Doctor of Philosophy / Department of Chemistry / Stefan Bossmann / Estrogen-derived DNA adducts in human could be the initiating step of breast and prostate cancer, as the scientific literature suggests. Previous studies demonstrated that 4-hydroxy-estrone (estradiol)-1-N3Adenine and 4-hydroxy-estrone (estradiol)-1-N7Guanine were the most abundant adducts found in urine of human subjects. Sensitive detection of these adducts in urine samples could lead to better breast and prostate cancer risk assessment. The standard adducts were synthesized and characterized by NMR and mass spectrometry. Since these adducts are not fluorescent at room temperature an aminomethyl (-CH2NH2) linker was introduced at the C-17 position for derivatization with fluorescence label. This linker allowed to attach highly fluorescent water soluble quantum dots (QDs) for indirect adduct detection. A direct gram-scale synthesis of highly fluorescent, photostable water soluble QDs was executed by developing a new class of 4,4’-bipyridinium salt based twin ligands with 85% and 15% of carboxylic acid and maleimide termini, respectively. These ligands not only stabilized the QDs in water but also provided versatile linkers for two labeling strategies. The twin ligands were afforded by a facile synthesis through SN2 nucleophilic substitution reaction. Labeling of adducts was achieved via a covalent coupling between the (-CH2NH2) linker and the carboxyl (-COOH) terminal ligand on the QDs. However, ELISA experiments utilizing an IgM antibody didn’t reveal any measurable signal from adduct-QD complexes suggesting that one QD is bound to a large number of adducts through –COOH terminal ligands present on QD surface. To explore the binding capabilities of QDs in more detail, a maleimide terminal ligand (a twin partner on the QDs) was synthesized to explore the thiol (-SH) functionality of thiopyrene. Preliminary ELISA showed that these QDs gave detectable fluorescent signal originating from the [pyrene-S-QD] ̶ 8E11 monoclonal antibody (mAb) complex when QD was selectively excited at 470 nm. This clearly indicates that it is necessary to develop a strategy for a distinct 1:1 labeling procedure between QD and the adduct of interest. In addition, IgG (instead of IgM) antibodies should be developed for biosensor application. The latter could afford binding of mAb in upright position, leading to an increase in surface density of mAb and better detection limit.

South Africans are engaged in daily battles with work-related and non-work related issues. Although an organisation is not capable of addressing or changing all the issues experienced by the South African population, it can intervene in order to improve the quality of its employees’ working lives. A suggested starting point is person-environment fit (PE fit), due to its effect on job satisfaction and intentions to leave. Consequently, when an individual experiences low PE fit, it will contribute to job dissatisfaction, and intentions to leave as international research has shown. To possibly decrease the impact of these relationships, it is important for leader empowering behaviour to be evident throughout the organisation. The objectives of this study were to determine possible relationships, indirect effects, and moderating effects between PE fit, job satisfaction, intentions to leave, and leader empowering behaviour. A convenience sample of employees working under the guidance of a leader/manager/supervisor was taken from a retail company in Gauteng. Participation in the study was voluntary. A measuring battery measuring PE fit (i.e. person-organisation fit, needs-supplies fit, and demands-abilities fit), job satisfaction, intentions to leave, and leader empowering behaviour (i.e. delegation of authority, accountability, self-directed decision making, information sharing, skills development, and coaching for innovative performance) was used. Descriptive and inferential statistics, Raykov’s rho coefficients, Pearson product-moment correlations, measurement models, structural models, and goodness-of-fit statistics were used to analyse the data. The results indicate that PE fit has a positive relationship with job satisfaction. Job satisfaction has a negative relationship with intentions to leave. PE fit has an indirect effect on intentions to leave via job satisfaction. Leader empowering behaviour moderates the relationship between job satisfaction and intentions to leave. Various recommendations were made for the selected retail company as well as for future research. The retail company and employees should comprehend the impact of PE fit on outcomes such as job satisfaction and intentions to leave, as both parties are equally affected by its implications. Therefore, both pro-active and re-active measures should be institutionalised to address PE fit. Additionally, the retail company should understand the importance of leader empowering behaviour and the impact it can have on their business unit and the organisation as a whole. Recommendations for future research include longitudinal research designs, as well as the expansion of research beyond the selected company in the retail industry. / MCom (Industrial Psychology)--North-West University, Vaal Triangle Campus, 2015

The measurement of cardiorespiratory fitness has been extensively researched among adult populations, but very few researchers have focused their attention on the cardiorespiratory fitness of children and adolescents. Due to various constraints of direct 2max VO testing, various indirect testing methods have been developed of which the 20-m Shuttle Run Test is the most widely used testing method. The influence of various anthropometric, physical and motor performance components as well as certain demographic factors such as gender, race, living area, and sport participation as well as physical activity level on the 2max VO value of participants seems to suggest that 2max VO can be predicted by including these components in prediction models. It is against this background that the objectives of this study are provided. The following four objectives of the study were achieved through a literature review: Firstly, to name and describe the various direct and indirect methods for determining 2max VO ; secondly, to provide a review on the findings with regard to the aerobic performances or 2max VO values of children and adolescents; thirdly, to discuss the possible influence of various anthropometric, physical and motor-performance components on the aerobic performances or 2max VO values of the last-mentioned groups of subjects. As part of this objective, other literature-identified factors such as certain demographic factors (living area, race and gender), sport and physical activity participation level which may also influence the aerobic performances or 2max VO values of the participants, were also discussed; fourthly, all literature identified models for the prediction of aerobic performances or 2max VO values in children, and in adolescents were mentioned and discussed. The next few objectives were achieved through a selected group, cross-sectional experimental research design; fifthly, to develop a valid 2max VO prediction function from several anthropometric measurements and demographic factors such as gender, race and living area as well as sport participation level of a cohort of adolescents living in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa; sixthly, to develop a 2max VO prediction function from the physical and motor-performance components as well as demographic variables such as gender, race and living area as well as sport participation level of a cohort of adolescents living in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa; and finally, to determine the validity of the 20-m SRT to estimate the 2 VO and 2max VO of a cohort of adolescent boys in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa. In order to fulfil the fifth and sixth objectives of the study, a total of 214 grade 8 adolescents (boys: 88 and girls: 126) (age: 15.82 ± 0.68 years) of high schools in the Tlokwe Local Municipality (Potchefstroom area) of the Dr Kenneth Kaunda District of the North West Province, South Africa were purposefully selected from pre-acquired class lists, from six secondary schools. Data was collected by means of various questionnaires, anthropometric measurements and physical and motor-performance tests, which also included the 20-metre SRT. For the fulfilment of the final objective of the study, 52 boys were purposefully selected from the above-mentioned group that completed various questionnaires as well as the 20-m SRT while they were fitted with a portable gas analyser apparatus. With regard to the anthropometric and demographic variable prediction model, the forward stepwise regression analysis results showed that muscle mass percentage, sport participation level, stature, hip circumference and ectomorphy act as significant predictors (p ≤ 0.05) of the indirect, 20-m SRT 2max VO values of a cohort of adolescents. Muscle mass percentage emerged as the strongest predictor (59%) of adolescents’ 2max VO values, followed by sport participation level (6%), ectomorphy (2%), stature (1%) and hip circumference (1%). The physical, motor-performance and demographic prediction model revealed that 10-metre speed, sit-up repetitions, sport participation level, handgrip strength, Vertical Jump Test (VJT) Tendo peak power, maximal heart rate (HRmax), living area, right shoulder external rotation flexibility (RPSERT), horizontal jump test distance (HJT) and right Modified Thomas iliopsoas flexibility (RMTIT) served as significant predictors (p ≤ 0.05) of the indirect, 20m-SRT-derived 2max VO values of a cohort of adolescents. However, only 10-metre speed served as a major contributor (53.5%) to the indirect 2max VO values of the adolescents. The rest of the variables contributed 17.4% to the overall variance in 2maxVO values. Overall, the last-mentioned anthropometric, physical, motor performance and demographic variables were responsible for 70.5% of the variance in the 2max VO values of the adolescents. Cross-validations also revealed that both models are valid for predicting the 20-m SRT-derived indirect 2max VO values of this cohort of adolescents. The 20-m SRT validity study showed that a significant difference (p ≤ 0.05) existed between the predicted indirect 2max VO results (42.06 ± 4.53 ml/kg/min) as obtained from the 20-m SRT booklet and the direct 2max VO results (50.62 ± 7.11 ml/kg/min) as obtained from the gas analysis. Furthermore, significant differences (p ≤ 0.05) were observed between the direct and indirectly predicted 2 VO values at levels 1-9 of the 20-m SRT compared to no significant differences at levels 10 and 11 of the 20-m SRT. In conclusion, to the researchers’ knowledge, this is the first study to develop valid 2max VO prediction functions from the use of several anthropometric measurements, physical and motorperformance test results and demographic information for a group of South African adolescents. Furthermore, this is also the first study to reveal that the 20-m SRT is not a valid test for the accurate prediction of 2 VO and 2max VO of a cohort of adolescent South African boys. The results of this study may possibly allow practitioners in the field of Human Movement Science to more accurately screen the indirect 2max VO values of adolescents by making use of easily obtainable measures and information, instead of the predicted 2max VO values of the 20-m SRT / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

South Africans are engaged in daily battles with work-related and non-work related issues. Although an organisation is not capable of addressing or changing all the issues experienced by the South African population, it can intervene in order to improve the quality of its employees’ working lives. A suggested starting point is person-environment fit (PE fit), due to its effect on job satisfaction and intentions to leave. Consequently, when an individual experiences low PE fit, it will contribute to job dissatisfaction, and intentions to leave as international research has shown. To possibly decrease the impact of these relationships, it is important for leader empowering behaviour to be evident throughout the organisation. The objectives of this study were to determine possible relationships, indirect effects, and moderating effects between PE fit, job satisfaction, intentions to leave, and leader empowering behaviour. A convenience sample of employees working under the guidance of a leader/manager/supervisor was taken from a retail company in Gauteng. Participation in the study was voluntary. A measuring battery measuring PE fit (i.e. person-organisation fit, needs-supplies fit, and demands-abilities fit), job satisfaction, intentions to leave, and leader empowering behaviour (i.e. delegation of authority, accountability, self-directed decision making, information sharing, skills development, and coaching for innovative performance) was used. Descriptive and inferential statistics, Raykov’s rho coefficients, Pearson product-moment correlations, measurement models, structural models, and goodness-of-fit statistics were used to analyse the data. The results indicate that PE fit has a positive relationship with job satisfaction. Job satisfaction has a negative relationship with intentions to leave. PE fit has an indirect effect on intentions to leave via job satisfaction. Leader empowering behaviour moderates the relationship between job satisfaction and intentions to leave. Various recommendations were made for the selected retail company as well as for future research. The retail company and employees should comprehend the impact of PE fit on outcomes such as job satisfaction and intentions to leave, as both parties are equally affected by its implications. Therefore, both pro-active and re-active measures should be institutionalised to address PE fit. Additionally, the retail company should understand the importance of leader empowering behaviour and the impact it can have on their business unit and the organisation as a whole. Recommendations for future research include longitudinal research designs, as well as the expansion of research beyond the selected company in the retail industry. / MCom (Industrial Psychology)--North-West University, Vaal Triangle Campus, 2015

The measurement of cardiorespiratory fitness has been extensively researched among adult populations, but very few researchers have focused their attention on the cardiorespiratory fitness of children and adolescents. Due to various constraints of direct 2max VO testing, various indirect testing methods have been developed of which the 20-m Shuttle Run Test is the most widely used testing method. The influence of various anthropometric, physical and motor performance components as well as certain demographic factors such as gender, race, living area, and sport participation as well as physical activity level on the 2max VO value of participants seems to suggest that 2max VO can be predicted by including these components in prediction models. It is against this background that the objectives of this study are provided. The following four objectives of the study were achieved through a literature review: Firstly, to name and describe the various direct and indirect methods for determining 2max VO ; secondly, to provide a review on the findings with regard to the aerobic performances or 2max VO values of children and adolescents; thirdly, to discuss the possible influence of various anthropometric, physical and motor-performance components on the aerobic performances or 2max VO values of the last-mentioned groups of subjects. As part of this objective, other literature-identified factors such as certain demographic factors (living area, race and gender), sport and physical activity participation level which may also influence the aerobic performances or 2max VO values of the participants, were also discussed; fourthly, all literature identified models for the prediction of aerobic performances or 2max VO values in children, and in adolescents were mentioned and discussed. The next few objectives were achieved through a selected group, cross-sectional experimental research design; fifthly, to develop a valid 2max VO prediction function from several anthropometric measurements and demographic factors such as gender, race and living area as well as sport participation level of a cohort of adolescents living in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa; sixthly, to develop a 2max VO prediction function from the physical and motor-performance components as well as demographic variables such as gender, race and living area as well as sport participation level of a cohort of adolescents living in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa; and finally, to determine the validity of the 20-m SRT to estimate the 2 VO and 2max VO of a cohort of adolescent boys in the Tlokwe Local Municipality (Potchefstroom area) of North West Province, South Africa. In order to fulfil the fifth and sixth objectives of the study, a total of 214 grade 8 adolescents (boys: 88 and girls: 126) (age: 15.82 ± 0.68 years) of high schools in the Tlokwe Local Municipality (Potchefstroom area) of the Dr Kenneth Kaunda District of the North West Province, South Africa were purposefully selected from pre-acquired class lists, from six secondary schools. Data was collected by means of various questionnaires, anthropometric measurements and physical and motor-performance tests, which also included the 20-metre SRT. For the fulfilment of the final objective of the study, 52 boys were purposefully selected from the above-mentioned group that completed various questionnaires as well as the 20-m SRT while they were fitted with a portable gas analyser apparatus. With regard to the anthropometric and demographic variable prediction model, the forward stepwise regression analysis results showed that muscle mass percentage, sport participation level, stature, hip circumference and ectomorphy act as significant predictors (p ≤ 0.05) of the indirect, 20-m SRT 2max VO values of a cohort of adolescents. Muscle mass percentage emerged as the strongest predictor (59%) of adolescents’ 2max VO values, followed by sport participation level (6%), ectomorphy (2%), stature (1%) and hip circumference (1%). The physical, motor-performance and demographic prediction model revealed that 10-metre speed, sit-up repetitions, sport participation level, handgrip strength, Vertical Jump Test (VJT) Tendo peak power, maximal heart rate (HRmax), living area, right shoulder external rotation flexibility (RPSERT), horizontal jump test distance (HJT) and right Modified Thomas iliopsoas flexibility (RMTIT) served as significant predictors (p ≤ 0.05) of the indirect, 20m-SRT-derived 2max VO values of a cohort of adolescents. However, only 10-metre speed served as a major contributor (53.5%) to the indirect 2max VO values of the adolescents. The rest of the variables contributed 17.4% to the overall variance in 2maxVO values. Overall, the last-mentioned anthropometric, physical, motor performance and demographic variables were responsible for 70.5% of the variance in the 2max VO values of the adolescents. Cross-validations also revealed that both models are valid for predicting the 20-m SRT-derived indirect 2max VO values of this cohort of adolescents. The 20-m SRT validity study showed that a significant difference (p ≤ 0.05) existed between the predicted indirect 2max VO results (42.06 ± 4.53 ml/kg/min) as obtained from the 20-m SRT booklet and the direct 2max VO results (50.62 ± 7.11 ml/kg/min) as obtained from the gas analysis. Furthermore, significant differences (p ≤ 0.05) were observed between the direct and indirectly predicted 2 VO values at levels 1-9 of the 20-m SRT compared to no significant differences at levels 10 and 11 of the 20-m SRT. In conclusion, to the researchers’ knowledge, this is the first study to develop valid 2max VO prediction functions from the use of several anthropometric measurements, physical and motorperformance test results and demographic information for a group of South African adolescents. Furthermore, this is also the first study to reveal that the 20-m SRT is not a valid test for the accurate prediction of 2 VO and 2max VO of a cohort of adolescent South African boys. The results of this study may possibly allow practitioners in the field of Human Movement Science to more accurately screen the indirect 2max VO values of adolescents by making use of easily obtainable measures and information, instead of the predicted 2max VO values of the 20-m SRT / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

Le succès reproducteur, défini comme l’aptitude d’un individu à se reproduire et ainsi transmettre son bagage génétique aux générations futures, constitue une des motivations fondamentales qui dictera plusieurs des comportements observés chez une espèce animale. L’étude de ces divers comportements est essentielle afin de comprendre les stratégies évolutives sous-jacentes qui permettent aux individus d’augmenter leurs chances de reproduction. La monogamie sociale avec polygamie génétique est un bel exemple de stratégie reproductive chez laquelle les individus peuvent potentiellement augmenter leur succès reproducteur en tentant d’acquérir des fertilisations d’individus autres que le mâle et la femelle constituant le couple social. Ces fertilisations dites hors-couples, qui sont communes chez les oiseaux, sont un moyen efficace pour les mâles d’augmenter leur succès reproducteur via leur nombre de jeunes produits dans diverses nichées pour une saison de reproduction donnée. Pour les femelles, les avantages que procure ce comportement restent encore obscurs malgré la panoplie d’études s’étant penchées sur la question. L’acquisition de bénéfices indirects, de nature génétique, est une hypothèse fréquemment mise de l’avant pour tenter d’expliquer les motivations des femelles à s’engager dans des copulations hors-couples. L’objectif de ma maîtrise consistait à évaluer si la femelle, via l’acquisition de paternités hors-couples au sein de sa nichée, tente d’acquérir des bénéfices de types indirects pour les oisillons issus de ce type de fertilisation chez une population sauvage d’Hirondelle bicolore (Tachycineta bicolor) dans le Sud du Québec. Ces bénéfices indirects peuvent se refléter au niveau des oisillons dits hors-couples en leur conférant des avantages génétiques et donc potentiellement une survie plus élevée, par rapport aux oisillons issus du couple social. En premier lieu, mes résultats indiquent une survie plus élevée pour les oisillons issus du couple social par rapport aux oisillons issus de paternités hors-couples contrairement aux prédictions initiales. Ensuite, en comparant une mesure intégratrice basée sur plusieurs mesures de capacité immunitaire, les résultats obtenus suggèrent une différence dans le patron d’allocation immunitaire des deux types d’oisillons. Les oisillons issus du couple social ayant une tendance à investir préférentiellement au niveau de l’immunité adaptative par opposition aux oisillons issus de paternités hors-couples ayant une tendance à investir dans les composantes de l’immunité constitutive. Cette différence d’investissement entre les composantes de l’immunité constitutive et adaptative pourrait représenter un développement asynchrone entre les oisillons en couple et hors-couple dû à un compromis d’allocation d’énergie entre les fonctions immunitaires et les paramètres de croissance. En conclusion, cette étude montre la complexité du phénomène des paternités hors-couples ainsi que les motivations qui poussent la femelle à rechercher de telles fertilisations. De plus, cette étude met l’emphase sur l’importance de considérer plus d’une mesure immunitaire lors de la comparaison entre individus.

La conception de turboréacteurs présente de plus en plus de défis. Le respect de l'environnement, naturel et sonore, est devenu un enjeu majeur pour les motoristes car il devient un argument de vente important et une condition sine qua non afin de valider les futures normes en aviation. Dans ce contexte, il est devenu nécessaire d'étudier et de prédire les différentes sources de bruit d'un turboréacteur pour les inclure dans sa conception. Parmi ces différentes sources de bruit, celle de la chambre de combustion est méconnue et devient une source de bruit aval de plus en plus importante dans les phases d'approche et de croisière où le bruit de jet a été significativement réduit. Nous pourrons aussi nous intéresser aux modes de conduit générés par les interactions rotor-stator des différents étages de compresseurs et de turbines en amont et aval de la chambre de combustion respectivement. L'effet de masquage étant réduit par la diminution du nombre d'étages de turbines, il est donc nécessaire d'évaluer la transmission et la réflexion des ondes acoustiques (responsables du bruit direct) mais aussi entropiques et de vorticité (responsables du bruit indirect) issues de la combustion ainsi que des modes de conduit à travers les étages de turbines d'un turboréacteur. L'objectif, dans le cadre de la Chaire de recherche en acoustique appliquée à l'aviation en collaboration avec Pratt & Whitney Canada, est de développer un modèle de pertes par transmission valide autant pour les basses fréquences (chambre de combustion) que pour des fréquences plus élevées (interactions rotor-stator). Différents niveaux de modélisation sont utilisés à partir de disques actifs ou semi-actifs. Ces théories sont utilisées pour les très basses fréquences en considérant que l'espace inter-aubes et la corde du profil sont faibles devant la longueur d'onde. Les théories plus complexes prennent en compte une corde non négligeable et donc des fréquences plus élevées. Parmi les modèles existants dans la littérature, nous avons choisi de sélectionner deux modèles en particulier. Tout d'abord un modèle de disque actif pour prendre en compte la déviation de l'écoulement par les aubes puis un modèle de grille d'aubes pour prendre en compte la corde et l'espace inter-aubes. L'objectif est de coupler ces deux modèles afin de prendre en compte tous les effets intervenant dans la transmission des ondes à travers les étages de turbines d'un turboréacteur.

Text in Afrikaans / Tradisioneel is aanvaar dat die indirekte voorwerp nie in Afrikaanse stelsinne kan optree sander die voorkoms van 'n direkte voorwerp in dieselfde sin nie. Hierdie ondersoek het aan die lig gebring dat sekere voorwerpe wat voorheen as "direkte voorwerpe" geklassifiseer is, eerder die eienskappe van indirekte Hulle word dus nou geklassifiseer as en die parameters van die indirekte ooreenkomstig uitgebrei. Aangesien daar geen formele merkers vir die uitkenning en onderskeiding van direkte en indirecte voorwerpe bestaan nie, is parameters vir die doel vasgestel. Skoon indireckte voorwerpe (op enkele uisonderings na) verskyn altyd direk na die SPIL-posisie in 'n stelsin toon 'n groot affiniteit vir voorsetsels (versa vir, aan), en kan in die koers van adjunk afgegradeer word, deur me 'n voorsetsel te verbind, en kan sodoende ook na' 'n adjunk verskyn. Direkte voorwerpe kan daarenteen nie met voorset-: sels verbind nie en kan buitendien na enige adjunk verskyn. / Language Education, Arts and Culture / M.A. (Afrikaans)

BACKGROUND: The abnormal signal intensity in cardiac T₂-weighted images is associated with various pathologies including myocardial edema. However, the assessment of pathologies based on signal intensity is affected by the acquisition parameters and the sensitivities of the receiver coils. T₂ mapping has been proposed to overcome limitations of T₂-weighted imaging, but most methods are limited in spatial and/or temporal resolution. Here we present and evaluate a double inversion recovery radial fast spin-echo (DIR-RADFSE) technique that yields data with high spatiotemporal resolution for cardiac T₂ mapping. METHODS: DIR-RADFSE data were collected at 1.5 T on phantoms and subjects with echo train length (ETL) = 16, receiver bandwidth (BW) = +/-32 kHz, TR = 1RR, matrix size = 256 x 256. Since only 16 views per echo time (TE) are collected, two algorithms designed to reconstruct highly undersampled radial data were used to generate images for 16 time points: the Echo-Sharing (ES) and the CUrve Reconstruction via pca-based Linearization with Indirect Echo compensation (CURLIE) algorithm. T₂ maps were generated via least-squares fitting or the Slice-resolved Extended Phase Graph (SEPG) model fitting. The CURLIE-SEPG algorithm accounts for the effect of indirect echoes. The algorithms were compared based on reproducibility, using Bland-Altman analysis on data from 7 healthy volunteers, and T₂ accuracy (against a single-echo spin-echo technique) using phantoms. RESULTS: Both reconstruction algorithms generated in vivo images with high spatiotemporal resolution and showed good reproducibility. Mean T₂ difference between repeated measures and the coefficient of repeatability were 0.58 ms and 2.97 for ES and 0.09 ms and 4.85 for CURLIE-SEPG. In vivo T₂ estimates from ES were higher than those from CURLIE-SEPG. In phantoms, CURLIE-SEPG yielded more accurate T₂s compared to reference values (error was 7.5-13.9% for ES and 0.6-2.1% for CURLIE-SEPG), consistent with the fact that CURLIE-SEPG compensates for the effects of indirect echoes. The potential of T₂ mapping with CURLIE-SEPG is demonstrated in two subjects with known heart disease. Elevated T₂ values were observed in areas of suspected pathology. CONCLUSIONS: DIR-RADFSE yielded TE images with high spatiotemporal resolution. Two algorithms for generating T₂ maps from highly undersampled data were evaluated in terms of accuracy and reproducibility. Results showed that CURLIE-SEPG yields T₂ estimates that are reproducible and more accurate than ES.

This study investigates the role of transformational leadership in influencing students’ outcomes in public secondary schools using Kuwait as a case study. The standard of academic achievement in Kuwait’s public schools has been declining over the years, which calls for a different type of leadership to transform these schools. It is argued in this thesis that there is merit in bringing in private sector business models to the public education sector in order to transform the sector and improve the schools’ outcomes. Furthermore, not much research has been undertaken on the paths through which transformational leadership influences public school outcomes in developing countries such as Kuwait. Following a critical review of leadership literature, a theoretical model for leadership that is transformational was conceptualised and this formed the basis of hypotheses formation and data collection. The thesis is thus original in its attempt to understand the paths through which school heads’ transformational leadership influence student’s outcomes in public secondary schools in a developing country (Kuwait). The study adopted a positivist ontology and objective epistemology and obtained data from 495 school heads and staff from 86 public secondary schools in Kuwait via a structured questionnaire. Confirmatory factor analysis (CFA) and structural equation models (SEM) tested the direct and indirect effects of school heads’ transformational leadership in influencing students’ outcomes the student “achievement” and the student “engagement” via several mediating variables including “school culture”, “class room condition” and “academic emphasis”. The analysis identified idealized influence (attributes) and idealized influence (behaviour) as the underlying dimensions of transformational leadership that directly and indirectly influences both student engagement and student achievement as the final outcome. The findings also confirmed differences between males and females in their leadership styles and subsequent influence on students’ achievement, and student engagement with the latter appearing to be better school heads. Therefore, two structure equation models were built to investigate the characteristics of each gender leadership style on the outcome variables. The findings also revealed that males’ leadership style has significant effect on student achievement but not student on engagement, while female leader ship style has significant effect on both student achievement and student engagement stronger than the males’ effect counterpart. Generally however, transformational leadership style has significant effect on both student achievement and student engagement. The study objectives were met and the study contributes to understanding the role of transformational leadership and its influence on staff and students’ achievement, from a developing country in the GCC. Managerial recommendations and suggestions for policy makers are made. Study limitations are highlighted leading to suggestions for further study.