Synthesis and evaluation of novel inhibitors of 1-Deoxy-D-xylolose-5-phosphate reductoisomerase as potential antimalarials
- Authors: Conibear, Anne Claire
- Date: 2013-07-19
- Subjects: Antimalarials -- Development , Malaria -- Chemotherapy , Drug development , Enzyme kinetics , Phosphate esters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4451 , http://hdl.handle.net/10962/d1008282 , Antimalarials -- Development , Malaria -- Chemotherapy , Drug development , Enzyme kinetics , Phosphate esters
- Description: Malaria continues to be an enormous health-threat in the developing world and the emergence of drug resistance has further compounded the problem. The parasite-specific enzyme, 1-deoxY-D-xylulose-S-phosphate reductoisomerase (DXR), has recently been validated as a promising antimalarial drug target. The present study comprises a combination of synthetic, physical organic, computer modelling and bioassay techniques directed towards the development of novel DXR inhibitors. A range of 2-heteroarylamino-2-oxoethyl- and 2- heteroarylamino-2-oxopropyl phosphonate esters and their corresponding phosphonic acid salts have been synthesised as analogues of the highly active DXR inhibitor, fosmidomycin. Treatment of the heteroarylamino precursors with chloroacetyl chloride or chloropropionyl chloride afforded chloroamide intermediates, Arbuzov reactions of which led to the corresponding diethyl phosphonate esters. Hydrolysis of the esters has been effected using bromotrimethylsilane. Twenty-four new compounds have been prepared and fully characterised using elemental (HRMS or combustion) and spectroscopic (1- and 2-D NMR and IR) analysis. A 31p NMR kinetic study has been carried out on the two-step silylation reaction involved in the hydrolysis of the phosphonate esters and has provided activation parameters for the reaction. The kinetic analysis was refined using a computational method to give an improved fit with the experimental data. Saturation transfer difference (STD) NMR analysis, computer-simulated docking and enzyme inhibition assays have been used to evaluate the enzyme-binding and -inhibition potential of the synthesised ligands. Minimal to moderate inhibitory activity has been observed and several structure-activity relationships have been identified. In silica exploration of the DXR active site has revealed an additional binding pocket and information on the topology of the active site has led to the de novo design of a new series of potential ligands. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Conibear, Anne Claire
- Date: 2013-07-19
- Subjects: Antimalarials -- Development , Malaria -- Chemotherapy , Drug development , Enzyme kinetics , Phosphate esters
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4451 , http://hdl.handle.net/10962/d1008282 , Antimalarials -- Development , Malaria -- Chemotherapy , Drug development , Enzyme kinetics , Phosphate esters
- Description: Malaria continues to be an enormous health-threat in the developing world and the emergence of drug resistance has further compounded the problem. The parasite-specific enzyme, 1-deoxY-D-xylulose-S-phosphate reductoisomerase (DXR), has recently been validated as a promising antimalarial drug target. The present study comprises a combination of synthetic, physical organic, computer modelling and bioassay techniques directed towards the development of novel DXR inhibitors. A range of 2-heteroarylamino-2-oxoethyl- and 2- heteroarylamino-2-oxopropyl phosphonate esters and their corresponding phosphonic acid salts have been synthesised as analogues of the highly active DXR inhibitor, fosmidomycin. Treatment of the heteroarylamino precursors with chloroacetyl chloride or chloropropionyl chloride afforded chloroamide intermediates, Arbuzov reactions of which led to the corresponding diethyl phosphonate esters. Hydrolysis of the esters has been effected using bromotrimethylsilane. Twenty-four new compounds have been prepared and fully characterised using elemental (HRMS or combustion) and spectroscopic (1- and 2-D NMR and IR) analysis. A 31p NMR kinetic study has been carried out on the two-step silylation reaction involved in the hydrolysis of the phosphonate esters and has provided activation parameters for the reaction. The kinetic analysis was refined using a computational method to give an improved fit with the experimental data. Saturation transfer difference (STD) NMR analysis, computer-simulated docking and enzyme inhibition assays have been used to evaluate the enzyme-binding and -inhibition potential of the synthesised ligands. Minimal to moderate inhibitory activity has been observed and several structure-activity relationships have been identified. In silica exploration of the DXR active site has revealed an additional binding pocket and information on the topology of the active site has led to the de novo design of a new series of potential ligands. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
A study of a class of invariant optimal control problems on the Euclidean group SE(2)
- Authors: Adams, Ross Montague
- Date: 2011
- Subjects: Matrix groups Lie groups Extremal problems (Mathematics) Maximum principles (Mathematics) Hamilton-Jacobi equations Lyapunov stability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5420 , http://hdl.handle.net/10962/d1006060
- Description: The aim of this thesis is to study a class of left-invariant optimal control problems on the matrix Lie group SE(2). We classify, under detached feedback equivalence, all controllable (left-invariant) control affine systems on SE(2). This result produces six types of control affine systems on SE(2). Hence, we study six associated left-invariant optimal control problems on SE(2). A left-invariant optimal control problem consists of minimizing a cost functional over the trajectory-control pairs of a left-invariant control system subject to appropriate boundary conditions. Each control problem is lifted from SE(2) to T*SE(2) ≅ SE(2) x se (2)*and then reduced to a problem on se (2)*. The maximum principle is used to obtain the optimal control and Hamiltonian corresponding to the normal extremals. Then we derive the (reduced) extremal equations on se (2)*. These equations are explicitly integrated by trigonometric and Jacobi elliptic functions. Finally, we fully classify, under Lyapunov stability, the equilibrium states of the normal extremal equations for each of the six types under consideration.
- Full Text:
- Date Issued: 2011
- Authors: Adams, Ross Montague
- Date: 2011
- Subjects: Matrix groups Lie groups Extremal problems (Mathematics) Maximum principles (Mathematics) Hamilton-Jacobi equations Lyapunov stability
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5420 , http://hdl.handle.net/10962/d1006060
- Description: The aim of this thesis is to study a class of left-invariant optimal control problems on the matrix Lie group SE(2). We classify, under detached feedback equivalence, all controllable (left-invariant) control affine systems on SE(2). This result produces six types of control affine systems on SE(2). Hence, we study six associated left-invariant optimal control problems on SE(2). A left-invariant optimal control problem consists of minimizing a cost functional over the trajectory-control pairs of a left-invariant control system subject to appropriate boundary conditions. Each control problem is lifted from SE(2) to T*SE(2) ≅ SE(2) x se (2)*and then reduced to a problem on se (2)*. The maximum principle is used to obtain the optimal control and Hamiltonian corresponding to the normal extremals. Then we derive the (reduced) extremal equations on se (2)*. These equations are explicitly integrated by trigonometric and Jacobi elliptic functions. Finally, we fully classify, under Lyapunov stability, the equilibrium states of the normal extremal equations for each of the six types under consideration.
- Full Text:
- Date Issued: 2011
Universal approximation properties of feedforward artificial neural networks.
- Authors: Redpath, Stuart Frederick
- Date: 2011
- Subjects: Neural networks (Computer science) , Artificial intelligence -- Biological applications , Functional analysis , Weierstrass-Stone Theorem , Banach-Hahn theorem
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5430 , http://hdl.handle.net/10962/d1015869
- Description: In this thesis we summarise several results in the literature which show the approximation capabilities of multilayer feedforward artificial neural networks. We show that multilayer feedforward artificial neural networks are capable of approximating continuous and measurable functions from Rn to R to any degree of accuracy under certain conditions. In particular making use of the Stone-Weierstrass and Hahn-Banach theorems, we show that a multilayer feedforward artificial neural network can approximate any continuous function to any degree of accuracy, by using either an arbitrary squashing function or any continuous sigmoidal function for activation. Making use of the Stone-Weirstrass Theorem again, we extend these approximation capabilities of multilayer feedforward artificial neural networks to the space of measurable functions under any probability measure.
- Full Text:
- Date Issued: 2011
- Authors: Redpath, Stuart Frederick
- Date: 2011
- Subjects: Neural networks (Computer science) , Artificial intelligence -- Biological applications , Functional analysis , Weierstrass-Stone Theorem , Banach-Hahn theorem
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5430 , http://hdl.handle.net/10962/d1015869
- Description: In this thesis we summarise several results in the literature which show the approximation capabilities of multilayer feedforward artificial neural networks. We show that multilayer feedforward artificial neural networks are capable of approximating continuous and measurable functions from Rn to R to any degree of accuracy under certain conditions. In particular making use of the Stone-Weierstrass and Hahn-Banach theorems, we show that a multilayer feedforward artificial neural network can approximate any continuous function to any degree of accuracy, by using either an arbitrary squashing function or any continuous sigmoidal function for activation. Making use of the Stone-Weirstrass Theorem again, we extend these approximation capabilities of multilayer feedforward artificial neural networks to the space of measurable functions under any probability measure.
- Full Text:
- Date Issued: 2011
An investigation of Grade 11 learners' mathematical preparedness in a selected Namibian school: a case study
- Mwandingi, Albertina Ndahambelela
- Authors: Mwandingi, Albertina Ndahambelela
- Date: 2011
- Subjects: Mathematics -- Study and teaching (Secondary) -- Namibia Education, Secondary -- Namibia Mathematical readiness
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1627 , http://hdl.handle.net/10962/d1003509
- Description: The proliferation in the number of schools offering junior secondary education in Namibia since independence in 1990 has led to an increase in the number of learners in the classroom and has created a wide range of mathematical proficiency among learners entering senior secondary education in grade 11. This broad range of basic mathematical ability among these learners, together with increasing classroom numbers has caused problems for the senior secondary mathematics teachers (Batchelor, 2004). The study shows that diagnostic testing can prove to be useful in assessing learners’ mathematical preparedness by identifying learners’ areas of weakness, which have hindered their mathematics learning and performance. Taking the results of a diagnostic test into consideration could help teachers cater for their learners who need remediation classes as early as possible before extending the mathematics curriculum. Setting and using diagnostic testing requires careful consideration; there are many pitfalls that are highlighted in this research. These include question coverage and general analysis of category totals.
- Full Text:
- Date Issued: 2011
- Authors: Mwandingi, Albertina Ndahambelela
- Date: 2011
- Subjects: Mathematics -- Study and teaching (Secondary) -- Namibia Education, Secondary -- Namibia Mathematical readiness
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1627 , http://hdl.handle.net/10962/d1003509
- Description: The proliferation in the number of schools offering junior secondary education in Namibia since independence in 1990 has led to an increase in the number of learners in the classroom and has created a wide range of mathematical proficiency among learners entering senior secondary education in grade 11. This broad range of basic mathematical ability among these learners, together with increasing classroom numbers has caused problems for the senior secondary mathematics teachers (Batchelor, 2004). The study shows that diagnostic testing can prove to be useful in assessing learners’ mathematical preparedness by identifying learners’ areas of weakness, which have hindered their mathematics learning and performance. Taking the results of a diagnostic test into consideration could help teachers cater for their learners who need remediation classes as early as possible before extending the mathematics curriculum. Setting and using diagnostic testing requires careful consideration; there are many pitfalls that are highlighted in this research. These include question coverage and general analysis of category totals.
- Full Text:
- Date Issued: 2011
Lumberjacks and hoodrats: negotiating subject positions of lesbian representation in two South African television programmes
- Authors: Donaldson, Natalie
- Date: 2011
- Subjects: Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2964 , http://hdl.handle.net/10962/d1002473 , Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Description: With the inclusion of sexual orientation in the Equality clause of the post-Apartheid constitution which demands equal rights and protection for all individuals regardless of sexual orientation, South Africa has been praised as one of the most liberal countries in the world. Because of this legal equality, gay and lesbian experiences have become a lot more visible in every day South African lives. This includes visibility in South African television programmes and film. Today, a number of South African produced television programmes have included at least one lesbian character in their storyline and many LGBTIQ activist organisations have deemed this increased visibility as a positive step for LGBTIQ rights. However, discriminatory discourses such as same-sex sexualities as 'un-African ' and unnatural, which often result in brutal hate crimes against LGBTIQ individuals (such as corrective rape), contribute to the social and cultural intolerance of same-sex sexualities. South African research into the lives of lesbian women has often related lesbian experience to that of gay men or has focused on lesbian women as victims of corrective rape and oppressive practices at the hands of the dominant heteronormative culture. This research was a discursive reception study, using three focus group discussions with self-identified lesbian audiences (black and white). The study explored how this audience received (interpreted/talked about) the available fictional representations of 'black' lesbian women and 'white' lesbian women in three clips from two South African television programmes, Society and The Mating Game. Using Wetherell's (1998) critical discursive psychology approach, this research focused on examining the 1) Subject positions made available in/by these representations; 2) Interpretive repertoires used by the audience in appropriating and/or negotiating and/or reSisting these subject positions; and 3) Ideological dilemmas experienced by participants in this negotiation process. The predominant subject positions made available in these representations were differentiated according to binary racial categories of white lesbian women and black lesbian women. For example, participants positioned white lesbian women as "lumberjacks" and "tomboys" while black lesbian women were positioned as "township lesbians" and "hood rats". In working with these subject positions, participants drew on interpretative repertoires of othering and otherness as well as interpretative repertoires of survival. In negotiating with these subject positions and others found in the discussions, ideological dilemmas often arose when participants found themselves having to draw on interpretative repertoires which extend from a heteronormative discourse. These kinds of interpretative repertoires included religion, nature, and compromise which contradicted and created a troubled position when used in relation to the participants' lesbian sexualities. Therefore, when the ideological dilemma and troubled position became apparent, participants had to work to repair the troubled position by justifying their use of these heteronormative interpretative repertoires.
- Full Text:
- Date Issued: 2011
- Authors: Donaldson, Natalie
- Date: 2011
- Subjects: Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:2964 , http://hdl.handle.net/10962/d1002473 , Lesbianism on television -- Research -- South Africa , Lesbians -- Research -- South Africa , Gay rights -- Research -- South Africa , Television actors and actresses -- Research -- South Africa
- Description: With the inclusion of sexual orientation in the Equality clause of the post-Apartheid constitution which demands equal rights and protection for all individuals regardless of sexual orientation, South Africa has been praised as one of the most liberal countries in the world. Because of this legal equality, gay and lesbian experiences have become a lot more visible in every day South African lives. This includes visibility in South African television programmes and film. Today, a number of South African produced television programmes have included at least one lesbian character in their storyline and many LGBTIQ activist organisations have deemed this increased visibility as a positive step for LGBTIQ rights. However, discriminatory discourses such as same-sex sexualities as 'un-African ' and unnatural, which often result in brutal hate crimes against LGBTIQ individuals (such as corrective rape), contribute to the social and cultural intolerance of same-sex sexualities. South African research into the lives of lesbian women has often related lesbian experience to that of gay men or has focused on lesbian women as victims of corrective rape and oppressive practices at the hands of the dominant heteronormative culture. This research was a discursive reception study, using three focus group discussions with self-identified lesbian audiences (black and white). The study explored how this audience received (interpreted/talked about) the available fictional representations of 'black' lesbian women and 'white' lesbian women in three clips from two South African television programmes, Society and The Mating Game. Using Wetherell's (1998) critical discursive psychology approach, this research focused on examining the 1) Subject positions made available in/by these representations; 2) Interpretive repertoires used by the audience in appropriating and/or negotiating and/or reSisting these subject positions; and 3) Ideological dilemmas experienced by participants in this negotiation process. The predominant subject positions made available in these representations were differentiated according to binary racial categories of white lesbian women and black lesbian women. For example, participants positioned white lesbian women as "lumberjacks" and "tomboys" while black lesbian women were positioned as "township lesbians" and "hood rats". In working with these subject positions, participants drew on interpretative repertoires of othering and otherness as well as interpretative repertoires of survival. In negotiating with these subject positions and others found in the discussions, ideological dilemmas often arose when participants found themselves having to draw on interpretative repertoires which extend from a heteronormative discourse. These kinds of interpretative repertoires included religion, nature, and compromise which contradicted and created a troubled position when used in relation to the participants' lesbian sexualities. Therefore, when the ideological dilemma and troubled position became apparent, participants had to work to repair the troubled position by justifying their use of these heteronormative interpretative repertoires.
- Full Text:
- Date Issued: 2011
An evaluation of the marketing and distribution channels of the Mzuzu Coffee Planters Cooperative Union (MZCPCU)
- Jussa, Leman Abdulrazak Wyson
- Authors: Jussa, Leman Abdulrazak Wyson
- Date: 2011
- Subjects: Mzuzu Coffee Planters Cooperative Union Coffee -- Marketing -- Malawi Marketing channels -- Evaluation -- Malawi Agricultural development projects -- Malawi
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:819 , http://hdl.handle.net/10962/d1008300
- Description: Literature and the cooperative movement in Malawi shows that the first cooperative was established in 1947. Since the economy of the country depends on agriculture, most cooperatives were strongly developed in the fields of agricultural production, and processing and marketing. The first coffee cooperative was registered in 1950, known as the Nchenachena Coffee Producers Cooperative Society. After Malawi 's independence in 1964, agricultural cooperatives were dissolved and government formed the Farmers Marketing Board (FMB) to take over all marketing activities of all crops, including coffee. The FMB was replaced by the Agricultural Development and Marketing Corporation (ADMARC) in 1967. After the dissolution of agricultural cooperatives, government saw the need for crop development and established Smallholder Coffee Authority in 1971. The Smallholder Coffee Authority worked up to 1999 when it collapsed because of administrative and financial problems. Due to the failure of the Smallholder Coffee Authority, the government of Malawi reintroduced agricultural cooperatives in 1999. Mzuzu Coffee Planters ' Cooperative Union was formed in 2006 following the re-introduction of cooperatives. The union is mandated to promote sustainable production, processing and marketing of Arabica coffee on behalf of the farmers. Since its inception, the output of coffee for export from the Mzuzu Coffee Planters Cooperative Union has increased from 156 tonnes in 2006 to over 400 tonnes in 2009. The increase in coffee exports was not by mere chance but a number of factors contributed to this success. The main reasons for this success were: • Strong prior relationship between the growers and the buyers • The uniqueness of the cooperative business model • The unique taste and quality of coffee grown • The introduction of a different approach to farming coffee Currently there is high demand for organic coffee and this could be a niche market that is not only rewarded with premium prices but also creates environmental friendly business. The union considers Fair Trade market as an alternative approach to conventional trade, aiming at improving the livelihoods of smallholder producers by improving payments, giving them fair prices and providing continuity in trading relationships.
- Full Text:
- Date Issued: 2011
- Authors: Jussa, Leman Abdulrazak Wyson
- Date: 2011
- Subjects: Mzuzu Coffee Planters Cooperative Union Coffee -- Marketing -- Malawi Marketing channels -- Evaluation -- Malawi Agricultural development projects -- Malawi
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:819 , http://hdl.handle.net/10962/d1008300
- Description: Literature and the cooperative movement in Malawi shows that the first cooperative was established in 1947. Since the economy of the country depends on agriculture, most cooperatives were strongly developed in the fields of agricultural production, and processing and marketing. The first coffee cooperative was registered in 1950, known as the Nchenachena Coffee Producers Cooperative Society. After Malawi 's independence in 1964, agricultural cooperatives were dissolved and government formed the Farmers Marketing Board (FMB) to take over all marketing activities of all crops, including coffee. The FMB was replaced by the Agricultural Development and Marketing Corporation (ADMARC) in 1967. After the dissolution of agricultural cooperatives, government saw the need for crop development and established Smallholder Coffee Authority in 1971. The Smallholder Coffee Authority worked up to 1999 when it collapsed because of administrative and financial problems. Due to the failure of the Smallholder Coffee Authority, the government of Malawi reintroduced agricultural cooperatives in 1999. Mzuzu Coffee Planters ' Cooperative Union was formed in 2006 following the re-introduction of cooperatives. The union is mandated to promote sustainable production, processing and marketing of Arabica coffee on behalf of the farmers. Since its inception, the output of coffee for export from the Mzuzu Coffee Planters Cooperative Union has increased from 156 tonnes in 2006 to over 400 tonnes in 2009. The increase in coffee exports was not by mere chance but a number of factors contributed to this success. The main reasons for this success were: • Strong prior relationship between the growers and the buyers • The uniqueness of the cooperative business model • The unique taste and quality of coffee grown • The introduction of a different approach to farming coffee Currently there is high demand for organic coffee and this could be a niche market that is not only rewarded with premium prices but also creates environmental friendly business. The union considers Fair Trade market as an alternative approach to conventional trade, aiming at improving the livelihoods of smallholder producers by improving payments, giving them fair prices and providing continuity in trading relationships.
- Full Text:
- Date Issued: 2011
The contribution made by Mr Justice EF Watermeyer to South African tax jurisprudence
- Authors: Thackwell, Robert Colin
- Date: 2011
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:881 , http://hdl.handle.net/10962/d1001635
- Description: The objective of this thesis is to highlight the colossal contributions made by the late Justice Watermeyer to South African tax jurisprudence. His contributions are viewed from a practical application point of view as well as from a statutory interpretative perspective. The style and technique with which he delivered his judgments are also considered to be a contribution in their own right. The core of this thesis is the analysis of seven of Justice Watermeyer‟s most influential judgments. The development and application of the principle or principles developed in each of these seven judgments is then traced chronologically through case law up until recent judgments. It is most notable that each and every phrase contained in section 11(a) of the Income Tax Act has been interpreted by Justice Watermeyer. These interpretations are still viewed as correct statements of the applicable law and will continue to be referred to on a regular basis given the fact that section 11(a) is one of the most widely contested provisions in the Income Tax Act. Several references to his approach to statutory interpretation are made through the course of the case analyses. Whilst significant evidence of a purposive oriented approach to interpretation appears in some judgments, such evidence is lacking in others. An absolute or conclusive submission in terms of his approach to statutory interpretation is not sufficiently supported. His style of judgment is also referred to and commented on, with particular focus placed on his use of illustrative examples. The contribution to South African tax law by Justice Watermeyer is found to be nothing short of enormous. He was and continues to be influential with respect to section 11(a),the definition of gross income in section 1, common law principles of tax avoidance as well as the interpretation of statutory laws of tax avoidance. It is anticipated that some of his interpretations with respect to statutory rules of tax avoidance will be referred to when the relatively new anti-avoidance provisions become the subject of litigation.
- Full Text:
- Date Issued: 2011
- Authors: Thackwell, Robert Colin
- Date: 2011
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:881 , http://hdl.handle.net/10962/d1001635
- Description: The objective of this thesis is to highlight the colossal contributions made by the late Justice Watermeyer to South African tax jurisprudence. His contributions are viewed from a practical application point of view as well as from a statutory interpretative perspective. The style and technique with which he delivered his judgments are also considered to be a contribution in their own right. The core of this thesis is the analysis of seven of Justice Watermeyer‟s most influential judgments. The development and application of the principle or principles developed in each of these seven judgments is then traced chronologically through case law up until recent judgments. It is most notable that each and every phrase contained in section 11(a) of the Income Tax Act has been interpreted by Justice Watermeyer. These interpretations are still viewed as correct statements of the applicable law and will continue to be referred to on a regular basis given the fact that section 11(a) is one of the most widely contested provisions in the Income Tax Act. Several references to his approach to statutory interpretation are made through the course of the case analyses. Whilst significant evidence of a purposive oriented approach to interpretation appears in some judgments, such evidence is lacking in others. An absolute or conclusive submission in terms of his approach to statutory interpretation is not sufficiently supported. His style of judgment is also referred to and commented on, with particular focus placed on his use of illustrative examples. The contribution to South African tax law by Justice Watermeyer is found to be nothing short of enormous. He was and continues to be influential with respect to section 11(a),the definition of gross income in section 1, common law principles of tax avoidance as well as the interpretation of statutory laws of tax avoidance. It is anticipated that some of his interpretations with respect to statutory rules of tax avoidance will be referred to when the relatively new anti-avoidance provisions become the subject of litigation.
- Full Text:
- Date Issued: 2011
Curating the reviled, beloved and quotidian: a retrospective of Vladimir Tretchikoff
- Authors: Lamprecht, Andrew Paul
- Date: 2011
- Subjects: Tretchikoff, Vladimir -- Criticism and interpretation Painters -- South Africa -- Criticism and interpretation Curatorship -- South Africa -- Art Kitsch
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2407 , http://hdl.handle.net/10962/d1002203
- Description: This thesis aims to contextualise my curation of 'Tretchikoff: The People's Painter' at the Iziko South African National Gallery by outlining the process by which I came to embark on this project and to examine the concepts of mass art and kitsch in relation to the painter. Mass art, in Noel Carroll's explication of the term, is art that utilises industrial processes of replication. Carroll argues that this leads to specific formal and structural tendencies in this art which have much in common with the pejorative concept of kitsch, or art that is lacking in taste or effuses excessive emotion. The latter term was and continues to be applied to Tretchikoff. Although some have attempted to 'reclaim' the word as a positive concept the negative associations that link this term to Tretchikoff are strong. Interrogating these concepts led me to decide to curate TretchikofPs retrospective by focusing on his painting and not including the prints for which he was so well known. Awareness of the complex associations and 'received knowledge' that his prints engender has influenced several curatorial decisions that I have taken. I consider the intellectual underpinnings of my curatorial strategy and argue for an 'open' exhibition which gives the viewer the opportunity to assess his work and legacy in an objective manner, free from as much curatorial mediation and didacticsm as possible. There are no answers to be offered in my curation of Tretchikxiff the People's Painter, rather I have aimed to set up dialogues, discussions, confrontations and challenges; I have offered simple relationships rather than complex juxtapositions I have aimed to position the artwork as the centre of the engagement relative to the viewer.
- Full Text:
- Date Issued: 2011
- Authors: Lamprecht, Andrew Paul
- Date: 2011
- Subjects: Tretchikoff, Vladimir -- Criticism and interpretation Painters -- South Africa -- Criticism and interpretation Curatorship -- South Africa -- Art Kitsch
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2407 , http://hdl.handle.net/10962/d1002203
- Description: This thesis aims to contextualise my curation of 'Tretchikoff: The People's Painter' at the Iziko South African National Gallery by outlining the process by which I came to embark on this project and to examine the concepts of mass art and kitsch in relation to the painter. Mass art, in Noel Carroll's explication of the term, is art that utilises industrial processes of replication. Carroll argues that this leads to specific formal and structural tendencies in this art which have much in common with the pejorative concept of kitsch, or art that is lacking in taste or effuses excessive emotion. The latter term was and continues to be applied to Tretchikoff. Although some have attempted to 'reclaim' the word as a positive concept the negative associations that link this term to Tretchikoff are strong. Interrogating these concepts led me to decide to curate TretchikofPs retrospective by focusing on his painting and not including the prints for which he was so well known. Awareness of the complex associations and 'received knowledge' that his prints engender has influenced several curatorial decisions that I have taken. I consider the intellectual underpinnings of my curatorial strategy and argue for an 'open' exhibition which gives the viewer the opportunity to assess his work and legacy in an objective manner, free from as much curatorial mediation and didacticsm as possible. There are no answers to be offered in my curation of Tretchikxiff the People's Painter, rather I have aimed to set up dialogues, discussions, confrontations and challenges; I have offered simple relationships rather than complex juxtapositions I have aimed to position the artwork as the centre of the engagement relative to the viewer.
- Full Text:
- Date Issued: 2011
The nexilitas factor: host-guest relationships in small owner managed commercial accommodation facilities in contemporary South Africa
- Von Lengeling, Volkher Heinrich Christoph
- Authors: Von Lengeling, Volkher Heinrich Christoph
- Date: 2011
- Subjects: Hospitality industry -- South Africa Interpersonal relations Social interaction Liminality Consumer behavior Home-based businesses -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2093 , http://hdl.handle.net/10962/d1002656
- Description: The commercialization of hospitality established arguably the oldest profession. Historically small commercial hospitality establishments, known as inns in the western world, were of ill repute. Perhaps connected to their reputation, this category of accommodation facility has been seriously neglected as an area of academic inquiry, particularly from the perspective of the host. While there has been a huge growth in the interdisciplinary field of tourism studies in recent decades, little attention has been paid to the role of the host in the host-guest relationship at whatever level of analysis. This thesis seeks to redress the balance. Hospitality is a basic form of social bonding. This type of bonding, where a hierarchy between strangers is implicit (as with hosts and guests), may be termed ‘nexilitas’; nexilitas is a form of social bonding in liminal circumstances. To that extent it is comparable to ‘communitas’ which describes social bonding between equals in certain liminal circumstances. The difference is that nexilitas is a form of bonding between individuals in a complex power relationship. The host controls the hospitality space, but custom also empowers the guest with certain expectations, especially in the commercial context. The thesis identifies the various forms of hospitality – traditional ‘true’ or ‘pure’ hospitality, social hospitality, cultural hospitality and commercial hospitality – and discusses these critically in their historical and cross-cultural contexts, with emphasis on the perspective of the host. The passage of hospitality is then traced through the three phases of preliminality, liminality and post-liminality and discussed along the themes anticipation, arrival and accommodation and finally departure of the guest. While the historical and ethnographic review is mainly based on written histories and the experiences of other anthropologists as guests as well as ethnographers, the passage of hospitality draws on the multi-sited auto-anthropological experiences of the author, both as host and as ethnographer of contemporary South African hosts in small owner-managed commercial hospitality establishments.
- Full Text:
- Date Issued: 2011
- Authors: Von Lengeling, Volkher Heinrich Christoph
- Date: 2011
- Subjects: Hospitality industry -- South Africa Interpersonal relations Social interaction Liminality Consumer behavior Home-based businesses -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2093 , http://hdl.handle.net/10962/d1002656
- Description: The commercialization of hospitality established arguably the oldest profession. Historically small commercial hospitality establishments, known as inns in the western world, were of ill repute. Perhaps connected to their reputation, this category of accommodation facility has been seriously neglected as an area of academic inquiry, particularly from the perspective of the host. While there has been a huge growth in the interdisciplinary field of tourism studies in recent decades, little attention has been paid to the role of the host in the host-guest relationship at whatever level of analysis. This thesis seeks to redress the balance. Hospitality is a basic form of social bonding. This type of bonding, where a hierarchy between strangers is implicit (as with hosts and guests), may be termed ‘nexilitas’; nexilitas is a form of social bonding in liminal circumstances. To that extent it is comparable to ‘communitas’ which describes social bonding between equals in certain liminal circumstances. The difference is that nexilitas is a form of bonding between individuals in a complex power relationship. The host controls the hospitality space, but custom also empowers the guest with certain expectations, especially in the commercial context. The thesis identifies the various forms of hospitality – traditional ‘true’ or ‘pure’ hospitality, social hospitality, cultural hospitality and commercial hospitality – and discusses these critically in their historical and cross-cultural contexts, with emphasis on the perspective of the host. The passage of hospitality is then traced through the three phases of preliminality, liminality and post-liminality and discussed along the themes anticipation, arrival and accommodation and finally departure of the guest. While the historical and ethnographic review is mainly based on written histories and the experiences of other anthropologists as guests as well as ethnographers, the passage of hospitality draws on the multi-sited auto-anthropological experiences of the author, both as host and as ethnographer of contemporary South African hosts in small owner-managed commercial hospitality establishments.
- Full Text:
- Date Issued: 2011
Investigation into the extended capabilities of the new DPS-4D ionosonde
- Authors: Ssessanga, Nicholas
- Date: 2011
- Subjects: Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5472 , http://hdl.handle.net/10962/d1005257 , Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Description: The DPS-4D is the latest version of digital ionosonde developed by the UMLCAR (University of Massachusetts in Lowell Center for Atmospheric Research) in 2008. This new ionosonde has advances in both the hardware and software which allows for the promised advanced capabilities. The aim of this thesis was to present results from an experiment undertaken using the Hermanus DPS-4D (34.4°S 19.2°E, South Africa), the first of this version to be installed globally, to answer a science question outside of the normally expected capabilities of an ionosonde. The science question posed focused on the ability of the DPS-4D to provide information on day-time Pc3 pulsations evident in the ionosphere. Day-time Pc3 ULF waves propagating down through the ionosphere cause oscillations in the Doppler shift of High Frequency (HF) radio transmissions that are correlated with the magnetic pulsations recorded on the ground. Evidence is presented which shows that no correlation exists between the ground magnetic pulsation data and DPS-4D ionospheric data. The conclusion was reached that although the DPS-4D is more advanced in its eld of technology than its predecessors it may not be used to observe Pc3 pulsations.
- Full Text:
- Date Issued: 2011
- Authors: Ssessanga, Nicholas
- Date: 2011
- Subjects: Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5472 , http://hdl.handle.net/10962/d1005257 , Ionosondes , Ionosphere , Ionosphere -- Observations -- South Africa -- Hermanus (Cape of Good Hope) , Ionosphere -- Research -- South Africa -- Hermanus (Cape of Good Hope)
- Description: The DPS-4D is the latest version of digital ionosonde developed by the UMLCAR (University of Massachusetts in Lowell Center for Atmospheric Research) in 2008. This new ionosonde has advances in both the hardware and software which allows for the promised advanced capabilities. The aim of this thesis was to present results from an experiment undertaken using the Hermanus DPS-4D (34.4°S 19.2°E, South Africa), the first of this version to be installed globally, to answer a science question outside of the normally expected capabilities of an ionosonde. The science question posed focused on the ability of the DPS-4D to provide information on day-time Pc3 pulsations evident in the ionosphere. Day-time Pc3 ULF waves propagating down through the ionosphere cause oscillations in the Doppler shift of High Frequency (HF) radio transmissions that are correlated with the magnetic pulsations recorded on the ground. Evidence is presented which shows that no correlation exists between the ground magnetic pulsation data and DPS-4D ionospheric data. The conclusion was reached that although the DPS-4D is more advanced in its eld of technology than its predecessors it may not be used to observe Pc3 pulsations.
- Full Text:
- Date Issued: 2011
The strategic management of intellectual capital : a case study in the banking and financial services sector in Zambia
- Authors: Banda, Japhet Mathias
- Date: 2011
- Subjects: Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1178 , http://hdl.handle.net/10962/d1002795 , Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Description: Fundamental changes in the global economy are changing the basis of organisational competitive advantage. The challenge in attaining a competitive advantage is characterised by factors such as increased competition, market volatility, geographically dispersed operations, customer awareness, raising workforce diversity and stringent regulatory regimes. These factors have driven, and in turn have been driven by, an increasing complexity of products, services and the processes that create value, resulting in changes in the structural and functional dimensions of the organisation. Business executives and academics recognise the shift in value creating assets from the traditional land, labour and capital to intangible assets such as knowledge and information becoming the most important resources an organisation can muster.The combination and integration of intangible assets such as human resources, structural and relational resources has been grouped under the umbrella of intellectual capital. This study comprises of a single descriptive case study analysis to ascertain how intellectual capital is managed strategically to gain a competitive advantage in an organisation in the banking and financial services sector in Zambia. Based on document review and semi-structured interviews, this thesis investigated the extent to which an organisation in the banking and financial services sector in Zambia leveraged intellectual capital to gain competitive advantage. In this study it was found that there is a low level appreciation of the intellectual capital phenomenon as a strategic management tool in the participating organisation. However, the organisation has adopted aspects of intellectual capital and has implemented them successfully accounting for the organisation‘s competitive edge in the market.
- Full Text:
- Date Issued: 2011
- Authors: Banda, Japhet Mathias
- Date: 2011
- Subjects: Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1178 , http://hdl.handle.net/10962/d1002795 , Intellectual capital -- Management , Intellectual capital -- Zambia , Banks and banking -- Zambia , Financial services industry -- Management -- Zambia
- Description: Fundamental changes in the global economy are changing the basis of organisational competitive advantage. The challenge in attaining a competitive advantage is characterised by factors such as increased competition, market volatility, geographically dispersed operations, customer awareness, raising workforce diversity and stringent regulatory regimes. These factors have driven, and in turn have been driven by, an increasing complexity of products, services and the processes that create value, resulting in changes in the structural and functional dimensions of the organisation. Business executives and academics recognise the shift in value creating assets from the traditional land, labour and capital to intangible assets such as knowledge and information becoming the most important resources an organisation can muster.The combination and integration of intangible assets such as human resources, structural and relational resources has been grouped under the umbrella of intellectual capital. This study comprises of a single descriptive case study analysis to ascertain how intellectual capital is managed strategically to gain a competitive advantage in an organisation in the banking and financial services sector in Zambia. Based on document review and semi-structured interviews, this thesis investigated the extent to which an organisation in the banking and financial services sector in Zambia leveraged intellectual capital to gain competitive advantage. In this study it was found that there is a low level appreciation of the intellectual capital phenomenon as a strategic management tool in the participating organisation. However, the organisation has adopted aspects of intellectual capital and has implemented them successfully accounting for the organisation‘s competitive edge in the market.
- Full Text:
- Date Issued: 2011
An organisation development intervention in an Anglican church theological seminary in Southern Africa
- Authors: Chinganga, Percy
- Date: 2013-08-08
- Subjects: College of the Transfiguration (Grahamstown, South Africa) Organizational change -- Church of England -- Africa, Southern Leadership -- Religious aspects -- Christianity -- Africa, Southern Church management -- Church of England -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1959 , http://hdl.handle.net/10962/d1008377
- Description: "Organisation development is a planned, systematic process in which applied behavioral science principles and practices are introduced into ongoing organisations toward the goal of increasing individual and organisational effectiveness. " [French and Bell] This study describes and analyses the implementation of Organisation Development (OD) to an Anglican Church theological seminary, The College of the Transfiguration (Cott), in the Anglican Church of the Province of Southern Africa (ACSA). The origins of OD are business related, emerging in the late 1950s and early 1960s. Over the years, and recently in South Africa, OD has been applied in educational change initiatives. Unlike more traditional change strategies, OD promotes collaboration in organisational change processes through the inclusive participation of all stakeholders. This study is unique in the sense that OD is applied to an Anglican Church theological institution in Southern Africa. The goal of theological institutions, particularly Cot!, is to "form, inform and transform" (Cot! Prospectus, 2011) those who feel called to ordained ministry. Personal experience in this practice has confirmed that organisational emphasis is placed more on product than process; on results rather than the leadership and management of the organisation. This study was an attempt to introduce a process of planned change to such an organisational context. OD was introduced to The College of the Transfiguration in the form of action research using the Survey Data Feedback (SDF) strategy. Data gathered was interpreted and analysed, followed by action planning and implementation of agreed plans. The process had a positive impact on both stakeholders and the organisation despite the challenges associated with the unpredictable world of organisations. Ultimately, I propose tentative recommendations which could help Cott and other educational institutions to achieve long-term improvement in organisational leadership and management.
- Full Text:
- Authors: Chinganga, Percy
- Date: 2013-08-08
- Subjects: College of the Transfiguration (Grahamstown, South Africa) Organizational change -- Church of England -- Africa, Southern Leadership -- Religious aspects -- Christianity -- Africa, Southern Church management -- Church of England -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1959 , http://hdl.handle.net/10962/d1008377
- Description: "Organisation development is a planned, systematic process in which applied behavioral science principles and practices are introduced into ongoing organisations toward the goal of increasing individual and organisational effectiveness. " [French and Bell] This study describes and analyses the implementation of Organisation Development (OD) to an Anglican Church theological seminary, The College of the Transfiguration (Cott), in the Anglican Church of the Province of Southern Africa (ACSA). The origins of OD are business related, emerging in the late 1950s and early 1960s. Over the years, and recently in South Africa, OD has been applied in educational change initiatives. Unlike more traditional change strategies, OD promotes collaboration in organisational change processes through the inclusive participation of all stakeholders. This study is unique in the sense that OD is applied to an Anglican Church theological institution in Southern Africa. The goal of theological institutions, particularly Cot!, is to "form, inform and transform" (Cot! Prospectus, 2011) those who feel called to ordained ministry. Personal experience in this practice has confirmed that organisational emphasis is placed more on product than process; on results rather than the leadership and management of the organisation. This study was an attempt to introduce a process of planned change to such an organisational context. OD was introduced to The College of the Transfiguration in the form of action research using the Survey Data Feedback (SDF) strategy. Data gathered was interpreted and analysed, followed by action planning and implementation of agreed plans. The process had a positive impact on both stakeholders and the organisation despite the challenges associated with the unpredictable world of organisations. Ultimately, I propose tentative recommendations which could help Cott and other educational institutions to achieve long-term improvement in organisational leadership and management.
- Full Text:
Investigating the popularity of the main news bulletin on Muvi TV, a Zambian television station: a reception study of Lusaka viewers
- Authors: Mbatha, Loisa
- Date: 2011
- Subjects: Television broadcasting of news -- Research -- Zambia Broadcast journalism -- Research -- Zambia Television programs -- Research -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3463 , http://hdl.handle.net/10962/d1002918
- Description: The "tabloid TV" genre, like tabloid newspapers has been chastised for depoliticising the public by causing cynicism, and lowering the standards of rational public discourse. Such criticisms are not always based on a close interrogation of the reasons for the popularity of such a genre amongst its consumers. The "tabloid TV" news genre is a relatively new phenomenon in Zambia and in the African context in general. This study is an investigation of the rise in popularity of the Zambian television station, Muvi TV. It is a reception study of Lusaka (capital city) viewers, particularly the working class community, who make up the majority of the TV stations' audience. Members of this social group who have hitherto been marginalised from mainstream media discourses were interviewed. In particular, the study explores the meanings obtained from the content of Muvi TVs' tabloidised main evening news and its relevance to their everyday lived experiences. The TV station gives prominence to "micro-politics of everyday life", alongside "serious" stories albeit in a more lurid, sensationalised and personalised manner. In undertaking this investigation, the study draws primarily on qualitative in-depth interviews - focus group and individual. These techniques unearth the manner in which the viewers decode the messages and appropriate the meanings into their lived experiences. The study establishes that the popularity of Muvi TV is due to the emphasis on human-interest stories epitomised by tabloid journalism values. The working class majority is able to relate and identify with these stories, and attaches greater believability to the station's news as compared to the public broadcaster, the Zambia National Broadcasting Corporation (ZNBC). As such, Muvi TV can be seen to fulfil a political function despite its sensationalised approach.
- Full Text:
- Date Issued: 2011
- Authors: Mbatha, Loisa
- Date: 2011
- Subjects: Television broadcasting of news -- Research -- Zambia Broadcast journalism -- Research -- Zambia Television programs -- Research -- Zambia
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3463 , http://hdl.handle.net/10962/d1002918
- Description: The "tabloid TV" genre, like tabloid newspapers has been chastised for depoliticising the public by causing cynicism, and lowering the standards of rational public discourse. Such criticisms are not always based on a close interrogation of the reasons for the popularity of such a genre amongst its consumers. The "tabloid TV" news genre is a relatively new phenomenon in Zambia and in the African context in general. This study is an investigation of the rise in popularity of the Zambian television station, Muvi TV. It is a reception study of Lusaka (capital city) viewers, particularly the working class community, who make up the majority of the TV stations' audience. Members of this social group who have hitherto been marginalised from mainstream media discourses were interviewed. In particular, the study explores the meanings obtained from the content of Muvi TVs' tabloidised main evening news and its relevance to their everyday lived experiences. The TV station gives prominence to "micro-politics of everyday life", alongside "serious" stories albeit in a more lurid, sensationalised and personalised manner. In undertaking this investigation, the study draws primarily on qualitative in-depth interviews - focus group and individual. These techniques unearth the manner in which the viewers decode the messages and appropriate the meanings into their lived experiences. The study establishes that the popularity of Muvi TV is due to the emphasis on human-interest stories epitomised by tabloid journalism values. The working class majority is able to relate and identify with these stories, and attaches greater believability to the station's news as compared to the public broadcaster, the Zambia National Broadcasting Corporation (ZNBC). As such, Muvi TV can be seen to fulfil a political function despite its sensationalised approach.
- Full Text:
- Date Issued: 2011
The zoogeography of the cetaceans in Algoa Bay
- Authors: Melly, Brigitte Leigh
- Date: 2011
- Subjects: Cetacea -- South Africa -- Algoa Bay , Cetacea -- Behavior -- South Africa -- Algoa Bay , Cetacea -- South Africa -- Algoa Bay -- Geographical distribution , Cetacea -- Counting -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4858 , http://hdl.handle.net/10962/d1005534 , Cetacea -- South Africa -- Algoa Bay , Cetacea -- Behavior -- South Africa -- Algoa Bay , Cetacea -- South Africa -- Algoa Bay -- Geographical distribution , Cetacea -- Counting -- South Africa -- Algoa Bay
- Description: The most recent study on cetaceans in Algoa Bay, South Africa, was conducted over 14 years ago. Consequently, knowledge of the cetacean species visiting this bay is currently based on incidental observations and stranding data. A number of developments in recent years: a deepwater port, proposed oil refinery, increased boating and fishing (commercial and recreational), a proposed Marine Protected Area, and the release of a whale-watching permit, all of which may impact these animals in some way, highlight the need for a baseline study on cetaceans. Therefore, the aim of this study was to determine the spatial and temporal distribution, and habitat preference of cetaceans in Algoa Bay. Boat-based surveys were conducted monthly between March 2009 and July 2010. At each sighting the GPS location, species, group size and composition, and behaviour were recorded. Using GIS, the sighting data was related to data layers of geographical variables such as sea surface temperature, depth and sea-floor substrate. Approximately 365 hours of search effort were completed over 57 surveys, with a total of 346 sightings. Species observed were: southern right whales (Eubalaena australis), humpback whales (Megaptera novaeangliae), Bryde’s whales (Balaenoptera brydei), Indian Ocean bottlenose dolphins (Tursiops aduncus), Indo-Pacific humpback dolphins (Sousa chinensis), and longbeaked common dolphins (Delphinus capensis). Southern right whales were observed during austral winter, utilising the shallow, protected areas of the bay as a mating and nursery ground. Humpback whales were also recorded extensively during winter, in more offshore waters, with a significant number of mother-calf pairs sighted. Bryde’s whales were recorded in offshore waters during summer and autumn, where they were primarily observed travelling and foraging. Bottlenose dolphins were the most prolific species sighted. They were recorded year-round throughout the inshore waters of the bay, with large group sizes (up to 500 animals), and displayed a wide variety of behaviours. Humpback dolphins were observed in extremely shallow and inshore waters (mean bottom depth of 6.6 m) along the south-west corner of the bay, in small groups of approximately three individuals. Common dolphins were the least observed species, and were mainly observed foraging in large groups of up to 800 individuals. The results of this study indicate how cetaceans utilise the bay in significantly different ways. Geographical and anthropogenic factors have influenced the spatial and temporal distribution of these animals and have resulted in habitat preferences, as well as potential key habitats, in the bay. Thus, this study has provided baseline information for future research and for better informed conservation and management strategies in Algoa Bay.
- Full Text:
- Date Issued: 2011
- Authors: Melly, Brigitte Leigh
- Date: 2011
- Subjects: Cetacea -- South Africa -- Algoa Bay , Cetacea -- Behavior -- South Africa -- Algoa Bay , Cetacea -- South Africa -- Algoa Bay -- Geographical distribution , Cetacea -- Counting -- South Africa -- Algoa Bay
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4858 , http://hdl.handle.net/10962/d1005534 , Cetacea -- South Africa -- Algoa Bay , Cetacea -- Behavior -- South Africa -- Algoa Bay , Cetacea -- South Africa -- Algoa Bay -- Geographical distribution , Cetacea -- Counting -- South Africa -- Algoa Bay
- Description: The most recent study on cetaceans in Algoa Bay, South Africa, was conducted over 14 years ago. Consequently, knowledge of the cetacean species visiting this bay is currently based on incidental observations and stranding data. A number of developments in recent years: a deepwater port, proposed oil refinery, increased boating and fishing (commercial and recreational), a proposed Marine Protected Area, and the release of a whale-watching permit, all of which may impact these animals in some way, highlight the need for a baseline study on cetaceans. Therefore, the aim of this study was to determine the spatial and temporal distribution, and habitat preference of cetaceans in Algoa Bay. Boat-based surveys were conducted monthly between March 2009 and July 2010. At each sighting the GPS location, species, group size and composition, and behaviour were recorded. Using GIS, the sighting data was related to data layers of geographical variables such as sea surface temperature, depth and sea-floor substrate. Approximately 365 hours of search effort were completed over 57 surveys, with a total of 346 sightings. Species observed were: southern right whales (Eubalaena australis), humpback whales (Megaptera novaeangliae), Bryde’s whales (Balaenoptera brydei), Indian Ocean bottlenose dolphins (Tursiops aduncus), Indo-Pacific humpback dolphins (Sousa chinensis), and longbeaked common dolphins (Delphinus capensis). Southern right whales were observed during austral winter, utilising the shallow, protected areas of the bay as a mating and nursery ground. Humpback whales were also recorded extensively during winter, in more offshore waters, with a significant number of mother-calf pairs sighted. Bryde’s whales were recorded in offshore waters during summer and autumn, where they were primarily observed travelling and foraging. Bottlenose dolphins were the most prolific species sighted. They were recorded year-round throughout the inshore waters of the bay, with large group sizes (up to 500 animals), and displayed a wide variety of behaviours. Humpback dolphins were observed in extremely shallow and inshore waters (mean bottom depth of 6.6 m) along the south-west corner of the bay, in small groups of approximately three individuals. Common dolphins were the least observed species, and were mainly observed foraging in large groups of up to 800 individuals. The results of this study indicate how cetaceans utilise the bay in significantly different ways. Geographical and anthropogenic factors have influenced the spatial and temporal distribution of these animals and have resulted in habitat preferences, as well as potential key habitats, in the bay. Thus, this study has provided baseline information for future research and for better informed conservation and management strategies in Algoa Bay.
- Full Text:
- Date Issued: 2011
Co-utilisation of microalgae for wastewater treatment and the production of animal feed supplements
- Authors: Johnson, Hailey E
- Date: 2011
- Subjects: Microalgae -- Biotechnology , Algae culture , Algae products , Waste products as feed , Sewage -- Purification , Organic wastes -- Recycling , Food industry and trade -- Waste disposal , Agriculture -- Waste disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3940 , http://hdl.handle.net/10962/d1003999 , Microalgae -- Biotechnology , Algae culture , Algae products , Waste products as feed , Sewage -- Purification , Organic wastes -- Recycling , Food industry and trade -- Waste disposal , Agriculture -- Waste disposal
- Description: Microalgae have a variety of commercial applications, the oldest of which include utilisation as a food source and for use in wastewater treatment. These applications, however, are seldom combined due to toxicity concerns, for ethical reasons, and generally the requirement for cultivation of a single algae species for use as a feed supplement. These problems might be negated if a “safer” wastewater such as that from agricultural and/or commercial food production facilities were to be utilised and if a stable algae population can be maintained. In this investigation preliminary studies were carried out using an Integrated Algae Pond System (IAPS) for domestic wastewater treatment to determine the species composition in the associated High Rate Algae Ponds (HRAPs). The effect of different modes of operation, continuous versus batch, on nutrient removal, productivity and species composition was also investigated. Furthermore, indigenous species in the HRAP were isolated and molecularly identified as, Chlorella, Micractinium, Scenedesmus and Pediastrum. Additionally, the effect of the nor amino acid, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) and its Cu-chelated derivative, on the growth and biochemical composition of Chlorella, Micractinium, Scenedesmus, Pediastrum and Spirulina was investigated. Species composition in the HRAP was stable under continuous operation with Micractinium dominating > 90% of the algae population. Under batch operation the population dynamic shifted; Chlorella outcompeted Micractinium possibly due to nutrient depletion and selective grazing pressures caused by proliferation of Daphnia. Higher species diversity was observed during batch mode as slower growing algae were able to establish in the HRAP. Nutrient removal efficiency and biomass productivity was higher in continuous mode, however lower nutrient levels were obtained in batch operation. HMTBA did not significantly affect growth rate, however treatment with 10 mg.L-1 resulted in slightly increased growth rate in Micractinium and increased final biomass concentrations in Chlorella, Micractinium and Spirulina (although this was not statistically significant for Micractinium and Spirulina), which are known mixotrophic species. Algae treated with Cu-HMTBA, showed reduced final biomass concentration with 10 mg.L-1, caused by Cu toxicity. Biochemical composition of the algae was species-specific and differed through the growth cycle, with high protein observed during early growth and high carbohydrate during late growth/early stationary phase. Additionally, 0.1 mg.L-1 HMTBA and Cu-HMTBA significantly reduced protein content in Chlorella, Micractinium, Scenedesmus and Pediastrum. In conclusion, operation of the HRAP in continuous culture provided suitable wastewater treatment with high productivity of an ideal species, Micractinium, for use in animal feed supplementation. This species had 40% protein content during growth (higher than the other species tested) and dominated the HRAP at > 90% of the algae population during continuous mode. Addition of HMTBA (> 1 mg.L-1) to algae cultivation systems and those treating wastewater, has the potential to improve productivity and the value of the biomass by enhancing protein content. Overall, the co-utilisation of microalgae for wastewater treatment and the generation of a biomass rich in protein, for incorporation into formulated animal feed supplements, represents a closed ecosystem which conserves nutrients and regenerates a most valuable resource, water.
- Full Text:
- Date Issued: 2011
- Authors: Johnson, Hailey E
- Date: 2011
- Subjects: Microalgae -- Biotechnology , Algae culture , Algae products , Waste products as feed , Sewage -- Purification , Organic wastes -- Recycling , Food industry and trade -- Waste disposal , Agriculture -- Waste disposal
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3940 , http://hdl.handle.net/10962/d1003999 , Microalgae -- Biotechnology , Algae culture , Algae products , Waste products as feed , Sewage -- Purification , Organic wastes -- Recycling , Food industry and trade -- Waste disposal , Agriculture -- Waste disposal
- Description: Microalgae have a variety of commercial applications, the oldest of which include utilisation as a food source and for use in wastewater treatment. These applications, however, are seldom combined due to toxicity concerns, for ethical reasons, and generally the requirement for cultivation of a single algae species for use as a feed supplement. These problems might be negated if a “safer” wastewater such as that from agricultural and/or commercial food production facilities were to be utilised and if a stable algae population can be maintained. In this investigation preliminary studies were carried out using an Integrated Algae Pond System (IAPS) for domestic wastewater treatment to determine the species composition in the associated High Rate Algae Ponds (HRAPs). The effect of different modes of operation, continuous versus batch, on nutrient removal, productivity and species composition was also investigated. Furthermore, indigenous species in the HRAP were isolated and molecularly identified as, Chlorella, Micractinium, Scenedesmus and Pediastrum. Additionally, the effect of the nor amino acid, 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) and its Cu-chelated derivative, on the growth and biochemical composition of Chlorella, Micractinium, Scenedesmus, Pediastrum and Spirulina was investigated. Species composition in the HRAP was stable under continuous operation with Micractinium dominating > 90% of the algae population. Under batch operation the population dynamic shifted; Chlorella outcompeted Micractinium possibly due to nutrient depletion and selective grazing pressures caused by proliferation of Daphnia. Higher species diversity was observed during batch mode as slower growing algae were able to establish in the HRAP. Nutrient removal efficiency and biomass productivity was higher in continuous mode, however lower nutrient levels were obtained in batch operation. HMTBA did not significantly affect growth rate, however treatment with 10 mg.L-1 resulted in slightly increased growth rate in Micractinium and increased final biomass concentrations in Chlorella, Micractinium and Spirulina (although this was not statistically significant for Micractinium and Spirulina), which are known mixotrophic species. Algae treated with Cu-HMTBA, showed reduced final biomass concentration with 10 mg.L-1, caused by Cu toxicity. Biochemical composition of the algae was species-specific and differed through the growth cycle, with high protein observed during early growth and high carbohydrate during late growth/early stationary phase. Additionally, 0.1 mg.L-1 HMTBA and Cu-HMTBA significantly reduced protein content in Chlorella, Micractinium, Scenedesmus and Pediastrum. In conclusion, operation of the HRAP in continuous culture provided suitable wastewater treatment with high productivity of an ideal species, Micractinium, for use in animal feed supplementation. This species had 40% protein content during growth (higher than the other species tested) and dominated the HRAP at > 90% of the algae population during continuous mode. Addition of HMTBA (> 1 mg.L-1) to algae cultivation systems and those treating wastewater, has the potential to improve productivity and the value of the biomass by enhancing protein content. Overall, the co-utilisation of microalgae for wastewater treatment and the generation of a biomass rich in protein, for incorporation into formulated animal feed supplements, represents a closed ecosystem which conserves nutrients and regenerates a most valuable resource, water.
- Full Text:
- Date Issued: 2011
Neuronal nitric oxide synthase : a biomarker for Alzheimers disease : interaction of neuronal nitric oxide synthase with beta-amyloid peptides in the brain
- Authors: Padayachee, Eden Rebecca
- Date: 2011 , 2013-07-19
- Subjects: Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4086 , http://hdl.handle.net/10962/d1007677 , Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Description: High levels of the amino acid arginine and low levels of the product citrulline in the cerebrospinal fluid of Alzheimer's patients could mean that there is a decrease in the enzymes that metabolize this amino acid. One such enzyme is neuronal nitric oxide synthase (nNOS). In this study, neuronal nitric oxide synthase (nNOS), sourced from bovine brain was extracted and concentrated using two methods of precipitation: poly (ethylene glycol) 20 000 (PEG) and ammonium sulphate [(NH₄)₂S0₄). These two techniques gave no increase in yield nor fold purification and hence were abandoned in favour of ion exchange chromatography by DEAE-Sepharose. The enzyme was then successfully purified by anion-exchange and after dialysis produced a 38% yield and three fold purification and yielded the highest specific activity of 2.27 U/mg. Neuronal nitric oxide synthase (nNOS) was a heterodimeric protein with a total molecular mass of ± 225 kDa (95 and 130 kDa monomers). The temperature and pH optima of the enzyme were 40⁰C and 6.5, respectively. The kinetic parameters (KM and Vmax) of nNOS were 70 μM and 0.332 μmol.min⁻¹, respectively. Moreover neuronal nitric oxide synthase (nNOS) was relatively stable at 40⁰C (t½ = 3 h). It was also confirmed that β-amyloid peptides inhibited nNOS when bound to the enzyme and that nNOS behaved as a catalyst in fibril formation through association-dissociation between enzyme and β-amyloid peptide. It was further shown that Aβ₁₇₋₂₈ inhibited nNOS the most with a Ki of 1.92 μM and also had the highest Stern-Volmer value (Ksv) of 0.11 μM⁻¹ indicating tight binding affinity to nNOS and easier accessibility to fluor molecules during binding. Congo red, turbidity, thioflavin-T assays and transmission electron microscopy were successfully used to detect and visualize the presence of fibrils by studying the process of fibrillogenesis. Computerized molecular modeling successfully studied protein dynamics and conformational changes of nNOS. These results correlated with resonance energy transfer (FRET) results which revealed the distance of tryptophan residues from the arginine bound at enzyme active site. Both the aforementioned techniques revealed that in the natural state of the enzyme with arginine bound at the active site, the tryptophan residues (TRP₆₂₅ and TRP₇₂₁) were positioned at the surface of the enzyme 28 Å away from the active site. When the amyloid peptide (Aβ₁₇₋₂₈) was bound to the active site, these same two amino acids moved 14 Å closer to the active site. A five residue hydrophobic fragment Aβ₁₇₋₂₁ [Leu₁₇ - Val₁₈ - Phe₁₉ - Phe₂₀ - Ala₁] within Aβ₁₇₋₂₈ was shown by computer modeling to be critical to the binding of the peptide to the active site of nNOS.
- Full Text:
- Date Issued: 2011
- Authors: Padayachee, Eden Rebecca
- Date: 2011 , 2013-07-19
- Subjects: Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4086 , http://hdl.handle.net/10962/d1007677 , Alzheimer's disease , Nitric-oxide synthase , Biochemical markers , Amyloid beta-protein , Peptide hormones
- Description: High levels of the amino acid arginine and low levels of the product citrulline in the cerebrospinal fluid of Alzheimer's patients could mean that there is a decrease in the enzymes that metabolize this amino acid. One such enzyme is neuronal nitric oxide synthase (nNOS). In this study, neuronal nitric oxide synthase (nNOS), sourced from bovine brain was extracted and concentrated using two methods of precipitation: poly (ethylene glycol) 20 000 (PEG) and ammonium sulphate [(NH₄)₂S0₄). These two techniques gave no increase in yield nor fold purification and hence were abandoned in favour of ion exchange chromatography by DEAE-Sepharose. The enzyme was then successfully purified by anion-exchange and after dialysis produced a 38% yield and three fold purification and yielded the highest specific activity of 2.27 U/mg. Neuronal nitric oxide synthase (nNOS) was a heterodimeric protein with a total molecular mass of ± 225 kDa (95 and 130 kDa monomers). The temperature and pH optima of the enzyme were 40⁰C and 6.5, respectively. The kinetic parameters (KM and Vmax) of nNOS were 70 μM and 0.332 μmol.min⁻¹, respectively. Moreover neuronal nitric oxide synthase (nNOS) was relatively stable at 40⁰C (t½ = 3 h). It was also confirmed that β-amyloid peptides inhibited nNOS when bound to the enzyme and that nNOS behaved as a catalyst in fibril formation through association-dissociation between enzyme and β-amyloid peptide. It was further shown that Aβ₁₇₋₂₈ inhibited nNOS the most with a Ki of 1.92 μM and also had the highest Stern-Volmer value (Ksv) of 0.11 μM⁻¹ indicating tight binding affinity to nNOS and easier accessibility to fluor molecules during binding. Congo red, turbidity, thioflavin-T assays and transmission electron microscopy were successfully used to detect and visualize the presence of fibrils by studying the process of fibrillogenesis. Computerized molecular modeling successfully studied protein dynamics and conformational changes of nNOS. These results correlated with resonance energy transfer (FRET) results which revealed the distance of tryptophan residues from the arginine bound at enzyme active site. Both the aforementioned techniques revealed that in the natural state of the enzyme with arginine bound at the active site, the tryptophan residues (TRP₆₂₅ and TRP₇₂₁) were positioned at the surface of the enzyme 28 Å away from the active site. When the amyloid peptide (Aβ₁₇₋₂₈) was bound to the active site, these same two amino acids moved 14 Å closer to the active site. A five residue hydrophobic fragment Aβ₁₇₋₂₁ [Leu₁₇ - Val₁₈ - Phe₁₉ - Phe₂₀ - Ala₁] within Aβ₁₇₋₂₈ was shown by computer modeling to be critical to the binding of the peptide to the active site of nNOS.
- Full Text:
- Date Issued: 2011
The reading of extended text in Oshindonga in grade 2 in selected Namibian schools
- Ngula, Elizabeth Njanjukweni-Aluhe
- Authors: Ngula, Elizabeth Njanjukweni-Aluhe
- Date: 2011
- Subjects: Ndonga language -- Study and teaching -- Namibia Reading comprehension -- Study and teaching (Primary) -- Namibia Reading (Primary) -- Namibia Teaching -- Namibia Teachers -- Attitudes -- Namibia Literacy -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1720 , http://hdl.handle.net/10962/d1003603
- Description: This study was conducted in order to understand to what extent Grade 2 teachers use books (or other forms of extended text) in their reading lessons in Oshindonga where very little published material is available, and, if so, whether they engage in shared reading with these materials or not. The study also explored ways to introduce more books (or other forms of extended text) into Oshindonga classrooms. The study took the form of an interpretive case study. It was conducted in two primary schools in Otjiwarongo district in the Otjozondjupa region of Namibia. Two qualified Grade 2 teachers were selected. The purpose of this sampling was to gain an in depth understanding of how these two selected teachers taught reading in Oshindonga. The data was gathered by using semi-structured interviews with open-ended questions, as well as lesson observations and stimulated recall with each individual teacher after each lesson. The purpose of this was to gain clarity in areas that were not clear during lesson presentations. A focus group interview was also conducted in order to generate ideas about how to introduce more extended texts into the classroom. The key fmdings are that both schools in the study lacked books in Oshindonga, and the teachers lacked an understanding of the importance of using books (or other forms of extended text). Other key findings are that teachers had a problem in choosing appropriate texts to read with their learners; teachers understand reading more as decoding than reading for meaning and pleasure; children were not asked any comprehension questions and the two teachers had different views on the value of shared reading. The research data revealed that there are problems in teaching literacy in Namibian African languages.
- Full Text:
- Date Issued: 2011
- Authors: Ngula, Elizabeth Njanjukweni-Aluhe
- Date: 2011
- Subjects: Ndonga language -- Study and teaching -- Namibia Reading comprehension -- Study and teaching (Primary) -- Namibia Reading (Primary) -- Namibia Teaching -- Namibia Teachers -- Attitudes -- Namibia Literacy -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1720 , http://hdl.handle.net/10962/d1003603
- Description: This study was conducted in order to understand to what extent Grade 2 teachers use books (or other forms of extended text) in their reading lessons in Oshindonga where very little published material is available, and, if so, whether they engage in shared reading with these materials or not. The study also explored ways to introduce more books (or other forms of extended text) into Oshindonga classrooms. The study took the form of an interpretive case study. It was conducted in two primary schools in Otjiwarongo district in the Otjozondjupa region of Namibia. Two qualified Grade 2 teachers were selected. The purpose of this sampling was to gain an in depth understanding of how these two selected teachers taught reading in Oshindonga. The data was gathered by using semi-structured interviews with open-ended questions, as well as lesson observations and stimulated recall with each individual teacher after each lesson. The purpose of this was to gain clarity in areas that were not clear during lesson presentations. A focus group interview was also conducted in order to generate ideas about how to introduce more extended texts into the classroom. The key fmdings are that both schools in the study lacked books in Oshindonga, and the teachers lacked an understanding of the importance of using books (or other forms of extended text). Other key findings are that teachers had a problem in choosing appropriate texts to read with their learners; teachers understand reading more as decoding than reading for meaning and pleasure; children were not asked any comprehension questions and the two teachers had different views on the value of shared reading. The research data revealed that there are problems in teaching literacy in Namibian African languages.
- Full Text:
- Date Issued: 2011
Probing the biocompatibility of biomedical interfaces using the Quartz Crystal Microbalance with Dissipation
- Authors: Cromhout, Mary
- Date: 2011
- Subjects: Biomedical materials , Nanostructured materials , Biomedical engineering , Quartz crystal microbalances , Blood proteins , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4102 , http://hdl.handle.net/10962/d1010660
- Description: The biomedical application of nanotechnology has come into the spotlight, with the promise of ‘personalised’ therapeutics that couple early diagnosis with targeted therapeutic activity. Due to the rapid growth of the biomedical applications of nanoparticles, along with the lack of understanding concerning their interactions with biomolecules, there is a pressing need for the development of standard methods directed at investigating the effect of introducing these unique particles into the human body. The central aim of this research is to establish a platform directed at assessing the biological fate of pioneering therapeutic particulate agents, such as metallophthalocyanines (MPcs) and multi-walled carbon nanotubes (FMWCNTs). In particular, we proposed, that Quartz Crystal Microbalance with Dissipation (QCM-D) technology may be employed to assess the composition of blood protein corona deposited on the therapeutic surface, and subsequently assess the biocompatibility of such particles. The proposed method of protein detection utilises the nanogram sensitivity of QCM-D technology to monitor highly specific antibody-antigen interactions. In particular those interactions which occur when probe antibodies are used to detect adsorbed blood proteins deposited on target particle-modified sensor surfaces. Protein detection analysis was directed toward identification of surface bound human serum albumin, complement factor C3c, and human plasma fibrinogen. Preliminary analysis of generic biomedical surfaces indicated human serum albumin demonstrates a higher binding affinity towards positively charged surfaces (i.e. cysteamine self-assembled monolayer), followed by hydrophobic surfaces. Detection of complement C3c, corresponded with literature, where lower levels were detected on negatively charged surfaces (i.e. mercapto undecanoic acid self-assembled monolayer), and higher levels of more hydrophobic surfaces (i.e. 11-amino undecane thiol self-assembled monolayer). Human plasma fibrinogen was observed to favour hydrophilic over hydrophobic self-assembled monolayer surfaces, which was in accordance with literature. Application of the proposed protein detection method for biocompatibility analysis of target therapeutic molecules, namely metallophthalocyanines and acid functionalised multi-walled carbon nanotubes, demonstrated a dependence on modified-surface film characteristics, such as surface charge and topography with regards to human serum albumin and human plasma fibrinogen analysis representing new insights into their potential biomolecular interactions The highest levels of detected human serum albumin and complement C3c were detected on the GePcSmix-modified surfaces. AlPcSmix-modified surfaces analysis suggested the highest levels of human plasma fibrinogen. Two methods of acid functionalisation were employed, using both nitric and sulphuric acid, and pure nitric acid. A general increase in detected human serum albumin, corresponding with an increase in functionalisation time, was observed. Complement C3c detection suggested an increase in deposited complement C3c, with increasing functionalisation time, when assessing nitric acid functionalised multi-walled carbon nanotubes, and a decrease, with increasing functionalisation time, when assessing nitric and sulphuric acid functionalised multi-walled carbon nanotubes. Analysis of human plasma fibrinogen was inconclusive, as were cytotoxicity experiments utilising MCF-7 cells in the presence of metallophthalocyanine complexes, raising simultaneously important considerations for their application and study. In the first such detailed examination of its kind it was concluded that the proposed method of protein detection, using QCM-D, allows for the rudimentary but rapid means of analysis of select protein corona deposited on particulate biomedical surfaces.
- Full Text:
- Date Issued: 2011
- Authors: Cromhout, Mary
- Date: 2011
- Subjects: Biomedical materials , Nanostructured materials , Biomedical engineering , Quartz crystal microbalances , Blood proteins , Nanoparticles
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4102 , http://hdl.handle.net/10962/d1010660
- Description: The biomedical application of nanotechnology has come into the spotlight, with the promise of ‘personalised’ therapeutics that couple early diagnosis with targeted therapeutic activity. Due to the rapid growth of the biomedical applications of nanoparticles, along with the lack of understanding concerning their interactions with biomolecules, there is a pressing need for the development of standard methods directed at investigating the effect of introducing these unique particles into the human body. The central aim of this research is to establish a platform directed at assessing the biological fate of pioneering therapeutic particulate agents, such as metallophthalocyanines (MPcs) and multi-walled carbon nanotubes (FMWCNTs). In particular, we proposed, that Quartz Crystal Microbalance with Dissipation (QCM-D) technology may be employed to assess the composition of blood protein corona deposited on the therapeutic surface, and subsequently assess the biocompatibility of such particles. The proposed method of protein detection utilises the nanogram sensitivity of QCM-D technology to monitor highly specific antibody-antigen interactions. In particular those interactions which occur when probe antibodies are used to detect adsorbed blood proteins deposited on target particle-modified sensor surfaces. Protein detection analysis was directed toward identification of surface bound human serum albumin, complement factor C3c, and human plasma fibrinogen. Preliminary analysis of generic biomedical surfaces indicated human serum albumin demonstrates a higher binding affinity towards positively charged surfaces (i.e. cysteamine self-assembled monolayer), followed by hydrophobic surfaces. Detection of complement C3c, corresponded with literature, where lower levels were detected on negatively charged surfaces (i.e. mercapto undecanoic acid self-assembled monolayer), and higher levels of more hydrophobic surfaces (i.e. 11-amino undecane thiol self-assembled monolayer). Human plasma fibrinogen was observed to favour hydrophilic over hydrophobic self-assembled monolayer surfaces, which was in accordance with literature. Application of the proposed protein detection method for biocompatibility analysis of target therapeutic molecules, namely metallophthalocyanines and acid functionalised multi-walled carbon nanotubes, demonstrated a dependence on modified-surface film characteristics, such as surface charge and topography with regards to human serum albumin and human plasma fibrinogen analysis representing new insights into their potential biomolecular interactions The highest levels of detected human serum albumin and complement C3c were detected on the GePcSmix-modified surfaces. AlPcSmix-modified surfaces analysis suggested the highest levels of human plasma fibrinogen. Two methods of acid functionalisation were employed, using both nitric and sulphuric acid, and pure nitric acid. A general increase in detected human serum albumin, corresponding with an increase in functionalisation time, was observed. Complement C3c detection suggested an increase in deposited complement C3c, with increasing functionalisation time, when assessing nitric acid functionalised multi-walled carbon nanotubes, and a decrease, with increasing functionalisation time, when assessing nitric and sulphuric acid functionalised multi-walled carbon nanotubes. Analysis of human plasma fibrinogen was inconclusive, as were cytotoxicity experiments utilising MCF-7 cells in the presence of metallophthalocyanine complexes, raising simultaneously important considerations for their application and study. In the first such detailed examination of its kind it was concluded that the proposed method of protein detection, using QCM-D, allows for the rudimentary but rapid means of analysis of select protein corona deposited on particulate biomedical surfaces.
- Full Text:
- Date Issued: 2011
The Iindaba Ziyafika project: a new community of practice?
- Authors: Nyathi, Sihle
- Date: 2011
- Subjects: Citizen journalism -- South Africa -- Grahamstown Journalism -- South Africa -- Grahamstown Iindaba Ziyafika project Grocott's Mail (Grahamstown, South Africa) Radio journalism -- South Africa -- Grahamstown Online journalism -- South Africa -- Grahamstown Mass media -- Social aspects -- South Africa -- Grahamstown Mass media -- Political aspects -- South Africa -- Grahamstown Journalism -- Objectivity -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3477 , http://hdl.handle.net/10962/d1002932
- Description: This study sought to investigate the practices of citizen journalists in the Iindaba Ziyafika project. The objectives of the research were to explore the evolving practices of citizen journalism in Grahamstown and to extrapolate how citizen journalists are securing a discursive space in relationship to conventional journalism. The study investigated whether the citizen journalists based at Grocotts Mail and Radio Grahamstown are developing practices and patterns that can be distinguished from the practices of conventional journalism. It also evaluated whether the content that is produced by citizen journalists differs from the content that is produced by professional journalists, so that it can be understood as "alternative" and as promoting engaged citizenship. A sub goal was also to explore whether citizen journalism does enable the practice of citizenship through expanding the public sphere. The findings of the research are that in the Iindaba Ziyafika project, citizen journalists see news as a process and not as a series of news events. This is clear departure from event-based news conceptualisation associated with mainstream journalism. They view news as unfolding social processes, allowing citizen journalists to question the factors which would have precipitated the event and investigate the causal factors of particular phenomena. The research also reveals that citizen journalists in the project are engaging in pro-am journalism. Part of the practice of citizen journalists involves a very significant amount of collaboration between professional journalists and citizen journalists. The collaboration is in the production of content and in the presentation of radio broadcasts. Part of the findings of the study are that journalists in the Iindaba Ziyafika project work in different mediums and this calls for them to acquire the competencies of the different mediums. The same citizen journalists produce content for print, radio and for online media. The diction used in the stories published by citizen journalists is couched in struggle and revolutionary language which seems to pit the community against the authorities. The citizen journalists also make use of every daily language in their radio broadcasts and borrow from their cultural expression. This they do through populist methods. The citizen journalists have also integrated communication brokering as part and parcel of their practice. This is because the citizen journalists have also made it their mandate to enable the flow of information between the residents and the local authority. In terms of sourcing there is a deliberate stance to include those who are not ordinarily given a voice in the mainstream media. Women and the poor appear frequently in stories as sources and this is a different scenario from that prevalent in mainstream journalism which frequently covers the rich and the powerful. The citizen journalists in the Iindaba Ziyafika project have also borrowed practices from professional journalism and this has been integrated into their daily practice. This includes following strategic rituals of journalism objectivity and balance.
- Full Text:
- Date Issued: 2011
- Authors: Nyathi, Sihle
- Date: 2011
- Subjects: Citizen journalism -- South Africa -- Grahamstown Journalism -- South Africa -- Grahamstown Iindaba Ziyafika project Grocott's Mail (Grahamstown, South Africa) Radio journalism -- South Africa -- Grahamstown Online journalism -- South Africa -- Grahamstown Mass media -- Social aspects -- South Africa -- Grahamstown Mass media -- Political aspects -- South Africa -- Grahamstown Journalism -- Objectivity -- South Africa -- Grahamstown
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3477 , http://hdl.handle.net/10962/d1002932
- Description: This study sought to investigate the practices of citizen journalists in the Iindaba Ziyafika project. The objectives of the research were to explore the evolving practices of citizen journalism in Grahamstown and to extrapolate how citizen journalists are securing a discursive space in relationship to conventional journalism. The study investigated whether the citizen journalists based at Grocotts Mail and Radio Grahamstown are developing practices and patterns that can be distinguished from the practices of conventional journalism. It also evaluated whether the content that is produced by citizen journalists differs from the content that is produced by professional journalists, so that it can be understood as "alternative" and as promoting engaged citizenship. A sub goal was also to explore whether citizen journalism does enable the practice of citizenship through expanding the public sphere. The findings of the research are that in the Iindaba Ziyafika project, citizen journalists see news as a process and not as a series of news events. This is clear departure from event-based news conceptualisation associated with mainstream journalism. They view news as unfolding social processes, allowing citizen journalists to question the factors which would have precipitated the event and investigate the causal factors of particular phenomena. The research also reveals that citizen journalists in the project are engaging in pro-am journalism. Part of the practice of citizen journalists involves a very significant amount of collaboration between professional journalists and citizen journalists. The collaboration is in the production of content and in the presentation of radio broadcasts. Part of the findings of the study are that journalists in the Iindaba Ziyafika project work in different mediums and this calls for them to acquire the competencies of the different mediums. The same citizen journalists produce content for print, radio and for online media. The diction used in the stories published by citizen journalists is couched in struggle and revolutionary language which seems to pit the community against the authorities. The citizen journalists also make use of every daily language in their radio broadcasts and borrow from their cultural expression. This they do through populist methods. The citizen journalists have also integrated communication brokering as part and parcel of their practice. This is because the citizen journalists have also made it their mandate to enable the flow of information between the residents and the local authority. In terms of sourcing there is a deliberate stance to include those who are not ordinarily given a voice in the mainstream media. Women and the poor appear frequently in stories as sources and this is a different scenario from that prevalent in mainstream journalism which frequently covers the rich and the powerful. The citizen journalists in the Iindaba Ziyafika project have also borrowed practices from professional journalism and this has been integrated into their daily practice. This includes following strategic rituals of journalism objectivity and balance.
- Full Text:
- Date Issued: 2011