VictorJuiz/thesis huggingface dataset:
A polymorphic locus in the promoter region of the IGFBP3 gene is associated with mammographic breast density

Objectives. To determine whether there is a relationship between polymorphic variations in the IGF1 and IGFBP3 genes and mammographic breast density. Methods. There is a total of 441 white women, recruited from Women's College Hospital, in this study. Each woman completed a questionnaire, detailing information on age, menstrual history, hormone use, diet, medical and mammography history. Blood samples were taken for DNA extraction to genotype the subjects for polymorphic variants in the two candidate genes. Mammographic films were digitized by a computer-assisted method to assess breast density. Statistical analyses were carried out using analysis of covariance models in SAS (proc glm). Results. There was a highly positive trend in the mean percentage of breast density by the number of A alleles at a polymorphic locus in the promoter region of the IGFBP3 gene among premenopausal women (P = 0.0005). Conclusions. We report a strong relationship between a polymorphic gene locus (IGFBP3) and mammographic breast density. This finding provides insight into the biological basis of breast density and determinants of its variation.
In-line skating injuries

In-line skating is rapidly gaining popularity. This research was undertaken in order to address various issues related to the safe practice of this sport. The objectives of this study were to describe injuries and determine associated risk factors. This was a retrospective, community based study in which data were collected from skaters all over Canada. In the summer of 1993, 3000 questionnaires were sent out to in-line skaters and 462 were returned by skaters (response rate 15.4%). One hundred and fifty-nine skaters (34.4%) suffered 298 injuries. From the data, it is further substantiated that protective gear can be protective but that significant injury can still happen. A human being moving at speed with poor stopping capabilities will be at risk of collision with obstacles in the vicinity. The challenge is to determine the efficacy of education (literature, videos and demonstration) and of protective gear (and their limitations) to minimize the number of significant accidents. The ability to stop safely in this sport may be improved by manufacturers and education. (Abstract shortened by UMI.)
Elucidation of the biological function of phosphotyrosine adaptor Shc A

Substantial biochemical data have suggested that ShcA participates in multiple protein-protein interaction mediated by its SH2 and PTB domains. However, the biological function of ShcA has remained obscure. Taking both molecular and genetic approaches, the work described in this thesis provides significant information regarding the biological role of ShcA in signal transduction. It has become clear that signaling proteins and the hierarchies in which they operate are highly conserved in evolution, in organisms as divergent as mammals and Drosophila. In order to understand ShcA function, I isolated cDNA from two distinct biological systems, Drosophila and mouse, each of which are highly homologous to human ShcA, suggesting an important function of ShcA has been conserved in evolution. In chapter 2, a cDNA from a Drosophila expression library was isolated using an antibody raised against human ShcA. Sequence alignment of this Shc-related gene with its mammalian counterparts not only revealed a high degree of amino acid identity and similar overall organization, but also led to the identification of a phosphotyrosine interaction domain. I then showed that dShc can interact through its PTB domain with the activated DER. Sequence conservation thus provided a wider perspective on the structural and functional importance of PTB and SH2 domains in evolution. With respect to studying mammalian ShcA function, I isolated and characterized the mouse genomic locus of ShcA, and targeted a mutation into the ShcA gene locus by homologous recombination. The phenotypic characterization of ShcA-deficient mice is described in chapter 3. I found that mice homozygous for this germline mutation are embryonic lethal, indicating that ShcA is essential during development. Further investigation revealed that ShcA has a specific role in the development of the cardiovascular system. Consistent with this observation, I found that ShcA expression is dynamic during embryonic development, while previous biochemical studies strongly suggested a broad range of biological activity and expression. I then established fibroblast cell lines from ShcA-deficient mouse embryos in order to study the biochemical properties of ShcA. The existing model suggested that ShcA link RTKs with regulation of the Ras/MAPK pathway. I found that ShcA is not essential for GF-induced MAPK activation at high concentrations of GF, however, it is required to activate MAPK at low GF concentration. This finding suggests that ShcA may function to sensitize cells to GF stimulation. Furthermore, I also demonstrated an important role of ShcA in integrins mediation of actin cytoskeletal reorganization and focal adhesions. Taken together, all of these findings have added to the understanding ShcA role. In Chapter 4, I propose that ShcA has an important function, to co-ordinate multiple signals to establish proper biological responses including cell proliferation and cytoskeletal architecture that are crucial for complex developmental processes such as formation of the cardiovascular system.
Search for standard model Higgs boson produced in association with a top-antitop quark pair in 1.96 TeV proton-antiproton collisions

This thesis describes the first search for Standard Model Higgs boson production in association with a top-antitop quark pair in proton-antiproton collisions at a centre of mass energy of 1.96 TeV. The integrated luminosity for this search corresponds to 319 pb−1 of data recorded by the Collider Detector at Fermilab. We outline the event selection criteria, evaluate the event acceptance and estimate backgrounds from Standard Model sources. Three events are observed that satisfy our event selection, while 2.16 ± 0.66 events are expected from background processes. No significant excess of events above background is thus observed, and we set 95% confidence level upper limits on the production cross section for this process as a function of the Higgs mass. For a Higgs boson mass of 115 GeV/ c2, we find that σtt H x BR(H → b b) < 690 fb at 95% C.L. These are the first limits set for ttH production. This search also allows us to anticipate the challenges and necessary strategies needed for future searches of ttH production.
Early predictors of later spelling abilities in EL1 and ELL learners: a 6-year longitudinal study

The purpose of the present study was to examine the English spelling development as well as the longitudinal predictors of English spelling dictation abilities in children whose first language is English (ELI; N= 50), or who are English Language Learners (ELL; N=118). Growth curve analyses were conducted to determine whether early spelling abilities and growth could be predicted by language status (ELI or ELL), native language group (English, Punjabi, Portuguese or Tamil), or risk status on the basis of two aspects of phonological processing; phonological awareness and naming speed, and community-level socio-economic status (SES Risk). Parallel correlational and regression analyses were also conducted for the two language status groups to identify early predictors (measured in Grades 1, 2 and 3) of Grade 6 spelling ability. The variables of interest included SES risk status, nonverbal reasoning, oral language, verbal memory, phonological awareness, and naming speed. Results indicated that instead of language status, risk status on phonological processing measures predicted spelling development. An additive effect of risk status on phonological awareness and naming speed was also noted across time intervals. Finally, despite some variability, the importance of phonological awareness and naming speed surpassed the influence that first language, SES, nonverbal reasoning, oral language proficiency, and verbal memory may exert on the development of spelling skills in school-aged children. Theoretical and clinical implications are discussed.

Keywords: English language, Orthography and spelling
English language, Orthography and spelling
Analysis and extension of time frequency masking to multiple microphones

An algorithm for speech enhancement with 2 microphones, known as Time-Frequency Masking (TFM), is analyzed in this thesis. It is shown that several standard beamforming algorithms are in fact special cases of TFM. The TFM technique is also extended to the case of more than two microphones. Experiments, conducted in a real environment with 0.1 second reverberation time and various background signal to noise ratios (SNRs), show that the extended TFM technique is perceptually better than current state-of-the-art beamforming-based speech enhancement techniques. For example, with 6 microphones, TFM can achieve over 40% word recognition accuracy gain over the non-filtered signal, and 35% over other beamforming techniques at a background SNR of −10dB. It also results in a 20% gain in word recognition accuracy over competing techniques at 10dB with 10 microphones. Furthermore, TFM offers better noise reduction resulting in a perceptual removal of the noise signal.
Chinese adolescents' conceptions of self-determination and nurturance rights

The study examined mainland Chinese adolescents' conceptions of their own rights, which have rarely been studied in Asian cultures that are considered to be collectivistic. 160 younger and older adolescents from urban and rural China provided evaluations and justifications in response to written scenarios in which a child wishes to exercise a right, but an authority denies the child the right. Three types of scenarios were included: self-determination rights, nurturance rights, and conflicts between self-determination and nurturance. Older participants were more likely to endorse self-determination rights than younger participants, in both straightforward and conflict situations. No age differences were found for nurturance rights. When supporting self-determination, participants appealed to individual rights, autonomy, and personal choice in their justifications. Overall, these findings reveal similar developmental patterns as prior studies in Western cultures and indicate that Chinese adolescents from diverse settings endorse a variety of self-determination rights.
Chromatic visual evoked potentials in offspring of women with thyroid disease in pregnancy

Animal literature has revealed that gestational thyroid hormone (TH) deficits lead to excess S-cones and a deficiency of M-cones. Because cones are essential for colour vision, it is hypothesized that gestational TH deficits in humans lead to abnormalities in colour processing. Chromatic Visual Evoked Potentials (cVEPs) were measured in infants of women with hypothyroidism in pregnancy (HYPO) (n = 23), infants of women taking antithyroid drugs (ATDs) for hyperthyroidism in pregnancy (HYPER) (n = 9) and controls (n = 21). HYPO and HYPER groups represent infants with TH insufficiencies in early and late gestation, due to insufficient maternal TH levels and the effect of ATDs on fetal thyroid function, respectively. Compared to controls, HYPO/HYPER groups had longer mean latencies to stimuli modulating the L/M-cone pathway and shorter latencies to S-cone modulating stimuli (non-significant). While these trends are suggestive of underlying L/M cone deficits, future studies in this field are required.
Technological protection measures and related issues on the verge of Canadian copyright reform

This paper deals with the Technological Protection Measures (TPMs) and the relevant anti-circumvention provisions in Canada and in a number of other jurisdictions. It outlines the main technological features of the TPMs in the context of balancing between the Intellectual Property (IP) rights' holders and users' rights. It argues that technological safeguards have little role in IP protection without effective legal backing directed against the provision of circumvention devices or services. Subsequently, it explores the existing framework of legal protection granted to TPMs both on the global and national levels outlining their main features and related critique. It further demonstrates how Canada attempted to adopt similar measures in the proposed copyright reform while providing a detailed outline of the key issues on the topic and the related critique. Consequently, it proceeds with outlining a number of perspectives on the future of the reform in Canada. And finally, after analysing a number of practical challenges, the paper concludes with questioning the immediate necessity of the reform in the changing digital environment.

Keywords: Technological innovations, Law and legislation
Technological innovations, Canada
Intellectual property, Canada
Inhaled aminoglycosides for the treatment of chronic respiratory Pseudomonas aeruginosa infections in cystic fibrosis

Cystic fibrosis (CF) is the most common, life-shortening single gene disorder among Caucasians. Lung disease is the major cause of morbidity and mortality in these patients. A vicious cycle of airway obstruction, persistent Pseudomonas aeruginosa (Psa) infection and intense neutrophil-dominated airway inflammation leads to lung destruction, bronchiectasis and ultimately lung failure. While inhaled antibiotic therapy has been prescribed for several decades to treat Psa-induced lung infections, we lack a complete understanding of the complexity of lung disease, the role of inhaled antibiotics, the optimal inhaled antibiotic, its dose and duration and the legitimacy of the use of the standard antibiotic susceptibility breakpoints for inhalational therapy. The research objectives of this thesis were to determine if treatment with an inhaled antibiotic to which Psa is said to be “resistant” results in a significant decrease in sputum bacterial density and improved lung function, to study the effect of inhaled aminoglycoside therapy on airway neutrophilia, and to develop a novel approach using 18fluorodeoxyglucose (18FDG) and positron emission tomography (PET) technology to determine the degree of lung inflammation in CF patients that can be used to evaluate the efficacy of potential anti-inflammatory therapies. It was found that the microbial and clinical response following an inhaled aminoglycoside to which Psa was defined as resistant was negligible compared with the treatment response following an antibiotic to which Psa was susceptible. Inhaled aminoglycoside therapy resulted in a significant decrease in sputum Psa density and improvement in lung function. However, a decrease in lung inflammation was not observed, as measured by sputum neutrophil counts and sputum supernatant levels of IL-8, MPO and fibrinogen. In those patients receiving more than one antibiotic cycle, there was no evidence of a cumulative decline in airway inflammation. Despite the presence of chronic neutrophilia in the lung, 18FDG-PET imaging technology demonstrated that the majority of CF patients had either a normal or slightly depressed rate of glucose metabolism suggesting that substantial 18FDG uptake by neutrophils in the lung was not occurring. These results suggest that the functioning of lung neutrophils may be impaired, eliminating the need for glucose metabolism and hence 18FDG uptake.
Social experiences of children and adolescents diagnosed with intractable epilepsy: maternal representations

When mothers describe their child's social experiences, they refer to the presence/absence of meaningful peer relationships, participation in activities, exposure to bullying and teasing, and social skills. Findings indicate that there are factors at the seizure, child, family, peer group and community levels that may play a role in either facilitating or constraining positive social experiences in this sample. This study documents the high levels of social distress that exist in this sample of children and adolescents, develops a theoretical model to guide both clinical assessment and a future program of research, and raises a number of important research questions that can be explored in future studies. The experience of social success is part of what childhood is all about. Yet, children and adolescents with intractable epilepsy experience inordinately high levels of social distress. However, there is variability in this outcome as some suffer from social isolation while others enjoy the support of their peer group. The purpose of this study was to develop a theoretical model to identify factors and processes involved in the experience of social success. A secondary qualitative and quantitative analysis was conducted using baseline data obtained from fifty-one subjects who participated in an original study pertaining to psychosocial outcomes of epilepsy surgery. Ethnographic interviews conducted with a subset of this sample (n = 20) were used in the analysis. These interviews with mothers solicited views of their child's physical, social, psychological, cognitive and family functioning. Factors and processes were identified using open and axial coding of these interviews and were used to develop a theoretical model. Three of these relationships were examined using the quantitative database.
Utilization in optical code-division multiple-access networks

In the process of studying O-CDMA through the spectral and network utilization, a number of specific original contributions are made: an impairment in O-CDMA networks---the spectral crosstalk---is studied for two different system configurations; a procedure is designed to evaluate the performance of O-CDMA signature sequences in realistic networking environments; and a technique is developed to allocate adaptively signature sequences which leads to an order of magnitude improvement in performance and provides a quality-of-service contract on the bit-error rate. In local-area networks with a high traffic load, an O-CDMA system with static allocation of signature sequences is shown to have a higher network utilization than a competing WDMA scheme. It is demonstrated that by increasing the adaptability of the next generation of O-CDMA systems, the performance may be further improved. This work provides the tools-the analytical frameworks, figures of merit and mechanisms for adaptability-that may be used to design and evaluate these future O-CDMA systems. This work investigates how O-CDMA exploits resources in multiwavelength optical fiber networks. For the first time, it examines this question fundamentally from the perspective of both transmission and network connectivity. Given the processing gain of O-CDMA, the spectral width of the transmitted signal may become appreciable relative to the spacing between adjacent channels. The assumption traditionally made in optical communications that these channels may be treated independently breaks down in this case. In this work, a figure of merit---the spectral utilization---together with an analytical framework are developed to treat the bandwidth of O-CDMA networks as a whole, rather than as a collection of independent segments. The studies of O-CDMA with this spectral utilization metric suggest that the technology cannot compete with wavelength-division multiple-access (WDMA) at the physical layer taken in isolation; however, this is not the sole measure of the value of a network. Factors such as channel or receiver contention and the statistics of the traffic being transported do not manifest themselves in the physical layer yet are important factors in determining the performance of an optical network. A different figure of merit---the network utilization---is therefore used to compare and evaluate various O-CDMA and WDMA systems in a networking context.
A computational approach for the development of a probe for detection of liquid aluminum flow direction

A computational approach will be presented to detect the direction of liquid aluminum flow. An advanced CFD code, namely FLOW-3D is utilized for the numerical computations. The melting times of various points within specially shaped specimens immersed in liquid aluminum are predicted using FLOW-3D. In these simulations, the specimens are made from solid aluminum, where the chemical composition of the solid is the same as the aluminum bath. Parameters investigated include: the liquid metal flow direction, magnitude of velocity, liquid metal superheat and variations in the specimen semi axes lengths.
Investigation of physically entrained matte in the flash furnace slag

Valuable metals such as Ni, Cu and Co are partially lost in the flash furnace slag during the smelting process. These metals are present in the slag either as dissolved metals or as physically entrained matte particles. In this study, the matte particle size distribution in the slag was measured and a mathematical model was developed to simulate the settling process of matte particles in the slag. The influence of the iron content in the slag on the loss of valuable metals was analyzed and a linear relationship between the Co and Fe content in the slag was found. In the process of matte separation from the slag, the matte particles inevitably collide and coalesce due to their velocity differences. A numerical model was developed to model the changes of the matte content and particle size distribution in the slag considering particle collision and coalescence.