world threat goals, as expected. Internalizing symptoms were negatively related to dominance and positively related to world threat goals, as anticipated. However, the results were more pronounced for male than for female participants and for peer-reports rather than for self-reports of goals. The balance of goals within individuals was also explored in an attempt to differentiate between children with higher and lower levels of symptomatology. On the basis of self- and peer-reports of goals, children who valued dominance more than protection goals had greater externalizing symptoms, while children who valued protection goals more than dominance goals had greater internalizing symptoms, as expected. Thus, there appeared to be a relationship between particular goal combinations and long-term patterns of emotional organization as indexed by behavioural symptoms. The associations between relational goals, behaviour and emotions are discussed as are issues pertaining to goal measurement.
Characterization and plasma protein binding studies of surface-modified polyethersulfone

Polyethersulfone (PES) has been adopted as a biomaterial for the fabrication of membranes used in medical applications. As a biomaterial its surface will influence protein and cell interactions, which defines in part the ultimate success or failure of implanted devices. In the present work, the surface of films are modified utilizing fluorinated surface modifying macromolecules (SMMs) in order to alter protein interactions, which lead to the generation of platelet activation. SMMs containing four chemical compositions were synthesized and characterized for elemental analysis and molecular weight. PES and PES/SMM films were characterized for surface morphology (using microscopy techniques) and surface composition (using X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS)), and then were compared with PES surfaces. Microscopy studies showed distinct phase morphologies for SMM/PES membranes relative to the PES controls. XPS and SIMS confirmed the presence of fluorine groups at the surface. Water droplet contact angle measurements for the mixture of SMM with PES blends indicated that the surfaces became more hydrophobic after adding the SMMs. Plasma protein binding studies indicated that PES blended with a propylene oxide based SMM was the material that adsorbed the least amount of proteins relative the other PES/SMM and non-modified PES membrane materials. It is suggested that the chemical nature of the SMM's central segment bad an important influence on plasma protein adsorption.
Combustion generated pollutant reduction through jet enhanced mixing, an experimental study

Rapid mixing is essential for waste gas flares to achieve high destruction efficiencies. Steelmelting furnaces use enclosed flares to destroy combustible gases in their exhaust. Recent measurements show that the composition of these gases contains up to 30% carbon monoxide and up to 30% hydrogen at 2000 K. The current flare designs are characterized by poor mixing with the combustion air entering through the gap, deflecting the main flow and slowly mixing via turbulent diffusion. Alternate air inlet geometries have been studied by investigating the mixing of various radial air jets configurations into a high temperature combusting crossflow. The effect of these configurations on the flame length and carbon monoxide has been investigated. The experimental results show that the flame length decreases with increasing jet mass flow. The carbon monoxide destruction efficiency does not follow the same trend. All configurations exhibit an optimum destruction that corresponds to the non-reacting optimum mixing conditions.
The Canadian face of Islam, Muslim communities in Toronto

This dissertation is the first to examine the various Muslim communities of Toronto. Toronto has a Muslim population of some 200,000 of the over 500,000 Muslims in Canada. This dissertation provides a description of many of the Muslim organizations in Toronto. The description and analysis of those organizations are based on reading texts, conducting interviews, participation and long-term participant observation. Muslims in Toronto struggle with being members of a minority tradition in a city that is the most cosmopolitan in the world. They are also forced to deal with the issues that arise from living in the modern North American world. It is the interplay of these factors, being a minority, being multicultural, being North American, speaking English, having internal diversity and being modern that creates Canadian ways of being Muslim. Canadian Islam offers an important window through which to view a future role for Islam to play in the world. Muslims in Toronto are engaged in creating distinct religious lives for themselves. This thesis argues that Islam in Toronto is not simply a collection of diaspora Islams, but instead is its own local manifestation of Canadian Islam.
Error propagation in ecology, an aquatic example

Composite calculations are an integral part of ecological research, yet the errors associated with the final experimental results are rarely quantified. Error propagation (EP) is a method that carries errors associated with contributing variables all the way through to a final result. In traditional methods, mathematical formulae are used to propagate errors, but these methods are impractical for complicated calculations. Alternative nonparametric and parametric bootstrapping methods were developed and are presented here using 'Bythotrephes' seasonal production as an example of complex composite calculations. Results show a six percent difference between errors propagated through the egg-ratio method from nonparametric and parametric bootstrap. In the parametric bootstrap, standard deviation estimates were over and underestimated by as much as 18 percent, depending upon model selection for input variables. Using simple examples, bootstrapping accurately (3% change) reproduced analytical EP.
Low involvement processing, effects of stimulus exposure and repetition on implicit memory, explicit memory and affect

Involvement is widely regarded as an important construct in consumer behaviour, particularly in terms of its role in moderating effects of advertising exposure on memory and affect. Effects and processes that characterize the higher end of the low involvement continuum, however, are much better understood in comparison to lower levels. This dissertation attempts to contribute to an understanding of the latter with three experiments that examine the effects of stimulus exposure and repetition on memory (experiments 1 and 2), as well as on affect (experiment 3), under conditions of involvement that may be described as 'very low'. In the first two experiments, using a selective attention procedure, subjects were incidentally exposed to advertising messages. Evidence that these exposures had an impact on memory was sought using two types of memory measures--direct and indirect measures, believed to tap explicit and implicit memory respectively. The results suggest that, despite minimum amounts of attention devoted to processing the advertising messages, there was implicit memory for the advertised brand names as evidenced by an increased propensity to respond with those brand names on the indirect measures of brand name generation (experiment 1), consideration set formation and choice (experiment 2). A concomitant finding was poor explicit memory for the same brand names. These results were, however, moderated by repetition status (1 exposure vs, 3 exposures) of the brand names at exposure. The third experiment examined, within the context of the mere exposure effect, the effects of perceptual fluency and conceptual fluency on liking for words encountered under low involvement conditions. In particular, the proposition that both types of fluency can give rise to the mere exposure effect was tested. The results support that proposition and also indicate that perceptual and conceptual fluency operated independently in generating the observed effects. Moreover, the effects on recognition bore similarity to that found for, affect. Repetition of the words was also found to have a moderating influence.
The role of phospholipases in signalling an elicitor-induced oxidative burst in tomato suspension cells

Plasma membrane associated and Ca$\sp{2+}$ dependent phospholipase C (PLC) activity was detected at 0.13 $\mu$mol min$\sp{-1}$ mg$\sp{-1}$ plasma membrane protein. This activity was non-specifically stimulated up to 150% by in vitro treatment with elicitor preparations and nucleotide analogues. The enzyme was fully inhibited by AIF$\sb4\sp-$ and by the PLC inhibitor U73122, but not by its inactive analogue U73343. The effect of inhibitors and/or activators of phospholipases, NADPH oxidases and G-proteins was tested on elicitor treated cells by an oxygen electrode (O$\sb2$ consumption) or fluorescent probe (H$\sb2$O$\sb2$ production) assay for the oxidative burst. Cell cultures increasingly consumed O$\sb2$ and generated hydrogen peroxide when challenged with elicitor preparations. These responses could be blocked by inhibitors of NADPH oxidase (DPI and $\alpha$-Naphthol). The involvement of phospholipases in the activation of the NADPH oxidase was investigated using an array of inhibitors and activators. The non-specific PLA inhibitor chlorpromazine and the PLC inhibitors U73122 and neomycin reduced both O$\sb2$ consumption and H$\sb2$O$\sb2$ accumulation. The generic G-protein activator mastoparan showed an initial DPI inhibitable rise in O$\sb2$ consumption at 5 $\mu$M suggesting G-protein mediated NADPH oxidase activation, but induced plasma membrane permeabilization at higher concentrations. The data suggest that NADPH-oxidase is the enzyme generating the active oxygen species in tomato cells treated in vivo with elicitor preparations or mastoparan (5 $\mu$M), and that the signalling cascade leading to the oxidative burst involves phospholipase C and G-proteins.
Occupational exposures of veterinary staff during pregnancy

In this study the reproductive effects associated with occupational exposure to inhaled anaesthetics and x-radiation were investigated. Ninety women contacted the Motherisk Program requesting counselling on their occupational exposures in veterinary medicine, of these 54 pregnant women were enrolled in the study, followed-up and matched to controls. The rates of major malformations (p = 0.71), spontaneous abortion (p = 0.98), pre-term delivery (p = 1.000) and low birth weight infants (p = 0.09) were similar between the study and control groups. Since the study patients were unable to provide the radiation levels to which they had been exposed, records of annual radiation doses of veterinary staff were obtained from the National Dose Registry and analyzed. All the veterinary practices had annual mean radiation doses below the whole-body annual permissible dose equivalent of 20 mSv. These findings suggest that veterinary staff exposed to inhaled anaesthetics and/or x-radiation are not at an increased risk for major malformation above the 3% baseline risk.