VictorJuiz/thesis huggingface dataset:
Influence of time of introduction to a milk feeding practice on size at six months

Two independent databases of convenience were available to conduct an in-depth analysis of the relationship between introductory milk feeding practices and size at six months. A negative linear association between age of introduction to formula and achieved size at six months, noted in both data sets, best demonstrates the relationship. The earlier the introduction of formula, the greater is the weight and length of the baby at six months. An independent and opposite association between age of introduction to solids and size at six months was noted in the first database but not the second, likely because, in the second database, both formula and solids were introduced very early, often in close proximity. While a definitive conclusion on a causal relationship among the introduction of formula, a consequent change in growth rate and a resultant difference in achieved size cannot be stated the analyses permitted a strong inference of causality.
Health-adjusted life expectancy at the local level in Ontario

Health-adjusted life expectancy (HALE) is a positive measure of general population health that is comprised of both mortality and a weighted measure of health-related quality of life. This thesis will be the first derivation and comparison of the Health Utility Index (HUI) and HALE between small areas, and the first derivation of life expectancy between small areas in Ontario. The HUI was derived for the forty-two Public Health Units (PHUs) in Ontario using responses from the 1990 Ontario Health Survey. Life tables were generated for the PHUs using the Registrar General's mortality files for 1988-1992. The HUI and the life tables were combined using the Sullivan method to generate HALE for the PHUs. The differences in the mean HUI between PHUs are small. However, there are large differences in life expectancy (6.05 for males, 6.42 for females at age 15) and HALE (6.93 for males and 6.30 for females) between northern and southern PHUs. HALE is a conceptually and practically useful general population health indicator for health planners at the local level.
Characterization of double-layer capacitors for power electronics applications

A new kind of capacitor, with large capacitance and high energy density, has become available in the last few years. These high energy capacitors are based on the double-layer technology. They have higher power handling capability and energy density compared to electrolytic power capacitors. So far, almost no research has been published with respect to the use of these capacitors; in addition, the information supplied by the manufacturer is not enough to establish an accurate model and to understand the operation of the capacitors. This thesis deals with the selection, identification and verification of a simple and accurate model for the double-layer capacitors. The model is based on the terminal behavior of the double-layer capacitors; therefore, the identification is given by a specific and repetitive process based on electrical measurements.
Molecular and cellular analysis of the osteoblast lineage

A challenge in analyzing transitional stages in the osteoblast lineage is to develop means by which to rank cells as more or less mature and to order them with respect to stage of differentiation. Primary cultures of fetal rat calvaria cells were used to follow single osteoprogenitors and their progeny to address in more detail sequential patterns of expression of osteoblast-related markers during differentiation. In initial experiments, I used immunocytochemistry and poly(A)-PCR to investigate different stages of osteogenic differentiation in individual cells and colonies identified morphologically as fibroblastic or osteoblastic. The results showed that colonies with fibroblastic morphology are distinguishable from immature osteogenic colonies and the latter are distinguishable from mature osteogenic colonies. As well, marked intercellular heterogeneity in expression of mRNA and protein in individual morphologically indistinguishable cells from the same colonies was also found. These results validated the technical approaches being used. They also confirmed some aspects of the osteoblast differentiation sequence as seen in mass populations, but extended it to a level of single cell expression and single cell heterogeneity not previously accessible. I next analyzed further expression of osteoblast-associated markers amongst individual mature osteoblasts. The results revealed extensive heterogeneity in the repertoire of genes expressed in clonally-derived, mature osteoblasts of equivalent in vitro lifetime, suggesting marked plasticity in phenotype of mature osteoblasts. These data also suggested that the most unambiguous marker of the mature osteoblast remains its ability to contribute with its siblings to the production of bone rather than in an absolute level of production of particular macromolecules. Finally, I validated a replica plating approach for studying primitive progenitors prior to their acquiring morphological characteristics of preosteoblasts/osteoblasts and used it with poly(A)-PCR to determine molecular fingerprints of immature osteoprogenitors compared to those of preosteoblasts and mature osteoblasts. The molecular profiles I established indicate that a temporal sequence of expression of multiple markers can be followed in these single colonies as they undergo differentiation, and that both discrete stages and a continuum of changing marker expression levels occur with much variation in expression of any given marker. I identified a novel transition point in osteoprogenitor development not previously seen in any model system or bone in vivo. Thus, the data have given new insights into the osteoblast differentiation sequence and have established new landmarks in early osteoblast development.
General pre-trial publicity and jury bias

The present study examined the influence of general pre-trial publicity (PTP) on mock jurors. One hundred and forty-seven university undergraduates read either factual, fictional, or neutral general PTP prior to viewing a trial and deliberating on a verdict. Results indicated that there is no differential influence between factual vs. fictional pre-trial publicity. When these two groups were combined, results suggested that general PTP exerted a strong influence to strengthen mock jurors' feelings of the defendants guilt both before deliberations as well as after deliberations. Results also suggested that general PTP influenced mock jurors confidence after deliberating so that jurors exposed to the PTP felt much less confident in their verdict choice than jurors in the control (neutral) condition. There was no effect of general PTP on the actual verdict choice.
Event-related potentials during learning and recognition of complex pictures

Event-related potentials (ERPs) were recorded while subjects learned a large set of complex, coloured pictures. Recognition memory was examined within the same day and after a 24 hour lag. Memory performance decreased from 88% to 65% over 24 hours. The ERP waveforms showed a prominent parietal-occipital P100-N150-P240 complex that was the same in learning and recognition. A centro-parietal P650 wave was larger during recognition than during learning for both the new and old pictures. During learning the pictures elicited a sustained positive potential maximally recorded in the occipital regions. Finally, in the recognition condition, new pictures elicited an N400 wave over frontal electrodes while old pictures elicited an earlier centroparietal P650 than novel pictures. Learning is most clearly associated with a sustained occipital positivity, recognition with a parietal positive wave, and novelty-detection with a frontal negative wave.
Applying human factors engineering to medical device design, an empirical evaluation of patient-controlled analgesia machine interfaces

This thesis was motivated by the fact that poor design of medical devices plays a significant role in inducing human error. The hypothesis explored in the thesis is that medical equipment can be made safer, more efficient, and easier to operate by applying human factors to equipment design. The Lifecare 4100 PCA Plus Infuser, a commonly used medical device was chosen as the testbed. The thesis first describes an analysis of the Lifecare PCA interface which employed cognitive task analysis and human factor design principles. Guided by the results of the analysis, a redesigned interface was developed. A set of empirical evaluations was then conducted to compare the redesigned interface with the existing Lifecare PCA interface with novice and experienced PCA users. The results of the evaluations provided evidence of improved efficacy of the redesigned interface over the existing Lifecare PCA interface; programming times were significantly faster and fewer errors were made with the redesigned interface than with the existing one. Additionally, a significant portion of the novice population reported lower mental workload with the redesigned interface, and the experienced population reported comparable levels of workload for both interfaces, despite having much more extensive experience with the existing one. These findings demonstrate that PCA machine operation can be improved by adopting a human factors approach to interface design. They also lend support to the broader prospect of applying these methods to other devices to improve medical device safety.
Aberrant Glycosylation in HEMPAS Patients

HEMPAS (hereditary erythroblastic multinuclearity with positive acidified serum lysis test) is a rare congenital anemia. A group of enzymatic lesions affecting the biosynthesis of N-linked oligosaccharides has been reported in HEMPAS. This study was conducted to investigate the molecular basis of HEMPAS in a group of Ontario patients. Lectin binding and endoglycosidase digestions were utilized to determine the nature of abnormal oligosaccharides on two erythrocyte membrane glycoproteins, Bands 3 and 4.5. The results suggest a hybrid or high mannose N-glycan in place of poly N-acetyllactosamine on these proteins, consistent with a defect in $\alpha$-mannosidase II. A reduction in the enzymatic activities of GnT II or $\beta$4GalT, as reported in some HEMPAS patients, was not detected in the cultured EBV-transformed lymphoblasts of our patients. Moreover, poly N-acetyllactosamine was present on proteins in these cells. The alteration in the oligosaccharide moiety of Band 4.5 did not interfere with its glucose transport function.
Role of patient severity in predicting length of hospital stay

This study assessed the role of the Computerized Severity Index (CSI$\sp\circler$) in predicting length of stay (LOS) for discharges from psychiatric inpatient units. Using the CSI, raters retrospectively reviewed medical charts, producing three continuous severity ratings for each patient-admission, maximum and discharge. Hierarchical and stepwise multiple regression analyses were conducted to predict LOS using CSI ratings and other patient data. Subgroups with psychotic disorders and major depressive disorders were modeled separately. In both groups severity measures predicted 8-10% variation in LOS controlling for discharge abstract variables, and final models predicted 14-19% variation in LOS. While severity improves capacity to predict LOS, prediction is still inadequate for funding purposes. Future work should concentrate on incorporating measures of personal and social functioning into severity ratings, and on assessing provider and site influences on LOS. In mental health, funding models based on program rather than individual performance may be more appropriate.
Stationkeeping in the Space Shuttle middeck, preliminary design for the dice bus module

The Space Shuttle middeck is an unlikely place to find a free-floating satellite. That, however, is just what DICE proposes to be: an untethered free-flyer under astronaut supervision. In support of the DICE project, this thesis examines the disturbance forces to which that free-flyer would fall prey, proposes a design for an actuation system which would counter those disturbances, and simulates the control of this actuation system. From a survey of middeck disturbance forces, five significant ones are examined: middeck air circulation, solar radiation pressure, atmospheric drag, gravity gradient torque, and orbital offset between Shuttle Orbiter and DICE mass centers. A simulation of these forces is created in XMath. Middeck air circulation proves to be the greatest disturbance, exerting forces up to 10$\sp{-3}$ N and torques up to 10$\sp{-4}$ Nm. In reply to these disturbances, an actuation system is proposed. It re-circulates middeck cabin air through the DICE bus and ejects it through 3 nozzle clusters in order to produce a net thrust. The airflow created by such an actuation system is characterised, while mock-up conditions, thruster location, and valve position are varied. The force output of one nozzle on the mock-up most faithful to current design is measured to be 10$\sp{-2}$ N.
Quality of life, exploring the perspective of patients with congestive heart failure

This study explored the experience of quality of life for persons with congestive heart failure. The descriptive-exploratory design, guided by Parse's theory of human becoming, elicited 11 participants' perspectives of quality of life. Participants spoke about limitations and losses, important relationships, comforting and not comforting experiences, hope, and yielding to change. The findings consisted of three themes of shared meaning which were joined together to form the unified description of the experience of quality of life for the participants study: Loss surfaces with diminishing vitality amid patterns of communion-aloneness that are consoling-not consoling while desired anticipations mingle with acceptance of what will be. The findings were discussed in relation to the participants' descriptions, theoretical principles and concepts, and related research literature. Conclusions and recommendations for professional practice and future research are offered.
On the design of multirate filter banks by H¦0¦0 optimization

The main topic of this thesis is M-channel maximally decimated filter banks, commonly called quadrature mirror filter (QMF) banks. These systems are linear periodically time varying (LPTV). The first result of this thesis is that for the general class of LPTV systems, the $\ell\sb2$-induced gain and RMS induced gain are equal, a known fact for linear time invariant systems. We advocate optimizing such gains for an error system as an effective design approach. For QMF banks, we show that this design method automatically suboptimizes traditional measures of distortion, namely, aliasing distortion, magnitude distortion, and phase distortion. We compare the QMF bank which is designed by the ${\cal H}\sb{\infty}$ optimization technique with one of the standard QMF banks used in subband coding. Specifically, we show that marginal improvement in performance can be achieved if a priori knowledge about the class of input signals is incorporated in the design. This gives hope that ${\cal H}\sb{\infty}$ optimization, a general purpose technique, will be beneficial in other signal processing systems.
Modulation of PTH-mediated signal transduction in osteoblasts by factors regulating cellular growth

Pertussis toxin (PTOX) treatment of ROS17/2.8 osteosarcoma cells has been reported to increase parathyroid hormone (PTH)-stimulated adenylyl cyclase (AC) and diminish PTH receptor desensitization. The objective of this study was to determine the effect of PTOX on AC activity in UMR106-01 osteosarcoma cells, and establish the mechanism of PTOX effects on this system. UMR106-01 cells were shown to express Gi$\sb{1-2}$ and Go proteins and their inhibition by PTOX treatment of whole cells led to increases in both PTH and PGE$\sb2$ stimulated AC activity. This increased activity was not mediated by release of Gi inhibition of AC since acute inhibition of this protein in cell membranes did not alter AC activity. Therefore, other effects of PTOX on the cells were investigated and it was demonstrated that PTOX inhibits the growth of UMR 106-01 cells by inhibiting their response to their own secreted growth factors. Modulation of cellular growth by different media revealed that AC responsiveness of the UMR 106-01 cells is also increased under low growth conditions. These studies help to define the role of Gi/o proteins in osteoblasts and demonstrate that the responses of UMR 106-01 cells to two bone resorbing agents can be profoundly influenced by the local bone growth factors.
Robust H¦0¦0 - based control of flexible joint robots with harmonic drive transmission

The problem of the control of flexible joint robots is considered. Motion and torque control of robot joints, especially those equipped with harmonic drive (HD) transmission, is a challenging task due to the inherent nonlinear characteristics and joint flexibility of such systems. Two issues related to the control of flexible joint robots are investigated. The first is the development of a systematic scheme for selecting uncertainty bounds of robot joint nonlinearity and flexibility for control design purposes. The second is the development of motion and torque control schemes that guarantee robust performance in the presence of model uncertainties. We propose a twofold robust control design for flexible joint robots with HD: an actuator-level torque control and a link-level motion control. We utilize multivariable ${\cal H}\sb\infty$-based optimal control laws supported entirely by frequency domain measures at both levels. The proposed method provides a unified framework for achieving the desired performance requirements and for preserving robust stability in the presence of model uncertainties. Using simulation it is shown that the proposed method is more robust than conventional methods because the uncertainties due to the actuator-transmission nonlinearity are explicitly considered in the control design procedure. In the design of the actuator level torque control, we analyze nonlinear harmonic drive phenomena that have been widely observed in experiments. The focus is on incorporating into the control design process a knowledge of the mismatch between the physical system and its mathematical models. The describing function and conic-sector-bounded nonlinearity methods are used to build into the control design process the effects of mismatch between hysteresis, friction and nonlinear stiffness of HD transmission and their mathematical models. In the design of the link level motion control, a nonlinear compensator based on the computed torque technique is derived. It is shown that the closed-loop system achieves robust performance using the proposed control design technique. Using the Small Gain theorem and the Lyapunov Function method, the stability of the proposed control scheme is verified. Finally, in order to illustrate the proposed technique two control designs are presented for the IRIS-facility experimental testbed (a versatile, modular, and reconfigurable prototype robot developed at the Robotics and Automaton Laboratory of the University of Toronto) together with simulation and experimental results
Numerical investigation of the performance characteristics of the inductively coupled plasma generators

The main objective of this work is to develop a numerical model for a radio-frequency inductively coupled plasma (rf ICP) generator by coupling a mathematical model of an ICP with a state-space representation of a free-running rf generator. The coupling of the two models permits the interaction between the ICP and generator, thus predicting system operating characteristics, efficiency, as well as the minimum sustainable power. In this work, the complete flow, energy, and electromagnetic fields of argon and nitrogen ICP are solved, and the vector potential form of Maxwell's equation is manipulated to compute the ICP's loading impedance. The impedance is assumed to be quasi-static, and the two models are iterated successively to obtain a common operating point. At the end, the power levels below which no stable plasma can be sustained are found, and they are proposed here as the minimum sustainable powers for argon and nitrogen ICP.
Occupational exposure to electromagnetic fields and female breast cancer

The present study was designed to examine the association between occupational exposure to electromagnetic fields (EMF) and female breast cancer, The study design was case control, within the study population of the National Breast Screening Study (NBSS) of Canada. The sample included 1156 cases and 3468 matched controls (3 controls were matched for each case). The NBSS epidemiologic questionnaire included the title of the most recently held occupation. Classification of the case and control subjects into the exposure categories were made by an expert. Conditional logistic regression modelling using PHREG procedure was used to estimate the relative risks and their related confidence intervals. The results of the study suggest that women whose occupation entails exposure above the general population level are at higher risk for breast cancer. Analysis of data for younger (40-49 years) and older women (50-59 years) suggests a more than double increase in the risk for both age groups which is significant for the older subjects but below the significance level for the younger subjects. This study also shows that there is a significant interaction between EMF exposure and regularity of periods. The risk of breast cancer associated with exposure to electromagnetic fields increases when periods are regular, but a smaller sample of women whose periods are irregular show a protective effect. The present study found that women who had undergone mammography prior to the NBSS, were at higher risk for breast cancer. A dose-response relation for the number of prior mammographies was found. (Abstract shortened by UMI.)
A case study analysis of girls' physical activity in one educational setting

A feminist, qualitative methodology was utilized in this study of girls age 11 and 12 in one educational setting. A combination of semi-structured interviews and participant observations provided a detailed picture of the girls' physical activity experiences. Data analysis indicated that the educational setting is an institution that reinforces patterns of male dominance through the "hidden curriculum". Girls in all three settings of this study, the playground, academic classroom, and physical education class, were prevented from achieving their full physical, intellectual, and emotional development as a result of both direct and indirect stereotypes and sexist ideologies. Children who did not conform to the dominant values of aggression, power, and strength challenged these values and discovered ways of negotiating their preferred mode of playing and competing.