The design of an aquaculture facility on the Keiskamma River at Hamburg, Province of the Eastern Cape
- Authors: Scholtz, Jeanne
- Date: 2014
- Subjects: Aquaculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/5280 , vital:20836
- Description: This dissertation addresses the nature and potential of an intrusive architectural typology in a sensitive river estuary environment through an understanding of the functional design principles of an Aquaculture plant. Furthermore the research engages with cultural, historical and sociological objectives to celebrate the historical landscape. Hamburg is caught between its value as a historic wilderness and it's need to establish and maintain an economy to alleviate poverty. The project is conceived as a provocation and speculation on how these two demands may be hybridized as an alternative to the typical conservationist practices applied. Proposing a type of hybrid ecology where industry and endemic wildlife can not only co-exist but also be mutually beneficial.
- Full Text:
- Date Issued: 2014
- Authors: Scholtz, Jeanne
- Date: 2014
- Subjects: Aquaculture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MArch
- Identifier: http://hdl.handle.net/10948/5280 , vital:20836
- Description: This dissertation addresses the nature and potential of an intrusive architectural typology in a sensitive river estuary environment through an understanding of the functional design principles of an Aquaculture plant. Furthermore the research engages with cultural, historical and sociological objectives to celebrate the historical landscape. Hamburg is caught between its value as a historic wilderness and it's need to establish and maintain an economy to alleviate poverty. The project is conceived as a provocation and speculation on how these two demands may be hybridized as an alternative to the typical conservationist practices applied. Proposing a type of hybrid ecology where industry and endemic wildlife can not only co-exist but also be mutually beneficial.
- Full Text:
- Date Issued: 2014
The design of quantum dots and their conjugates as luminescent probes for analyte sensing
- Authors: Adegoke, Oluwasesan
- Date: 2014
- Subjects: Quantum dots Anolytes Luminescent probes Luminescence spectroscopy Phthalocyanines Nanoparticles
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4457 , http://hdl.handle.net/10962/d1010866
- Description: The design and applications of quantum dots (QDs) as fluorescent probes for analyte sensing is presented. Cadmium based thiol-capped QDs were employed as probe for the detection of analytes. Comparative studies between core CdTe and core-shell CdTe@ZnS QDs showed that the overall sensitivity and selectivity of the sensor was dependent on the nature of the capping agent and the QDs employed, hence making CdTe@ZnS QDs a more superior sensor than the core. To explore the luminescent sensing of QDs based on the fluorescence “turn ON” mode, L-glutathione-capped CdTe QDs was conjugated to 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT) to form a QDs-4AT conjugate system. The QDs-4AT nanoprobe was highly selective and sensitive to the detection of bromide ion with a very low limit of detection. Subsequently, metallo-phthalocyanines (MPcs) were employed as host molecules on the surface of QDs based on the covalent linking of the QDs to the MPc. Elucidation of the reaction mechanism showed that the fluorescence “turn ON” effect of the QDs-MPc probe in the presence of the analyte was due to axial ligation of the analytes to the Pc ring. Studies showed that the type of substituent attached to the MPc ring influenced the overall sensitivity of the probe. Additionally, a comparative investigation using newly synthesized phthalocyanine and triaza-benzcorrole complexes was conducted when these complexes were conjugated to CdSe@ZnS QDs for analyte sensing. Results showed that the triaza-benzcorrole complex can be employed as a host-molecule sensor but displayed a lower sensitivity for analyte sensing in comparison to the phthalocyanine complex.
- Full Text:
- Date Issued: 2014
- Authors: Adegoke, Oluwasesan
- Date: 2014
- Subjects: Quantum dots Anolytes Luminescent probes Luminescence spectroscopy Phthalocyanines Nanoparticles
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4457 , http://hdl.handle.net/10962/d1010866
- Description: The design and applications of quantum dots (QDs) as fluorescent probes for analyte sensing is presented. Cadmium based thiol-capped QDs were employed as probe for the detection of analytes. Comparative studies between core CdTe and core-shell CdTe@ZnS QDs showed that the overall sensitivity and selectivity of the sensor was dependent on the nature of the capping agent and the QDs employed, hence making CdTe@ZnS QDs a more superior sensor than the core. To explore the luminescent sensing of QDs based on the fluorescence “turn ON” mode, L-glutathione-capped CdTe QDs was conjugated to 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT) to form a QDs-4AT conjugate system. The QDs-4AT nanoprobe was highly selective and sensitive to the detection of bromide ion with a very low limit of detection. Subsequently, metallo-phthalocyanines (MPcs) were employed as host molecules on the surface of QDs based on the covalent linking of the QDs to the MPc. Elucidation of the reaction mechanism showed that the fluorescence “turn ON” effect of the QDs-MPc probe in the presence of the analyte was due to axial ligation of the analytes to the Pc ring. Studies showed that the type of substituent attached to the MPc ring influenced the overall sensitivity of the probe. Additionally, a comparative investigation using newly synthesized phthalocyanine and triaza-benzcorrole complexes was conducted when these complexes were conjugated to CdSe@ZnS QDs for analyte sensing. Results showed that the triaza-benzcorrole complex can be employed as a host-molecule sensor but displayed a lower sensitivity for analyte sensing in comparison to the phthalocyanine complex.
- Full Text:
- Date Issued: 2014
The determination of compensation in unfair dismissal cases
- Authors: Dayimani, Vuyisile
- Date: 2014
- Subjects: Unfair labor practices -- South Africa , Employees -- Dismissal of -- Law and legislation -- South Africa , Workers' compensation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10275 , http://hdl.handle.net/10948/d1020775
- Description: The LRA 66 of 1995 was established to give effect to section 23(1) of the Constitution of the Republic of South Africa, which guarantees that everyone has a right to fair labour practices. Amongst others, the purpose of the LRA is to advance economic development, labour peace and the effective resolution of labour disputes. At common law termination of employment was occasioned by the conduct of the employer or employee, in terms of which either party may terminate an employment contract by giving agreed notice or reasonable notice. The LRA broadened the common law concept of “repudiation” of a contract of employment in terms of which section 186 of the LRA now defines the term “dismissal” to mean various possible instances that can be caused by the employer or employee. Furthermore, section 185 of the same Act clearly states that a dismissal can be found to be unfair and makes provision for redress to an employee who would be aggrieved by a dismissal. Compensation is one of the remedies that can be awarded to an employee who is found to have been unfairly dismissed. Unlike the LRA of 1956 which gave the courts an unfettered discretion regarding the compensation that could be awarded, section 194 of the current LRA places a limit on the compensation amount that can be awarded. A decision hereon is determined with reference to whether the dismissal is found to have been procedurally, substantively unfair or both. The Act further requires that the compensation must be just and equitable. A challenge in applying section 194 of the Act in this regard is that there would be vast inconsistencies in terms of the amount of compensation to be awarded and that certain presiding officers could consider different approaches in considering factors to be determined when deciding on compensation. In many other instances compensation for unfair dismissal would be decided around the idea of solely punishing the employer. This research document is mainly concerned with identifying the said challenges through case law by considering the decisions of the commissioners and judges in interpreting the old and current provisions of section 194 of the Act. The old section 194 of the Act created a formula to be followed by presiding officers when making a determination on the compensation awarded. The interpretation of the section and its formula brought with it its own complications. The amended section 194 on the other hand, conferred a discretion on presiding officers to award compensation within the caps of 12 months and 24 months for procedurally and substantively unfair dismissal respectively, for as long as the compensation would be just and equitable in all circumstances. Relevant case law and the opinions of labour law experts have been of great assistance in interpreting the current section 194. The factors do not constitute an exhaustive list. They are a mere guideline to presiding officers so as to eliminate or minimize inconsistencies in awarding compensation.
- Full Text:
- Date Issued: 2014
- Authors: Dayimani, Vuyisile
- Date: 2014
- Subjects: Unfair labor practices -- South Africa , Employees -- Dismissal of -- Law and legislation -- South Africa , Workers' compensation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:10275 , http://hdl.handle.net/10948/d1020775
- Description: The LRA 66 of 1995 was established to give effect to section 23(1) of the Constitution of the Republic of South Africa, which guarantees that everyone has a right to fair labour practices. Amongst others, the purpose of the LRA is to advance economic development, labour peace and the effective resolution of labour disputes. At common law termination of employment was occasioned by the conduct of the employer or employee, in terms of which either party may terminate an employment contract by giving agreed notice or reasonable notice. The LRA broadened the common law concept of “repudiation” of a contract of employment in terms of which section 186 of the LRA now defines the term “dismissal” to mean various possible instances that can be caused by the employer or employee. Furthermore, section 185 of the same Act clearly states that a dismissal can be found to be unfair and makes provision for redress to an employee who would be aggrieved by a dismissal. Compensation is one of the remedies that can be awarded to an employee who is found to have been unfairly dismissed. Unlike the LRA of 1956 which gave the courts an unfettered discretion regarding the compensation that could be awarded, section 194 of the current LRA places a limit on the compensation amount that can be awarded. A decision hereon is determined with reference to whether the dismissal is found to have been procedurally, substantively unfair or both. The Act further requires that the compensation must be just and equitable. A challenge in applying section 194 of the Act in this regard is that there would be vast inconsistencies in terms of the amount of compensation to be awarded and that certain presiding officers could consider different approaches in considering factors to be determined when deciding on compensation. In many other instances compensation for unfair dismissal would be decided around the idea of solely punishing the employer. This research document is mainly concerned with identifying the said challenges through case law by considering the decisions of the commissioners and judges in interpreting the old and current provisions of section 194 of the Act. The old section 194 of the Act created a formula to be followed by presiding officers when making a determination on the compensation awarded. The interpretation of the section and its formula brought with it its own complications. The amended section 194 on the other hand, conferred a discretion on presiding officers to award compensation within the caps of 12 months and 24 months for procedurally and substantively unfair dismissal respectively, for as long as the compensation would be just and equitable in all circumstances. Relevant case law and the opinions of labour law experts have been of great assistance in interpreting the current section 194. The factors do not constitute an exhaustive list. They are a mere guideline to presiding officers so as to eliminate or minimize inconsistencies in awarding compensation.
- Full Text:
- Date Issued: 2014
The development and implementation of a mental toughness training programme for cricketers
- Authors: McInerney, Michael
- Date: 2014
- Subjects: Sports -- Psychological aspects , Athletes -- Conduct of life , Mental discipline , Achievement motivation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3234 , http://hdl.handle.net/10962/d1013155
- Description: The professional turn in sports has prompted the search for explanations beyond the physical when discussing quality of performance. Mental Toughness has been recognised as one of the most important psychological attributes in achieving performance excellence across multiple sport settings. Yet, despite this, little research has been conducted into mental toughness development. This research seeks to answer the question: What insights can the development and implementation of a mental toughness programme for a semi-professional South African cricket team provide regarding Mental Toughness development? Based on a theoretical framework of mental toughness in cricket, a programme was developed in collaboration with the Border Cricket Team and Coaches. Incorporating elements that focussed on education, environment, awareness and mental skills, the programme was implemented in both individual and group settings during the off- and pre-seasons. An analysis of the participants’ experiences identified the need for a theoretical understanding of mental toughness within teams, facilitating the design of interventions that integrate the team and the individual. Future programmes should include measures of mastery, and individually customised approaches to mental toughness enhancement that acknowledge the potential contextual and individual variation in mental toughness.
- Full Text:
- Date Issued: 2014
- Authors: McInerney, Michael
- Date: 2014
- Subjects: Sports -- Psychological aspects , Athletes -- Conduct of life , Mental discipline , Achievement motivation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3234 , http://hdl.handle.net/10962/d1013155
- Description: The professional turn in sports has prompted the search for explanations beyond the physical when discussing quality of performance. Mental Toughness has been recognised as one of the most important psychological attributes in achieving performance excellence across multiple sport settings. Yet, despite this, little research has been conducted into mental toughness development. This research seeks to answer the question: What insights can the development and implementation of a mental toughness programme for a semi-professional South African cricket team provide regarding Mental Toughness development? Based on a theoretical framework of mental toughness in cricket, a programme was developed in collaboration with the Border Cricket Team and Coaches. Incorporating elements that focussed on education, environment, awareness and mental skills, the programme was implemented in both individual and group settings during the off- and pre-seasons. An analysis of the participants’ experiences identified the need for a theoretical understanding of mental toughness within teams, facilitating the design of interventions that integrate the team and the individual. Future programmes should include measures of mastery, and individually customised approaches to mental toughness enhancement that acknowledge the potential contextual and individual variation in mental toughness.
- Full Text:
- Date Issued: 2014
The development of a financing model for agricultural production in South Africa
- Authors: Oberholster, Jacobus Hoon
- Date: 2014
- Subjects: Agriculture -- South Africa -- Finance , Agricultural productivity -- South Africa , Agricultural industries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/3041 , vital:20389
- Description: The world agricultural industry, despite numerous supply and demand challenges, has to significantly increase its production capacity to satisfy the increased demand for food and successfully address the issues surrounding food security. Access to credit is however a key enabler in this regard, while a lack of it limits the adaptive capacity of agricultural producers. The financing needs of agricultural producers however vary and are influenced by the different production systems which have different investment, revenue and risk patterns. The sector is unique in that the risk and uncertainty in agriculture are increased by the nature of agricultural production systems, which is in many cases driven by unpredictable external factors such as adverse weather conditions. In addition agricultural production systems also function within the total food system which consists of a number of interrelated subsystems, each presenting agricultural producers with a unique set of risk factors that need to be taken into account. The development of new and innovative financing solutions for the sector therefore requires a thorough understanding of the multidimensional nature of agriculture and the unique characteristics of the sector. The purpose of this study was to contribute to the development of new and innovative financing solutions for the agricultural sector in South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Oberholster, Jacobus Hoon
- Date: 2014
- Subjects: Agriculture -- South Africa -- Finance , Agricultural productivity -- South Africa , Agricultural industries -- South Africa
- Language: English
- Type: Thesis , Doctoral , DBA
- Identifier: http://hdl.handle.net/10948/3041 , vital:20389
- Description: The world agricultural industry, despite numerous supply and demand challenges, has to significantly increase its production capacity to satisfy the increased demand for food and successfully address the issues surrounding food security. Access to credit is however a key enabler in this regard, while a lack of it limits the adaptive capacity of agricultural producers. The financing needs of agricultural producers however vary and are influenced by the different production systems which have different investment, revenue and risk patterns. The sector is unique in that the risk and uncertainty in agriculture are increased by the nature of agricultural production systems, which is in many cases driven by unpredictable external factors such as adverse weather conditions. In addition agricultural production systems also function within the total food system which consists of a number of interrelated subsystems, each presenting agricultural producers with a unique set of risk factors that need to be taken into account. The development of new and innovative financing solutions for the sector therefore requires a thorough understanding of the multidimensional nature of agriculture and the unique characteristics of the sector. The purpose of this study was to contribute to the development of new and innovative financing solutions for the agricultural sector in South Africa.
- Full Text:
- Date Issued: 2014
The development of a personal philosophy and practice of servant leadership : a grounded theory study
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
- Authors: Taylor, Simon Michael
- Date: 2014
- Subjects: Hilton College (Pietermaritzburg, South Africa) , Servant leadership , Grounded theory , Community and school -- South Africa -- KwaZulu-Natal , Student volunteers in social service -- South Africa -- KwaZulu-Natal , Educational leadership -- South Africa -- KwaZulu-Natal
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1199 , http://hdl.handle.net/10962/d1012986
- Description: The purpose of this study is to develop a substantive grounded theory explaining the development of a philosophy and the practice of leadership amongst young adults who had attended Hilton College and whom were exposed to their servant leadership development programme. The grounded theory method in this study was developed using conventions identified by Strauss and Corbin (1990) and relying upon a collection of incidents noted during interviews with former students, teachers, housemasters, headmaster and Hiltonian Society board members. In total thirty-six interviews were conducted over a period of four years in South Africa, the United Kingdom and Kenya. Using the grounded theory methodology, an understanding of the theoretical model emerged through the development of a personal philosophy and the practice of servant leadership. Related to the central phenomenon of individual leadership philosophy and practice, the causal condition of opportunity to lead, influenced how the individual philosophy and practice emerged. Strategies used by the participants to nurture their philosophy and practice of leadership were the leadership development programme, community service, feedback and reflection. The data identified the intervening conditions and conditions relating to the context of the leadership philosophy and practice. The consequences of developing a leadership philosophy and practice were related to leadership behaviour; self-esteem; growth; follower relations; empowering of others; and relationship to institutions. The theoretical model illustrated the holistic nature of an individual’s leadership philosophy and practice. In this instance, the nature of the data revealed that the individual's leadership philosophy and practice that developed amongst the participants was predominately servant leadership. The different approaches to leadership development were scrutinised with the intention of locating the grounded theory that developed in this study, within the available literature. The literature did provide some useful insights, in particular the social field theory of Bourdieu (1998), which offered a more encompassing explanation and showed much promise in providing an understanding of leadership development. Wheatley's (1999) interpretation of field theory further explained the influence of servant leadership in leadership development. Finally, the researcher developed a set of propositions and recommendations for practice and future research and discussed the value of this research.
- Full Text:
- Date Issued: 2014
The development of functionalized electrospun nanofibers for the control of pathogenic microorganisms in water.
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
- Authors: Kleyi, Phumelele Eldridge
- Date: 2014
- Subjects: Electrospinning , Nanofibers , Pathogenic microorganisms , Pathogenic microorganisms -- Detection , Drinking water -- Microbiology , Water quality -- Measurement , Imidazoles , Spectrum analysis , Anti-infective agents , Polymerization
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4497 , http://hdl.handle.net/10962/d1013134
- Description: The thesis presents the development of functionalized electrospun nylon 6 nanofibers for the eradication of pathogenic microorganisms in drinking water. Imidazole derivatives were synthesized as the antimicrobial agents and were characterized by means of NMR spectroscopy, IR spectroscopy, elemental analysis and X-ray crystallography. The first set of compounds (2-substituted N-alkylimidazoles) consisted of imidazole derivatives substituted with different alkyl groups (methyl, ethyl, propyl, butyl, heptyl, octyl, decyl and benzyl) at the 1-position and various functional groups [carboxaldehyde (CHO), alcohol (CH2OH) and carboxylic acid (COOH)] at the 2-position. It was observed that the antimicrobial activity of the compounds increased with increasing alkyl chain length and decreasing pKa of the 2-substituent. It was also observed that the antimicrobial activity was predominantly against a Gram-positive bacterial strains [Staphylococcus aureus (MIC = 5-160 μg/mL) and Bacillus subtilis subsp. spizizenii (MIC = 5-20 μg/mL)], with the latter being the more susceptible. However, the compounds displayed poor antimicrobial activity against Gram-negative bacterial strain, E. coli (MIC = 150- >2500 μg/mL) and did not show any activity against the yeast, C. albicans. The second set of compounds consisted of the silver(I) complexes containing 2-hydroxymethyl-N-alkylimidazoles. The complexes displayed a broad spectrum antimicrobial activity towards the microorganisms that were tested and their activity [E. coli (MIC = 5-40 μg/mL), S. aureus (MIC = 20-80 μg/mL), Bacillus subtilis subsp. spizizenii (MIC = 5-40 μg/mL) and C. albicans (MIC = 40-80 μg/mL)] increased with the alkyl chain length of the 2-hydroxymethyl-N-alkylimidazole. The third set of compounds consisted of the vinylimidazoles containing the vinyl group either at the 1-position or at the 4- or 5- position. The imidazoles with the vinyl group at the 4- or 5-position contained the alkyl group (decyl) at the 1-position. For the fabrication of the antimicrobial nanofibers, the first two sets of imidazole derivatives (2-substituted N-alkylimidazoles and silver(I) complexes) were incorporated into electrospun nylon 6 nanofibers while the third set (2-substituted vinylimidazoles) was immobilized onto electrospun nylon 6 nanofibers employing the graft polymerization method. The antimicrobial nylon nanofibers were characterized by IR spectroscopy and SEM-EDAX (EDS). The electrospun nylon 6 nanofibers incorporated with 2-substituted N-alkylimidazoles displayed moderate to excellent levels of growth reduction against S. aureus (73.2-99.8 percent). For the electrospun nylon 6 nanofibers incorporated with silver(I) complexes, the levels of growth reduction were >99.99 percent, after the antimicrobial activity evaluation using the shake flask method. Furthermore, the grafted electrospun nylon 6 nanofibers showed excellent levels of growth reduction for E. coli (99.94-99.99 percent) and S. aureus (99.93-99.99 percent). The reusability results indicated that the grafted electrospun nylon 6 nanofibers maintained the antibacterial activity until the third cycle of useage. The cytotoxicity studies showed that grafted electrospun nylon 6 nanofibers possess lower cytotoxic effects on Chang liver cells with IC50 values in the range 23.48-26.81 μg/mL. The thesis demonstrated that the development of antimicrobial electrospun nanofibers, with potential for the eradication of pathogenic microoganisms in water, could be accomplished by incorporation as well as immobilization strategies.
- Full Text:
- Date Issued: 2014
The developmental state, social policy and social compacts: a comparative policy analysis of the South African case
- Authors: Gwaindepi, Abel
- Date: 2014
- Subjects: Economic development -- Political aspects -- South Africa , Income distribution -- South Africa , Democracy -- South Africa , Industrial policy -- Developing countries , South Africa -- Economic conditions , South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1101 , http://hdl.handle.net/10962/d1013278
- Description: The history of economic thought is ‘flooded’ with neo-classical accounts despite the fact that neoclassical economics did not occupy history alone. This has caused the discourses on ‘lost alternatives’ to be relegated as the deterministic ‘straight line’ neo-classical historical discourses are elevated. Globally hegemonic neo-classical discourse aided this phenomenon as it served to subordinate any counterhegemonic local discursive processes towards alternatives. This study is premised on the theme of non-neoclassical ‘lost alternatives’ using the post-apartheid South Africa as a case study. Emerging from the apartheid regime, the impetus towards non-neoclassical redistributive policies was strong in South Africa but this did not gain traction as the ANC’s ‘growth through redistribution’ was replaced by globally hegemonic discourse which favoured ‘redistribution through growth’. This thesis postulates the idea of two waves of ‘internal’ discursive formations; capturing the transition to democracy up to 1996 as the first wave and the period from 2005 to about 2009 as the second wave. The developmental state paradigm (DSP) emerged as the central heterodox paradigm with ideas such as industrial policy, welfare, and social dialogue/compacts being main elements. The DSP was expressly chosen in the early 1990s, the first period of strong internal discursive formation, but faded as neo-classical policies, epitomised through GEAR, dominated the policy space. The DSP discourse gained vitality in the second wave of internal discursive formation (2005-2009) and it was associated with the subsequent Zuma’s administration. The study illustrates that the DSP has failed to be fully developed into a practical framework but remained only at rhetorical level with the phrase ‘developmental state’ inserted into government policy documents and documents of ANC as a ruling party. The thesis further illustrates that the DSP fared well ideologically because of its inclination to the ideology of ‘developmentalism’ tended to trump any socialist inclined policies such as a generous welfare regime. The thesis rebuts the notion of the DSP in South Africa which has only been amorphously developed with the phrase ‘developmental state’ becoming a mere buzzword. The thesis argues that the DSP in the 21st century is much more complex and the growing ‘tertiarisation’ of the economy makes the Social Democratic Paradigm SDP’s capability centric approach much more relevant for South Africa. The study goes further to argue that a (SDP) is much more suitable alternative for addressing South African colonial/apartheid legacies and consolidation of democracy.
- Full Text:
- Date Issued: 2014
- Authors: Gwaindepi, Abel
- Date: 2014
- Subjects: Economic development -- Political aspects -- South Africa , Income distribution -- South Africa , Democracy -- South Africa , Industrial policy -- Developing countries , South Africa -- Economic conditions , South Africa -- Social conditions
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1101 , http://hdl.handle.net/10962/d1013278
- Description: The history of economic thought is ‘flooded’ with neo-classical accounts despite the fact that neoclassical economics did not occupy history alone. This has caused the discourses on ‘lost alternatives’ to be relegated as the deterministic ‘straight line’ neo-classical historical discourses are elevated. Globally hegemonic neo-classical discourse aided this phenomenon as it served to subordinate any counterhegemonic local discursive processes towards alternatives. This study is premised on the theme of non-neoclassical ‘lost alternatives’ using the post-apartheid South Africa as a case study. Emerging from the apartheid regime, the impetus towards non-neoclassical redistributive policies was strong in South Africa but this did not gain traction as the ANC’s ‘growth through redistribution’ was replaced by globally hegemonic discourse which favoured ‘redistribution through growth’. This thesis postulates the idea of two waves of ‘internal’ discursive formations; capturing the transition to democracy up to 1996 as the first wave and the period from 2005 to about 2009 as the second wave. The developmental state paradigm (DSP) emerged as the central heterodox paradigm with ideas such as industrial policy, welfare, and social dialogue/compacts being main elements. The DSP was expressly chosen in the early 1990s, the first period of strong internal discursive formation, but faded as neo-classical policies, epitomised through GEAR, dominated the policy space. The DSP discourse gained vitality in the second wave of internal discursive formation (2005-2009) and it was associated with the subsequent Zuma’s administration. The study illustrates that the DSP has failed to be fully developed into a practical framework but remained only at rhetorical level with the phrase ‘developmental state’ inserted into government policy documents and documents of ANC as a ruling party. The thesis further illustrates that the DSP fared well ideologically because of its inclination to the ideology of ‘developmentalism’ tended to trump any socialist inclined policies such as a generous welfare regime. The thesis rebuts the notion of the DSP in South Africa which has only been amorphously developed with the phrase ‘developmental state’ becoming a mere buzzword. The thesis argues that the DSP in the 21st century is much more complex and the growing ‘tertiarisation’ of the economy makes the Social Democratic Paradigm SDP’s capability centric approach much more relevant for South Africa. The study goes further to argue that a (SDP) is much more suitable alternative for addressing South African colonial/apartheid legacies and consolidation of democracy.
- Full Text:
- Date Issued: 2014
The diet of the calanoid copepod, Pseudodiaptomus hessei, in a permanently open southern African estuary inferred from fatty acid analyses
- Noyon, Margaux, Froneman, P William
- Authors: Noyon, Margaux , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70901 , vital:29758 , https://doi.org/10.1093/plankt/fbu037
- Description: The fatty acid (FA) composition of Pseudodiaptomus hessei, one of the most abundant copepod species in southern African estuaries and lakes, reveals potential food selectivity and the importance of flagellate prey in their diets. Differences in FA profiles between males and females were recorded; however, none of these patterns matched the reproductive activities of the copepod. Our findings stress the importance of improving our knowledge of FA biosynthesis pathways to employ fatty acids as trophic markers in feeding studies of zooplankton in temperate environments.
- Full Text:
- Date Issued: 2014
- Authors: Noyon, Margaux , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70901 , vital:29758 , https://doi.org/10.1093/plankt/fbu037
- Description: The fatty acid (FA) composition of Pseudodiaptomus hessei, one of the most abundant copepod species in southern African estuaries and lakes, reveals potential food selectivity and the importance of flagellate prey in their diets. Differences in FA profiles between males and females were recorded; however, none of these patterns matched the reproductive activities of the copepod. Our findings stress the importance of improving our knowledge of FA biosynthesis pathways to employ fatty acids as trophic markers in feeding studies of zooplankton in temperate environments.
- Full Text:
- Date Issued: 2014
The educational interventions of the NGO Ikamva Youth
- Authors: Nomsenge, Sinazo Onela
- Date: 2014
- Subjects: Non-governmental organizations -- South Africa -- Cape Town , Community development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9317 , http://hdl.handle.net/10948/d1020602
- Description: NGOs continue to play a central role in the delivery of services in South Africa. Many of the gaps left by government in small and vulnerable communities are filled by community and nation-based organisations aimed at providing specific needs for communities. Education-based NGOs, more specifically, play the role of satisfying education and skills-related needs. This treatise is founded on the theoretical assumption that society functions just like a human body with all its different parts, or elements, interdependent: the one cannot function without the other. Central to this study is the understanding that when analysing and evaluating one area or element of society, it is vital to consider the impact of that area or element on other areas or elements of society. Such is the case with IKamva Youth, an NGO situated in Khayelitsha, a township on the outskirts of Cape Town. Although the organisation is independent and exists on its own terms, it is affected and influenced by the community and context within which it exists. Khayelitsha is considered a previously disadvantaged area, characterised by socio-economic challenges such as high levels of crime, poor quality of education, lack of sanitation, illness and disease and unemployment. IKamva Youth, situated in such a community, was founded with the purpose of addressing such issues. The purpose of this study was to evaluate the extent to which the organisation has been effective in doing so. Paying specific attention to the community of Khayelitsha and the challenges it faces, the effectiveness of the organisation was evaluated according the overall purpose of NGOs and this organisation’s own vision, mission, purpose and objectives. This evaluation was done using the organisation’s different programs which are tasked with the responsibility of carrying out the purpose of the organisation. These programs were outlined and explained and used as the units of measuring the extent to which the organisation has been effective. In order to obtain an in-depth knowledge of these programs, the organisation was first located within its broader context after which these various programs were evaluated for effectiveness using responses from sampled participants. A questionnaire and in-depth interviews were compiled as measuring instruments for this evaluation. Data collected by means of the instruments formed the central point of reference that crafted the conclusion that in the midst of a number of socio-economic challenges, IKamva Youth has been effective in carrying out its purpose as an NGO and fulfilling its own vision and mission.
- Full Text:
- Date Issued: 2014
- Authors: Nomsenge, Sinazo Onela
- Date: 2014
- Subjects: Non-governmental organizations -- South Africa -- Cape Town , Community development -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9317 , http://hdl.handle.net/10948/d1020602
- Description: NGOs continue to play a central role in the delivery of services in South Africa. Many of the gaps left by government in small and vulnerable communities are filled by community and nation-based organisations aimed at providing specific needs for communities. Education-based NGOs, more specifically, play the role of satisfying education and skills-related needs. This treatise is founded on the theoretical assumption that society functions just like a human body with all its different parts, or elements, interdependent: the one cannot function without the other. Central to this study is the understanding that when analysing and evaluating one area or element of society, it is vital to consider the impact of that area or element on other areas or elements of society. Such is the case with IKamva Youth, an NGO situated in Khayelitsha, a township on the outskirts of Cape Town. Although the organisation is independent and exists on its own terms, it is affected and influenced by the community and context within which it exists. Khayelitsha is considered a previously disadvantaged area, characterised by socio-economic challenges such as high levels of crime, poor quality of education, lack of sanitation, illness and disease and unemployment. IKamva Youth, situated in such a community, was founded with the purpose of addressing such issues. The purpose of this study was to evaluate the extent to which the organisation has been effective in doing so. Paying specific attention to the community of Khayelitsha and the challenges it faces, the effectiveness of the organisation was evaluated according the overall purpose of NGOs and this organisation’s own vision, mission, purpose and objectives. This evaluation was done using the organisation’s different programs which are tasked with the responsibility of carrying out the purpose of the organisation. These programs were outlined and explained and used as the units of measuring the extent to which the organisation has been effective. In order to obtain an in-depth knowledge of these programs, the organisation was first located within its broader context after which these various programs were evaluated for effectiveness using responses from sampled participants. A questionnaire and in-depth interviews were compiled as measuring instruments for this evaluation. Data collected by means of the instruments formed the central point of reference that crafted the conclusion that in the midst of a number of socio-economic challenges, IKamva Youth has been effective in carrying out its purpose as an NGO and fulfilling its own vision and mission.
- Full Text:
- Date Issued: 2014
The effect of foster care placement on children and foster families
- Authors: Time, Lumka
- Date: 2014
- Subjects: Foster home care , Foster children , Foster parents
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9246 , http://hdl.handle.net/10948/d1021151
- Description: Clearly very little is known about the dynamics within foster families and the effects of fostering on children. The intention of this study was to understand what happens in the lives of children during their period of placement in foster homes and it affected them and to explore and describe the experiences of the foster parent. It was learned that there is often a breakdown in the relationship between foster parents and the children they foster, particularly with regards to the gaining of trust, the socio economic status of the foster parents also played a part in the success of the placement. This research has found that substance abuse on the part of the children was prevalent leading to great tension within the households.
- Full Text:
- Date Issued: 2014
- Authors: Time, Lumka
- Date: 2014
- Subjects: Foster home care , Foster children , Foster parents
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9246 , http://hdl.handle.net/10948/d1021151
- Description: Clearly very little is known about the dynamics within foster families and the effects of fostering on children. The intention of this study was to understand what happens in the lives of children during their period of placement in foster homes and it affected them and to explore and describe the experiences of the foster parent. It was learned that there is often a breakdown in the relationship between foster parents and the children they foster, particularly with regards to the gaining of trust, the socio economic status of the foster parents also played a part in the success of the placement. This research has found that substance abuse on the part of the children was prevalent leading to great tension within the households.
- Full Text:
- Date Issued: 2014
The effect of outsourcing a South African automotive company's material handling activities on its operational performance
- Authors: Dolley-Ryneveld, Mieshkah
- Date: 2014
- Subjects: Contracting out -- South Africa , Industrial management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8936 , http://hdl.handle.net/10948/d1021202
- Description: Outsourcing has become a popular trend in the last two decades and has been applied in both non-essential and critical business functions. It has been viewed as a vital source of competitive advantage and is expected to remain an important component in future business strategies. Over the past few years, the outsourcing of logistics functions in particular has shown strong growth. Thus, an abundance of research on the outsourcing of logistics is available. However, there has been little research on the outsourcing of material handling activities as a sub-component of logistics, nor its effect on a company’s operational performance. The purpose of this treatise is to determine the effects of outsourcing a South African automotive company’s material handling activities on its operational performance. It further aims to compare the company’s expected outcomes for outsourcing with actual outcomes. In addition, the factors which contributed positively and negatively to the operation of the outsourced material handling activities at the company, are established. The automotive company in this study is situated in Port Elizabeth, but due to confidentiality reasons the name of the company is not mentioned in the study. The study consists of a literature review on the background of outsourcing, outsourcing theories, outsourcing trends, important outsourcing considerations and gaps in outsourcing research. Primary data, collected through the use of a questionnaire to determine the effects outsourcing has on the company’s operational performance, is collected, reported and analysed in the study. The performance criteria used to determine these effects are: cost; delivery speed and reliability; flexibility; quality; the outsourcing relationship and the management of the outsourcing relationship. The study results reveal that the operational performance of the company remained the same after outsourcing.
- Full Text:
- Date Issued: 2014
- Authors: Dolley-Ryneveld, Mieshkah
- Date: 2014
- Subjects: Contracting out -- South Africa , Industrial management -- South Africa
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:8936 , http://hdl.handle.net/10948/d1021202
- Description: Outsourcing has become a popular trend in the last two decades and has been applied in both non-essential and critical business functions. It has been viewed as a vital source of competitive advantage and is expected to remain an important component in future business strategies. Over the past few years, the outsourcing of logistics functions in particular has shown strong growth. Thus, an abundance of research on the outsourcing of logistics is available. However, there has been little research on the outsourcing of material handling activities as a sub-component of logistics, nor its effect on a company’s operational performance. The purpose of this treatise is to determine the effects of outsourcing a South African automotive company’s material handling activities on its operational performance. It further aims to compare the company’s expected outcomes for outsourcing with actual outcomes. In addition, the factors which contributed positively and negatively to the operation of the outsourced material handling activities at the company, are established. The automotive company in this study is situated in Port Elizabeth, but due to confidentiality reasons the name of the company is not mentioned in the study. The study consists of a literature review on the background of outsourcing, outsourcing theories, outsourcing trends, important outsourcing considerations and gaps in outsourcing research. Primary data, collected through the use of a questionnaire to determine the effects outsourcing has on the company’s operational performance, is collected, reported and analysed in the study. The performance criteria used to determine these effects are: cost; delivery speed and reliability; flexibility; quality; the outsourcing relationship and the management of the outsourcing relationship. The study results reveal that the operational performance of the company remained the same after outsourcing.
- Full Text:
- Date Issued: 2014
The effect of phytocannabinoid treatment on adipogenesis and lipolysis in 3T3-L1 cells
- Authors: Ramlugon, Sonaal
- Date: 2014
- Subjects: Cannabinoids , Adipose tissues , Cannabis -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10361 , http://hdl.handle.net/10948/d1021072
- Description: During the 1800’s cannabis use was described as a treatment for a variety of metabolic disorders but its recreational use in the twentieth century resulted in laws which made the usage of cannabis illegal despite its medicinal properties. Cannabis usage has been reported to be useful in the treatment of Type 2 diabetes but unfortunately conflicting results are often published and its mechanism of action is still unknown. The aim of this project was to investigate the effect of phytocannabinoid treatment on adipogenesis and lipolysis in 3T3-L1 cells, to unravel their mechanism of action and also to test for potential anti-diabetic properties. The studies showed that phytocannabinoid treatment promoted higher glucose uptake and significantly less fat accumulation when compared to Rosiglitazone. Rosiglitazone is an anti-diabetic drug that has recently been withdrawn from the market since its usage has been associated with severe side effects. It was also found that during the 1800’s cannabis use was described as a treatment for a variety of metabolic disorders but its recreational use in the twentieth century resulted in laws which made the usage of cannabis illegal despite its medicinal properties. Cannabis usage has been reported to be useful in the treatment of Type 2 diabetes but unfortunately conflicting results are often published and its mechanism of action is still unknown. The aim of this project was to investigate the effect of phytocannabinoid treatment on adipogenesis and lipolysis in 3T3-L1 cells, to unravel their mechanism of action and also to test for potential anti-diabetic properties. The studies showed that phytocannabinoid treatment promoted higher glucose uptake and significantly less fat accumulation when compared to Rosiglitazone. Rosiglitazone is an anti-diabetic drug that has recently been withdrawn from the market since its usage has been associated with severe side effects. It was also found that phytocannabinoid treatment was able to reverse the insulin-resistant state of 3T3-L1 cells. The study indicates that the mechanism of action occurs at the mitochondrial level where enzymes such as succinate dehydrogenase and glycerol-3-phosphate dehydrogenase are modulated thereby affecting oxidative phosphorylation involved in the respiratory chain. In addition the effect observed with phytocannabinoid treatment is time dependent and affects the cells differently at different developmental stages. Therefore it can be concluded that phytocannabinoid treatment not only helps to maintain the balance between adipogenesis and lipolysis in 3T3-L1 cells but its use may also be helpful in the treatment of Type 2 diabetes and/or obesity-related insulin resistance.phytocannabinoid treatment was able to reverse the insulin-resistant state of 3T3-L1 cells. The study indicates that the mechanism of action occurs at the mitochondrial level where enzymes such as succinate dehydrogenase and glycerol-3-phosphate dehydrogenase are modulated thereby affecting oxidative phosphorylation involved in the respiratory chain. In addition the effect observed with phytocannabinoid treatment is time dependent and affects the cells differently at different developmental stages. Therefore it can be concluded that phytocannabinoid treatment not only helps to maintain the balance between adipogenesis and lipolysis in 3T3-L1 cells but its use may also be helpful in the treatment of Type 2 diabetes and/or obesity-related insulin resistance.
- Full Text:
- Date Issued: 2014
- Authors: Ramlugon, Sonaal
- Date: 2014
- Subjects: Cannabinoids , Adipose tissues , Cannabis -- Therapeutic use
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10361 , http://hdl.handle.net/10948/d1021072
- Description: During the 1800’s cannabis use was described as a treatment for a variety of metabolic disorders but its recreational use in the twentieth century resulted in laws which made the usage of cannabis illegal despite its medicinal properties. Cannabis usage has been reported to be useful in the treatment of Type 2 diabetes but unfortunately conflicting results are often published and its mechanism of action is still unknown. The aim of this project was to investigate the effect of phytocannabinoid treatment on adipogenesis and lipolysis in 3T3-L1 cells, to unravel their mechanism of action and also to test for potential anti-diabetic properties. The studies showed that phytocannabinoid treatment promoted higher glucose uptake and significantly less fat accumulation when compared to Rosiglitazone. Rosiglitazone is an anti-diabetic drug that has recently been withdrawn from the market since its usage has been associated with severe side effects. It was also found that during the 1800’s cannabis use was described as a treatment for a variety of metabolic disorders but its recreational use in the twentieth century resulted in laws which made the usage of cannabis illegal despite its medicinal properties. Cannabis usage has been reported to be useful in the treatment of Type 2 diabetes but unfortunately conflicting results are often published and its mechanism of action is still unknown. The aim of this project was to investigate the effect of phytocannabinoid treatment on adipogenesis and lipolysis in 3T3-L1 cells, to unravel their mechanism of action and also to test for potential anti-diabetic properties. The studies showed that phytocannabinoid treatment promoted higher glucose uptake and significantly less fat accumulation when compared to Rosiglitazone. Rosiglitazone is an anti-diabetic drug that has recently been withdrawn from the market since its usage has been associated with severe side effects. It was also found that phytocannabinoid treatment was able to reverse the insulin-resistant state of 3T3-L1 cells. The study indicates that the mechanism of action occurs at the mitochondrial level where enzymes such as succinate dehydrogenase and glycerol-3-phosphate dehydrogenase are modulated thereby affecting oxidative phosphorylation involved in the respiratory chain. In addition the effect observed with phytocannabinoid treatment is time dependent and affects the cells differently at different developmental stages. Therefore it can be concluded that phytocannabinoid treatment not only helps to maintain the balance between adipogenesis and lipolysis in 3T3-L1 cells but its use may also be helpful in the treatment of Type 2 diabetes and/or obesity-related insulin resistance.phytocannabinoid treatment was able to reverse the insulin-resistant state of 3T3-L1 cells. The study indicates that the mechanism of action occurs at the mitochondrial level where enzymes such as succinate dehydrogenase and glycerol-3-phosphate dehydrogenase are modulated thereby affecting oxidative phosphorylation involved in the respiratory chain. In addition the effect observed with phytocannabinoid treatment is time dependent and affects the cells differently at different developmental stages. Therefore it can be concluded that phytocannabinoid treatment not only helps to maintain the balance between adipogenesis and lipolysis in 3T3-L1 cells but its use may also be helpful in the treatment of Type 2 diabetes and/or obesity-related insulin resistance.
- Full Text:
- Date Issued: 2014
The effect of real exchange rate volatility on export performance: evidence from South Africa (2000-2011)
- Authors: Chamunorwa, Wilson
- Date: 2014
- Subjects: Monetary policy -- South Africa , Economic development -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11499 , http://hdl.handle.net/10353/d1018600 , Monetary policy -- South Africa , Economic development -- South Africa , Foreign exchange rates -- South Africa
- Description: The effect of real exchange rate volatility on export performance: evidence from South Africa (2000-2011) This study sought to investigate the relationship between exchange rate volatility and export performance in South Africa. The main objective of the study was to examine the impact of exchange rate volatility on export performance in South Africa. This relationship was examined using GARCH methods. Exports were regressed against real effective exchange rate, trade openness and capacity utilisation. The research aimed to establish whether exchange rate volatility impacts negatively on export performance in the manner suggested by the econometric model. The result obtained showed that exchange rate volatility had a significantly negative effect on South African exports in the period 2000-2011.
- Full Text:
- Date Issued: 2014
- Authors: Chamunorwa, Wilson
- Date: 2014
- Subjects: Monetary policy -- South Africa , Economic development -- South Africa , Foreign exchange rates -- South Africa
- Language: English
- Type: Thesis , Masters , M Com
- Identifier: vital:11499 , http://hdl.handle.net/10353/d1018600 , Monetary policy -- South Africa , Economic development -- South Africa , Foreign exchange rates -- South Africa
- Description: The effect of real exchange rate volatility on export performance: evidence from South Africa (2000-2011) This study sought to investigate the relationship between exchange rate volatility and export performance in South Africa. The main objective of the study was to examine the impact of exchange rate volatility on export performance in South Africa. This relationship was examined using GARCH methods. Exports were regressed against real effective exchange rate, trade openness and capacity utilisation. The research aimed to establish whether exchange rate volatility impacts negatively on export performance in the manner suggested by the econometric model. The result obtained showed that exchange rate volatility had a significantly negative effect on South African exports in the period 2000-2011.
- Full Text:
- Date Issued: 2014
The effect of sap-sucking by Falconia intermedia (Hemiptera: Miridae) on the emission of volatile organic compounds from the leaves of Lantana camara varieties
- Heshula, Lelethu U P, Hill, Martin P
- Authors: Heshula, Lelethu U P , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406141 , vital:70242 , xlink:href="https://hdl.handle.net/10520/EJC150957"
- Description: Evidence from more than 100 plant species has confirmed that plants emit volatile organic chemicals (VOC) in response to herbivory (Karban and Baldwin 1997; Dicke et al. 2003; Arimura et al. 2005). Feeding-induced plant responses may result in higher levels of volatiles, and different bouquets of compounds being emitted by plants following herbivore damage (Wei et al. 2006). The emission of volatile chemicals may be beneficial to plants in two ways; undamaged plants may interpret the chemical signals from damaged plants and in turn prime themselves for defence (Arimura et al. 2000; Dicke et al. 2003; Agrawal 2005), or volatiles emitted by damaged plants may attract natural enemies of the herbivores, which may reduce further damage to the plants (Tumlinson et al. 1993; De Moraes et al. 1998; Dicke and Vet 1999).
- Full Text:
- Date Issued: 2014
- Authors: Heshula, Lelethu U P , Hill, Martin P
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/406141 , vital:70242 , xlink:href="https://hdl.handle.net/10520/EJC150957"
- Description: Evidence from more than 100 plant species has confirmed that plants emit volatile organic chemicals (VOC) in response to herbivory (Karban and Baldwin 1997; Dicke et al. 2003; Arimura et al. 2005). Feeding-induced plant responses may result in higher levels of volatiles, and different bouquets of compounds being emitted by plants following herbivore damage (Wei et al. 2006). The emission of volatile chemicals may be beneficial to plants in two ways; undamaged plants may interpret the chemical signals from damaged plants and in turn prime themselves for defence (Arimura et al. 2000; Dicke et al. 2003; Agrawal 2005), or volatiles emitted by damaged plants may attract natural enemies of the herbivores, which may reduce further damage to the plants (Tumlinson et al. 1993; De Moraes et al. 1998; Dicke and Vet 1999).
- Full Text:
- Date Issued: 2014
The effect of the youth credit scheme in the Omaheke region of Namibia
- Authors: Karuuombe, Elvisia
- Date: 2014
- Subjects: Youth -- Employment -- Namibia , Youth development -- Namibia , Youth -- Namibia -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/11135 , vital:26888
- Description: The primary purpose of the research project was to explore the impact the Namibian Youth Credit Scheme (NYCS) modelled on the Commonwealth Youth Scheme (CYS) is impacting the programme beneficiaries in the Omaheke Region. Namibia as a whole as well as the research locale has a high percentage of youth unemployment where most of the youth experience chronic poverty with limited opportunities to change their fortunes around. Through a qualitative research strategy, the researcher set out to investigate the level and type of impact the programme has had on the beneficiaries of the programme, as well as to ascertain the challenges and sustainability thereof. The researcher utilized the opportunity provided by one of the post-training workshops by converting it into two focus groups of fifteen participants in each. Two implementing agents (IAs) were individually interviewed to gain some insight from employees into the inner working and outlook of the workers in the NYCS programme. Lastly, ten beneficiaries were interviewed as a form of internal triangulation in sourcing credible data. The research found the programme has made a tremendous difference economically in the lives and families of beneficiaries. The programme not only improved their livelihood but it also contributed educationally to their knowledge base and skills formation. Psychologically the programme improved their social outlook generally and their political stance specifically, the latter as it pertains to the NYCS programme in particular. The study concluded by making several recommendations on how the programme could improve. These recommendations are not definitive; they are suggestive. In order for the recommendations to be conclusive, several other factors in terms of the research process would have to be considered. Even so, within its research dimension the research proved the programme to be highly effective.
- Full Text:
- Date Issued: 2014
- Authors: Karuuombe, Elvisia
- Date: 2014
- Subjects: Youth -- Employment -- Namibia , Youth development -- Namibia , Youth -- Namibia -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10948/11135 , vital:26888
- Description: The primary purpose of the research project was to explore the impact the Namibian Youth Credit Scheme (NYCS) modelled on the Commonwealth Youth Scheme (CYS) is impacting the programme beneficiaries in the Omaheke Region. Namibia as a whole as well as the research locale has a high percentage of youth unemployment where most of the youth experience chronic poverty with limited opportunities to change their fortunes around. Through a qualitative research strategy, the researcher set out to investigate the level and type of impact the programme has had on the beneficiaries of the programme, as well as to ascertain the challenges and sustainability thereof. The researcher utilized the opportunity provided by one of the post-training workshops by converting it into two focus groups of fifteen participants in each. Two implementing agents (IAs) were individually interviewed to gain some insight from employees into the inner working and outlook of the workers in the NYCS programme. Lastly, ten beneficiaries were interviewed as a form of internal triangulation in sourcing credible data. The research found the programme has made a tremendous difference economically in the lives and families of beneficiaries. The programme not only improved their livelihood but it also contributed educationally to their knowledge base and skills formation. Psychologically the programme improved their social outlook generally and their political stance specifically, the latter as it pertains to the NYCS programme in particular. The study concluded by making several recommendations on how the programme could improve. These recommendations are not definitive; they are suggestive. In order for the recommendations to be conclusive, several other factors in terms of the research process would have to be considered. Even so, within its research dimension the research proved the programme to be highly effective.
- Full Text:
- Date Issued: 2014
The effectiveness of centralised human resource management on service delivery: a case of Bedford Hospital, Department of Health, Province of the Eastern Cape
- Authors: Ncebakazi, Frances Qalase
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11683 , http://hdl.handle.net/10353/d1013557
- Description: The Eastern Cape Department of Health centralised Human Resource functions from the facilities to the provincial office. This according to the provincial office was to address the over expenditure on Compensation of employees that was highlighted by the Auditor General report of 2008/2009. The researcher was of the opinion that various issues of concern were over looked by the provincial office before or during the implementation of the centralisation of HRM. The primary objective of this study was to examine the effectiveness of the centralisation of HRM on service delivery in the ECDoH and Bedford hospital. The secondary objective was to find out what centralisation is and its implications. Lastly, to develop recommendations which address the outcomes of the study. Purposive sampling was used to identify key informants from Bedford hospital and the provincial office. Interview questions were used to collect data from both respondents. The study examined both responses and grouped them into themes. The findings did not imply that centralisation does not improve service delivery but have indicated a lack of service delivery focus on the part of the provincial office. The Eastern Cape Department of Health centralised Human Resource functions from the facilities to the provincial office. This according to the provincial office was to address the over expenditure on Compensation of employees that was highlighted by the Auditor General report of 2008/2009. The researcher was of the opinion that various issues of concern were over looked by the provincial office before or during the implementation of the centralisation of HRM. The primary objective of this study was to examine the effectiveness of the centralisation of HRM on service delivery in the ECDoH and Bedford hospital. The secondary objective was to find out what centralisation is and its implications. Lastly, to develop recommendations which address the outcomes of the study. Purposive sampling was used to identify key informants from Bedford hospital and the provincial office. Interview questions were used to collect data from both respondents. The study examined both responses and grouped them into themes. The findings did not imply that centralisation does not improve service delivery but have indicated a lack of service delivery focus on the part of the provincial office. The research has also revealed that amongst the challenges identified, there were those that were key challenges. The researcher was of the opinion that addressing those key generic challenges would minimise all other challenges and improve service delivery. Lack of communication on organisation strategies and lack of Monitoring and Evaluation systems were identified as key challenges that cut across the entire ECDoH. The study has recommended that the provincial office should improve on communication strategies with the facilities whenever decisions are taken. Secondly, to develop M&E systems in order to ensure that performance standards are monitored and evaluated. This according to the researcher would improve service delivery in the ECDoH and Bedford hospital.that were key challenges. The researcher was of the opinion that addressing those key generic challenges would minimise all other challenges and improve service delivery. Lack of communication on organisation strategies and lack of Monitoring and Evaluation systems were identified as key challenges that cut across the entire ECDoH. The study has recommended that the provincial office should improve on communication strategies with the facilities whenever decisions are taken. Secondly, to develop M&E systems in order to ensure that performance standards are monitored and evaluated. This according to the researcher would improve service delivery in the ECDoH and Bedford hospital.
- Full Text:
- Date Issued: 2014
- Authors: Ncebakazi, Frances Qalase
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: vital:11683 , http://hdl.handle.net/10353/d1013557
- Description: The Eastern Cape Department of Health centralised Human Resource functions from the facilities to the provincial office. This according to the provincial office was to address the over expenditure on Compensation of employees that was highlighted by the Auditor General report of 2008/2009. The researcher was of the opinion that various issues of concern were over looked by the provincial office before or during the implementation of the centralisation of HRM. The primary objective of this study was to examine the effectiveness of the centralisation of HRM on service delivery in the ECDoH and Bedford hospital. The secondary objective was to find out what centralisation is and its implications. Lastly, to develop recommendations which address the outcomes of the study. Purposive sampling was used to identify key informants from Bedford hospital and the provincial office. Interview questions were used to collect data from both respondents. The study examined both responses and grouped them into themes. The findings did not imply that centralisation does not improve service delivery but have indicated a lack of service delivery focus on the part of the provincial office. The Eastern Cape Department of Health centralised Human Resource functions from the facilities to the provincial office. This according to the provincial office was to address the over expenditure on Compensation of employees that was highlighted by the Auditor General report of 2008/2009. The researcher was of the opinion that various issues of concern were over looked by the provincial office before or during the implementation of the centralisation of HRM. The primary objective of this study was to examine the effectiveness of the centralisation of HRM on service delivery in the ECDoH and Bedford hospital. The secondary objective was to find out what centralisation is and its implications. Lastly, to develop recommendations which address the outcomes of the study. Purposive sampling was used to identify key informants from Bedford hospital and the provincial office. Interview questions were used to collect data from both respondents. The study examined both responses and grouped them into themes. The findings did not imply that centralisation does not improve service delivery but have indicated a lack of service delivery focus on the part of the provincial office. The research has also revealed that amongst the challenges identified, there were those that were key challenges. The researcher was of the opinion that addressing those key generic challenges would minimise all other challenges and improve service delivery. Lack of communication on organisation strategies and lack of Monitoring and Evaluation systems were identified as key challenges that cut across the entire ECDoH. The study has recommended that the provincial office should improve on communication strategies with the facilities whenever decisions are taken. Secondly, to develop M&E systems in order to ensure that performance standards are monitored and evaluated. This according to the researcher would improve service delivery in the ECDoH and Bedford hospital.that were key challenges. The researcher was of the opinion that addressing those key generic challenges would minimise all other challenges and improve service delivery. Lack of communication on organisation strategies and lack of Monitoring and Evaluation systems were identified as key challenges that cut across the entire ECDoH. The study has recommended that the provincial office should improve on communication strategies with the facilities whenever decisions are taken. Secondly, to develop M&E systems in order to ensure that performance standards are monitored and evaluated. This according to the researcher would improve service delivery in the ECDoH and Bedford hospital.
- Full Text:
- Date Issued: 2014
The effectiveness of tender practises in municipal supply chain management: an exploration of two municipalities in Amathole District Municpality in the Eastern Cape province (2009-2012)
- Authors: Ngqase, S A
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/1119 , vital:26527
- Description: The tendering process is central to acquisition of public services and goods in all over South Africa. Municipalities and government institutions just like any private institution need to buy products and services in order to perform their functions effectively. But the procurement function has not been an easy one for the government with the tender process being slow and not transparent which can lead to a process of selling invoices taking up to three months, potentially destroying small businesses. The primary objective of the study therefore, is to find the causes of nepotisms, bribery, and corruption in tender practices in the two selected municipalities of the Amathole District and the factors that lead to delayed payments in the tender practices and further makes recommendations on how to eliminate such factors. The study used a mixed method approach research methodology which is a combination of qualitative and quantitative methods and included the two municipalities from the Amathole District Municipality, the Buffalo City Metropolitan Municipality and Nkonkobe Municipality, and used questionnaires and an interview to collect a data.
- Full Text: false
- Date Issued: 2014
- Authors: Ngqase, S A
- Date: 2014
- Language: English
- Type: Thesis , Masters , MPA
- Identifier: http://hdl.handle.net/10353/1119 , vital:26527
- Description: The tendering process is central to acquisition of public services and goods in all over South Africa. Municipalities and government institutions just like any private institution need to buy products and services in order to perform their functions effectively. But the procurement function has not been an easy one for the government with the tender process being slow and not transparent which can lead to a process of selling invoices taking up to three months, potentially destroying small businesses. The primary objective of the study therefore, is to find the causes of nepotisms, bribery, and corruption in tender practices in the two selected municipalities of the Amathole District and the factors that lead to delayed payments in the tender practices and further makes recommendations on how to eliminate such factors. The study used a mixed method approach research methodology which is a combination of qualitative and quantitative methods and included the two municipalities from the Amathole District Municipality, the Buffalo City Metropolitan Municipality and Nkonkobe Municipality, and used questionnaires and an interview to collect a data.
- Full Text: false
- Date Issued: 2014
The effects of age on the worker capacity and mechanisation on the task demands in a South African manufacturing industry
- Bezuidenhout, Samantha Catherine
- Authors: Bezuidenhout, Samantha Catherine
- Date: 2014
- Subjects: Age and employment -- South Africa , Labor -- Social aspects -- South Africa , Brickmaking -- South Africa -- Automation , Brickmaking -- Social aspects -- South Africa , Brick trade -- South Africa , Aging -- Social aspects -- South Africa , Aging -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5151 , http://hdl.handle.net/10962/d1013167
- Description: The focus of the study was two-fold, firstly to determine the effect of age on the capacity of manual materials handling workers and secondly to determine the effect of increasing task mechanisation on the workers’ responses to task demands. The first component of this study, namely Part I, 101 male and 12 female ‘unskilled’ manual workers – of various ages – from a brick manufacturing industry were assessed. Anthropometric, health and strength factors were measured to improve the understanding of the South African manual worker capacity and more specifically, the effect of age on this capacity. Data collection was done between 7.30am and 9.30am in a laboratory-type setting on-site. Anthropometric characteristics (including body mass index, waist to hip ratio, waist circumference and body fat percentage) provided information on the state of obesity and the impact of age in the South African context. Linked to this, the health factors (including blood pressure, resting heart rate and a self-reported questionnaire) provide an extra snapshot of the disease profile in South Africa, and could potentially influence other capacity factors. Isometric strength capacities (of eight different areas, namely: back, leg, bicep, shoulder, pinch, pinch and pull) demonstrated whether South African manual workers show the same decline in strength with aging as seen in industrially advanced countries. The second component of the study, Part II, was performed in situ and measured the workers’ responses to task demands of three brick palletising tasks, one manual (n=21) and two with increasing mechanisation (n=12 each). Spinal kinematics, joint forces and working heart rate were assessed on normal work days during a 30-lift duration and body discomfort measures were taken at the start, middle and end of the work-shift. Spinal kinematics were measured dynamically using a lumbar motion monitor, whereas the spinal forces were estimated using the three dimensional static strength prediction program. The worker capacity results showed that waist to hip ratio, waist circumference and body fat percentage increased significantly with aging, whereas body mass index was not affected by age. All body morphology values were within ‘normal’ ranges. Although diastolic blood pressure increased significantly with age, systolic was not affected significantly by age. Both groups, however, showed an increasing prevalence of hypertension with aging. There were no significant changes in resting heart rate with aging, with a range of 66 bt.min⁻¹ to 74.86 bt.min⁻¹, therefore within normal ranges. Of the strength factors, age only affected shoulder and push strength significantly: Showing a decrease in shoulder strength from 49.89 kgF to 39.91 kgF in the men aged 20-29 to the 50-59 respectively and an increase in push strength from men aged 30-39 and 40-49 to those aged 50-59. Part II results revealed highly frequent lift rates and large degrees of sagittal flexion and lateral bending in all three tasks. These postures adopted for long durations are likely to lead to the development of musculoskeletal disorders. Heart rates of workers from the three tasks were significantly different and heart rates for two tasks were above the recommended 110 bt.min⁻¹. Similarly the body discomfort ratings of the three tasks differed, although a common trend was seen in that lower back pain was the most commonly reported area of discomfort in all tasks. South African manual materials handling males did not show the same responses to aging as men from industrially advanced countries, calling for further research into these differences. Due to the high risks of the three tasks assessed, future research and interventions are required to reduce the risk of injury in the assessed tasks.
- Full Text:
- Date Issued: 2014
- Authors: Bezuidenhout, Samantha Catherine
- Date: 2014
- Subjects: Age and employment -- South Africa , Labor -- Social aspects -- South Africa , Brickmaking -- South Africa -- Automation , Brickmaking -- Social aspects -- South Africa , Brick trade -- South Africa , Aging -- Social aspects -- South Africa , Aging -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5151 , http://hdl.handle.net/10962/d1013167
- Description: The focus of the study was two-fold, firstly to determine the effect of age on the capacity of manual materials handling workers and secondly to determine the effect of increasing task mechanisation on the workers’ responses to task demands. The first component of this study, namely Part I, 101 male and 12 female ‘unskilled’ manual workers – of various ages – from a brick manufacturing industry were assessed. Anthropometric, health and strength factors were measured to improve the understanding of the South African manual worker capacity and more specifically, the effect of age on this capacity. Data collection was done between 7.30am and 9.30am in a laboratory-type setting on-site. Anthropometric characteristics (including body mass index, waist to hip ratio, waist circumference and body fat percentage) provided information on the state of obesity and the impact of age in the South African context. Linked to this, the health factors (including blood pressure, resting heart rate and a self-reported questionnaire) provide an extra snapshot of the disease profile in South Africa, and could potentially influence other capacity factors. Isometric strength capacities (of eight different areas, namely: back, leg, bicep, shoulder, pinch, pinch and pull) demonstrated whether South African manual workers show the same decline in strength with aging as seen in industrially advanced countries. The second component of the study, Part II, was performed in situ and measured the workers’ responses to task demands of three brick palletising tasks, one manual (n=21) and two with increasing mechanisation (n=12 each). Spinal kinematics, joint forces and working heart rate were assessed on normal work days during a 30-lift duration and body discomfort measures were taken at the start, middle and end of the work-shift. Spinal kinematics were measured dynamically using a lumbar motion monitor, whereas the spinal forces were estimated using the three dimensional static strength prediction program. The worker capacity results showed that waist to hip ratio, waist circumference and body fat percentage increased significantly with aging, whereas body mass index was not affected by age. All body morphology values were within ‘normal’ ranges. Although diastolic blood pressure increased significantly with age, systolic was not affected significantly by age. Both groups, however, showed an increasing prevalence of hypertension with aging. There were no significant changes in resting heart rate with aging, with a range of 66 bt.min⁻¹ to 74.86 bt.min⁻¹, therefore within normal ranges. Of the strength factors, age only affected shoulder and push strength significantly: Showing a decrease in shoulder strength from 49.89 kgF to 39.91 kgF in the men aged 20-29 to the 50-59 respectively and an increase in push strength from men aged 30-39 and 40-49 to those aged 50-59. Part II results revealed highly frequent lift rates and large degrees of sagittal flexion and lateral bending in all three tasks. These postures adopted for long durations are likely to lead to the development of musculoskeletal disorders. Heart rates of workers from the three tasks were significantly different and heart rates for two tasks were above the recommended 110 bt.min⁻¹. Similarly the body discomfort ratings of the three tasks differed, although a common trend was seen in that lower back pain was the most commonly reported area of discomfort in all tasks. South African manual materials handling males did not show the same responses to aging as men from industrially advanced countries, calling for further research into these differences. Due to the high risks of the three tasks assessed, future research and interventions are required to reduce the risk of injury in the assessed tasks.
- Full Text:
- Date Issued: 2014
The effects of extracellular and intracellular Hop on cell migration processes
- Authors: Contu, Lara
- Date: 2014
- Subjects: Heat shock proteins , Metastasis , Cancer Chemotherapy , Molecular chaperones , Cell migration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193961 , vital:45410
- Description: The Hsp70/Hsp90-organising protein (Hop) is a 60 kDa co-chaperone that acts as an adaptor molecule, facilitating the transfer of client proteins between the Hsp70 and Hsp90 chaperone systems. Hop functions both intracellularly and extracellularly and has been implicated in many processes involved in cancer progression, including cell migration and invasion. Little is known about the mechanisms or domains by which extracellular Hop functions. In addition, little is known about the effects of Hop on signalling molecules involved in cell migration and invasion through regulation of actin dynamics. It was hypothesised that both extracellular and intracellular pools of Hop would regulate distinct cell migration processes by activation of cell signalling pathways or direct interactions with signalling intermediates. HS578T cells were treated with recombinant full length and truncated murine Hop proteins (overexpressed and purified in this study) to determine the effects of extracellular Hop and the independent domains on cell migration processes. Additionally, RNA interference (RNAi) techniques were used to determine the effect of Hop knockdown on cell migration related signalling intermediates and cell morphologies. A short hairpin RNA (shRNA) system for the stable knockdown of Hop was developed and used for a number of these studies. Treatment of HS578T cells with the TPR2A2B and TPR1 domains of Hop resulted in a significant decrease in cell migration and caused changes in the actin cytoskeleton and extracellular matrix proteins, gelatin and fibronectin. RhoC immunoprecipitated in a common complex with Hop and Hsp90. Hop knockdown reduced levels of actin and total RhoC, as well as active RhoC. In addition, knockdown of Hop resulted in a reduced migratory phenotype. We interpreted these data to indicate that intracellular Hop played a role in cell migration through regulation of RhoC activity, either through a direct interaction between Hop and RhoC, or an indirect interaction of RhoC with the Hsp90 multichaperone heterocomplex. Taken together, the data suggested that extracellular and intracellular Hop played distinct roles in extracellular and intracellular processes that lead to actin dynamics and cell migration. Understanding the mechanistic role of Hop in these processes is essential as it would aid in assessing the viability of Hop as a potential drug target for the treatment of metastatic cancers. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 2014
- Full Text:
- Date Issued: 2014
- Authors: Contu, Lara
- Date: 2014
- Subjects: Heat shock proteins , Metastasis , Cancer Chemotherapy , Molecular chaperones , Cell migration
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/193961 , vital:45410
- Description: The Hsp70/Hsp90-organising protein (Hop) is a 60 kDa co-chaperone that acts as an adaptor molecule, facilitating the transfer of client proteins between the Hsp70 and Hsp90 chaperone systems. Hop functions both intracellularly and extracellularly and has been implicated in many processes involved in cancer progression, including cell migration and invasion. Little is known about the mechanisms or domains by which extracellular Hop functions. In addition, little is known about the effects of Hop on signalling molecules involved in cell migration and invasion through regulation of actin dynamics. It was hypothesised that both extracellular and intracellular pools of Hop would regulate distinct cell migration processes by activation of cell signalling pathways or direct interactions with signalling intermediates. HS578T cells were treated with recombinant full length and truncated murine Hop proteins (overexpressed and purified in this study) to determine the effects of extracellular Hop and the independent domains on cell migration processes. Additionally, RNA interference (RNAi) techniques were used to determine the effect of Hop knockdown on cell migration related signalling intermediates and cell morphologies. A short hairpin RNA (shRNA) system for the stable knockdown of Hop was developed and used for a number of these studies. Treatment of HS578T cells with the TPR2A2B and TPR1 domains of Hop resulted in a significant decrease in cell migration and caused changes in the actin cytoskeleton and extracellular matrix proteins, gelatin and fibronectin. RhoC immunoprecipitated in a common complex with Hop and Hsp90. Hop knockdown reduced levels of actin and total RhoC, as well as active RhoC. In addition, knockdown of Hop resulted in a reduced migratory phenotype. We interpreted these data to indicate that intracellular Hop played a role in cell migration through regulation of RhoC activity, either through a direct interaction between Hop and RhoC, or an indirect interaction of RhoC with the Hsp90 multichaperone heterocomplex. Taken together, the data suggested that extracellular and intracellular Hop played distinct roles in extracellular and intracellular processes that lead to actin dynamics and cell migration. Understanding the mechanistic role of Hop in these processes is essential as it would aid in assessing the viability of Hop as a potential drug target for the treatment of metastatic cancers. , Thesis (MSc) -- Faculty of Science, Biochemistry, Microbiology and Biotechnology, 2014
- Full Text:
- Date Issued: 2014