A Facile Effective Method for the Synthesis of Au-Cdse Nanostructures and their Characterisations.
- Authors: Gaxela, Nelisa Ncumisa
- Date: 2016-5
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3238 , vital:43198
- Description: ABSTRACT We report the synthesis of aqueous and organically soluble cadmium selenide (CdSe) nanoparticles (NPs) doped with gold via a facile and effective method. Briefly the synthesis involves the reduction of selenium powder using sodium sulphite to produce sodium selenosulphate which acts as the selenium source, followed by the addition of CdX (X = Cl2, CH3COO, NO3). The nanoparticles were passivated with trisodium citrate, mercaptopropanoic acid (MPA), potassium sodium tartarate (PST) and L-cysteine which rendered them soluble in water and also acted as stabilizing agents, while passivation with hexadecylamine (HDA) made them soluble in organic solvent which also enhanced their stability. The high quality of the as-synthesized nanoparticles was confirmed using absorption and photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and high resolution TEM (HRTEM). The systematic study of the effect of mole ratio, temperature, capping agent, growth time, cadmium precursor and ratio of Au on the size, optical and structural properties on the water soluble CdSe nanoparticles were investigated. All the as-synthesised particles, are blue-shifted in relation to the bulk band gap of CdSe. As the Cd: Se mole ratio increases, the intensity of the citrate capped CdSe materials also increases and the particle sizes are in the range of 2.06 – 4.00 nm. When the temperature was increased, the luminescence intensity quenched whereas the particle size increased. As the growth time increased, the intensity increased and then decreased again towards the end of the reaction. When different capping agents were used the particle sizes range from 2.06 – 3.36 nm for citrate, 2.08 – 3.33 nm for MPA, 2.01 – 2.28 nm for L-cysteine and polydispersed for PST. The luminescence intensity decreased in the order citrate > cysteine > PST > MPA when CdCl2 was used as cadmium precursor. When different cadmium precursors were used for L-cysteine, the particle sizes range from 2.06 – 2.31 nm for Cd(CH3COO)2 and 2.00 – 2.37 nm for Cd(NO3)2 while the intensity increased as the reaction time increased, however, still lower than the CdCl2 materials. The effect of Au ratio showed that the intensity of Au-doped cysteine capped-CdSe increased as the Au ratio decreased. The systematic study of the effect of temperature and growth time in the organic soluble CdSe nanoparticles on the size, optical and structural properties was also investigated. All the as-synthesised particles were blue-shifted in relation to the bulk CdSe. As the temperature increased the particle sizes of the undoped materials range between 2.92 – 2.95 nm at 160 °C and 5.35 – 5.39 nm at 200 °C while for the doped materials the particle size range from 2.53 – 2.61 nm at 160 °C, 3.97 nm at 200 °C and 4.20 – 4.72 nm at 240 °C. The intensity of the doped materials increased as the reaction time increased and then decreased again towards the end of the reaction. After ligand exchange the intensity of the as-synthesized doped and undoped-CdSe NPs was very low compare to the parent organically capped doped and un-doped CdSe. It was discovered that without any further purification, the quality of the materials formed by this method is comparable to that of the best CdSe NPs reported in the literature. This method is safe, inexpensive and reproducible. , Thesis (MsC Chemistry) -- Faculty of Natural Sciences, 2019
- Full Text:
- Date Issued: 2016-5
- Authors: Gaxela, Nelisa Ncumisa
- Date: 2016-5
- Language: English
- Type: Masters theses , text
- Identifier: http://hdl.handle.net/11260/3238 , vital:43198
- Description: ABSTRACT We report the synthesis of aqueous and organically soluble cadmium selenide (CdSe) nanoparticles (NPs) doped with gold via a facile and effective method. Briefly the synthesis involves the reduction of selenium powder using sodium sulphite to produce sodium selenosulphate which acts as the selenium source, followed by the addition of CdX (X = Cl2, CH3COO, NO3). The nanoparticles were passivated with trisodium citrate, mercaptopropanoic acid (MPA), potassium sodium tartarate (PST) and L-cysteine which rendered them soluble in water and also acted as stabilizing agents, while passivation with hexadecylamine (HDA) made them soluble in organic solvent which also enhanced their stability. The high quality of the as-synthesized nanoparticles was confirmed using absorption and photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and high resolution TEM (HRTEM). The systematic study of the effect of mole ratio, temperature, capping agent, growth time, cadmium precursor and ratio of Au on the size, optical and structural properties on the water soluble CdSe nanoparticles were investigated. All the as-synthesised particles, are blue-shifted in relation to the bulk band gap of CdSe. As the Cd: Se mole ratio increases, the intensity of the citrate capped CdSe materials also increases and the particle sizes are in the range of 2.06 – 4.00 nm. When the temperature was increased, the luminescence intensity quenched whereas the particle size increased. As the growth time increased, the intensity increased and then decreased again towards the end of the reaction. When different capping agents were used the particle sizes range from 2.06 – 3.36 nm for citrate, 2.08 – 3.33 nm for MPA, 2.01 – 2.28 nm for L-cysteine and polydispersed for PST. The luminescence intensity decreased in the order citrate > cysteine > PST > MPA when CdCl2 was used as cadmium precursor. When different cadmium precursors were used for L-cysteine, the particle sizes range from 2.06 – 2.31 nm for Cd(CH3COO)2 and 2.00 – 2.37 nm for Cd(NO3)2 while the intensity increased as the reaction time increased, however, still lower than the CdCl2 materials. The effect of Au ratio showed that the intensity of Au-doped cysteine capped-CdSe increased as the Au ratio decreased. The systematic study of the effect of temperature and growth time in the organic soluble CdSe nanoparticles on the size, optical and structural properties was also investigated. All the as-synthesised particles were blue-shifted in relation to the bulk CdSe. As the temperature increased the particle sizes of the undoped materials range between 2.92 – 2.95 nm at 160 °C and 5.35 – 5.39 nm at 200 °C while for the doped materials the particle size range from 2.53 – 2.61 nm at 160 °C, 3.97 nm at 200 °C and 4.20 – 4.72 nm at 240 °C. The intensity of the doped materials increased as the reaction time increased and then decreased again towards the end of the reaction. After ligand exchange the intensity of the as-synthesized doped and undoped-CdSe NPs was very low compare to the parent organically capped doped and un-doped CdSe. It was discovered that without any further purification, the quality of the materials formed by this method is comparable to that of the best CdSe NPs reported in the literature. This method is safe, inexpensive and reproducible. , Thesis (MsC Chemistry) -- Faculty of Natural Sciences, 2019
- Full Text:
- Date Issued: 2016-5
Public-private partnerships as an alternative mechanism for effective public service delivery in Johannesburg Metropolitan Municipality, Gauteng Province, Republic of South Africa
- Authors: Madziro, Emmanuel Kudzanai
- Date: 2016-11
- Subjects: Public-private sector cooperation , Municipal services , Local government
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22990 , vital:53396
- Description: Public-Private Partnerships developed in the 1980`s mainly associated with privatising and laissez faire concept and it emerged with the leadership of Regan in the USA and Thatcher in the UK. During this period the role of national governments was intensely debated (Deloitte, 2010). These debates generated the notion of New Public Management theory, that tried to use competitive techniques and certain free market principles within government entities that considered the involvement of the free enterprise in the provision of government service delivery (Kaberuka, 2011). Public-Private Partnerships are a vital component; it is the main reason why they were recognized significantly particularly during the 1990s, predominantly in first world countries and subsequently in developing countries. Basically a Public Private Partnership (PPP) denotes a legal agreement between the public sector and a private enterprise (Kaberuka, 2011). It aims to unite the ability of both public and private sector in manner that will ensure that neither of the side execute the plan on its own. Under this binding agreement, the expertise and wealth, assets of both public and private sector procedure of decision-making are used mutually during the provision of public services or facilities. Both of these parties carry the risk associated, as well as the benefits that will be accrued from the projects. There are particular reasons why the public sector prefers PPPs. These include reduction of the total costs and the primary expenditure that will allow the private sector to help in the elimination of the expenditures to be incurred. (Reynaers et al, 2014). Some of the reasons include the lack of government managerial competencies and certain technical expertise. Furthermore, efficient and novelty in the delivering of public services and goods mainly due to the ability of private sector to have leadership and managerial competencies that allow the provision of supplementary benefits in the PPP in contradictory to conventional projects. (Reynaers et al, 2014). PPPs also ensure competitiveness between the private and public sector entities, which encourage the elimination of unnecessary expenses and the provision of standard services. One of the main characteristics of PPPs is the amalgamating and generation provision of particular public services (Raja et al, 2011). This mean that the particular private entity will execute both projects. Hence therefore, it will have less commitment pertaining to the prioritization of the construction phase, given the fact that it will accrue rewards in the future, particularly during the operation stage. (Raja et al, 2011). This mechanism is pragmatic if the magnitude of service that has to be provided when the quality of service that has to be provided can be precisely be depicted and examined during the course of contractual legal discussion between the two parties. Facilities are usually transferred to the public sector after a pre-determined period. The responsibilities of public and private sector must be specified during the discussion of the contractual agreement. The public participant should the assume the responsibility for establishing social benefit of a project, facilitating with influential decision makers, evaluation of standards, guaranteeing the interests of the public, consequently it should also assume the financial unprofitability of investments, the approximation of the expenditure and sup ply of fundamental information pertaining the projects (Heald et al, 2011). Public-private partnership is a relationship that necessitates the inclusion of both stakeholders which include the private and public sector. PPPs are perceived as solution for effective provision of social infrastructure that is vital for economic development and consistency in both developing and developing worlds (Heald et al 2011). The fiscal, expertise, and lack of competency personnel in public sector can be resolved through engaging the concept of PPPs. , Thesis (MPA) -- Faculty of Management and Commerce, 2016
- Full Text:
- Date Issued: 2016-11
- Authors: Madziro, Emmanuel Kudzanai
- Date: 2016-11
- Subjects: Public-private sector cooperation , Municipal services , Local government
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22990 , vital:53396
- Description: Public-Private Partnerships developed in the 1980`s mainly associated with privatising and laissez faire concept and it emerged with the leadership of Regan in the USA and Thatcher in the UK. During this period the role of national governments was intensely debated (Deloitte, 2010). These debates generated the notion of New Public Management theory, that tried to use competitive techniques and certain free market principles within government entities that considered the involvement of the free enterprise in the provision of government service delivery (Kaberuka, 2011). Public-Private Partnerships are a vital component; it is the main reason why they were recognized significantly particularly during the 1990s, predominantly in first world countries and subsequently in developing countries. Basically a Public Private Partnership (PPP) denotes a legal agreement between the public sector and a private enterprise (Kaberuka, 2011). It aims to unite the ability of both public and private sector in manner that will ensure that neither of the side execute the plan on its own. Under this binding agreement, the expertise and wealth, assets of both public and private sector procedure of decision-making are used mutually during the provision of public services or facilities. Both of these parties carry the risk associated, as well as the benefits that will be accrued from the projects. There are particular reasons why the public sector prefers PPPs. These include reduction of the total costs and the primary expenditure that will allow the private sector to help in the elimination of the expenditures to be incurred. (Reynaers et al, 2014). Some of the reasons include the lack of government managerial competencies and certain technical expertise. Furthermore, efficient and novelty in the delivering of public services and goods mainly due to the ability of private sector to have leadership and managerial competencies that allow the provision of supplementary benefits in the PPP in contradictory to conventional projects. (Reynaers et al, 2014). PPPs also ensure competitiveness between the private and public sector entities, which encourage the elimination of unnecessary expenses and the provision of standard services. One of the main characteristics of PPPs is the amalgamating and generation provision of particular public services (Raja et al, 2011). This mean that the particular private entity will execute both projects. Hence therefore, it will have less commitment pertaining to the prioritization of the construction phase, given the fact that it will accrue rewards in the future, particularly during the operation stage. (Raja et al, 2011). This mechanism is pragmatic if the magnitude of service that has to be provided when the quality of service that has to be provided can be precisely be depicted and examined during the course of contractual legal discussion between the two parties. Facilities are usually transferred to the public sector after a pre-determined period. The responsibilities of public and private sector must be specified during the discussion of the contractual agreement. The public participant should the assume the responsibility for establishing social benefit of a project, facilitating with influential decision makers, evaluation of standards, guaranteeing the interests of the public, consequently it should also assume the financial unprofitability of investments, the approximation of the expenditure and sup ply of fundamental information pertaining the projects (Heald et al, 2011). Public-private partnership is a relationship that necessitates the inclusion of both stakeholders which include the private and public sector. PPPs are perceived as solution for effective provision of social infrastructure that is vital for economic development and consistency in both developing and developing worlds (Heald et al 2011). The fiscal, expertise, and lack of competency personnel in public sector can be resolved through engaging the concept of PPPs. , Thesis (MPA) -- Faculty of Management and Commerce, 2016
- Full Text:
- Date Issued: 2016-11
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Community Dialogues, stakeholders' process and experts' input - two detailed reports
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , Government, Resistance to -- South Africa , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41348 , vital:36452 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , Government, Resistance to -- South Africa , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41348 , vital:36452 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Conference Publication: Healing Through Heritage and Memorialisation
- Date: 2016-10
- Subjects: South Africa -- Politics and government , South Africa -- History -- 20th century , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41338 , vital:36451 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: South Africa -- Politics and government , South Africa -- History -- 20th century , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41338 , vital:36451 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Educational Programme (including a healing component)
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41358 , vital:36453 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41358 , vital:36453 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Institutional structure, governance and management model (including a tool box to establish a legal entity and to manage an NPO)
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41368 , vital:36454 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: South Africa -- History -- 20th century , South Africa -- Politics and government , Government, Resistance to -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41368 , vital:36454 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Oral accounts of people affected by the 1990 Uprising
- Date: 2016-10
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41251 , vital:36422 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41251 , vital:36422 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
Feasibility Study: Imagining A Cultural/Healing Centre for the Northern Areas of Nelson Mandela Bay: Project introduction, historical overview, case studies and recommended sites
- Date: 2016-10
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41239 , vital:36420 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
- Date: 2016-10
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10948/41239 , vital:36420 , Bulk File 7
- Description: The Northern Areas History and Heritage Project consists of a variety workshops and materials examining the history of this part of Port Elizabeth to which people of colour had been removed in the 1970s. The materials include a book and DVD on the Northern Areas Uprising; six booklets entitled ‘Feasibility Study: Imagining a Cultural/ Healing Centre for the Northern Areas of Nelson Mandela Bay’ covering topics such as the Northern Areas Uprising, healing through memorialisation, architecture, non-profit organisations, archives and databases; 35 DVDs consisting of interviews with individuals, communities and focus groups, as well as a Winter School Project on Apartheid and the Group Areas Act. Also included are two maps relating to the area’s history.
- Full Text: false
- Date Issued: 2016-10
An exploration of knowledge sharing as a means of improving municipal governance in selected Limpopo municipalities
- Dikotla, Maoka Andries https://orcid.org/0000-0002-6699-6782
- Authors: Dikotla, Maoka Andries https://orcid.org/0000-0002-6699-6782
- Date: 2016-08
- Subjects: Knowledge management , Information services , Organizational learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24750 , vital:63548
- Description: The aim of this study was to underscore the role of knowledge sharing in improving the municipal governance in the local government sector of South Africa. The objectives of the study were to find out the kind of knowledge management programmes which are in place in the municipalities of Limpopo Province; establish the extent to which municipalities in Limpopo encourage knowledge sharing for improvement of municipal governance; determine factors which affect knowledge sharing among employees of municipalities of Limpopo Province, and propose recommendations and strategies on how to optimally share knowledge in Limpopo municipalities. The nature of this study warranted the use of two research paradigms, namely positivist and interpretivist approaches. The study employed an integrated research method which covered both the qualitative and quantitative approach. In collecting data, data instruments were triangulated. In this regard, the researcher mostly used a questionnaire with little employment of interviews and observation. The researcher sampled 438 employees and 21 managers from the selected municipalities. Quantitative data was analysed using IBM Statistical Package for Social Science (SPSS) version 23. Qualitative data was analysed using thematic analysis. The major findings of the study are the following: poor knowledge management programmes in Limpopo municipalities, knowledge sharing among the employees and across the municipalities is not encouraged, knowledge sharing in Limpopo municipalities is affected by both individual and organisational barriers and under-utilisation of information communication technology tools to support knowledge management programmes and practices. Comparatively, the findings of this study to a large extent support what has been recorded in literature. However, the study contradicts a typical mind set of many people that “knowledge is power” and cannot be shared freely. The study recommended to Limpopo municipalities to develop Knowledge sharing strategies that need to be linked to municipal strategic plans; involvement of top management in knowledge management activities; development of knowledge-friendly culture and utilisation of information communication technology tools in support of knowledge sharing. Some recommendations for further study were also provided. Among others, the study recommended that a study on the use of incentive systems as a means of encouraging knowledge sharing be conducted in selected municipalities. This was because studies on the use of incentive systems for motivating knowledge sharing yielded contradictory findings in many organisations. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2016
- Full Text:
- Date Issued: 2016-08
- Authors: Dikotla, Maoka Andries https://orcid.org/0000-0002-6699-6782
- Date: 2016-08
- Subjects: Knowledge management , Information services , Organizational learning
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24750 , vital:63548
- Description: The aim of this study was to underscore the role of knowledge sharing in improving the municipal governance in the local government sector of South Africa. The objectives of the study were to find out the kind of knowledge management programmes which are in place in the municipalities of Limpopo Province; establish the extent to which municipalities in Limpopo encourage knowledge sharing for improvement of municipal governance; determine factors which affect knowledge sharing among employees of municipalities of Limpopo Province, and propose recommendations and strategies on how to optimally share knowledge in Limpopo municipalities. The nature of this study warranted the use of two research paradigms, namely positivist and interpretivist approaches. The study employed an integrated research method which covered both the qualitative and quantitative approach. In collecting data, data instruments were triangulated. In this regard, the researcher mostly used a questionnaire with little employment of interviews and observation. The researcher sampled 438 employees and 21 managers from the selected municipalities. Quantitative data was analysed using IBM Statistical Package for Social Science (SPSS) version 23. Qualitative data was analysed using thematic analysis. The major findings of the study are the following: poor knowledge management programmes in Limpopo municipalities, knowledge sharing among the employees and across the municipalities is not encouraged, knowledge sharing in Limpopo municipalities is affected by both individual and organisational barriers and under-utilisation of information communication technology tools to support knowledge management programmes and practices. Comparatively, the findings of this study to a large extent support what has been recorded in literature. However, the study contradicts a typical mind set of many people that “knowledge is power” and cannot be shared freely. The study recommended to Limpopo municipalities to develop Knowledge sharing strategies that need to be linked to municipal strategic plans; involvement of top management in knowledge management activities; development of knowledge-friendly culture and utilisation of information communication technology tools in support of knowledge sharing. Some recommendations for further study were also provided. Among others, the study recommended that a study on the use of incentive systems as a means of encouraging knowledge sharing be conducted in selected municipalities. This was because studies on the use of incentive systems for motivating knowledge sharing yielded contradictory findings in many organisations. , Thesis (PhD) -- Faculty of Social Sciences and Humanities, 2016
- Full Text:
- Date Issued: 2016-08
Analysis of work environment factors as correlate of school management teams' productivity in Mount Frere Education District
- Authors: Majova, L A
- Date: 2016-08
- Subjects: School management teams , School management and organization
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24684 , vital:63516
- Description: There is a perception that SMTs are not effective in some schools in South Africa. Hence, a huge number of learners in the public schools, particularly in high schools are not getting a good pass in their matric exams. The ineffectiveness of SMTs in some schools results in poor performance, as evidenced in poor matric results ever since 1994 in Mount Frere District, since the end of the homeland system in South Africa. To this end, the study was conducted to analyse work environment factors that affect productivity of school management teams‟ in Mount Frere Education District. Therefore, 64 schools, which formed the sample in this study, were selected randomly from the target of 210 schools (population) in Mount Frere District of Education. It was revealed that the following factors are central to the ineffectiveness of SMTs: lack of knowledge, skills, behaviours and attitudes, Human immune deficiency virus (HIV); redeployment; teachers‟ absenteeism and non-availability and mismanagement of resources. Consequently, the researcher employed quantitative research method to explore the work environment of SMTs in Mount Frere District of Education. To collect data from the SMTs, the SMT Productivity Questionnaire (SPQ) and the SMT performance appraisal form (SPAF) were used. The results were analysed using descriptive statistics like frequency count, percentages, charts and tables, and inferential statistics of Pearson product moment correlation (PPMC). It was discovered that the work environmental factors as espoused by the literature, negatively affect the performance or productivity of SMTs. The findings in the data analysis prove beyond reasonable doubt that redeployment of educators negatively affects the productivity of School Management Teams in various schools. In other words, the study confirmed the literature. , Thesis (MEd) -- Faculty of Education, 2016
- Full Text:
- Date Issued: 2016-08
- Authors: Majova, L A
- Date: 2016-08
- Subjects: School management teams , School management and organization
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24684 , vital:63516
- Description: There is a perception that SMTs are not effective in some schools in South Africa. Hence, a huge number of learners in the public schools, particularly in high schools are not getting a good pass in their matric exams. The ineffectiveness of SMTs in some schools results in poor performance, as evidenced in poor matric results ever since 1994 in Mount Frere District, since the end of the homeland system in South Africa. To this end, the study was conducted to analyse work environment factors that affect productivity of school management teams‟ in Mount Frere Education District. Therefore, 64 schools, which formed the sample in this study, were selected randomly from the target of 210 schools (population) in Mount Frere District of Education. It was revealed that the following factors are central to the ineffectiveness of SMTs: lack of knowledge, skills, behaviours and attitudes, Human immune deficiency virus (HIV); redeployment; teachers‟ absenteeism and non-availability and mismanagement of resources. Consequently, the researcher employed quantitative research method to explore the work environment of SMTs in Mount Frere District of Education. To collect data from the SMTs, the SMT Productivity Questionnaire (SPQ) and the SMT performance appraisal form (SPAF) were used. The results were analysed using descriptive statistics like frequency count, percentages, charts and tables, and inferential statistics of Pearson product moment correlation (PPMC). It was discovered that the work environmental factors as espoused by the literature, negatively affect the performance or productivity of SMTs. The findings in the data analysis prove beyond reasonable doubt that redeployment of educators negatively affects the productivity of School Management Teams in various schools. In other words, the study confirmed the literature. , Thesis (MEd) -- Faculty of Education, 2016
- Full Text:
- Date Issued: 2016-08
Entrepreneurial development paths and livelihood strategies in smallholder irrigation schemes in the Eastern Cape province, South Africa
- Gidi, Lungile Sivuyile https://orcid.org/0000-0002-2896-2709
- Authors: Gidi, Lungile Sivuyile https://orcid.org/0000-0002-2896-2709
- Date: 2016-07
- Subjects: Farms, Small , Irrigation farming -- Economic aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24906 , vital:63670
- Description: South Africa has implemented several successful rural poverty relief initiatives; however, poverty continues to strain rural development efforts. The aim of the study was to analyse the entrepreneurial development paths and livelihood strategies in smallholder irrigation schemes in the Eastern Cape Province of South Africa. The study has outlined five hypothesizes for the basis of concrete scientific research. Initially the study hypothesizes that a smallholder’s socio-cultural contexts such as village level institutions especially village governance as well as household circumstances including age, education and gender compositions of the household membership as well as household income can determine a smallholder’s transformation ability. The second hypothesis was that alternative economic activities especially farming activities such as livestock and crop production as well as off-farm economic opportunities which were open to a household could influence a smallholder’s willingness to change from homestead gardening to food crop production under government irrigation programme. The third hypothesis was on the smallholder’s assessment of available market for the products of his or her food crop irrigation farming which could be an important consideration in his or her willingness to change. The fourth assumption was that entrepreneurial skills are lacking, in particular the ability to search for opportunities and willingness to do something different than the masses and take risks in that process. Finally, the study hypothesized that the government irrigation scheme governance could determine the attractiveness of the scheme and thereby influencing the willingness of a smallholder to participate. Specifically, the legal and regulatory environments are very restrictive and they are not conducive to effective value and job creation in the villages and for the principal crop and livestock enterprises. The study used cross-sectional data collected from both scheme farmers and non-scheme farmers. There were 107 smallholder farmers administered. Cobb-Douglass production and Multiple Regression Models were used. The results indicated 62 percent were male household head and 38 percent were female household head. The majority of the farmers were above middle age for both men and women households head. Specifically, about 80percent were above 51 years of age. Wage employment on the other hand contributed 8percent for both scheme and non-scheme farmers. The majority of the family members were dominated by students and pensioners indicating 27percent of the respondents who were unemployed, among them students were included and pensioners were indicated by 9percent. The overall findings were that there are important differences in behavior regarding the transition from homestead gardening to irrigation farming. Smallholder farmers of Mnquma and Mbhashe municipalities have a great potential in maize, beans, potatoes, pumpkin, butternut production, as well as cattle, sheep, goats, pigs and poultry production. Lastly, the study has highlighted various factors affecting livelihoods sources. Therefore, there is a need for these smallholder farmers to engage consistently with the market to enhance information flow. Extension officers must play a role using the recent extension approach of participatory rural appraisal through discussions with farmers and empower them for marketing problems and solutions. Smallholder farmers must ensure frequent consultation with extension or agricultural advisors for financial and production input support. Government need to strengthen agricultural activities in the rural areas in order to sustain rural livelihoods for rural dwellers. Once the rural economy becomes transformed through agricultural activities then rural dwellers can achieve good standard of living in line with a key macroeconomic objective the South African government. , Thesis (PhD) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-07
- Authors: Gidi, Lungile Sivuyile https://orcid.org/0000-0002-2896-2709
- Date: 2016-07
- Subjects: Farms, Small , Irrigation farming -- Economic aspects
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24906 , vital:63670
- Description: South Africa has implemented several successful rural poverty relief initiatives; however, poverty continues to strain rural development efforts. The aim of the study was to analyse the entrepreneurial development paths and livelihood strategies in smallholder irrigation schemes in the Eastern Cape Province of South Africa. The study has outlined five hypothesizes for the basis of concrete scientific research. Initially the study hypothesizes that a smallholder’s socio-cultural contexts such as village level institutions especially village governance as well as household circumstances including age, education and gender compositions of the household membership as well as household income can determine a smallholder’s transformation ability. The second hypothesis was that alternative economic activities especially farming activities such as livestock and crop production as well as off-farm economic opportunities which were open to a household could influence a smallholder’s willingness to change from homestead gardening to food crop production under government irrigation programme. The third hypothesis was on the smallholder’s assessment of available market for the products of his or her food crop irrigation farming which could be an important consideration in his or her willingness to change. The fourth assumption was that entrepreneurial skills are lacking, in particular the ability to search for opportunities and willingness to do something different than the masses and take risks in that process. Finally, the study hypothesized that the government irrigation scheme governance could determine the attractiveness of the scheme and thereby influencing the willingness of a smallholder to participate. Specifically, the legal and regulatory environments are very restrictive and they are not conducive to effective value and job creation in the villages and for the principal crop and livestock enterprises. The study used cross-sectional data collected from both scheme farmers and non-scheme farmers. There were 107 smallholder farmers administered. Cobb-Douglass production and Multiple Regression Models were used. The results indicated 62 percent were male household head and 38 percent were female household head. The majority of the farmers were above middle age for both men and women households head. Specifically, about 80percent were above 51 years of age. Wage employment on the other hand contributed 8percent for both scheme and non-scheme farmers. The majority of the family members were dominated by students and pensioners indicating 27percent of the respondents who were unemployed, among them students were included and pensioners were indicated by 9percent. The overall findings were that there are important differences in behavior regarding the transition from homestead gardening to irrigation farming. Smallholder farmers of Mnquma and Mbhashe municipalities have a great potential in maize, beans, potatoes, pumpkin, butternut production, as well as cattle, sheep, goats, pigs and poultry production. Lastly, the study has highlighted various factors affecting livelihoods sources. Therefore, there is a need for these smallholder farmers to engage consistently with the market to enhance information flow. Extension officers must play a role using the recent extension approach of participatory rural appraisal through discussions with farmers and empower them for marketing problems and solutions. Smallholder farmers must ensure frequent consultation with extension or agricultural advisors for financial and production input support. Government need to strengthen agricultural activities in the rural areas in order to sustain rural livelihoods for rural dwellers. Once the rural economy becomes transformed through agricultural activities then rural dwellers can achieve good standard of living in line with a key macroeconomic objective the South African government. , Thesis (PhD) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-07
Cultural and social factors affecting crop production at Gqumahashe and Melani, Alice District
- Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Authors: Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Date: 2016-06
- Subjects: Sharecropping , Food crops
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23023 , vital:55001
- Description: Over the years, sharecropping and work-parties have been seen as variables that maintain social cohesion among people and maximize agricultural production. This study seeks to validate the authenticity of this assertion in the context of two neighbouring villages. Although there are other variables that affect crop production in the study areas, Lower Gqumahashe and Melani, in the light of time constraints and the insignificant impact of these variables, the study focused only on sharecropping and work-parties. The study adopted empirical research design. The researcher realised that empirical research design would offer him an opportunity for intense or prolonged contact with informants in order to have a holistic picture of their behaviour. The researcher did not choose theoretical research design because it would not allow him to have an extensive interaction with informants since it relies on secondary data. The findings of the study suggest that sharecropping and work parties are the main variables that hinder the rate of crop production in the study areas. However, there are other secondary variables hindering crop production but they have insignificant impact. These are clan and kinship relations, political structure, religion and social identity. This study concludes that although local informants were in favour of sharecropping and work-parties in the past, they have discontinued them due to exploitation and hoodwinking. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
- Authors: Komanisi, Mzwandile Paul 0000-0003-0866-666X
- Date: 2016-06
- Subjects: Sharecropping , Food crops
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/23023 , vital:55001
- Description: Over the years, sharecropping and work-parties have been seen as variables that maintain social cohesion among people and maximize agricultural production. This study seeks to validate the authenticity of this assertion in the context of two neighbouring villages. Although there are other variables that affect crop production in the study areas, Lower Gqumahashe and Melani, in the light of time constraints and the insignificant impact of these variables, the study focused only on sharecropping and work-parties. The study adopted empirical research design. The researcher realised that empirical research design would offer him an opportunity for intense or prolonged contact with informants in order to have a holistic picture of their behaviour. The researcher did not choose theoretical research design because it would not allow him to have an extensive interaction with informants since it relies on secondary data. The findings of the study suggest that sharecropping and work parties are the main variables that hinder the rate of crop production in the study areas. However, there are other secondary variables hindering crop production but they have insignificant impact. These are clan and kinship relations, political structure, religion and social identity. This study concludes that although local informants were in favour of sharecropping and work-parties in the past, they have discontinued them due to exploitation and hoodwinking. , Thesis (PhD) -- Faculty of Social Science and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
Health factors associated with traditional circumcision of adolescent males in Alice, Raymond Mhlaba local municipality, Eastern Cape
- Mpateni, Aphiwe https://orcid.org/0000-0002-6823-9179
- Authors: Mpateni, Aphiwe https://orcid.org/0000-0002-6823-9179
- Date: 2016-06
- Subjects: Circumcision , Penis -- Surgery http://id.loc.gov/authorities/subjects/sh85099485
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19726 , vital:43183
- Description: This research explored the health challenges associated with male adolescents during traditional male circumcision in Alice,Raymond Mhlaba Local Municipality in Eastern Cape. This researcher used the views, attitudes and perceptions of the male adolescents who recently underwent traditional male circumcision, the parents of the male adolescents, health practitioners, community leaders, traditional nurses, traditional surgeons and a member of Association of Ingcibi Namakhankatha. The research study aimed at achieving the following specific objectives: 1. to interrogate the attitudes and views of people on the health factors associated with male adolescents who undergo traditional male circumcision 2; to establish the psychological, social, emotional and behavioural impacts of health challenges experienced by male adolescents undergoing male traditional circumcision; and 3. to document the health hazards experienced by male adolescents undergoing during traditional male circumcision. This researcher espoused a qualitative research method. The study was conducted through qualitative research instruments such as in-depth interviews, focus groups interviews and key informants in collecting the data. The study utilized socio cultural theory. The smaple in this study was made up of 25 participants: five (5) traditionally circumcised youth, ten (10) health practitioners, five (5) parents, one (1) traditional surgeon, two (2) traditional nurses, one (1) community leader and one (1) member of Association of Ingcibi Namakhankatha. Non probability sampling methodology was used, specifically purposive sampling to select the participants because of their knowledge and experiences about traditional male circumcision. Data was analysed thematically. The study came with the following findings: An array of health hazard experienced associated with circumcision rite; Horror emanating from the deaths of the initiates; Possible contraction and transmission of diseases during the rite; Cultural custodians disregarding health ethos and sanitation; Traditional male circumcision becoming a forum of learning immoral behaviours; Tightening of the bandages was believed to expedite healing; Amputation of penis due to complications; Psychological and emotional state of the initiates who suffer clinical hazards; Incompetence of traditional surgeons and untrained traditional nurses compromising the health of the initiates; Parental ignorance leading to their sons falling victims of the clinical health hazards; and subjugation of women in cultural practices. The research study made the following recommendations: strengthening the monitoring and evaluation of traditional practitioners; Community engagements by training boys to prepare for traditional male circumcision; Emphasizing the role of culture as stated by section 31 of the South African constitution; bolstering the selection criteria of traditional nurses.The traditional male circumcision practice to enlist the role of women as important stakeholders because they are the mothers; and imposing strict penalties against cultural custodians operating illegal schools This researcher, therefore, hopes that all the health hazards associated with male adolescents during traditional male circumcision can be addressed and that the government and the communities need to engage one another inorder to come with ways and strategies of managing cultures. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
- Authors: Mpateni, Aphiwe https://orcid.org/0000-0002-6823-9179
- Date: 2016-06
- Subjects: Circumcision , Penis -- Surgery http://id.loc.gov/authorities/subjects/sh85099485
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/19726 , vital:43183
- Description: This research explored the health challenges associated with male adolescents during traditional male circumcision in Alice,Raymond Mhlaba Local Municipality in Eastern Cape. This researcher used the views, attitudes and perceptions of the male adolescents who recently underwent traditional male circumcision, the parents of the male adolescents, health practitioners, community leaders, traditional nurses, traditional surgeons and a member of Association of Ingcibi Namakhankatha. The research study aimed at achieving the following specific objectives: 1. to interrogate the attitudes and views of people on the health factors associated with male adolescents who undergo traditional male circumcision 2; to establish the psychological, social, emotional and behavioural impacts of health challenges experienced by male adolescents undergoing male traditional circumcision; and 3. to document the health hazards experienced by male adolescents undergoing during traditional male circumcision. This researcher espoused a qualitative research method. The study was conducted through qualitative research instruments such as in-depth interviews, focus groups interviews and key informants in collecting the data. The study utilized socio cultural theory. The smaple in this study was made up of 25 participants: five (5) traditionally circumcised youth, ten (10) health practitioners, five (5) parents, one (1) traditional surgeon, two (2) traditional nurses, one (1) community leader and one (1) member of Association of Ingcibi Namakhankatha. Non probability sampling methodology was used, specifically purposive sampling to select the participants because of their knowledge and experiences about traditional male circumcision. Data was analysed thematically. The study came with the following findings: An array of health hazard experienced associated with circumcision rite; Horror emanating from the deaths of the initiates; Possible contraction and transmission of diseases during the rite; Cultural custodians disregarding health ethos and sanitation; Traditional male circumcision becoming a forum of learning immoral behaviours; Tightening of the bandages was believed to expedite healing; Amputation of penis due to complications; Psychological and emotional state of the initiates who suffer clinical hazards; Incompetence of traditional surgeons and untrained traditional nurses compromising the health of the initiates; Parental ignorance leading to their sons falling victims of the clinical health hazards; and subjugation of women in cultural practices. The research study made the following recommendations: strengthening the monitoring and evaluation of traditional practitioners; Community engagements by training boys to prepare for traditional male circumcision; Emphasizing the role of culture as stated by section 31 of the South African constitution; bolstering the selection criteria of traditional nurses.The traditional male circumcision practice to enlist the role of women as important stakeholders because they are the mothers; and imposing strict penalties against cultural custodians operating illegal schools This researcher, therefore, hopes that all the health hazards associated with male adolescents during traditional male circumcision can be addressed and that the government and the communities need to engage one another inorder to come with ways and strategies of managing cultures. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2016
- Full Text:
- Date Issued: 2016-06
Evaluation of cellulase and xylanase production by two actinobacteria species belonging to the Micrococcus genus isolated from decaying lignocellulosic biomass
- Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
- Authors: Mmango-Kaseke, Ziyanda https://orcid.org/0000-0002-8936-1149
- Date: 2016-05
- Subjects: Lignocellulose , Biomass energy
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24197 , vital:62442
- Description: Bacteria were isolated from sawdust and screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC) and birchwood xylan agar. The bacteria showing halo forms around the colony were selected for further analyses and those isolates with the highest cumulative halozone size (isolate PLY1 and MLY10) were chosen for detailed studies. Evaluation of cellulase and xylanase production by saw dust actinobacterial species whose 16S rDNA nucleotide sequences were deposited in GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371 and Micrococcus yunnanensis strain SAMRC-UFH4 with accession number KU171372. Optimum culture conditions for the production of cellulase for respective axenic culture include incubation period (96 h), incubation temperature (25oC), agitation speed (50 rpm), and pH 5. For xylanase production, the optimum culture conditions in the presence of 1percent (w/v) birchwood xylan include incubation period (84 h), incubation temperature (25oC), agitation speed (200 rpm), and pH 10. For Micrococcus yunnanensis strain SAMRC-UFH4 cellulase production was optimal under such conditions as, incubation temperature (30oC), agitation speed (0 rpm), and pH 5, while xylanase production was optimal at, incubation temperature (30oC), agitation speed (150 rpm), and pH 10. The high cellulase and xylanase activity obtained from these isolates suggest suitability of the organisms as important candidates for commercial application. , Thesis (MSc) -- Faculty of Science and Agriculture, 2016
- Full Text:
- Date Issued: 2016-05
The implementation of foundational provision programmes in a rural based University in South Africa: implications for student academic development practices
- Authors: Marhaya, Luyanda
- Date: 2016-05
- Subjects: Education, Higher -- South Africa , College student development programs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24706 , vital:63529
- Description: The purpose was to establish how foundational provision programmes were implemented in a rural based university in South Africa and implications to student development practices. The study was located in the- post- positivism research paradigm, followed a mixed methods research approach and utilised a concurrent triangulation research design. For the qualitative component of the research, participants (academics and Coordinators of the foundation programmes and senior students who had enrolled through foundational provision programmes) were purposively sampled. The sample for the quantitative data comprised all the students who enrolled in foundation provision programmes between the years 2008 to 2011 and mainstream students who had enrolled between the years 2009 and 2012. For qualitative approach, focus group discussions were conducted, semi-structured interviews and document analysis. Quantitative data was sought from university institutional data storage warehouse, HIGHER EDUCATION MANAGEMENT INFORMATION SYSTEM (HEMIS). For qualitative approach, the data analysis for all data collection methods was done through thematic analysis. For quantitative approach, a longitudinal analysis was conducted to track and compare two cohorts of mainstream and foundation students in terms of retention, attrition and graduation rates. Quantitative data were analysed statistically by use of descriptive and some inferential statistics. Main findings were that: there was inadequate capacity institutionally for developed systems of admission for students entering foundation programmes, lack of curriculum compliance by different lecturers and lack of knowledge of curriculum reforms by lecturers who teach in foundation level, funding for foundation provision programmes was not adequate and lacked transparency. However, there were adequate recruitment processes in the university for lecturers that teach in foundational foundation provision programme and there was no government interference into how foundation programmes are governed. The study also found that students had experienced the student development practices positively, however, these practices were not enough, and equally most responsive student development practice did not exist at the institution under study. The study also found that there had been consistent funding from government but there was no proper expenditure systems in the institution. The study found that, in terms of graduation rates, the two groups compared relatively the same as there was no significant differences in patterns and trends that were observed. However, retention rates suggest that, in the first year, the two groups perform relatively the same, thereafter, there is a significant difference into how the two groups perform as they proceed to other years, especially the second year, where the mainstream cohort showed better performance than their foundation provision programme counterparts. Consequently, high attrition rates were experienced by foundation provision students than mainstream students, this was also experienced a lot more during the second year and third year transition. The implication of these findings was that due to institutional factors that affect the implementation of foundation programmes, these had notable impact on the attrition and dropout rates on foundation provision students. In addition, due to a lack of responsive student development practices, foundation programmes compared relatively low to their mainstream counterparts in retention. The study has recommended a model that can be implemented in the institution. The first component of the model is to put an admission system in place. Institution has to establish a platform where faculties present development plans for foundation provision programmes. In addition, there should be a dedicated Accountant managing finances of the foundation programme. The institution should establish the Tracking and Monitoring student development practice, establish Writing Centres and Learning Communities and employ more people in the Centre for Higher Education, Teaching and Learning department to ensure full implementation of existing student development practices and those that will be established. , Thesis (PhD) -- Faculty of Education, 2016
- Full Text:
- Date Issued: 2016-05
- Authors: Marhaya, Luyanda
- Date: 2016-05
- Subjects: Education, Higher -- South Africa , College student development programs
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24706 , vital:63529
- Description: The purpose was to establish how foundational provision programmes were implemented in a rural based university in South Africa and implications to student development practices. The study was located in the- post- positivism research paradigm, followed a mixed methods research approach and utilised a concurrent triangulation research design. For the qualitative component of the research, participants (academics and Coordinators of the foundation programmes and senior students who had enrolled through foundational provision programmes) were purposively sampled. The sample for the quantitative data comprised all the students who enrolled in foundation provision programmes between the years 2008 to 2011 and mainstream students who had enrolled between the years 2009 and 2012. For qualitative approach, focus group discussions were conducted, semi-structured interviews and document analysis. Quantitative data was sought from university institutional data storage warehouse, HIGHER EDUCATION MANAGEMENT INFORMATION SYSTEM (HEMIS). For qualitative approach, the data analysis for all data collection methods was done through thematic analysis. For quantitative approach, a longitudinal analysis was conducted to track and compare two cohorts of mainstream and foundation students in terms of retention, attrition and graduation rates. Quantitative data were analysed statistically by use of descriptive and some inferential statistics. Main findings were that: there was inadequate capacity institutionally for developed systems of admission for students entering foundation programmes, lack of curriculum compliance by different lecturers and lack of knowledge of curriculum reforms by lecturers who teach in foundation level, funding for foundation provision programmes was not adequate and lacked transparency. However, there were adequate recruitment processes in the university for lecturers that teach in foundational foundation provision programme and there was no government interference into how foundation programmes are governed. The study also found that students had experienced the student development practices positively, however, these practices were not enough, and equally most responsive student development practice did not exist at the institution under study. The study also found that there had been consistent funding from government but there was no proper expenditure systems in the institution. The study found that, in terms of graduation rates, the two groups compared relatively the same as there was no significant differences in patterns and trends that were observed. However, retention rates suggest that, in the first year, the two groups perform relatively the same, thereafter, there is a significant difference into how the two groups perform as they proceed to other years, especially the second year, where the mainstream cohort showed better performance than their foundation provision programme counterparts. Consequently, high attrition rates were experienced by foundation provision students than mainstream students, this was also experienced a lot more during the second year and third year transition. The implication of these findings was that due to institutional factors that affect the implementation of foundation programmes, these had notable impact on the attrition and dropout rates on foundation provision students. In addition, due to a lack of responsive student development practices, foundation programmes compared relatively low to their mainstream counterparts in retention. The study has recommended a model that can be implemented in the institution. The first component of the model is to put an admission system in place. Institution has to establish a platform where faculties present development plans for foundation provision programmes. In addition, there should be a dedicated Accountant managing finances of the foundation programme. The institution should establish the Tracking and Monitoring student development practice, establish Writing Centres and Learning Communities and employ more people in the Centre for Higher Education, Teaching and Learning department to ensure full implementation of existing student development practices and those that will be established. , Thesis (PhD) -- Faculty of Education, 2016
- Full Text:
- Date Issued: 2016-05
A case study of the opportunities and trade-offs associated with deproclamation of a protected area following a land claim in South Africa
- Krüger, Ruth, Cundill, Georgina, Thondhlana, Gladman
- Authors: Krüger, Ruth , Cundill, Georgina , Thondhlana, Gladman
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67791 , vital:29145 , https://doi.org/10.1080/13549839.2015.1065804
- Description: Publisher version , Reconciling conservation and social justice imperatives is a major challenge facing many postcolonial states worldwide. Where historically disenfranchised communities have laid legal claim to protected areas, the typical resolution has been collaborative management agreements between the state and claimant communities. The real outcomes of such strategies for people and ecosystems have been seriously questioned, although alternative approaches are seldom explored. Here, we reflect on one such alternative that was pursued in a case in South Africa, where the land was handed back to the community and a replacement protected area created. Our objective was to explore the opportunities and trade-offs associated with this approach for communities and conservation agencies alike, and to compare these to typical collaborative management outcomes. Methods included key informant interviews, focus group discussions and household surveys. We find that, surprisingly, this approach created more benefits for the conservation agency than for claimant communities. Indeed, the community experiences bore a striking resemblance to those experienced in collaborative management settings: intra-community conflict, confusion over leadership and serious questions about the boundaries of the “community”. Processes aimed at redressing past injustice in disputes over conservation land, regardless of the approach adopted, must bring with them a strong commitment to building institutional and leadership capacities within communities, and pay serious attention to the ways in which equity and social justice can be fostered after the settlement of a land claim. Settlement agreements are frequently treated as the final step towards social justice, but are in fact just the beginning.
- Full Text: false
- Date Issued: 2016
- Authors: Krüger, Ruth , Cundill, Georgina , Thondhlana, Gladman
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67791 , vital:29145 , https://doi.org/10.1080/13549839.2015.1065804
- Description: Publisher version , Reconciling conservation and social justice imperatives is a major challenge facing many postcolonial states worldwide. Where historically disenfranchised communities have laid legal claim to protected areas, the typical resolution has been collaborative management agreements between the state and claimant communities. The real outcomes of such strategies for people and ecosystems have been seriously questioned, although alternative approaches are seldom explored. Here, we reflect on one such alternative that was pursued in a case in South Africa, where the land was handed back to the community and a replacement protected area created. Our objective was to explore the opportunities and trade-offs associated with this approach for communities and conservation agencies alike, and to compare these to typical collaborative management outcomes. Methods included key informant interviews, focus group discussions and household surveys. We find that, surprisingly, this approach created more benefits for the conservation agency than for claimant communities. Indeed, the community experiences bore a striking resemblance to those experienced in collaborative management settings: intra-community conflict, confusion over leadership and serious questions about the boundaries of the “community”. Processes aimed at redressing past injustice in disputes over conservation land, regardless of the approach adopted, must bring with them a strong commitment to building institutional and leadership capacities within communities, and pay serious attention to the ways in which equity and social justice can be fostered after the settlement of a land claim. Settlement agreements are frequently treated as the final step towards social justice, but are in fact just the beginning.
- Full Text: false
- Date Issued: 2016
A case study on the health risks related to flood disasters in South Africa
- Tandlich, Roman, Ncube, Mbonisi, Khamanga, Sandile M, Zuma, Bongumusa M
- Authors: Tandlich, Roman , Ncube, Mbonisi , Khamanga, Sandile M , Zuma, Bongumusa M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/75917 , vital:30482 , DOI: 10.20965/jdr.2016.p0732
- Description: Floods occurred in the Ndlambe Local Municipality in South Africa in October 2012. During various stages of the post-disaster recovery, bacterial concentrations were measured in water and soil samples from the flood zone. All drinking water concentrations of E. coli were below 1–3 colony forming units per 100 millilitres (CFUs/100 mL). The flood waters contained between 46500 to more than 100000 CFUs/100 mL of E. coli. {The concentrations of Salmonella spp. in the flood waters varied from 5000 to 250000 CFUs/100 mL. The presumptive Vibrio spp. concentrations in flood waters ranged from 1000 to over 150000 CFUs/100 mL. {The soil concentrations for E. coli ranged from 1 to above 330 colony-forming units per 1 g of soil dry weight (CFUs/g). The soil concentrations of Salmonella spp. varied from below 1 to 22 CFUs/g. The estimated airborne fungal concentrations ranged from 16820 to 28540 colony-forming units per 1 cubic meter. An outbreak of an infectious disease was recorded among the volunteers who assisted with the post-disaster recovery. The likely bacterial causative agents included strains of Aeromonas spp. and Vibrio cholerae. Any human contact with either the contaminated flood waters or of flooded dwellings should only occur, if the individuals in questions are equipped with the full-body personal protective gear. Non-governmental stakeholders performed majority of the post-disaster recovery operations, as the local government could only cover 11% of the required costs. Applying sanitation funds to disaster recovery and increased use of the low-cost flood defence products in high risk areas could provide a solution for the future.
- Full Text: false
- Date Issued: 2016
- Authors: Tandlich, Roman , Ncube, Mbonisi , Khamanga, Sandile M , Zuma, Bongumusa M
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/75917 , vital:30482 , DOI: 10.20965/jdr.2016.p0732
- Description: Floods occurred in the Ndlambe Local Municipality in South Africa in October 2012. During various stages of the post-disaster recovery, bacterial concentrations were measured in water and soil samples from the flood zone. All drinking water concentrations of E. coli were below 1–3 colony forming units per 100 millilitres (CFUs/100 mL). The flood waters contained between 46500 to more than 100000 CFUs/100 mL of E. coli. {The concentrations of Salmonella spp. in the flood waters varied from 5000 to 250000 CFUs/100 mL. The presumptive Vibrio spp. concentrations in flood waters ranged from 1000 to over 150000 CFUs/100 mL. {The soil concentrations for E. coli ranged from 1 to above 330 colony-forming units per 1 g of soil dry weight (CFUs/g). The soil concentrations of Salmonella spp. varied from below 1 to 22 CFUs/g. The estimated airborne fungal concentrations ranged from 16820 to 28540 colony-forming units per 1 cubic meter. An outbreak of an infectious disease was recorded among the volunteers who assisted with the post-disaster recovery. The likely bacterial causative agents included strains of Aeromonas spp. and Vibrio cholerae. Any human contact with either the contaminated flood waters or of flooded dwellings should only occur, if the individuals in questions are equipped with the full-body personal protective gear. Non-governmental stakeholders performed majority of the post-disaster recovery operations, as the local government could only cover 11% of the required costs. Applying sanitation funds to disaster recovery and increased use of the low-cost flood defence products in high risk areas could provide a solution for the future.
- Full Text: false
- Date Issued: 2016
A chiral hemiporphyrazine derivative
- Wu, Yanping, Gai, Lizhi, Xiao, Xuqiong, Lu, Hua, Li, Zhifang, Mack, John, Harris, Jessica, Nyokong, Tebello, Shen, Zhen
- Authors: Wu, Yanping , Gai, Lizhi , Xiao, Xuqiong , Lu, Hua , Li, Zhifang , Mack, John , Harris, Jessica , Nyokong, Tebello , Shen, Zhen
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240404 , vital:50831 , xlink:href="https://doi.org/10.1002/asia.201600754"
- Description: The synthesis of an optically active hemiporphyrazine with chiral binaphthyl substituents (1) is reported, providing the first example of the incorporation of an intrinsically chiral moiety into the macrocyclic core of a hemiporphyrazine analogue. A negative circular dichroism (CD) signal is observed in the 325–450 nm region of the CD spectrum of (S,S)-1, while mainly positive bands are observed in the 220–325 nm region. Mirror symmetry is observed across the entire wavelength range of the CD spectra of (R,R)-1 and (S,S)-1. An irreversible one-electron oxidation wave with an onset potential at 1.07 V is observed by cyclic voltammetry, along with a reversible one-electron reduction wave at −0.85 V. Density functional calculations reproduce the experimentally observed data and trends, and provide further insight into the nature of the electronic transitions.
- Full Text:
- Date Issued: 2016
- Authors: Wu, Yanping , Gai, Lizhi , Xiao, Xuqiong , Lu, Hua , Li, Zhifang , Mack, John , Harris, Jessica , Nyokong, Tebello , Shen, Zhen
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240404 , vital:50831 , xlink:href="https://doi.org/10.1002/asia.201600754"
- Description: The synthesis of an optically active hemiporphyrazine with chiral binaphthyl substituents (1) is reported, providing the first example of the incorporation of an intrinsically chiral moiety into the macrocyclic core of a hemiporphyrazine analogue. A negative circular dichroism (CD) signal is observed in the 325–450 nm region of the CD spectrum of (S,S)-1, while mainly positive bands are observed in the 220–325 nm region. Mirror symmetry is observed across the entire wavelength range of the CD spectra of (R,R)-1 and (S,S)-1. An irreversible one-electron oxidation wave with an onset potential at 1.07 V is observed by cyclic voltammetry, along with a reversible one-electron reduction wave at −0.85 V. Density functional calculations reproduce the experimentally observed data and trends, and provide further insight into the nature of the electronic transitions.
- Full Text:
- Date Issued: 2016
A comparative physicochemical study of unsymmetrical indium phthalocyanines in the presence of magnetic nanoparticles or quantum dots
- Osifeko, Olawale L, Nyokong, Tebello
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188743 , vital:44781 , xlink:href="https://doi.org/10.1080/00958972.2016.1152628"
- Description: Asymmetric indium phthalocyanine (3, containing an NH2 group) was conjugated (via an amide bond) to magnetic nanoparticle (MNP) functionalized with carboxylic acid or glutathione-capped CdTe/ZnSe/ZnO quantum dots to form 3-MNPs or 3-QDs. Techniques such as time-resolved fluorescence measurements, transmission electron microscopy, XPS, elemental analysis, FTIR, NMR (1H, 13C, and cozy), electronic spectroscopy, as well as mass spectroscopy were employed to characterize 3 and its nanoconjugates. The phthalocyanine conjugated to quantum dot (3-QDs) possesses the lowest Фpd higher Ф∆ and ФT as well as longer triplet lifetimes compares to 3-MNPs and free phthalocyanine.
- Full Text:
- Date Issued: 2016
- Authors: Osifeko, Olawale L , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188743 , vital:44781 , xlink:href="https://doi.org/10.1080/00958972.2016.1152628"
- Description: Asymmetric indium phthalocyanine (3, containing an NH2 group) was conjugated (via an amide bond) to magnetic nanoparticle (MNP) functionalized with carboxylic acid or glutathione-capped CdTe/ZnSe/ZnO quantum dots to form 3-MNPs or 3-QDs. Techniques such as time-resolved fluorescence measurements, transmission electron microscopy, XPS, elemental analysis, FTIR, NMR (1H, 13C, and cozy), electronic spectroscopy, as well as mass spectroscopy were employed to characterize 3 and its nanoconjugates. The phthalocyanine conjugated to quantum dot (3-QDs) possesses the lowest Фpd higher Ф∆ and ФT as well as longer triplet lifetimes compares to 3-MNPs and free phthalocyanine.
- Full Text:
- Date Issued: 2016
A cytotoxic pentadecapeptide from a South African Didemnid tunicate
- Gallegos, D, Serrill, J, Parker-Nance, Shirley, Dorrington, Rosemary A, Ishmael, J, McPhail, Kerry L
- Authors: Gallegos, D , Serrill, J , Parker-Nance, Shirley , Dorrington, Rosemary A , Ishmael, J , McPhail, Kerry L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65935 , vital:28863 , https://doi.org/10.1055/s-0036-1596683
- Description: publisher version , The rate of discovery of new natural product chemical entities has plateaued, and unique populations of endemic, biologically diverse sessile marine organisms represent increasingly critical opportunities to discover new chemistry. Discovery of the mandelalides [1] as potent inhibitors of cancer cell growth from the new South African tunicate Lissoclinum mandelai is an example of the diverse suites of metabolites with potent biological activities that have been isolated from tunicates and other filter-feeding sessile marine organisms that house complex microbial consortia. Further investigation of archived and new tunicate collections from Algoa Bay, South Africa, has revealed a group of didemnid tunicates with an unusual gelatinous morphology similar to Lissoclinum mandelai. Using a bioassay-guided isolation approach, a new “gelatinous” species of the genus Didemnum has yielded a cytotoxic pentadecapeptide with a molecular mass of 1603.7688 Da, comprising fifteen residues including both proteinogenic and non-proteinogenic amino acids. The pure compound inhibited both HeLa cervical cancer and NCI-H460 non-small cell lung cancer cell lines when tested at 30 nM in preliminary assays against cells seeded at low densities. Inhibition of cancer cells at low starting density may be indicative of an anti-proliferative mechanism of action. The compound did not show antibacterial activity against Vibrio cholera. Didemnin B and its clinically approved analogue dehydrodidemnin B (plitidepsin, Aplidin®) [2, 3] are important macrocyclic depsipeptides from a didemnid tunicate. The pentadecapeptide reported here provides justification for our continued investigation of unique, endemic didemnid tunicates from South Africa as a source of new macrocyclic natural products with cytotoxic, anti-viral or antimicrobial activity. , We acknowledge the South African government for permission to collect the subject tunicate (Collection Permit No. 278 RES2013/43)
- Full Text: false
- Date Issued: 2016
- Authors: Gallegos, D , Serrill, J , Parker-Nance, Shirley , Dorrington, Rosemary A , Ishmael, J , McPhail, Kerry L
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/65935 , vital:28863 , https://doi.org/10.1055/s-0036-1596683
- Description: publisher version , The rate of discovery of new natural product chemical entities has plateaued, and unique populations of endemic, biologically diverse sessile marine organisms represent increasingly critical opportunities to discover new chemistry. Discovery of the mandelalides [1] as potent inhibitors of cancer cell growth from the new South African tunicate Lissoclinum mandelai is an example of the diverse suites of metabolites with potent biological activities that have been isolated from tunicates and other filter-feeding sessile marine organisms that house complex microbial consortia. Further investigation of archived and new tunicate collections from Algoa Bay, South Africa, has revealed a group of didemnid tunicates with an unusual gelatinous morphology similar to Lissoclinum mandelai. Using a bioassay-guided isolation approach, a new “gelatinous” species of the genus Didemnum has yielded a cytotoxic pentadecapeptide with a molecular mass of 1603.7688 Da, comprising fifteen residues including both proteinogenic and non-proteinogenic amino acids. The pure compound inhibited both HeLa cervical cancer and NCI-H460 non-small cell lung cancer cell lines when tested at 30 nM in preliminary assays against cells seeded at low densities. Inhibition of cancer cells at low starting density may be indicative of an anti-proliferative mechanism of action. The compound did not show antibacterial activity against Vibrio cholera. Didemnin B and its clinically approved analogue dehydrodidemnin B (plitidepsin, Aplidin®) [2, 3] are important macrocyclic depsipeptides from a didemnid tunicate. The pentadecapeptide reported here provides justification for our continued investigation of unique, endemic didemnid tunicates from South Africa as a source of new macrocyclic natural products with cytotoxic, anti-viral or antimicrobial activity. , We acknowledge the South African government for permission to collect the subject tunicate (Collection Permit No. 278 RES2013/43)
- Full Text: false
- Date Issued: 2016