Engineering analysis is applied to two problems: (1) an experimental study of time-dependent blood flow and (2) a theoretical study of oxygen (O(,2)) transport in a red blood cell (RBC). Since in vivo blood flow is time-dependent, the ability to predict unsteady blood flow from steady-flow rheological data for blood is of interest. Oscillatory and pulsatile flow of blood and related suspensions was studied in 400 (mu)m and 218 (mu)m glass tubes at 37(DEGREES)C. The flow was sinusoidally driven with a frequency of 0.5 Hz to 3.0 Hz, and the resulting pressure gradient in the tube was measured. The pressure and flow data were compared to a predicted relation obtained from solving the momentum equation subject to rheological data; these data were acquired from steady-flow viscometers at a hematocrit (RBC concentration) value equal to the average tube hematocrit. For a given pressure-gradient amplitude for oscillatory flow, the predicted flowrate amplitude is smaller than that found by experiment. The discrepancy is attributable to a residual Fahraeus-Lindqvist effect not compensated for by using the average tube hematocrit in the predictions. In addition, the discrepancy depends on the RBC suspending medium and the hematocrit, and is less than about 10 percent for RBC in plasma. Pulsatile flow was more predictable than oscillatory flow, indicating possible differences in the Fahraeus-Lindqvist effect for the two cases. Viscoelastic fluid effects were negligible. The second problem deals with O(,2) transport in a red cell. A significant fraction of intracapillary resistance to O(,2) transport occurs in the red cell and is not well understood. A simple model is used to study the interaction of diffusion, facilitated diffusion, and reaction kinetics during the O(,2) unloading of a red cell. The nonequilibrium region adjacent to the RBC membrane is elucidated using boundary layer analysis, and the O(,2) transport equations are solved numerically using double orthogonal collocation. The minimum time required to unload O(,2) from a red cell is calculated and depends strongly on the plasma surrounding the cell. The minimum release time is comparable to some estimates of capillary transit time in working skeletal muscle. The present model is compared to the standard Krogh model for O(,2) transport.

This dissertation describes a model of the visual cortex of the cat. The model has been applied to some of the problems faced by contemporary computer vision systems. The model goes beyond previous models of visual cortex in that it models both the anatomy of visual cortex and the ability of individual cells in visual cortex to learn. The model is based on the hypothesis that image processing in the cat's visual system consists of three levels: the retinothalamic, the primary and secondary cortical (Area 17, 18, and 19), and the associative. The retinothalamic system is modeled by using operators modeling different types of retinal ganglion cells (X, Y, and W). Cells in Areas 17, 18, and 19 are modeled using CAMs, which are models of cortical cells having associative and plastic properties. CAMs modeling Areas 17, 18 and 19 use unsupervised learning to form primitives for segmenting preprocessed images on the basis of edges, moving edges, and texture. Only one associative area, Area 21, is modeled. The model of Area 21 receives input from the models of Areas 17 and 19 via the model of the Lateral Pulvinar, which transforms the segmentations into geometrical features on the basis of the two-dimensional regions. The model of Area 21 uses supervised learning to form pattern classes which are specific and hence useful to a particular domain (environment). The domains used to test the model are Roman text, Japanese text, digitized photographs of house scenes, and examples of various textures. Experiments demonstrate that the model is relevant to computer vision research because it presents a method of solving the problem of domain-specific knowledge in computer vision systems. The model also demonstrates that many techniques for computer vision systems are suggested by the anatomy and physiology of the cat's visual system.

Includes bibliographical references (leaves 90-112) / The current study focused on investigating the relationship between sleep problems, learning disabilities and substance use in adolescence. The literature suggests that adolescents with learning disabilities are more vulnerable to engaging in risk behaviours than adolescents who do not have learning disabilities. Early childhood sleep problems also seem to be a robust marker for substance use in adolescence. The prevalence of sleep problems among adolescents is increasing and is particularly high among those with learning disabilities.

Includes abstract. / Includes bibliographical references (p. 72-84). / The reproductive biology of the commercially exploited fish St. Joseph or Cape Elephant fish Callorhinchus capensis, is described based on 173 fishes caught by gillnets in October 2010 from Velddrif along the west coast of South Africa. Segregation by sex was reflected by a difference in sex ratio from 1:1 for females to males fishes collected from the fishery (?2 = 16.23, d.f. = 1, p = 5.6 x 10-5).

This study featured the use of ... a comprehensive battery [of tests], designed to assess general spatial ability as well as varieties of spatial cognition (including spatial navigation).

Bibliography: leaves 89-101. / The lifestyle and personality changes of 61 participants after a five day stress management programme were assessed. A pre-and post-programme lifestyle questionnaire was developed to investigate changes in areas covered on the programme: nutrition, fitness, health beliefs and behaviour, relationships, work life and coping resources. Participants were requested to complete this questionnaire before the course, and a follow-up questionnaire three weeks and six months after the course. Personality variables measured were Locus of Control, Sense of Coherence, and Type A behaviour. These variables were assessed prior to the course and at the six month follow-up. The effect of these personality variables on lifestyle and lifestyle change was examined. Three weeks after the course, significant changes in the self-reported lifestyle measures of nutrition, health beliefs and behaviour, and fitness were found. From the pretest to the six-month follow-up, significant changes in nutrition, health beliefs and behaviour, and relationships were found. The majority of delegates reported positive attitudes towards goals set on the course after three weeks and six months. No change was demonstrated in personality variables from the pre-test to six months after the course. No relationship was found between personality variables and lifestyle or lifestyle change. Implications for future evaluations, and for stress management programmes in general are highlighted.

In this thesis we aim to explore how electricity generation companies cope with the transition to a competitive environment in a newly deregulated electricity industry. Analyses and discussions are generally performed from the perspective of a Generator/Producer, otherwise they are undertaken with respect to the market as a whole. The techniques used for tackling the complex issues are diverse and wide-ranging as ascertained from the existing literature on the subject. The global ideology focuses on combining two streams of thought: the production optimisation and equilibrium techniques of the old monopolistic, cost-saving industry and; the new dynamic profit-maximising and risk-mitigating competitive industry. Financial engineering in a new and poorly understood market for electrical power must now take place in conjunction with - yet also constrained by - the physical production and distribution of the commodity.

Aim: The aim of this thesis was to contribute to a better understanding of heart rate during exercise with the aim of improving the precision with which heart rate can be used to measure intensity during running. Accordingly, heart rate responses were examined in long distance runners during different types of training and racing. The thesis also examined the effects of environmental and body temperature on heart rate during submaximal and maximal running. Study 1: Ten male provincial and national class road runners (VO₂max = 67.1 ± 3.8 mlO₂.kg⁻¹. min⁻¹) were recruited for the study. All the subjects completed questionnaires on their training history and recorded their training sessions in their diaries. The subjects wore heart rate monitors during training and racing. There was no convincing evidence that competitive runners who train at higher intensities have a better running performance. A poor relationship was found between %VO₂max and %HRmax. Finally, heart rate during races was higher compared to heart rates during training. The cause of the elevated heart rate during races was not clear. Study 2: The relationship between heart rate and running speed during competition was not well understood. Accordingly, an elite long distance male runner (25 years, VO₂max = 71 mlO₂.kg⁻¹. min⁻¹) was studied over a 5-month period during which time he participated in 9 races (5 km - 28 km). The subject wore a heart rate monitor which measured his heart rate throughout the race and his split running times each kilometre. The subject underwent a field test during which the heart rate/running speed relationship was determined under non-competitive conditions (r = 0.99). However, in the race situation there was no relationship between heart rate and running speed (r = 0.02). It was concluded that during competition there was no relationship between heart rate and running speed, whereas in a non-competitive situation heart rate was proportional to running intensity. Study 3: With a poor relationship found between heart rate and running speed during races in the previous study, other factors like environmental conditions and core temperature were hypothesised to have effects on heart rate. Accordingly, twelve highly trained distance runners were recruited for the study. Each subject ran on a treadmill (30 minutes at 70% peak treadmill running speed, followed by 8 km time trial) in different ambient temperatures (15°C, 25°C and 35°C) with humidity (60%) and wind speed (15 km.h⁻¹) kept constant. Heart rate, RPE and Tre were recorded every 5 minutes during the submaximal and the maximal trials. When subjects were exercising at 70% of peak treadmill running speed at 15°C, no cardiovascular drift was observed, at least for 30 minutes. However, during the same exercise test at 25 °C and 35°C there was a significant increase in heart rate. In the maximal exercise test the average heart rate was significantly higher during the trial at 35°C compared to the trials at 15° C and 25° C. It was concluded that heart rate can be used as an accurate measure of running intensity in cooler (15 ° C) ambient temperature. In summary, this thesis described the practical use of heart rate monitors during training and competition and at different temperatures. Data are provided which suggest that heart rate can accurately assess exercise intensity providing factors which affect the heart rate/running speed relationship are controlled.

Includes abstract. / Includes bibliographical references (leaves 92-96). / Working from the transfer-inappropriate processing shift (Schooler, 2002), this project aimed to investigate whether a shift from automatic to controlled processing would impair face recognition rates, much like the manipulated Navon letters do (Perfect, Weston, Dennis, & Snell, 2008), thus providing an alternative explanation for the mechanism underlying the verbal overshadowing effect (Schooler & Engstler-Schooler, 1990).

Includes bibliographical references (leaves 91-97). / Sexual violence has been increasingly used against women during conflicts. The harm of war on women has been poorly visible due to the associated stigma and traditions that blame women for male sexual exploitation. As a result, it creates a collusion of secrecy around issues of sexual violence between women, perpetrators and society. Present literature on issues of trauma tends to draw on a PTSD (Post-traumatic stress disorder) model with a focus on the individual. As a result, it restricts, and limits the experiences of refugee women by neglecting a collective view of trauma. Research on the war rape experiences of refugee women is a step towards making the harm of war more visible and provides a meaning and context for their experiences.