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Polymer nanofibers are gaining importance due to their wide applicability in diverse fields, such as tissue engineering, fuel cells, photonics and sensors. For these applications, manufacturing aligned polymer nanofibers with precisely controlled morphology and well characterized mechanical properties in a bottom up configuration is essential. In this work, we developed an isodiametric design space for fabrication of aligned polystyrene nanofibers (diameter 60-800nm) using non-electrospinning Spinneret based Tunable Engineered Parameter (STEP) technique. By adjusting the processing parameters such as relative humidity, solvent volatility and polarity, porous polymer tubes are demonstrated having large specific surface areas. Combining STEP with sol-gel process, aligned inorganic nanofibers, such as Titanium Oxide (TiO2) with varied morphologies can be conveniently obtained. Mechanical properties of aligned polymer nanofibers (diameter from 50nm to several hundred nanometers) with fixed-fixed boundary conditions were estimated using a lateral force microscope (LFM). We find that the tension in the fiber caused during fabrication process scales with fiber diameter and it dominates fiber stiffness. Our studies demonstrate isotropic arrangement of polymer chains in the fibers and anisotropic arrangement in the necking region for fibers undergone deformation. Finally, this study demonstrates development of force sensors capable of measuring single cell forces, which scale with the fiber structural stiffness. The ability to measure cell forces during cell division, migration and apoptosis provides new insights in cell mechanobiology. / Ph. D.

This study into the architectural profession reviews developed decision support frameworks (graphics to inform and improve decision making through access to more information) as knowledge sharing devices. These developed frameworks first, influence decision makers: the students and their decisions in their personal architectural design process and second, develop a framework on vegetated assemblies (building assemblies that incorporate plants such as green roofs and walls) as vegetated assemblies relate to color theory and its implications in design methodology. This decision support framework assists students in their design process in studio and studio-like educational environments. The purpose of this decision support framework is to influence the students in using vegetated assemblies in their future design inquiry. After implementation, the purpose was to determine the worth of the framework as a mechanism for knowledge sharing. Both purposes were reviewed in developing the framework using immersive case studies, classes both in traditional studios and studio-like courses, website development and member feedback. The evidence of the resulting improvement of decision making or design work was found through the use of surveys, student reflective writing, and personal interpretation of student works and my own immersive design studies, classes, and development of the framework and its website. The surveys and reflective writing were collected from multiple years of involvement in traditional studio and studio-like classes to refine the framework and its use. The results of the study suggest that students do have a larger body of knowledge to make decisions about utilizing vegetated assemblies than before the use of the framework and go on the continue using vegetated assemblies in design work. The framework presents the various factors that impact decisions into vegetated assemblies and develop future designs. By influencing and improving knowledge of such factors on the design of vegetated assemblies early in a student's education, improves decision making in future designs and later professional work. Future work would be targeted at refining the framework and potential courses to include other topics of interest in relation to vegetated assemblies. Finally, the framework could be adapted into a more codified, interactive tool in the future. / Ph. D. / This study looks at how graphics and representation can improve the making of decisions on the basis of access to more information across different learning environments. This process of gathering and then sharing information with others can develop into knowledge sharing devices. These devices also known as decision support structures are a scaffold or framework for influencing decision makers: the students. The influence is on their developed design process, how students go about designing, and on their knowledge of vegetated assemblies, which are parts of buildings that incorporate plants such as green roofs and walls, and color theory, which is a method for using color in design. This decision support structures assists students in their design process in studio and studio-like educational environments. The purpose of this dissertation is to review how decision support structures can be used various learning environments to assist students in exploring lines of inquiry. These lines of inquiry are a deliberate process of exploring an idea or family of ideas. This use of the decision support structure was reviewed using immersive case studies, classes both in traditional studios and studio-like courses, and the development of a website. The results of the study suggest that students do have a larger body of knowledge to make decisions when using the developed decision support structure. This work presents the various factors that impact decisions into developing future designs based on vegetated assemblies and color theory as topics. This work also improves decision making in future designs and later professional work. Future work would be targeted at refining the developed decision support structure and potential courses to include other topics of interest in relation to vegetated assemblies. Finally, the framework could be adapted and expanded in the future.

This study sought to investigate and redefine the initial training of pastors, including the management training of student pastors at the colleges of the International Assemblies of God Church (IAG) of South Africa. Unlike in the past when pastors could lead churches without proper formal training based on their spirituality as viewed by the IAG and them professing to be called as ministers, today in this church tradition the need for the formal educational formation of pastors is taken for granted. This stance raises questions about the quality of graduates as well as matters of curriculum development, as the world is continually in a state of flux with far- reaching consequences for training institutions. It is generally accepted that churches play an important role in the lives of citizens in a predominantly Christian country like South Africa. On the other hand there is a continuing contestation and debate regarding the role pastors play in their churches in management and administrative issues. This also relates to the preparedness or unpreparedness of graduate pastors for their job. The day to day performance of duties by serving pastors in their organisations is generally viewed as below expectation compared to their counterparts in other occupations. A qualitative research approach was followed to elicit the necessary information to answer the research questions. Participants who were regarded as information rich cases on the training of pastors of the IAG were selected to shed more light on this particular aspect. Two focus group interviews and seven individual interviews were conducted. The interviews included members of the national and provincial executive committees, serving pastors, directors of the training colleges, pastor trainees in their final year of study and a newly graduated student. The current curriculum of initial training programmes was reviewed. Within a transformational management framework and utilising a purposeful intervention strategy, the study posits the Community Needs Responsive Management Training Model (CNRMTM) to enhance the initial training programmes of pastors and to use aspects of this model in the development and presentation of life-long learning programmes arranged for serving pastors. Recommendations and suggestions for future research were made. / Educational Leadership and Management / D. Ed. (Education Management)

Cette thèse porte sur le développement d’un essai mécanique pour la caractérisation de l’adhérence d’une colle à un substrat. L’enjeu est d’étudier les différentes méthodes de la caractérisation de l’adhérence dans les assemblages collés et de pouvoir modéliser le comportement associé. La première partie de la thèse consiste en une étude bibliographique des essais mécaniques permettant de caractériser l’adhérence. Ceux-ci sont classés en distinguant les essais en propagation et ceux en initiation de rupture. Cet état de l’art fait ressortir l’intérêt de l’utilisation de l’essai de flexion 3 points et de butt joint pour cette étude. La seconde partie de la thèse présente les différents matériaux utilisés et les différents traitements de surface permettant de faire varier l’adhésion des adhésifs au substrat. La troisième partie présente le cœur de ces travaux de thèse qui est l’essai de flexion 3 points. L’étude montre que cet essai de flexion 3 points permet, avec les adhésifs de l’étude, d’initier systématiquement une rupture adhésive localisable à la surface du substrat. Une approche énergétique a permis de déterminer un critère d’adhérence indépendant des paramètres physiques des matériaux et des dimensions de l’éprouvette. D’autre part, il a été montré que plus l’épaisseur du substrat est fine, plus les résultats de mesure de l’adhérence sont précis. Enfin, une quatrième partie s’attèle à la modélisation numérique par la méthode des éléments finis. Les résultats obtenus montrent que la contrainte d’ouverture en mode I est celle qui initie la rupture. En conclusion, l’essai de flexion 3 points permet de mesurer l’énergie d’initiation de rupture adhésive. / This thesis deals with the development of a mechanical test for the characterization of the practical adhesion of an adhesive to a substrate. The aim is to study the different methods of characterization of the adhesive strength in bonded joints and to model the associated behaviour. The first part of the thesis consists of a bibliographic study of the mechanical tests to characterize this adhesive strength. These tests are classified by distinguishing them in propagation or in initiation of rupture. This state of the art demonstrates the advantage of using the 3-point bending and the butt joint tests for this study. The second part of the thesis presents the different materials and the various surface treatments used to vary the adhesion of adhesives to the substrate. The third part presents the core of this thesis work which is the 3-point bending test. The study shows that this 3-point bending test leads systematically to initiate a localizable adhesive rupture on the surface of the substrate, at least for the adhesives used in our study. An energy approach of the test allows to determine an adhesion criterion independent of the physical parameters of the materials and dimensions of the specimen. On the other hand, it has been shown that the thinner the substrate, the more precise the results of the adhesive strength. Finally, a fourth part is devoted to numerical modelling by the finite element method. The results obtained show that opening constraint in mode I is that which controls the rupture. In conclusion, the 3-point bending test clearly allows to measure the energy of the adhesive rupture initiation.

This study sought to investigate and redefine the initial training of pastors, including the management training of student pastors at the colleges of the International Assemblies of God Church (IAG) of South Africa. Unlike in the past when pastors could lead churches without proper formal training based on their spirituality as viewed by the IAG and them professing to be called as ministers, today in this church tradition the need for the formal educational formation of pastors is taken for granted. This stance raises questions about the quality of graduates as well as matters of curriculum development, as the world is continually in a state of flux with far- reaching consequences for training institutions. It is generally accepted that churches play an important role in the lives of citizens in a predominantly Christian country like South Africa. On the other hand there is a continuing contestation and debate regarding the role pastors play in their churches in management and administrative issues. This also relates to the preparedness or unpreparedness of graduate pastors for their job. The day to day performance of duties by serving pastors in their organisations is generally viewed as below expectation compared to their counterparts in other occupations. A qualitative research approach was followed to elicit the necessary information to answer the research questions. Participants who were regarded as information rich cases on the training of pastors of the IAG were selected to shed more light on this particular aspect. Two focus group interviews and seven individual interviews were conducted. The interviews included members of the national and provincial executive committees, serving pastors, directors of the training colleges, pastor trainees in their final year of study and a newly graduated student. The current curriculum of initial training programmes was reviewed. Within a transformational management framework and utilising a purposeful intervention strategy, the study posits the Community Needs Responsive Management Training Model (CNRMTM) to enhance the initial training programmes of pastors and to use aspects of this model in the development and presentation of life-long learning programmes arranged for serving pastors. Recommendations and suggestions for future research were made. / Educational Leadership and Management / D. Ed. (Education Management)

Macromolecular assemblies such as the ribosome, spliceosome, polymerases are imperative for cellular functions. The current understanding of these important machineries and many other assemblies at the molecular level is poor. The lack of structural data for many macromolecular assemblies further causes a bottleneck in understanding the cellular processes and the various disease manifestations. Hence, it is essential to characterize the structures and molecular architectures of these macromolecular assemblies. Though the number of 3-D structures for individual proteins structures or domains in the Protein Data Bank (PDB) is growing, the number of structures deposited for macromolecular assemblies is relatively poor. Hence, apart from the use of experimental techniques for characterizing macromolecular assembly structures, the use of computational techniques would help in supplementing the growth of macromolecular assembly structures. This thesis deals with the use of integrative approaches where computational methods are combined with experimental data to model and understand the mechanistic features of macromolecular assemblies with a special focus on a sub-complex of the spliceosome machinery. Chapter 1 of this thesis provides an introduction to protein-protein interactions and macromolecular assemblies. Further, the modelling of macromolecular assemblies using integrative methods are discussed, with a subsequent introduction to the spliceosome machinery. In chapter 2, modelling studies were performed on the proteins involved in the general amino acid control mechanism, which is triggered in yeast under amino acid starvation conditions. The proteins involved in the study were Gcn1, a ribosome binding protein and the RWD-domain containing proteins Gcn2, Yih1, Gir2 and Mtc5. From laboratory experiments it is known that in order for Gcn2 activation, an eIF2α kinase, its RWD-domain has to bind to Gcn1 and the residue Arg-2259 is important for this interaction. As the 3-D structure for the Gcn1 region containing Arg-2259 is not currently available, its 3-D structure was inferred using fold recognition and comparative modelling techniques. Further, in order to understand the Gcn2 RWD domain-Gcn1 molecular interaction, a complex structure was inferred by using a restrained protein-protein docking procedure. As the proteins, Yih1 and Gir2 are known to bind to Gcn1 using their RWD-domains, first the structures of the RWD-domain containing proteins including Mtc5 were inferred using a Gcn2 RWD domain NMR structure. Additionally, the Gcn1-Gcn2 complex was used to build a set of complexes to explain the binding of other RWD domain containing proteins Yih1, Gir2 and Mtc5. The important molecular interactions were obtained on analysing the interacting residues in these complexes. Thus, the Gcn1-Gcn2 interaction at the molecular level has been proposed for the first time. Future experiments guided by the protein-protein complex models and the proposed set of mutations should provide an understanding about the critical molecular interactions involved in the general amino acid control mechanism. Chapter 3 describes an integrative approach that was used to decipher a pseudo-atomic model of the closed form of human SF3b complex. SF3b is a multi-protein complex containing seven components – p14, SF3b49, SF3b155, SF3b145, SF3b130, SF3b14b and SF3b10. It recognizes the branch point adenosine in the pre-mRNA as part of U2 snRNP or U11/U12 di-snRNP in the spliceosome. Although, the cryo-EM map for human SF3b complex has been available for more than a decade, the structure and relative spatial arrangement of all components in the complex are not yet known. The integrative modelling approach used here involved utilizing structural data in the form of available X-ray and NMR structures, fold recognition and comparative modelling as well as currently available experimental datasets, along with the available cryo-EM density map to provide a model with high structural coverage. Hence, the molecular architecture of closed form human SF3b complex was derived that can now provide insights into the functioning of SF3b in splicing. This might also help the future high resolution structure determination efforts of the entire human spliceosome machinery In chapter 4, the molecular architecture of the closed form of SF3b complex obtained from the use of integrative modelling approach (Chapter 3) is extensively discussed. The structure-function relationships for some of the SF3b components based on the pseudo-atomic model has also been provided. In addition, the extreme flexibility associated with some of the SF3b components based on dynamics analysis has also been examined. Further, using an existing U11/U12 di-snRNP cryo-EM map and the closed form SF3b complex pseudo-atomic model, an open form of the SF3b complex was modelled and the component structures were fit into it. Hence, it was found that the transition between closed and open forms is primarily caused by a flap containing the HEAT repeat protein, SF3b155. This Protein is also known to harbour cancer causing mutations and has the potential to affect the Closed to open transition as well as SF3b complex structure and stability. Thus, this provides a framework for the future understanding of the closed to open transition in SF3b functioning within the spliceosome. Chapter 5 builds upon the integrative modelling approach (Chapter 3) that proposed the molecular architecture of the closed form of human SF3b complex and an open form of SF3b that was derived due to a flap opening of the closed form and which might help in accommodating RNA and other trans-acting factors within the U11/U12 di-snRNP (Chapter 4). In the current chapter, the SF3b open form and its interaction with the RNA elements is studied. The 5' end of U12 snRNA and its interaction with pre-mRNA in branch point duplex was modelled guided by the open form of SF3b that provided the necessary structural constraints and the RNA model is topologically consistent with the existing biochemical data. Further, utilizing the SF3b opens form-RNA model and the existing experimental knowledge, an extensive discussion has been provided on how the architecture of SF3b acts as a scaffold for U12 snRNA: pre-mRNA branch point duplex formation as well as its potential implications for branch point adenosine recognition fidelity. Moreover, the reasons for SF3b to be defined as a “fuzzy” complex - a complex with highly flexible folded regions along with intrinsically disordered regions is also discussed. Hence, the current work adds to the excellent developments made previously and deepens the understanding of the structure-function relationship of the human SF3b complex in the context of the spliceosome machinery. In chapter 6, a methodology has been proposed for the use of evolutionary conservation of protein-protein interfacial residues in multiple protein cryo-EM density based fitting of the protein components in the low-resolution density maps of multi-protein assemblies. First, the methodology was tested on a dataset of simulated density maps generated at four different resolutions -10, 15, 20 and 25 Å. On utilizing the evolutionary conservation scores obtained from multiple sequence alignments to score the fitted complexes, it was found that there was a decrease in the conservation scores when compared to that of the crystal structures, which were used to generate the simulated density maps. Further, the assessment of the multiple protein density fitting technique to align the actual protein-protein interface residues correctly using a performance metric called F-measure showed there was a decrease in performance as the resolutions became poorer. Hence, based on evolutionary conservations scores as well as F-measure the decrease in conservation scores or performance was found to be mainly due to the errors associated with the fitting process. Subsequently, a refinement methodology was designed involving the use of conservation scores, which improved the accuracy of the fitted models and the same, was observed in an experimental cryo-EM density test case of RyR1-FKBP12 complex. Hence, the conservation information acts as an effective filter to distinguish the incorrectly fitted structures and improves the accuracy of the fitting of the protein structures in the density maps. Thus, one can incorporate the conserved surface residues information in the current density fitting tools to reduce ambiguity and improve the accuracy of the macromolecular assembly structures determined using cryo-EM. In the concluding chapter 7, the learnings on the structural and mechanistic features of protein assemblies obtained from the use of computational techniques and integration of experimental datasets is discussed. In chapter 2, the modelling of a binary macromolecular complex such as the Gcn1-Gcn2 complex was performed using computational structure prediction strategies to understand the molecular basis of its interaction. Due to the potential inaccuracies which can exist in computational modelling, the chapters 3 to 5 dealt with the use of integrative approaches, primarily guided by the cryo-EM map, in order to decipher the molecular architecture of the human SF3b complex in the closed and open forms as well as its contribution for branch point adenosine recognition. Based on the extensive experience gained in modelling of assemblies using cryo-EM data in the previous chapters, a new method has been proposed on the use of evolutionary conservation information to improve the accuracy of cryo-EM density based fitting. Hence, these studies have provided strategies for modelling macromolecular assemblies as well as a deeper understanding of its mechanistic features.

A number of articles in books and newspapers have been written on the life and work of Nicholas Bhengu, in the past four decades. However, to date no focused academic research had been devoted to his life, his mission, his message and his influence in South Africa as well as beyond the borders of South Africa. The different chapters in the thesis focus on Bhengu’s life, his call to ministry and the role he played in South Africa, in rest of Africa, and beyond the borders of our continent. Although Bhengu did not overtly address political issues by supporting either the liberation movements nor the Nationalist Government, the impact of his work was felt by both to the extent that liberation movements such as ANC criticised him for not lending his public support to the struggle they waged against apartheid. On the other hand, the South African government also tried to co-opt him as an ally of their socio-political ideology. The government disappointed by Bhengu’s lack of support for its political programme, became suspicious of his intentions and set the Special Branch of the South African Police to monitor his movements, teaching and preaching. Bhengu ministered during a tumultuous period in the history of South Africa which called for people as well as the faith communities to take sides for or against the system of apartheid. Bhengu’s teaching and preaching had a great impact on the social and political psyche of the people in South Africa. Through his Back to God Crusade he, with great effectiveness, called people to return to God. Thousands devoted their lives to God. Wherever Bhengu conducted his crusades, crime went down significantly, with criminals turning in their weapons of trade and returning stolen goods to the police. He also performed spectacular healings and miracles. Apart from his evangelistic campaigns, Bhengu planted churches, established a formidable women’s ministry that to this day continues to raise millions of Rand to fund the Back to God Crusade. The Youth Ministry provides bursaries for young people to study in any field of their choice. Bhengu’s goal for providing these bursaries was to empower a new generation to contribute to the development of their country. He also established self-governing, self-supporting and self-propagating churches, at a time when Black Churches were dependent on handouts from missionary sending agencies. The study finally evaluates the contribution and lasting legacy of Bhengu: his example, his missionary endeavours, his preaching and church planting efforts, his socio-political involvement, and his leadership. The strategies that he employed to building a cohesive and successful movement – the Back to God/Assemblies of God Movement – receive special attention. The impact of the movement is still felt in South Africa and the neighbouring countries, Swaziland, Namibia, Lesotho, Botswana, Mozambique and Zimbabwe, twenty five years after his death. There is every reason to consider Nicholas Bhengu to be the Billy Graham of Africa. / Thesis (PhD)--University of Pretoria, 2010. / Science of Religion and Missiology / unrestricted