Includes bibliographical references (leaves 273-325).

Includes bibliographical references (p. 91-98). / In the realm of sports performance it is self-evident that not all athletes or teams are made equal, and thus it is understandable that researchers concerned with the quest for high performance in sport would wish to identify empirically what differentiates high from low performance. While research into the relationship between emotions and sport performance is a well established field of study, the emergence of the construct emotional intelligence has opened up a new research focus and addition to the literature. However, despite the increasingly widespread view that emotional intelligence may be linked to sports performance, currently few empirical research studies have been undertaken, and thus there is a paucity of substantive scientific evidence to support this contention. This reality was the point of departure for this thesis, with the aim of investigating the role of emotional intelligence (EI) in team sports performance. Given the centrality of the construct EI in this research line of enquiry, it was necessary at the outset to address both ontological and epistemological issues.

The aims of this thesis were to explore the accuracy in measuring free-living total daily energy expenditure (TDEE), by examining existing indirect measures of energy expenditure (EE) measurement and further, developing new techniques, for improved accuracy and application, in population-based studies. In a number of the studies, the research focus is the heart rate (HR) monitoring technique, for TDEE estimation as a result of its low cost and ease of implementation in large population-based studies. This thesis represents a progression from the application of the HR monitoring technique for estimating EE in response to training, or as a means to validate a physical activity recall instrument. However, what is highlighted are the limitations of the existing methodology for estimated TDEE in this way. Therefore, this thesis introduces a novel concept in the HR monitoring technique, incorporating group-based EE equations, and further, by including the effects of the previous minutes HR response on the estimation of EE from HR. Finally, this thesis validates these modifications, using a respiration chamber, purpose-built as a part of this dissertation. It should be noted, however, that in some instances, the thesis was constrained by opportunistic sampling, or the fact that in the case of Chapter 4, the study sample was part of a larger study designed for another purpose. Nevertheless, the outcomes of this research, in particular, the group-based HR-EE prediction equations, have important implications for large population-based epidemiological research concerning physical activity dose-response. Bibliography: p. 227-253.

Includes abstract. / Includes bibliographical references (p. 157-171).

Includes abstract. Includes bibliographical references.

Includes bibliographical references (p. 197-218). / Scientific research is playing an increasingly important role in the development of optimal exercise training programmes that meet specific goals within specified times. Improving the accuracy of training prescription first involves quantifying what the athlete is currently doing. Secondly, it needs to be established whether or not the athlete is adapting favourably to the training programme. This thesis investigated current methods of quantifying training load, and proposed the use of heart rate recovery to monitor the physiological response to training. The quantification of exercise training may involve athletes self-reporting their exercise.

Includes abstract.~Includes bibliographical references. / Rugby Union is a popular international team sport characterised by frequent high impact bodily collisions known as the tackle. This aspect of the game exposes players to muscle damage and a high risk of injury. Tackle-related injuries account for up to 61% of all injuries during a rugby match. Furthermore, players’ ability to win the tackle contest has an influence on the outcome of the match. Given the nature and frequency of the tackle situation, tackle contact skills are a prerequisite for participation in rugby union. However, coaching and training drills prescribed to train the tackle to date are largely based on anecdotal evidence. To develop effective tackle training strategies (i.e. technical skills training, physical conditioning, training drills, and equipment) that will produce a successful outcome and reduce the risk of injury for both the ball-carrier and tackler, studying the tackle in real match situations is warranted. Therefore, in accordance with this goal the purpose of this thesis was to; (i) assess the current attitudes and behaviours of players during training and match play, and (ii) study the tackle and defensive strategies in real match situations.

The inherited retinal degenerative disorders are a common cause of severe visual handicap in the W estem world. Retinitis pigmentosa (RP) is a group of retinopathies in which a primary feature is a progressive loss of photoreceptor and retinal pigment epithelium function. Over the last decade, investigations into the patho-physiology of RP have identified numerous disease-causing genes and loci (for a current listing refer to the web site http://www.sph.uth.tmc.edu/Retnet/). A study of a South African family with an autosomal dominant form of RP (adRP) forms the basis of this dissertation. In this family, comprising 44 individuals, the first manifestation of visual disturbance is usually evident between 20 and 30 years of age. Subsequently, another South African adRP family, consisting of 25 members, was also incorporated into this investigation. Genetic linkage analysis facilitated the mapping of the disease phenotype in the two South African adRP families to a 10 cM interval on chromosome 17q22. This novel locus, designated RP17, is the eighth identified for adRP. Haplotype construction in the two kindreds, in conjunction with multipoint analyses subsequently fine mapped RP17 to a 1 cM region between microsatellite markers D17S1604 and D17S948. Although the two families are from ethnically diverse population groups, they share the same disease-associated haplotype spanning 12 cM, which suggests that the disorder may be caused by the same pathogenic mutation in the same gene. The positional cloning approach was utilised in an endeavour to identify the RP17 gene and an attempt was made to construct a physical map of the 1 cM critical region. A contig consisting of seven yeast artificial chromosome (YAC) clones was assembled using sequence-tagged-site (STS) content mapping. In order to close a gap in the YAC contig, a bacterial artificial chromosome (BAC) library was screened and the vectorette PCR technique was used to verify overlapping sequences. This contig should provide a useful tool for the purpose of isolating genes or transcription units within the RP17 critical interval. In this regard, purified YAC DNA was isolated using pulsed-field gel electrophoresis and the cDNA selection technique was employed to generate a transcription map. This approach was applied to YAC 75Ic12 using a foetal brain cDNA library, and two rounds of selection were performed to create a sub-library for enriched cDNAs derived from this clone. Screening for the presence of contaminating sequences in the 480 transformants revealed that (i) approximately 7% of the selected clones contain COT-1 DNA and (ii) none of the clones were contaminated with yeast AB1380 DNA. Ten randomly chosen clones were sequenced and subjected to BLASTN analysis, which revealed the presence of a 23 bp contaminant, known genes as well as novel transcripts. In order to optimise efforts to isolate the adRP gene, four positional candidates residing on 17q were screened for evidence implicating them in the adRP phenotype in the two 17q22-linked families. The genes investigated were: PDEG (gamma subunit of rod phosphodiesterase), TIMP2 (tissue inhibitor of metalloproteinases-2), PKCA (protein kinase C alpha) and retinal fascin. These candidates were chosen on the basis of (i) mapping to 17q, (ii) expression in the retina and/or (iii) potential involvement in the rod phototransduction pathway. Recombination events between the adRP locus and a single strand conformation polymorphism (SSCP) in PDEG, and a restriction fragment length polymorphism (RFLP) in TIMP2 provided evidence for the exclusion of these candidate genes. A novel SSCP detected in the promoter region of retinal fascin was genotyped in the two adRP families and showed a lack of co-segregation with the disease locus. Furthermore, direct DNA sequencing of the coding regions as well as the promoter region of retinal fascin in RP affected family members did not reveal any pathogenic mutations. In addition, data is provided which suggests that PKCA does not reside on any of the YACs and BACs encompassing the RP17 critical interval. This gene is therefore unlikely to be responsible for the adRP phenotype in the two RP17-linked families. Ultimately, the work reported in this thesis may contribute to the body of knowledge on inherited retinal degenerative disorders. Moreover, this investigation should provide the basis for further study of the aetiology of RP in all families linked to the RP17 locus on chromosome 17q22. The immediate application of these molecular findings is the potential for pre-symptomatic testing of at-risk members from the two adRP kindreds.

Includes bibliographical references. / The anterior segment of the eye includes the cornea, lens, iris, ciliary body and trabecular meshwork, with each of these elements playing a vital role in the maintenance of vision. The primary objective of this research is to contribute towards the understanding of how specific genes control tissue specification and structural morphogenesis of the developing anterior segment of the eye. Despite its extensive use as a model organIsm, very little is known about the structure and development of the ciliary body in the mouse eye. Using scanning electron microscopy (SEM) the ciliary processes in the adult mouse were shown to form an irregular pattern, crossing over and interweaving, rather than lying parallel to one another, as observed in other mammals. Histological and SEM studies from E14.5 to P7 revealed that the first morphological sign of differentiation in the ciliary body is the appearance of an annular bulge around the optic cup margin; this is then gradually moulded to form discrete ciliary processes. A striking similarity between the developing capillary network and the adult ciliary folds was observed and suggests that the patterning template for the ciliary processes could be the underlying capillary network. Cell proliferation measurements and cell height assessments indicated that one of the first events occurring during the morphogenesis of ciliary processes is a proliferative surge occurring at about PO in the outer ciliary epithelium. It is likely that this surge together with increasing cell heights leads to a bulging of this layer. After a slight delay, the inner ciliary epithelium responds by proliferating and extending inwards towards the lens. Final shaping of the ciliary processes is achieved through cell height reductions in the inner ciliary epithelium. Gene expression analyses revealed dynamic changes in Bmp4 and LEF] expression patterns over the period of ciliary folding, while TgffJ1i4 expression in the ciliary body did not change during morphogenesis. These differences suggest that these genes play different roles in directing the specification and morphogenesis of the ciliary body. The temporal correlation between mitotic and cell height changes during ciliary body morphogenesis suggests that these processes play an integral role in the shaping of ciliary processes.

Includes abstract. / Includes bibliographical references (p. 183-214). / Obesity and obesity-related diseases are a large global problem in both developed and developing nations. In South Africa, a country currently undergoing epidemiological transition, the prevalence of obesity is high, particularly in urban black women. Early detection of overweight and obese individuals is essential for the management of obesity and its related co-morbidities; however, there is no ethnic-specific field measure of body fat percent validated for use in black South African women. Further, despite high levels of adiposity, these women have an atypical presentation of cardiovascular disease (CVD) risk factors, presenting with relatively low levels of visceral adipose tissue (VAT) and a favourable lipid profile compared to white women. As a result of this atypical presentation of CVD risk factors, a high prevalence of “healthy obesity” has been reported, although the determinants of this phenotype have not been systematically investigated. In addition, the applicability of commonly used diagnostic criteria for the determination of insulin resistance, which include enlarged waist circumference and dyslipidemia as components, has not been investigated in this population. Therefore, the overall aim of this thesis was to investigate the impact of body fat and its distribution on the presentation and identification of CVD risk factors in relatively young black South African women, prior to the onset of CVD. More specifically, the objectives were; i) to determine if near infrared interactance (NIR) is a valid field measure of body fat percent in South African women; ii) to determine the agreement between International Diabetes Federation (IDF) and National Cholesterol Education Program (Adult treatment panel III) (ATP III) metabolic syndrome criteria and the degree to which these criteria can predict insulin resistance, and explore the extent to which these phenomena can be explained by body fat and its distribution; iii) to identify determinants of the “metabolically healthy obese” (MHO) and “metabolically obese normal weight” (MONW) phenotypes; and iv) to complete a preliminary investigation of the association between polymorphisms within genes that encode for proteins involved in tissue-specific glucocorticoid metabolism and obesity, body fat distribution and CVD risk factors in black South African women. As obesity is associated with increased risk of cardiovascular disease, accurate quantification of body fatness is particularly important in health risk appraisal. However, in developing countries, “gold standard” measures of body fat percent such as underwater weighing and dual energy x-ray absorptiometry (DXA) are not always practical, as access to facilities and resources are limited. Therefore, a valid field measure of body fat percent is needed for the purpose of health risk appraisal. NIR is a potentially useful field measure of body fat percent that is currently used in South Africa for this purpose. However, NIR cannot be used with confidence in South Africa until it has been validated in different ethnic populations. Therefore, the first study in this thesis examined the validity of singlesite NIR (Futrex-6100 A/ZL) as a measure of body fat percent compared to the criterion method of DXA in black and white South African women.